IGCCPUERTOLLANO

A CLEANCOAL GASIFICATION

POWER PLANT

FOREWORD

It gives me great pleasure to present this book on the ELCOGAS Puertollano Integrated

Gasification with Combined Cycle (IGCC) plant, which represents a new milestone in the

development of clean combustion technology for the production of electricity in Europe.

The plant uses low-cost fuels in a clean manner, as the gas produced during the

gasification process is cleaned before being burned in the gas turbine. Furthermore, its

high level of efficiency keeps CO2 emissions to a minimum.

This book has been written on the basis of the Final Report submitted to the European

Commission Directorate General for Energy and Transport in October 2000, under the

Thermie Programme. It describes the nature of the plant and the technology therein, as

well as the results produced to date. The Puertollano IGCC plant was a target project for

the Thermie Programme, as it complied with two of its foremost objectives: promoting

new, clean and efficient energy use and production on the market, and reducing harmful

emissions, particularly those of CO2, as a consequence of burning fossil fuels. The

Puertollano Plant also contributes to European Commission objectives in terms of

guaranteeing Europe’s energy supply, as it uses autochthonous fossil fuels, reducing

dependence on external energy sources.

At present, now that we have overcome the many, wide-ranging difficulties that this new

and complex technology presented during the IGCC plant design, construction and

commissioning phases, performance is satisfactory, with more than 900,000 MWh having

been produced with synthetic gas in 2000.

IGCC technology is demonstrating its technical viability, showing unique characteristics

and a singular potential for the incorporation of improvements in the near future. Currently

in an experimental phase, these improvements should lead to the attainment of that

notoriously elusive balance between energy, environment and economy.

José Damián Bogas Gálvez

President of ELCOGAS

1

The purpose of this publication

The Integrated Gasification with Combined Cycle (IGCC) plant stands out in the field of

clean coal technology, due to its excellent environmental features and its potential for

improvement and development, which will allow it to become more competitive in the future

with respect to alternative energy sources.

This fact, accepted by all energy technology experts, becomes highly significant if we

examine what the near future holds for electricity supplies. In effect, the question is to find

the best way to meet growing energy needs throughout the world among all the available

possibilities.

In Europe, reflections on energy policy are set out in the Green Paper on Energy outlook to

the year 2020 document, which the European Commission’s Directorate General for

Transport and Energy presented in November 2000.

Deeper reflection on the issue of the possibility of controlling demand through increased

efficiency or saving energy, together with the choices offered by a range of alternative

energy sources, including natural gas, nuclear energy, renewable energy sources and bio

energy, which does not contribute to the greenhouse effect, leaves a very important role for

coal to play, provided that its use corresponds to the clean possibilities permitted by current

techniques. This role clearly exists, even before we consider the political and strategic

factors that affect some of the aforementioned solutions and which reinforce coal’s qualities

as a resource with a stable price and a diversified supply.

The Puertollano power station is European IGCC technology’s showcase project. The

power station constitutes a reference point in terms of demonstrating how this technology

can contribute to a satisfactory solution to the problem of supplying electricity in the near

future. This book provides data and describes real experiences that will help to clarify the

real value of this technology.

This is our reason for publishing it.

Manuel Treviño Coca

Chief Executive Officer

1

CONTENTS

Page

1. THE PUERTOLLANO IGCC PLANT ..............................................................................................81.1. GENERAL ......................................................................................................................................81.2. ADVANTAGES OF IGCC PLANTS 9

2. PLANT AND TECHNOLOGY DESCRIPTION............................................................................122.1. LOCATION ..................................................................................................................................122.2. GENERAL DESCRIPTION ......................................................................................................142.3. FUEL..............................................................................................................................................15

2.3.1. GENERAL.............................................................................................................................152.3.2. FUEL DATA .........................................................................................................................16

2.4. PLANT SYSTEMS ......................................................................................................................172.4.1. GASIFICATION ...................................................................................................................17

2.4.1.1. General..............................................................................................................................172.4.1.2. Fuel Yard ..........................................................................................................................182.4.1.3. Coal Preparation ...............................................................................................................192.4.1.4. Pressurization and feeding ...............................................................................................202.4.1.5. Gasification process..........................................................................................................212.4.1.6. Ceramic filters ..................................................................................................................232.4.1.7. Slag System.......................................................................................................................232.4.1.8. Gas cleaning and desulphurization ..................................................................................232.4.1.9. Sulphur Recovery Unit.....................................................................................................25

2.4.2. AIR SEPARATION UNIT ...................................................................................................262.4.2.1. General..............................................................................................................................262.4.2.2. Chilling and purification ..................................................................................................262.4.2.3. Distillation.........................................................................................................................27

2.4.3. COMBINED CYCLE ...........................................................................................................282.4.3.1. General..............................................................................................................................282.4.3.2. Gas Turbine ......................................................................................................................282.4.3.3. Heat recovery steam generator.........................................................................................302.4.3.4. Steam Turbine...................................................................................................................31

2.4.4. INTEGRATION SYSTEM...................................................................................................332.4.5. AUXILIARY AND SERVICE SYSTEMS.........................................................................35

2.4.5.1. Cooling system .................................................................................................................352.4.5.2. Auxiliary boilers ...............................................................................................................362.4.5.3. Flare...................................................................................................................................362.4.5.4. Emergency Diesel generator ............................................................................................372.4.5.5. Water Treatment...............................................................................................................372.4.5.6. Other service and auxiliary plant systems.......................................................................37

2.4.6. ELECTRIC SYSTEMS.........................................................................................................382.4.6.1. General..............................................................................................................................382.4.6.2. Generators.........................................................................................................................39

2.4.7. CONTROL SYSTEM ...........................................................................................................402.4.7.1. General..............................................................................................................................402.4.7.2. Control levels....................................................................................................................40

2.4.9. PLANT FUNCTIONAL BASIC OUTLINE.......................................................................412.4.10. SUMMARY OF BASIC TECHNICAL DATA................................................................42

2.5. TECHNOLOGICAL VALUE AND INNOVATION.............................................................432.5.1. TECHNOLOGICAL INNOVATION..................................................................................43

2

2.5.2. ACQUISITION OF SPECIFIC “KNOW-HOW” ..............................................................432.6. ENVIRONMENTAL CONSIDERATIONS............................................................................45

2.6.1. GENERAL.............................................................................................................................452.6.2. COMPARISON OF EMISSIONS FROM DIFFERENT TECHNOLOGIES TYPES.....47

3. ELCOGAS AND THE PROJECT’S ORGANIZATION ..............................................................493.1. THE ELCOGAS COMPANY....................................................................................................493.2. ORGANIZATION .......................................................................................................................51

3.2.1. GENERAL.............................................................................................................................513.2.2. PROJECT MANAGEMENT AND SUPERVISION .........................................................523.2.3. OUTLINE OF PROJECT CONTRACTS ...........................................................................53

3.2.3.1. GENERAL AND BALANCE OF PLANT ENGINEERING.......................................543.2.3.2. MAIN SUPPLIES ............................................................................................................553.2.3.3. SUPPLY OF BALANCE OF PLANT EQUIPMENT...................................................573.2.3.4. CONSTRUCTION. CIVIL WORK AND EQUIPMENT ASSEMBLY .....................603.2.3.5. QUALITY PLAN INSPECTION AGENCIES..............................................................643.2.3.6. OPERATION TRAINING ..............................................................................................643.2.3.7. FUEL SUPPLY................................................................................................................64

3.3. PROJECT DEVELOPMENT....................................................................................................653.3.1. GENERAL.............................................................................................................................653.3.2. BASIC PROJECT DATES...................................................................................................673.3.3. PROJECT BUDGET AND FINANCING...........................................................................68

3.3.3.1. Project Budget ..................................................................................................................683.3.3.2. Capital costs......................................................................................................................693.3.3.3. Project Financing..............................................................................................................70

3.4. AUTHORIZATIONS AND LICENSES..................................................................................714. PLANT OPERATION.........................................................................................................................72

4.1. OPERATION ORGANIZATION.............................................................................................724.2. PLANT OPERATION ASSESSMENT AND DATA.............................................................73

4.2.1. ASSESSMENT OF THE TOTAL PLANT PERFORMANCE .........................................734.2.1.1. Plant status update ............................................................................................................734.2.1.2. Main operation interruptions and type of failures...........................................................774.2.1.3. Lessons learned.................................................................................................................79

4.2.2. ASSESSMENT OF THE PERFORMANCE OF INDIVIDUAL EQUIPMENT.............804.2.2.1. Main operation interruptions classified by areas ............................................................804.2.2.2. Gasification Island............................................................................................................824.2.2.3. Air Separation Unit (ASU) ..............................................................................................944.2.2.4. Combined Cycle ...............................................................................................................964.2.2.5. Auxiliary systems (Balance of Plant) ..............................................................................98

4.2.3. PROCESS DATA..................................................................................................................994.2.3.1. Fuel heat rate. Year 2000 .................................................................................................994.2.3.2. Auxiliary power. Year 2000 ............................................................................................994.2.3.3. Consumption of consumables and catalysers................................................................1004.2.3.4. Generation of electricity.................................................................................................101

4.2.4. FINANCIAL DATA ...........................................................................................................1064.2.4.1 Production Costs..............................................................................................................1064.2.4.2. Operation Income ...........................................................................................................107

4.2.5. ENVIRONMENTAL DATA..............................................................................................1084.2.5.1. Absolute environmental data .........................................................................................1084.2.5.2. Emission data..................................................................................................................1094.2.5.3. By-products and waste data ...........................................................................................1134.2.5.4. Trace element mass balance...........................................................................................115

4.3. ASSESSMENT OF OPERATION WITH DIFFERENT FUELS......................................1174.3.1. INTRODUCTION...............................................................................................................117

3

4.3.2. FUEL CHARACTERIZATION.........................................................................................1184.3.3. ASSESSMENT OF TESTS AND EXPERIENCE WITH DIFFERENT FUELS ..........121

4.3.3.1. History of test operation.................................................................................................1214.3.3.2. Individual analysis of performance op processing parts...............................................1284.3.3.3. Fuel consumption and other consumables ....................................................................1374.3.3.4. Electricity, by-products and wastes production ............................................................1384.3.3.5. Gasification behaviour of feedstock ..............................................................................1394.3.3.6. Main data on emissions and by-products ......................................................................1444.3.3.7. Thermo-economic diagnosis..........................................................................................151

4.3.4. REFERENCES ....................................................................................................................1605. IMPROVEMENTS FOR FUTURE IGCC PLANTS 161

5.1. ASSESSMENT OF THE GLOBAL OPERATION RESULTS FOR FUTURE IGCCPLANTS 1615.2. ASSESSMENT OF THE DIFFERENT PROCESS PARTS 163

5.2.1. PROCESS OPTIMISATION AND ADJUSTMENT .......................................................1635.2.1.1. Coal dust preparation......................................................................................................1635.2.1.2. Coal dust conveying, sluicing and feeding....................................................................1635.2.1.3. Gasifier and gas quenching............................................................................................1645.2.1.4. Waste Heat Recovery System........................................................................................1645.2.1.5. Slag handling ..................................................................................................................1655.2.1.6. Dry dedusting system.....................................................................................................1655.2.1.7. Wet scrubbing and gas stripping....................................................................................1665.2.1.8. Desulphurization system................................................................................................1665.2.1.9. Air separation unit (ASU) ..............................................................................................1665.2.1.10. Saturator........................................................................................................................1675.2.1.11. Gas turbine....................................................................................................................1675.2.1.12. Auxiliary systems (Balance of Plant) ..........................................................................1675.2.1.13. Control system..............................................................................................................1685.2.1.14. General layout...............................................................................................................168

5.3. CONCLUSIONS FOR FUTURE IGCC PLANTS 171

4

Index of Tables

Table 1. Coal and pet-coke parameters (50% weight mix) 16Table 2. Feedstock parameters 18Table 3. Coal preparation. Flow composition and heating value 20Table 4. Coal preparation parameters 20Table 5. Gasification process design values 21Table 6. Gasifier parameters 22Table 7. Clean gas specifications 24Table 8. Air Separation Unit parameters 27Table 9. Auxiliary boilers parameters 36Table 10. Electric transformers parameters 39Table 11. Basic technical data 42Table 12. Comparison of emissions between coal technology types (mg/Nm3, 6% O2) 47Table 13. Comparison of emissions (g/kWh) between coal technology types. Output 320 MW 48Table 14. ELCOGAS capital share 49Table 15. Equipment Suppliers 57Table 16. Civil work contractors 60Table 17. Mechanical Assembly, Electrical and I&C Installation Contract packages 61Table 18. Main site work units 63Table 19. Project Budget constant currency Base 1991 68Table 20. IGCC's Capital costs forecast 69Table 21. Main milestones of operation. 74Table 22. Raw gas and clean gas composition 93Table 23. Main results of the Acceptance Test. 96Table 24. Plant operation consumables. 100Table 25. IGCC Plant electricity gross output. Accumulated 101Table 26. IGCC Plant electricity gross output. Year 2000 102Table 27. Total Plant electricity gross output. 103Table 28. Total Plant electricity gross output. 104Table 29. IGCC Plant emission data for 2000 109Table 30. IGCC Plant waste data for 2000 114Table 31. Fuel range designation. 118Table 32. Fuels selected for demonstration tests. 118Table 33. Actual and predicted composition of the mixtures tested. 119Table 34. Coal and coke composition during the tests. 120Table 35. Main test conditions. 121Table 36. Fuel consumption and other consumables. 137Table 37. Electricity, by-products and wastes production. 138Table 38. Carbon conversion during tests. 139Table 39. Composition of solid residues. 146Table 40. Composition of wash and Venturi water. 150Table 41. Performance Input Data. 151Table 42. Performance Output Data. 152Table 43. Mass balances. 153Table 44. Heat Balances. 154Table 45. Cost fixed for the financial study. 155Table 46. Financial costs. 155Table 47. Summary of the main system improvements based on the experience in Puertollano. 171

5

Index of Figures

Figure 1. Perspective of the Puertollano IGCC Plant 11Figure 2. Map of the Puertollano area 12Figure 3. View of Puertollano town 13Figure 4. Encasur coal mine 15Figure 5. Fuel yard 18Figure 6. Coal preparation plant 19Figure 7. Gasifier building 21Figure 8. Gas cleaning and desulphurization 24Figure 9. Gasification and gas cleaning process 25Figure 10. Air Separation Unit 26Figure 11. Gas Turbine 28Figure 12. Gas Turbine VT 94.3 with internals 29Figure 13. Heat recovery boiler and gas saturator buildings 30Figure 14. Steam Turbine 31Figure 15. Energy balance of the plant 32Figure 16. Outline of the IGCC plant's main system's interfaces 34Figure 17. Cooling tower 35Figure 18. Flare 36Figure 19. Main transformer and substation 38Figure 20. Plant control room 40Figure 21. Simplified flow diagram of the Puertollano Plant 41Figure 22. Puertollano IGCC Plant 46Figure 23. EU emission limits and IGCC plant design emissions 47Figure 24. Comparison of emissions between different technology types 48Figure 25. ELCOGAS capital share 50Figure 26. ELCOGAS Basic organization chart 51Figure 27. ELCOGAS Project organization chart 52Figure 28. Project Interfaces and Contracts 53Figure 29. Transport of the gas turbine 59Figure 30. Civil construction work on the plant 60Figure 31. Assembly of the gasifier 62Figure 32. Project schedule 65Figure 33. The Puertollano IGCC Plant Project Progress 66Figure 34. Project Budget distribution. Constant currency October 1991 68Figure 35. IGCC's Capital costs forecast 69Figure 36. Operation Chart 72Figure 37. Accumulated gasifier and IGCC run time. 75Figure 38. Gasifier and IGCC run time. 75Figure 39. IGCC and NGCC availability factor. 76Figure 40. Gasifier stoppages classified by type of failure. 77Figure 41. Gas turbine syngas operation interruptions classified by type of failure. 78Figure 42. Gasifier stoppages classified by areas. 80Figure 43. Gas turbine syngas operation interruptions classified by areas. 81Figure 44. Gasifier stoppages classified by Gasification Systems. 82Figure 45. Gas turbine syngas operation interruptions classified by Gasification Systems. 83Figure 46. Comparison of fouling behaviour between September 1999 and August 2000. 87Figure 47. Candle filter fouling factor and solids in Venturi during operation. 91Figure 48. Fly ash size distribution. 92Figure 49. Main gas turbine parameters to control the “switch over”. 97

6

Figure 50. Main gas turbine parameters to control the “switch back”. 97Figure 51. Fuel heat rate 99Figure 52. Plant auxiliary power 99Figure 53. IGCC Plant yearly electricity generation records 101Figure 54. IGCC Plant Monthly electricity gross output. Year 2000 102Figure 55. Total plant yearly gross output 103Figure 56. Total Plant monthly electricity gross output. Year 2000 104Figure 57. Plant availability for 2000 (up to November) 105Figure 58. NOx emission mg/Nm3 for 2000 110Figure 59. Specific NOx emission g/kWh for 2000 110SO2 emission mg/Nm3 for 2000 111Figure 61. Specific SO2 emission g/kWh for 2000 111Particulate emission mg/Nm3 for 2000 112Figure 63. Specific particulate emission g/kWh year 2000 112Figure 64. Trace distribution in feedstock. 115Figure 65. Trace distribution in by-products. 116Figure 66. Main process input data during the tests. Mixture 1 122Figure 67. Main process input data during the tests. Mixture 2 122Figure 68. Main process input data during the tests. Mixture 3 123Figure 69. Main process input data during the tests. Mixture 4 123Figure 70. Main process output data during the tests. Mixture 1 124Figure 71. Main process output data during the tests. Mixture 2 124Figure 72. Main process output data during the tests. Mixture 3 125Figure 73. Main process output data during the tests. Mixture 4 125Figure 74. Main gas composition data during the tests. Mixture 1 126Figure 75. Main gas composition data during the tests. Mixture 2 126Figure 76. Main gas composition data during the tests. Mixture 3 127Figure 77. Main gas composition data during the tests. Mixture 4 127Figure 78. Main data of the slag extraction system during the tests. Test 1. 129Figure 79. Main data of the slag extraction system during the tests. Test 2 129Figure 80. Main data of the slag extraction system during the tests. Test 3 130Figure 81. Main data of the slag extraction system during the tests. Test 4 130Figure 82. Fouling data during the tests. Test 1. 132Figure 83. Fouling data during the tests. Test 2. 132Figure 84. Fouling data during the tests. Test 3. 133Figure 85. Fouling data during the tests. Test 4. 133Figure 86. Candle filter performance during the tests. Test 1 135Figure 87. Candle filter performance during the tests. Test 2 135Figure 88. Candle filter performance during the tests. Test 3 136Figure 89. Candle filter performance during the tests. Test 4. 136Figure 90. Cold Gas efficiency against O2/ feedstock ratio 140Figure 91. Cold Gas Efficiency against fuel carbon content. 140Figure 92. Cold Gas Efficiency against fuel ash content. 141Figure 93. Cold Gas Efficiency against fuel volatile matter. 141Figure 94. Slag/ash split. 143Figure 95. Emission data during fuel tests. 144Figure 96. Comparison of emission levels during fuel tests. 145Figure 97. Distribution of trace elements among by-product streams. Mixture 1 147Figure 98. Distribution of trace elements among by-product streams. Mixture 2 147Figure 99. Distribution of trace elements among by-product streams. Mixture 3 148Figure 100. Distribution of trace elements among by-product streams. Mixture 4 148Figure 101. Distribution of ash among by-product streams. 149Figure 102. Test No. 1 (Mixture 3). 156

7

Figure 103. Test No. 2 (Mixture 4). 157Figure 104. Test No. 3 (Mixture 2). 158Figure 105. Test No. 4 (Mixture 1). 159Figure 106. IGCC 2000 simplified flow diagram. 162Figure 107. General layout of ELCOGAS plant. 169Figure 108. Expected IGCC Efficiency Potential 173

8

1. THE PUERTOLLANO IGCC PLANT

1.1. GENERAL

In the late eighties, looking for the development of European technologies in the energy field for the clean

use of coal, a group of European electric utilities, led by Endesa and EDF, promoted the project involving

the design, construction and demonstration of a power plant using the emerging technology of coal

gasification integrated with combined cycle. This initiative was designated as target project (projet ciblé)

by the European Commission's Directorate General of Energy because its characteristics of clean and

efficient combustion plant and was also included in the Spanish Government's National Energy Plan

1991-2001.

ELCOGAS Company was formed in 1992 by the European electric utilities Endesa, Electricité de France,

Sevillana de Electricidad, Iberdrola, Hidroeléctrica del Cantábrico, and Electricidade de Portugal to

develop the integrated coal gasification with combined cycle (IGCC) power plant project, with a gross

electric output of about 330 MW (ISO conditions), to be built in the central south area of Spain, close to

Puertollano, Ciudad Real.

The Puertollano IGCC project was launched with the signature of the contracts for the supply of

gasification and combined cycle main equipment on July 1992 with two European technology suppliers:

Siemens and Krupp Koppers, together with Babcock Wilcox Española, as manufacturer partner.

In 1993 two other important European utilities, Enel and National Power, joined ELCOGAS. The main

suppliers of the plant technology, Siemens Ag, Krupp Koppers, together with Babcock Wilcox Española

became partners of ELCOGAS few months later on.

9

1.2. ADVANTAGES OF IGCC PLANTS

In terms of electric power production, there are clear advantages to the use of IGCC plants as regards

environmental and economic considerations, feedstock and product flexibility, and ease of integration

using advanced technologies to achieve high efficiency levels. This type of plants makes it possible to use

coal and other widely available fuels in an environmentally friendly manner, contributing to the

diversification of the energy offer and to the security of energy supply. IGCC technology, already

economically competitive as regards variable costs, will benefit from further improvements in terms of

fixed costs and the increased efficiency of its main equipment.

A clean environment

IGCC plants can meet all projected environmental regulations, solving the compliance problems of

electric power generation. Because it operates at higher efficiency levels than conventional fossil-fuelled

power plants, IGCC systems emit less CO2 per unit of energy, thus contributing to reach the objectives of

the Kioto Protocol, as regards world reduction in CO2 emissions to the atmosphere. IGCC plants

emissions of sulphur dioxide and nitrogen oxides, gases linked to acid rain, are a small fraction of

allowable limits. The water required to run an IGCC plant is less than half that required to run a pulverised

coal plant with a flue gas scrubbing system. The solid residues obtained are, in its majority, vitrified, non

leacheable slag or pure products resulting in usable by-products of the process.

Feedstock flexibility

The gasifier has the flexibility to handle a variety of feedstocks. In addition to coal, possible feedstocks

include petroleum coke, refinery liquids, bio-mass, municipal solid waste, tires, plastics, hazardous wastes

and chemicals, and sludge. These alternative feedstocks are typically low-cost, sometimes even of

negative cost.

When a low-cost feed is used, the economics of gasification are usually enhanced and marketable

products are created from the waste stream, avoiding disposal costs and environmental concerns.

10

Product flexibility

An advantage of gasification lies in its ability to operate in a coproduction mode. Coproduct options help

reduce business risk by allowing the company to choose the plant configuration that best suits market

demands, producing goods that have the highest value to that particular business. System efficiencies are

improved to when transportation fuels are produced and enhanced when some of the steam is used

directly in industrial applications.

Attractive plant economics

The economic advantages of the IGCC system are its use of low-cost feedstocks, its high efficiency in

resource use and its economically efficient reduction of environmental pollutants. In addition, it can

deliver high-value marketable by-products, such as sulphur and slag. Modularity and phased construction

can distribute capital expenditures to meet financing requirements. By utilisation of part of synthetic gas,

IGCC can also produce high value products like pure hydrogen, pure carbon monoxide and other

byproductss. Because IGCC uses regenerable sorbents and catalysts, the costs of replenishing these

supplies as well as the costs of disposal can be minimised. Continued operating experience and the design

of additional units can further reduce capital and operating costs, increasing IGCC's economic

competitiveness.

Ease of integration with advanced technologies to achieve high efficiencies.

Current IGCC plant efficiency is higher than 40% compared with 35% for conventional plants. The

increased efficiency of the IGCC process significantly reduces CO2 emissions and those that cause acid

rain, and lowers the cost of power and products. As advanced technologies for gasification, turbines, fuel

cells, coproduction, gas separation and gas cleaning become available, each of these can be readily

integrated to improve overall efficiency.

Further, coal gasification with gas cleaning can be readily added to existing natural-gas combined-cycle

plants to attain a full IGCC system. Most important, system evaluations can determine the best

combinations of components to achieve cost reductions while minimising wastes and environmental

impacts.

11

Figure 1. Perspective of the Puertollano IGCC Plant

12

2. PLANT AND TECHNOLOGY DESCRIPTION

2.1. LOCATION

The plant is located in the central south part of Spain, 200 Km from Madrid, in the area of Puertollano, in

the province of Ciudad Real. The site is 10 Km East-South-East of the town of Puertollano, approximately

3 km to the North-East of El Villar, on the kilometre 27 of the road between Calzada de Calatrava and

Puertollano. The ELCOGAS site occupies an area of 480,000 m2.

Figure 2. Map of the Puertollano area

13

Besides the existence of coal mines producing coal suitable for gasification, Puertollano was chosen due

to its more-than-adequate industrial infrastructure . The area has a long mining tradition and is important

in industrial terms, encompassing a Repsol petrochemical complex and refinery and an ENDESA coal

power plant, as well as coal mines, the most important of which is the ENCASUR mine. The area is

linked to both to the electrical and natural gas national networks.

Puertollano is well communicated with road and train transport facilities, including the High Speed Train,

connection with Madrid and Seville.

Figure 3. View of Puertollano town

14

2.2. GENERAL DESCRIPTION

The Puertollano IGCC plant uses the pressurized entrained flow gasification technology. The synthetic

gas obtained is cleaned and burnt as fuel in a combined cycle plant (gas and steam turbines). The synthetic

gas is a result of the reaction between a mix of coal and petroleum coke with oxygen at high temperatures

of up to 1600 ºC. The oxygen required for the gasification process is produced in an integrated Air

Separation Unit, which also produces also nitrogen for drying the pulverised coke, for fuel transportation

and for the safety inertization of the different circuits.

The synthetic gas obtained, which basically consists of CO and H2, is subsequently subjected to an

exhaustive cleaning process to eliminate the small parts of pollutants. The gas, free of pollutants, is

saturated and burnt, with a high efficiency level, in a combined cycle electricity-generating unit gas

turbine. The Combined Cycle Unit gas turbine is capable of operating with both synthetic and natural

gases. The gas turbine exhaust gases with residual heat are fed into a heat recovery boiler, producing

steam that is used together with the steam produced in the gasification process to generate additional

electricity in a conventional steam turbine with condensation cycle. The Plant's target energy efficiency is

45% in ISO conditions.

The design of the heat exchangers battery is particularly relevant in terms of efficiency, basically as

regards steam production and consumption, incorporating two heat recovery boilers, one for the crude gas

produced in the gasifier and the other for the turbine exhaust gases. Furthermore, the steam acts as a heat

conductor with for several uses in the coal preparation, gasification, desulphurization and air separation

processes.

15

2.3. FUEL

2.3.1. GENERAL

The plant's basic fuel is coal from the local ENCASUR mines. The coal is mixed with petroleum coke

from the Puertollano REPSOL refinery. The project's technology allows the clean combustion of a coal

and coke feedstock with a normal weight proportion of 50:50.

The plant burns 700,000 tons of mixed fuel per year at full operational capacity. The coal is sub-

bituminous, high ash content (41.1%) hard coal, from the ENCASUR mine in Puertollano. The mine has

exploitable reserves of 60 million tons. The pet-coke, a by-product from the Repsol Puertollano refinery,

has a high sulphur content (5.5%).

Figure 4. Encasur coal mine

This plant's Combined Cycle can operate fuelled with natural gas. The plant needs natural gas for fuel

during gasification start up and shut down.

16

2.3.2. FUEL DATA

Main parameters for the plant fuel components: coal , pet-coke and mix are shown in the table.

Coal Coke Mix

Humidity % 11.8 7.00 9.40

Ashes % 41.10 0.26 20.68

Carbon % 36.27 82.21 59.21

Hydrogen % 2.48 3.11 2.80

Nitrogen % 0.81 1.90 1.36

Oxygen % 6.62 0.02 3.32

Sulphur % 0.93 5.50 3.21

LHV (MJ/kg.) 13.10 31.99 22.55

HHV (MJ/kg.) 13.58 32.65 23.12

Table 1. Coal and pet-coke parameters (50% weight mix)

Composition of limestone used as additive is 95% CaCO3, 5% ashes. Grain size of limestone is less than

25 mm.

17

2.4. PLANT SYSTEMS

2.4.1. GASIFICATION

2.4.1.1. General

The Puertollano IGCC Plant's gasification system is based on a process developed by Krupp Koppers.

This technology, which has been used previously at atmospheric pressure in chemical plants, has been

adapted for application to a combined cycle through the generation of coal gas under pressure.

The first step in the development of this technology consisted of a test programme that took place in the

Fürstenhausen pilot plant, with a gasification capacity of 50 t/day. The aim of the programme was to

determine the optimum performance conditions for the process. The tests were carried our with a 50%

weight mix of unwashed Puertollano coal and petroleum coke.

18

2.4.1.2. Fuel Yard

Coal is delivered to the site from the ENCASUR mine, 18 km away. Petroleum coke comes from the

nearby (7 km) REPSOL refinery. Coal yard management is carried out according with production supply

analysis. Feedstock is delivered in trucks carrying loads of 25 ton. The unloading conveyors take the coal

or coke to the corresponding silo. The storage capacity is roughly 100 000 t, what represents 40 days

stock..

Feedstock 50% coal -50% petroleum coke

Mills capacity 120 - 140 t/h

Material fineness 5 mm < 60 % -90 % < 100 mm

Operation range 50% -100%

Table 2. Feedstock parameters

Figure 5. Fuel yard

19

2.4.1.3. Coal Preparation

In the rest of this document, the mixture of coal and coke will be generically referred to as coal. The coal

is mixed with limestone in order to lower the ash melting point and milled in two grinding roller mills. It

is then fed into two drying circuits with hot gases, corresponding to the specified 2 % moisture for the

gasifier feeding in the coal preparation plant, producing a flow of about 28.5 kg/s. The energy supply for

mixture plant drying comes from a hot gas generator operating with natural gas and steam generated in the

gasification island.

This plant is designed for 7,200 hours of operation per year and reduces the size of the fuel mix by up to

50-60 micron, with a spread of 26%. The coal dust produced is separated from the inert gases in sleeve

filters and is stored in hoppers at atmospheric pressure.

Figure 6. Coal preparation plant

20

The table shows flow composition and heating value.

Flow composition and heating value

C 61.68% S total 3.34%

H 2.92 % Cl 0.02%

O 3.45% Ashes 25.17%

N 1.42% Water 2.00%

LHV 24,087 kJ/kg HHV 23,493 kJ/kg

Table 3. Coal preparation. Flow composition and heating value

Value Unit

Number of mills 2

Solid fuel input 2,600 t/day

Size of milled grain 50-60 micron

Output flow rate 28.5 kg/s

Type of filters sleeve

Table 4. Coal preparation parameters

2.4.1.4. Pressurization and feeding

The feed mixture is pressurized (to 30 bar) in a lockhoppers system and then conveyed to the gasifier.

Pure nitrogen is used both for pressurization and as carrier gas. A full cycle within the lockhoppers

consists of filling, pressurization, discharging and depressurization.

21

2.4.1.5. Gasification process

Design values at nominal capacity are:

Input:

2600 t/d feed (pulverised coal)

Oxygen (85 %) upon C/O

Medium pressure steam upon C/H2O ratio

Output:

180000 m3/h raw gas

230 t/h high pressure steam

23 t/h medium pressure steam

Table 5. Gasification process design values

Coal dust enters the gasifier through four burners set at 90º. The oxygen, at 85% purity, comes through a

separate line from the air separation unit (ASU) to the gasifier, where it is mixed with the steam produced

by the gasifier itself. The process is carried out at a pressure of 25 bar and at a temperature of 1200-

1600ºC. Most of the ash produced is removed from the bottom of the gasifier in liquid form. A small part

is entrained by the gas (fly ash).

Figure 7. Gasifier building

22

The fuel particles are heated with a high temperature gradient when leaving the burners. Volatile

components spontaneously become free and oxidise with the free oxygen in exothermic reactions, as

shown below:

C + 1/2 O2 = COC + O2 = CO2CO + 1/2 O2 = CO2H2 + 1/2 O2 = H2O

The temperature increases and the following endothermic reactions are produced:

C + H2 O = CO + H2C + CO2 = 2 CO

Methane is produced transitorily, subsequently reacting with water producing CO y H2 .

Gases resulting from the reaction between the coal and the gasifying agents are cooled immediately, with

recycled cool gas flow at a 235 ºC in order to reduce the temperature to 800 ºC, at which point ash

becomes solid. The limestone, used as additive, lowers the ash fusion point temperature.

The gas heat is recovered in a high pressure convection boiler, cooling it to 400 ºC and producing high

pressure (HP) steam (127 bar). This operation is produced in a 60 m. high vessel with a 5 m. diameter.

The gas moves to a second stage, cooling to 235 ºC generating intermediate pressure (IP) steam (35 bar)

in a second convection boiler. The steam produced (HP and IP), at saturation conditions, is sent to the

combined cycle heat recovery steam boiler. After being re-heated the gas expands in the steam turbine.

Raw gas production in normal operation is about 180,000 Nm3/h.

Value Unit

Gasifier vessel high 15 m

Gasifier vessel diameter 5.6 m

Mix Input flow rate 107 t/h

Number of burners 4

Oxygen flow 25.3 kg/s

Combustion chamber temperature 1600-1200 ºC

Combustion chamber pressure 25 bar

Table 6. Gasifier parameters

23

2.4.1.6. Ceramic filters

The gas, at 235 ºC, is filtered in two vessels through ceramic candle filters, where the fly ash is retained.

There are more than a thousand elements (candles) in each vessel where the entrained ashes are retained

and the gas dust content is reduced to 3 mg/Nm3. The use of ceramic filters for the dust reduction is

noticeably innovative in power plants. At the exit of the ceramic filters, a significant part of the gas,

containing less than 3 mg/Nm3, is compressed in a centrifugal quench gas compressor of 1,500 kW and

recirculated to the gasifier in order to obtain the desired cooling effect on the reaction gases.

To be able to operate at any load range, the compressor is equipped with a variable speed control.

2.4.1.7. Slag System

The slag leaves the gasifier in a liquefied state (temperature above melting point) and follows into a water

bath, where it is cooled and crashed. A slag crasher, located at the discharge point, reduces the grain size if

necessary.

The solidified slag is taken to a slag collector, then depressurized in a lockhopper system and discharged

with a conveyor belt. The slag water circuit includes filters for solids, allowing the water to be recycled.

2.4.1.8. Gas cleaning and desulphurization

Venturi scrubber:

The gas physical wash in the Venturi allows halides and other compounds (HCl, HF, NH3, and H2S) to be

removed. Neutralisation is performed using a NaOH solution. Through the entire range of operations, the

pressure lost in the Venturi is less than 600 mbar. The wash water is recycled from the gas/water separator

down stream from the Venturi scrubber.

Stripping:

The Venturi wash water goes to a stripper separator that allows the water to be treated separately: the

containing organic compounds are treated in the ozoniser, and acid gas (containing H2S and NH3) are

treated in the Claus plant (sulphur recovery plant). The pH is set by sulphuric acid and sodium hydroxide.

The halides content (Cl-) mainly depends on the feedstock composition.

24

The stripper consists of an acid column for separating CO2, H2S and HCN, and a basic column for

separating NH3.

Desulphurization:

The sulphur content of the gas is eliminated in an absorption column with MetilDiEtanolAmine (MDEA),

which selectively captures sulfhydric acid (H2S). To maximise sulphur retention, the carbonyl oxysulphur

(COS) is converted into H2S beforehand in a catalytic reactor.

The MDEA solution is regenerated at approx. 100 ºC in a stripper column, which separates the acid gas.

The complex salts enrichment of the MDEA solution, based on ionic interchange, is controlled by a

desalting unit.

Value Units

Flow rate (dry basis) 183,000 Nm3/h

Maximum sulphur content 25 mg/Nm3

Maximum solids content 3,263 mg/kg

LHV (Lower Heating Value) 10,000 kJ/kg

HHV (Higher Heating Value) 10,470 kJ/kg

Table 7. Clean gas specifications

Figure 8. Gas cleaning and desulphurization

25

2.4.1.9. Sulphur Recovery Unit

The acid gas is sent to the Claus oven and reactor within the Claus plant, for the conversion of H2S to

elementary sulphur. In addition, ammonia (NH3) and cyanide (HCN) are converted into elemental

nitrogen using a catalyst.

The tail gas, which contains sulphuric acid (H2SO4), is recycled and sent to the hydrogenation reactor,

avoiding the use of an incinerator.

The Claus plant is designed to produce zero emissions, in such a way that the queue gases, which

normally contain non converted sulphur, can be recyclable at the top of the desulphurization unit and

reprocessed, avoiding atmospheric sulphur emissions.

Due to the flexibility in the supply of the fuel required by the Plant, the Claus unit has been duplicated in

order to be able to operate with medium and high sulphur content coal. Thus production capacity is

approximately 70 t/day, corresponding to coal with a 4% sulphur content.

Figure 9. Gasification and gas cleaning process

���������������������������������������������

oxygen/steam

+

���������������������������������������������������������������� HF+NaO

HHCl+NaOH

����������������������������

quench gas

fly ash

dust, HCN,HCl, HF

NH3,H2S,COS

fly ash

����������������������������������������

→→ 2O

ozone

recy

cle

gas

sulfurLiquid

MDEA DESORBER

clean gas to TURBINE

Na OH

H2 SO4

COS, H2S

������������������������COS+H 2O-->CO2+H2S

clau

s ga

s (H

2S, C

O2)

(H2S, CO2, HCN)

pretreated waste water(CN-, Cl-, SO4

2- salts)treated water

clea

n M

DEA

O2

MDEA ABSORBER2 �������������������

MDEA (H 2S, CO 2)

��������������������������������

����������������

����������������������������

����������������

H2S

��������������������������������������������������������������������������������������������������������������������������������SULFUR RECOVERY

������������������������������������������������������������������������������

������������������������������������������������������������������������

H2S+ 1/2O 2--> S+H 2O

2 NH3--->3H2+N2

���������������������������������������������������������������WATER

TREATMENT

����������������������������

��������������

air

QUENCH GASCOMPRESSOR

IPBOILER

CERAMICFILTER

LOCK HOPPER &FEED BIN

WETSCRUBBING

HYDROLYSIS REACTOR

235ºC

coal

HP BOILER

HP steam

nitrogen

������������������������������������������������

������������������������������������������������

��������

GASIFIER

slag

380ºC

235ºC

120ºC

40ºC

130ºC

140ºC 33ºC

98ºC

SULFUR RECOVERY

80ºC

180º

C

130ºC40

ºC

���������������������

FLY ASH DISCHARGE STRIPPERS

filter cake

������������������������

����������������������������������������������������������������������������������������������������

��������������������

NaOH

FILTER

NH3H2SCN-

Cl-,F-

dust,NH3H2SCN-

Cl-,F-

���������������������������

���������������������������

H2 SO4

NH3

IP steam

clean gas to SULFURRECOVERY

clean gas

sourgas

26

2.4.2. AIR SEPARATION UNIT

2.4.2.1. General

The air separation unit plant produces the oxygen required for gasification, with a 85% purity by volume.

This plant also produces two grades of nitrogen, one of 99.9% purity for inertization and the coal

preparation unit and another, of 98% purity, used to dilute of gas before it is burnt in the gas turbine

combustion chamber.

Figure 10. Air Separation Unit

2.4.2.2. Chilling and purification

The air flow, initially cooled in a cooling unit, carries substances that must be removed for technical and

safety reasons.

• Water and carbon dioxide, which solidify approximately 0 ºC and -130 ºC respectively at

atmospheric conditions. Since air separation is based on a cryogenic process and reaches

temperatures of below -170 ºC , these substances could cause piping blockage.

• Hydrocarbons, which, like oxygen, can give raise to potentially hazardous situations.

27

2.4.2.3. Distillation

The cold box is a counter-current heat exchanger where inlet air is cooled by column products (nitrogen

and oxygen). The distillation column operates at high pressure, which is proportional to the gas turbine

load, and produces rich gaseous nitrogen at the top and rich liquid oxygen at the bottom.

This unit is designed to follow load variations in the gasifier and combined cycle, supplying nitrogen and

oxygen with the specified degree of purity. The air separation products are then compressed at the

pressure required by the process, by means of electrically actuated compressors.

Liquid oxygen and nitrogen can be stored with their corresponding evaporators, as these gases are needed

during gasifier start up and shutdown. Oxygen supply capacity operating normally is approximately,

70,000 Nm3/h.

Value Unit

Gaseous Oxygen

Flow 70,000 Nm3/h

Purity 85 %

Pressure 31 bar

IP-Nitrogen

Flow 22,100 Nm3/h

Purity 99.9 %

Pressure 49 bar

LP-Nitrogen

Flow 8,150 Nm3/h

Purity 99.9 %

Pressure 4 bar

Waste Nitrogen

Flow 188,000 Nm3/h

Purity >98 %

Pressure 13 bar

Liquid flow 25 Nm3/h

Air flow 288,000 Nm3/h

Table 8. Air Separation Unit parameters

28

2.4.3. COMBINED CYCLE

2.4.3.1. General

The SIEMENS combined cycle selected for this plant uses the most advanced technology available in the

market at the contract date. In its entirety, the combined cycle plant can generate an output of 335 MWe

(ISO conditions). Taking into account the plant's internal energy consumption (air separation unit, cycle,

gasification, and auxiliaries) a total net output of 300 MW can be delivered to the electric grid.

2.4.3.2. Gas Turbine

Before combustion takes place in the Gas Turbine, the clean coal gas is subjected to a process of water

saturation in order to reduce nitrogen oxides (NOx) formation during combustion. The gas is subsequently

heated to a temperature of 260 ºC by water from the high pressure boiler and is finally mixed with residual

nitrogen from the air separation unit, which acts as an inert dilutant with the aim of reducing NOx

formation further during combustion. As a result of these two operations (saturation and dilution),

together with the use of low NOx burners, contamination levels of less than 60 mg/Nm3 should be

obtained when 15% O2 is used.

The turbine at Puertollano is V94.3 Siemens model. This turbine has two external hopper combustion

chambers, which can burn natural gas and coal gas, individually or in mixtures maintaining high

performance level in terms of rate, efficiency and pollution. The gas turbine's gross output in ISO

conditions is 200 MW.

Figure 11. Gas Turbine

29

The 17 stages compressor reaches a compression ratio of 15.6:1. The stationary blades of the first four

stages have variable inlet guide vanes. During part-load operations, these vanes are closed so as to reduce

the compressor air mass flow down to about 80% of the base load value, which results in a constant

turbine exhaust temperature down to about 65% load. This control allows maintaining high efficiencies

for the combined cycle, even at part load.

Each combustion chamber is equipped with 8 burners able to burn natural gas and coal gas,

independently. When the turbine runs with natural gas there is no possibility, previously to its combustion,

to saturate the gas or to mix it with nitrogen in order to reduce NOx formation. Therefore, IP steam from

the HRSG is directly injected inside the combustion chambers to control NOx formation. The firing

temperature is of 1250 ºC.

Figure 12. Gas Turbine VT 94.3 with internals

30

2.4.3.3. Heat recovery steam generator

The heat from the gas turbine exhaust gases (535 ºC) is largely recovered in the heat recovery steam

generator, producing water steam at three pressure levels (127/35/6.5 bar).

Furthermore, this boiler re-heats its own steam, as well as the steam from the gasification island. Its

efficiency level is therefore higher than those of conventional boilers with 1 or 2 pressure levels. The

exhaust gases are cooled to a temperature of approximately 105 ºC in this boiler.

Figure 13. Heat recovery boiler and gas saturator buildings

31

2.4.3.4. Steam Turbine

The steam generated in the heat recovery boiler is sent to the steam turbine. The steam turbine is of two

stages, single shat design. In the first stage, inlet steam at approximately 122 bar and 506 ºC is expanded

in the high and intermediate pressure stages. In the second stage, the low pressure steam is expanded by

means of a double flow turbine.

Figure 14. Steam Turbine

The expanded steam in the high pressure turbine stage is re-heated along with the intermediate pressure

steam from the heat recovery boiler, before being sent to the intermediate pressure turbine stage,

optimising the process. The steam turbine's gross output in ISO conditions is 135 MW.

The exhaust steam in the low pressure turbine stage is condensed in vacuum conditions at about 40 ºC,

using cooling water in a closed circuit. The surface condenser has a double flow box, with water boxes on

each side. The condensate produced is sent back to the recovery boiler by means of the condensate pump.

32

Figure 15. Energy balance of the plant

33

2.4.4. INTEGRATION SYSTEM

The Puertollano IGCC plant is designed using a full integration concept., which means:

· Air to air separation unit fed from the gas turbine compressor.

· Optimal use of all energy levels in the heat exchanger network.

· The waste nitrogen produced in the air separation unit is sent to the gas turbine.

· Feed water is sent to the gasification island from the combined cycle and the generated steam is

exported to the combined cycle.

Air:

The air fed to the air separation unit is fed from the gas turbine compressor at 14 bar and 400 ºC at full

load.

In keeping with the air separation unit's temperature requirements (less than 127 ºC), the air is cooled in

the following heat exchangers:

- Waste nitrogen pre-heater.

- Two air coolers, where water circulating the flash tank is heated. This stream is used to supply the

required heat to the saturator water.

Waste nitrogen, O2 and pure N2:

Waste nitrogen (2 % O2) produced in the air separation unit is pre-heated at 360 ºC with the extracted air

and mixed with the saturated clean gas. This allows NOx formation to be reduced during the combustion

and improves the gas turbine power output, due to the higher expanded mass flow.

Clean gas:

Clean gas is saturated with steam before the combustion, to reduce the formation of NOx. It is then pre-

heated to approximately. 260 ºC with feed water and mixed with the waste nitrogen from the air

separation unit.

34

Water steam:

The combined cycle and gasification island water/steam system are fully integrated. The gasification

island feedwater comes from the combined cycle, and the steam produced in the gasifier waste heat boiler

is exported to the combined cycle drums, to be superheated and then expanded in the steam turbine. Part

of the steam produced in the gasifier is used for the internal consumption.

Figure 16. Outline of the IGCC plant's main system's interfaces

HRSGSteam Turbine Generator

����������������������������������������������������������������������������������������

Coal Preparation

Gasifier Gas cleanning Gas Saturation Gas Turbine Generator

Sulphur recovery

Efluent treatment

Air Cooling

Air Separation

Unit

Demineralized water

Exhaust Gases

Steam Steam Condensates

Steam

Nitrogem Oxygen

Air

Waste Nitrogen

Water

LP Steam

Sulphur Dry sludge

Coal Petcoke

Slag

Electricity

Electricity

Air

Exhaust Gses

Fly Ashes

Raw Gas Clean Gas Satur. Gas

Desulphuration

Effluent

35

2.4.5. AUXILIARY AND SERVICE SYSTEMS

Besides the three main islands, the Puertollano plant is equipped with many auxiliary and service systems

that facilitate correct operation.

2.4.5.1. Cooling system

The cycle condenser is cooled by means of a wet cooling tower system. The circulation system cools two

open circuits, one for the gasification and air separation and the other for the combined cycle equipment.

The cooling tower is 122 m. high and is cooled with water from the raw water storage system. Make up

system consumption is about 500 m3/h, to compensate for the effects of evaporation and concentration.

The pumping station consists of two semi-axial flow pumps, with a capacity of 60% of the circulating

water nominal flow each.

A yearly supply of approximately 6 hm3 of clean raw water is required. This water is taken from the

Jándula river, through the artificial Montoro lake in the Guadalquivir basin.

Figure 17. Cooling tower

36

2.4.5.2. Auxiliary boilers

There are two auxiliary steam generators, which operate with natural gas, for the purpose of supplying

low and intermediate pressure steam to the plant systems. Auxiliary steam is mainly used during

combined cycle and gasification island start-up (systems preheating) and shut-down (purging) operations.

Boiler Flow rate and pressure

IP auxiliary steam boiler: 11 kg/s, 36 bar and steam lamination at 6.5 bar.

LP auxiliary steam boiler: 2.5 kg/s, 6.5 bar.

Table 9. Auxiliary boilers parameters

2.4.5.3. Flare

The coal gas produced in the gasifier during the start-up and the gases purged during plant shut-down are

burnt in the flare. The flare system is designed for 100 % coal gas production. To assure complete gas

combustion, which may have a low calorific value, natural gas is added in the flare. To increase the safety

of the flare, a redundant ignition system, operated with independent propane gas, was added during the

commissioning phase.

Figure 18. Flare

37

2.4.5.4. Emergency Diesel generator

In the case of a power cut, a back-up 2400 kW Diesel generator is connected to the 400 V line to provide

electric power to the equipment that is essential for plant safety. This essential equipment includes the

gasifier's circulating pumps and the slag cooling system.

2.4.5.5. Water Treatment

The IGCC plant includes an ozoniser to prepare the stripper water for the end effluent conditions (cyanide

content below 0.2 mg/l), before disposing of it in the Ojailén river.

The water treatment plant involves the following operations: stripper, effluent ozoniser and

homogenisation deposit.

2.4.5.6. Other service and auxiliary plant systems

The plant is also integrated by the following auxiliary and service systems:

• natural gas station

• raw water supply

• demineralised water plant

• auxiliary cooling system

• heating, ventilation and air conditioning

• compressed air

• fire fighting system

• waste water treatment plant

• cooling water conditioning plant

• others

38

2.4.6. ELECTRIC SYSTEMS

2.4.6.1. General

The electric plant systems include the systems, equipment, components and connections required to

supply electricity to the grid when the combined cycle is operating, and to supply electrical energy to the

plant's auxiliary systems when the plant is in shutdown or during starts.

The electric system includes the following equipment and systems:

• 230 MVA electric generators for both gas and steam turbines.

• High voltage system, including the 220 kV bars, the generation breaker and the 234/15/75 kV main

transformers. Two connection lines to the 220 kV grid.

• 45 kV emergency system.

• Intermediate voltage system, including the 15.75 kV/6kV bars for auxiliary equipment and the 10.5

kV bar for feeding the air and nitrogen compressor.

• 400/230 V low voltage system.

• 400 V 1200 kW emergency diesel generator.

• Uninterrupted power supply system.

• 125/24 V DC system.

Figure 19. Main transformer and substation

39

2.4.6.2. Generators

The twin shaft design consists of a gas turbine generator (nominal power 230 MWA) and a steam turbine

generator (nominal power 230 MWA) both connected to main transformers by the corresponding

breakers.

Both machines are bipolar, with a direct air cooling system for rotor wiring and an indirect system for

stator wiring. The rotor bearings are lubricated by the corresponding turbine oil system. Generators are

provided with protection devices to account for fault to earth, under-excitation, over-current, over-voltage,

unbalanced load, under-frequency and power inversion. The gas turbine generator is equipped with a

static frequency converter, which allows to drive the generator during gas turbine run-up and other

operations. This converter is fed from the 6kV system.

Transformers Name Power MVA Transformation relation

1 BAT 10 Main transformer TG 216 234±10% / 15.75 kV

2BAT 10 Main transformer T. 176 234±10% / 15.75 kV

1BBT 10 Auxiliary transformer 24/16-16 15.75±10% / 6.3-6.3 kV

2BBT 10 Auxiliary transformer 24/16-16 15.75±10% / 6.3-6.3 kV

BDT 10 Support transformer 24/16-16 45±10% / 6.3-6.3 kV

1BBT 20 Transf. compr. Air-N2 40 15.75±10% / 10.5 kV

Table 10. Electric transformers parameters

40

2.4.7. CONTROL SYSTEM

2.4.7.1. General

The Puertollano IGCC plant is equipped with a Siemens Teleperm XP distributed control system. This

system has a modular structure and consists of the following subsystems:

• An automatic system for automatic function implementation at the lowest control level.

• A communications network.

• An operation control and monitoring system for operation processes and information interchange.

• An engineering system for planning, configuration and start up.

Figure 20. Plant control room2.4.7.2. Control levels

This system's automation and control levels are as follows:

Field level: The lowest level where sensors are located and data is withdrawn. Its function is to receive

signals from sensors and to transmit them to the higher levels or the actuators.

Automation level: Individual control level: Basic control of operations with analogue and binary signals.

Actuators control in open loop and individual control in closed loop.

• Group control level: Automatic functions such as closed loop regulations, open loop control and signal

protection management.

Process level: Storage of process data and transfer of the dynamic information to the man-machine

interface.

Operation and control level: Association of the man-machine interface with the interaction supervision

and configuration systems.

41

2.4.9. PLANT FUNCTIONAL BASIC OUTLINE

The Puertollano IGCC Plant functional basic outline is shown next.

Figure 21. Simplified flow diagram of the Puertollano Plant

42

2.4.10. SUMMARY OF BASIC TECHNICAL DATA

Technology. Pressurized Entrained Flow (Prenflo by Krupp Koppers) Gasification process integrated

with SIEMENS (KWU V94.3) Combined Cycle

Fuel. Coal and petroleum coke 50% in weight

Coal Pet-coke Mix

LHV (MJ/kg) 13.10 31.99 22.55

HHV (MJ/kg) 13.58 32.65 23.12

Output (MW)

Gas Turbine Steam Turbine Raw

Site Conditions 182.3 135.4 317.7

ISO Conditions 200 135 335

Consumption

Per year Per hour

Fuel 700,000 t/year 107,000 kg/h

Limestone 24,000 t/year 3,700 kg/h

Raw water 5 hm3/year 720 m3/h

Gross Efficiency (LHV)

Value

Thermal rate 47.12%

Specific consumption 1,825 te/MWh

Emissions (6% O2)

(Design values) t/year g/kWh mg/Nm3

SO2 138 0.07 25

NOx 826 0.40 150

Particles 41 0.02 7.5

Solid by-products: 625 t/day of vitrified and inert slag and fly ash.

Table 11. Basic technical data

43

2.5. TECHNOLOGICAL VALUE AND INNOVATION

The technological value of the ELCOGAS Project is based on two key points: technological innovation,

that might allow to design a second generation plant using this technology and the acquisition of specific

know-how in IGCC projects.

Provided that the IGCC plants incorporate systems that can be used in other production processes

(gasification, filtration, desulphurization, heat recovery boilers ...), the technology incorporated and

developed by ELCOGAS becomes versatile regarding its industrial applications.

2.5.1. TECHNOLOGICAL INNOVATION

The following points constitute technological innovation in the IGCC plant:

• Utilisation for the first time of equipment, materials and processes (specially in gasification).

• World reference point in scaling IGCC technology of European origin.

• Vital experience for reducing costs in future projects.

2.5.2. ACQUISITION OF SPECIFIC “KNOW-HOW”

The following points constitute the acquisition of specific “know-how” in IGCC projects:

• Experience of managing highly complex projects:

• Role of the plant architect-engineer.

• Interface co-ordination.

• Quality Control.

• Construction and Start-Up Management.

• Experience of operating a commercial size IGCC plant:

• Operating procedures.

• Training.

• Elaboration of “performance tests”.

• Adaptation and prediction control.

• Development of advanced technology:

• Gasifier and burners.

44

• Adaptive/preventive control

• Ceramic Filters and ionic exchanger.

• Queue and Quench Gas Compressors.

• Gas Turbine.

• Distributed Control.

• Experience in manufacturing and assembling complex equipment:

• New materials.

• "In situ" gasifier assembly.

• Steam Turbine with high and intermediate pressure stages.

In terms of technological innovation, the construction of an IGCC plant with technological characteristics

that differ from those used elsewhere has involved a significant investment in R&D in Spain, which has

had a positive effect as regards industrial and energy development. The most significant differences are:

• Largest scale equipment in the world:

• Gasifier. Krupp Koppers high pressure entrained flow. (2500 t/day).

• Air Separation Unit. High pressure supply of O2 and N2.

• Gas Turbine. Siemens V94.3 with dual gas burners.

• New generation technology to reduce emissions:

• Ceramic Candle Filters.

• Tail gas recycling compressor.

• Heat recovery boiler with three levels of steam pressure.

• Gas quenching by means of recirculation with quench compressor.

• Integration of all elements:

• Residual Nitrogen Compressor with gasifier and combined cycle.

• Gas Turbine Compressor feeding the Air Separation Unit.

• Distributed Control System from a development stage.

• Adaptive/predictive control o certain functions.

45

2.6. ENVIRONMENTAL CONSIDERATIONS

2.6.1. GENERAL

Legislation for environmental protection is becoming more and more demanding every day. It is very

important for an electric utility to anticipate the evolution of this legislation and to master the new

technologies that provide a greater protection for our environment.

The Puertollano IGCC plant is demonstrating that it is possible to burn poor quality coal, with an ash

content of more than 40% and refinery by-products with sulphur content of over 5%, such as petroleum

coke, with a very small environmental impact.

• NOx emissions are reduced saturating coal gas with water and mixing it with residual nitrogen before

burning, resulting in a lower flame temperature.

• SO2 emissions are reduced by more than 99%, thanks to coal gas desulphurization. The sulphur is

separated as elementary sulphur, and forms no part of the plant's solid waste.

• At a temperature of about 1400 ºC, slag flows from the bottom of the gasifier vessel and is rapidly

cooled with water, forming a vitrified substance that encapsulates heavy metals in a non-soluble form.

Fly ash entrained by the gas is separated and recovered as a by-product, already used in the cement

preparation.

• CO2 emissions are reduced, due to a higher thermal efficiency, down to a 85% of the CO2 emissions

in a modern conventional plant.

The plant also offers other environmental advantages, such as the higher level of water consumption

efficiency and the recovery of slag in vitrified form, which has multiple industrial applications.

In addition to the environmental advantages, the plant is highly flexible in terms of the fuels it can use

(natural gas, domestic coals and refinery by-products) attaining efficiency rates using resources

compatible with the present combined cycles (when operating with natural gas) and performing better

regarding efficiency than clean coal technologies in sub-critical conditions.

46

Figure 22. Puertollano IGCC Plant

47

2.6.2. COMPARISON OF EMISSIONS FROM DIFFERENT TECHNOLOGIES TYPES

Table 12 shows atmospheric emissions from the following technology types: (1) pulverised coal with no

gas cleaning process, (2) the same plant with desulphurization system (90%), low level NOx (50%)

burners and electrostatic precipitators (99,2%), (3) ACFBC with cyclone filters (96%) and (4) Puertollano

IGCC Plant. They are all compared to the limits established by Community Directive 88/609.

In order to establish a homogenous comparison basis the same standard fuel has been considered, with a

content of 3.2% sulphur, 20.68% ashes and 23.12 MJ/kg (the Puertollano design fuel), with a gross output

of 320 MWe. The emissions measured in mg/Nm3 refer to a dry composition with 6% oxygen. For the

fluidised bed plant, the SO2 emissions have a dependence on the Ca/S rate in the bed.

Base: 320 MWe, 6% O2 , η = 37.5 HHV for ABFC & PC plants SO2

(mg/Nm3)

NOx

(mg/Nm3)

Particles

(mg/Nm3)

(1) Pulverised Coal without cleaning process 7300 1300 > 10000

(2) Pulverised Coal DeSOx(90%)/LNB(50%)ESP(99,2%) 730 650 100

(3) AFBC + cyclone filters (96% effic.) 200-400 170-230 30-50

(4) Puertollano IGCC 25 150 7.5

Limits of emissions (88/609/EEC)1 400 650 501 This directive does not apply to gas turbine plants.

Table 12. Comparison of emissions between coal technology types

NOx (mg/Nm3)

650

150

0100200300400500600700800

SO2 (mg/Nm3)

400

25

0

100

200

300

400

500

Part. (mg/Nm3)

50

7,5

0

10

20

30

40

50

60

Figure 23. EU emission limits and IGCC plant design emissions

48

For comparison purposes, conventional plants and AFBC plants have been considered to have an

efficiency level of 37,5% (HHV). The value has been estimated on the basis of EPA data [3] which

contains a representative sample for plants of each technology type.

Base: 320 MWe, 6% O2 , η = 37.5 HHV for ABFC & PC plants SO2

(g/kWh)

NOx

(g/kWh)

Particles

(g/kWh)

(1) Pulverised coal without cleaning process 25.3 4.5 > 40

(2) Pulverised coal DeSOx(90%)/LNB(50%)ESP(99,2%) 2.5 2.3 0.34

(3) AFBC + cyclonic filters (96% effic,) 1.5 0.80 0.10

(4) Puertollano IGCC 0.066 0.397 0.020

Table 13. Comparison of emissions (g/kWh) between coal technology types. Output 320 MW

The following graphs show a comparison between EU directive emission limits and the Puertollano IGCC

Plant's forecasted emissions.

Figure 24. Comparison of emissions between different technology types

49

3. ELCOGAS AND THE PROJECT’S ORGANIZATION

3.1. THE ELCOGAS COMPANY

The ELCOGAS Company was founded on April, 8th 1992, as a mercantile Company subject to Spanish

legislation, with the objective of the construction and exploitation of the Puertollano IGCC Plant.

The founding members were six European electrical companies: Endesa, Iberdrola, Sevillana and

Hidrocantábrico from Spain, EDF from France and EDP from Portugal. New European members were

later incorporated to the Project, namely the electrical companies National Power from Great Britain and

ENEL from Italy, along with the main combined cycle and gasification plant suppliers, Krupp Koppers

and Siemens from Germany, in association with Babcock Wilcox Española, from Spain as manufacturer,.

The current members, (including Sevillana in the Endesa Group), and their percentage of shares in the

ELCOGAS company capital are as follows:

COMPANY % of share

ENDESA 37.93%

EDF 29.13%

IBERDROLA 11.10%

HIDROCANTABRICO 4.00%

EDP 4.00%

ENEL 4.00%

NATIONAL POWER 4.00%

BABCOCK WILCOX ESPAÑOLA 2.50%

SIEMENS 2.34%

KRUPP KOPPERS 1.00%

Table 14. ELCOGAS capital share

The capital share is shown graphically in the following figure.

50

Figure 25. ELCOGAS capital share

IBERDROLA

EDF

ENDESA

HIDROCANTÁBRICO

KRUPP KOPPERS

NATIONAL POW ER

ENEL

EDP

BABCOCK W ILCOX SIEM ENS

51

3.2. ORGANIZATION

3.2.1. GENERAL

The ELCOGAS company's basic organization for the commercial phase is structured in three managerial

areas, reporting to the Chief Executive Officer, as shown in the following chart:

Figure 26. ELCOGAS Basic organization chart(*) With EEC participation.

As at November, 2000, ELCOGAS has a staff of 157 employees.

CHIEF EXECUTIVE OFFICER

OPERATION DIRECTION ADMINISTRATION & FINANCE DIRECTION COMMERCIAL DIRECTION

ELCOGAS BOARD

FOLLOW-UP COMMITTEEFINANCIAL COMMITTEE

DEPUTY CHIEF EXECUTIVE OFFICEROPERATION COMMITTEE *

52

3.2.2. PROJECT MANAGEMENT AND SUPERVISION

The project's management and supervision was organized and established in Madrid and Puertollano. A

Steering Committee has existed since the initial phase of the project, with the participation of

representatives of the ELCOGAS members and the European Community Commission. The Steering

Committee established the project's technical guidelines and supervised its development and progress.

Additionally, a Project Follow up Committee, including the participation of local authorities, was

established and still meets regularly. The ELCOGAS general organization flowchart for the last phases of

the project and plant construction until late 1997 is shown in the figure.

Figure 27. ELCOGAS Project organization chart

CHIEF EXECUTIVE OFFICER

CONSTRUCTION MANAGER

OPERATION MANAGER FINANCE MANAGER

BOARD

STEERING COMMITTEE

ENGINEERING

CIVIL WORK & ASSEMBLY

COMMISSIONING

QUALITY ASSURANCE

PROCUREMENT

SCHEDULING & COST CONTROL

CIVIL WORK

COMBINED CYCLE

GASIFICATION & ASU

BALANCE OF PLANT

I6C

GENERAL SERVICES & SECURITYIINTEGRATION &

OPTIMIZATION

53

3.2.3. OUTLINE OF PROJECT CONTRACTS

In accordance with a project work breakdown structure, ELCOGAS distributed certain project functions

related to the basic engineering of the plant, the engineering and supply of basic systems and equipment,

the supply of balance of plant equipment, construction and assembly, etc., among different organizations

specialised in the areas in question. This distribution of responsibilities is shown by the different contracts

between ELCOGAS and these organizations.

Figure 28. Project Interfaces and Contracts

The distribution of activities in the corresponding contracts and the final status of the contracts are

described next.

ELCOGAS

OWNERS

EU COMMISSION

OCICARBÓN

CENTRAL ADMIINSTRATION

REGIONAL ADMINISTRATION

LOCAL ADMINISTRATION

GASIFICATION SUPPLIER

COMBINED CYCLE SUPPLIER

AIR SEPARATION UNIT SUPPLIER

DCS SUPPLIER

BALANCE OF PLANT SUPPLIERS

COORDINATION AND BALANCE OF PLANT ENGINEERING

SUBCONTRACTED ENGINEERING

SITE CONTRACTORS

CONSULTANTSELCOGAS BOARD

54

3.2.3.1. GENERAL AND BALANCE OF PLANT ENGINEERING

The general and balance of plant systems engineering services were awarded at the end of July 1992 to the

Spanish engineering company, INITEC, and to Electricidade de Portugal.

INITEC subcontracted and/or co-ordinated the following areas of plant engineering:

- Civil Engineering, with Electricidade de Portugal (EDP).

- Control and Instrumentation engineering, with Electricité de France (EDF).

- Water Circulation systems engineering, with Electricité de France (EDF).

- Detail electric engineering, with Empresarios Agrupados (EA).

INITEC was responsible for the co-ordination of the entire engineering effort and was the direct contact

for the project.

Certain specialised engineering and studies activities (environmental, geo-technical, risk analysis,

security, etc.) were contracted out to specialised organizations.

55

3.2.3.2. MAIN SUPPLIES

3.2.3.2.1. Gasification System

The contract for engineering, manufacturing and equipment supply, materials and services related to the

coal gasification system was awarded, at the end of July 1992, to the consortium formed by Krupp

Koppers, with experience in plants using this type of technology, and Babcock Wilcox Española, a

Spanish power equipment supplier. The contract's scope of supply included:

- Fuel preparation system.

- Gasifier reactor, together with heat recovering units, gas cleaning system and other auxiliaries.

- Gas treatment system.

- Claus unit for sulphur separation.

The system supplier also dealt with its assembly in the plant and supervised star-up se services.

3.2.3.2.2. Air Separation Unit

The contract for engineering, manufacturing, equipment supply, materials and services and the assembly

activities related to with the air separation unit, required for oxygen supply to the gasifier, was awarded in

February 1993 to Air Liquide, a specialised supplier to plants of this type.

3.2.3.2.3. Combined Cycle

The contract for engineering, manufacturing and equipment supply, materials and services contract

related to the combined cycle unit with gas and steam turbines, arranged with separated shafts, was

awarded, at the end of July 1992, to the joint venture formed by Siemens AG, with experience in units

using this type of technology, and Babcock Wilcox Española, Spanish power equipment supplier. The

contract's scope of supply includes:

- BWE Scope of Supply

- Heat recovery steam generator and GT flue gas duct

- Piping system water/steam cycle

- Condenser

- Siemens Scope of Supply

- Gas turboset V94.3 (GT)

- Steam turboset KN (ST)

- Instrumentation and control for turbosets

- Turbine house cranes (GT + ST)

- Heat exchangers (cooling air cooler, saturator water and clean gas preheater)

56

- Saturator system for clean gas

- Electrical equipment

Overall plant control system

The supplier of the combined cycle also dealt with its assembly in the plant and supervised start-up

services.

3.2.3.2.4. Distributed Control System

The contract for engineering, manufacturing and supply of the Distributed Control System (DCS) and

services related to the assembly and start up of this system was awarded in December 1994 to the joint

venture formed by Siemens AG, Scape, Disel y Sainco.

57

3.2.3.3. SUPPLY OF BALANCE OF PLANT EQUIPMENT

3.2.3.3.1. Equipment Supply

The contracts for the remaining plant systems, equipment, components and materials were awarded to

appropriate suppliers.

Contracts packages in this area for significant units and systems are the following:

SUBJECT

Demineralised Water Plant

Distributed Control Systems (DCS)

Fuel handling plant

Fire protection system

Ventilating and Air conditioning system

Plant telephone & megaphone systems.

Plant lighting

Natural Gas Station

Plant lighting

Waste Water Treatment Plant

Slag Removal Plant

Solidification Sulphur Plant

Table 15. Equipment Suppliers

The balance of plant equipment included:

- Piping

- Miscellaneous Valves

- Control Valves

- Coal and limestone hoppers

- Tanks

- Cranes

- Lifts

- Water Circulation Pumps

- Miscellaneous pumps

- Heat Exchangers

- Air Compressors and Dryers

58

- Auxiliary Boilers IP and MP

- 45 kV Site Line and Substation

- Site Electrical ring and transformers

- Machine Breaker

- Main, back up and auxiliary Transformers

- Isolated Phase Bars

- Substation 220 kV structures

- Substation 220 kV equipment

- Electric cabinets

- Medium and low voltage electric motors control cabinets

- Medium and low voltage electric motors, motor booster for gas turbine, synchronous motor

for ASU.

- Cable trays and supports. Conduits.

- Electrical and instrumentation Cables

- Batteries and chargers

- UPS units

- Emergency Electric Generator

- Dynamic Simulator

- Instruments

- Cooling Water Treatment Plant

- Lightning-conductors

- Gas emission Control System

- Nitrogen buffer

- Water laboratory equipment

- Electrical laboratory equipment

- Instrumentation laboratory equipment

- Coal and coke mixer

- Insulation for Air Separation Plant

- Fuel Weight System

- Nitrogen vent

59

3.2.3.3.2. Complementary services

• Equipment Supply Expediting Services

• Special Transport Services

Figure 29. Transport of the gas turbine

• Insurance

The Insurance Policy for the Plant, covering the construction and operation periods, was taken out with a

consortium of Insurance companies.

60

3.2.3.4. CONSTRUCTION. CIVIL WORK AND EQUIPMENT ASSEMBLY

The construction work was supervised by ELCOGAS and was carried out in several stages.

3.2.3.4.1. Civil Work

The civil construction package contracts for buildings, outside structures, etc., were awarded to various

construction contractors specialised in power plants. The following are the main construction contract

packages:

SUBJECT

Site preparation

Combined Cycle Buildings and Structures.

Cooling Tower and Cooling Water System

Gasification area foundation.

Gasification Plant, Fuel Handling Plant and Effluent Treatment Plant

Air Separation Unit and balance of gasification

Administration Building, Workshop and Water Treatment Plant

Raw Water Supply. Pumping system and ducts

Roads connecting with the coal mine

Cooling Water treatment plant

Miscellaneous Civil Works

Table 16. Civil work contractors

ELCOGAS shared with other industrial companies of the area the construction of the aqueduct Jándula-

Montoro for the supply of water to the Puertollano area, including water supply for the plant.

Figure 30. Civil construction work on the plant

61

3.2.3.4.2. Mechanical Assembly, Electrical and I&C Installation

The mechanical, electrical, instrumentation and control systems and equipment assembly was carried out

over several stages and contracted out to various specialised companies. The assembly was supervised by

ELCOGAS. The main gasification equipment, the combined cycle and the air separation unit assembly

was further supervised by the relevant main suppliers. The main assembly contract packages for the plant

are listed below:

SUBJECT

Mechanical Assembly for the Combined Cycle and Auxiliary Systems

Construction of Heavy equipment (Gasifier, Heat Recovery Boiler)..

Assembly of steel structure Coal Preparation Building

Mechanical Assembly of BOP equipment phase I.

Mechanical Assembly of equipment in gasification area

Mechanical Assembly of equipment: Sulphur Recovery, Recycle Gas

Compressor, N2/O2 Systems, Fly Ash Discharge and Slag Water Filter

Electrical Assembly for the Combined Cycle and Auxiliary Systems

I&C equipment Assembly for the Combined Cycle and Auxiliary Systems

Insulation of equipment and piping for the Combined Cycle

Painting for Combined Cycle.

Mechanical Assembly of BOP equipment phase II.

Instrumentation and electrical assembly for the gasification island

Insulation of equipment and piping for the Gasification island.

Painting for Gasification Island.

Gasification plant electrical tracing.

BOP and ASU electrical tracing

Table 17. Mechanical Assembly, Electrical and I&C Installation Contract packages

62

Figure 31. Assembly of the gasifier

63

3.2.3.4.3. Main Work Units

Main work units performed at the site until the end of July 1998 were the following:

Concept Work units

Site preparation

Excavation 864,187 m3

Terracing 641,143 m3

Drain system

Piping (concrete) 10,776 m

Wells 324

Services

Piping 9,460 m

Wells (waste and registers) 178

Roads and walks

Asphalt coating 45,061 m2

Road banks 13,388 m

Sums 349

Structural

Reinforcing Steel 7,480 t

Concrete 97,040 m3

Building structures 8.478 t

Process Piping

Piping 3,425 t

Electrical cable

Installation 1,135,448 m

Connections 259,184

General

Man hours accumulated in construction 6,449,673

Table 18. Main site work units

64

3.2.3.5. QUALITY PLAN INSPECTION AGENCIES

The necessary inspection services to ensure the quality level required for the equipment manufacturing,

civil construction and site equipment assembly were contracted with specialised agencies.

3.2.3.6. OPERATION TRAINING

Training services for the operation of the combined cycle, gasification and air separation systems are

included in the contracts for the supply of the corresponding equipment. Other specific training courses

have been contracted as required with specialised contractors and suppliers.

3.2.3.7. FUEL SUPPLY

Contract for the supply of coal

ELCOGAS had an agreement with ENCASUR, the mining company owning the main Puertollano coal

mines, for the supply of the coal. In March 1998, ELCOGAS signed a contract with Encasur for the

supply of coal from local mines for twelve years.

Contract for the supply of petroleum coke

ELCOGAS has a contract with Repsol, petrol and chemical company with important refinery and

chemical plants in Puertollano, for the supply of the petroleum coke from the Puertollano refinery for a

period of 6 years, renewable to 12.

Contract for the supply of natural gas

ELCOGAS has a contract with ENAGAS, the Spanish gas operator, for the supply of natural gas required

for the plant operation.

65

3.3. PROJECT DEVELOPMENT

3.3.1. GENERAL

Project activities developed as shown in the following chart:

Figure 32. Project schedule

Puertollano IGCC project activities were complete when the first gasification process was achieved and

the first synthetic gas was produced. This event that took place on December 19th, 1997, ten months after

the date planned at the Project start. Delays were mainly due to design changes in the gasification area and

delays in delivery of engineering documentation and some gasification equipment.

PUERTOLLANO IGCC PROJECT BASIC PLAN

ACTIVITY JuAgSeOcNoDicEnFe MaAbMaJu Ju AgSeOcNoDicEnFe MaAbMaJu Ju AgSeOcNoDicEnFe MaAbMaJu Ju AgSeOcNoDicEnFe MaAbMaJu Ju AgSeOcNoDicEnFe MaAbMaJu Ju AgSeOcNoD

AWARD OF MAIN EQUIPMENT & ENGINEERING

ENGINEERING AND DESIGN

SITE PREPARATION

GASIFICATION PLANT MANUFACTURING AND SUPPLY

COMBINED CYCLE MANUFACTURING AND SUPPLY

CIVIL WORK

COMBINED CYCLE ERECTION AND START UP

COMBINED CYCLE 100 H. PERFORMANCE TEST

GASIFICATION ERECTION

19971992 1993 1994 1995 1996

��

66

The project percentage progress curve up to December 1997, the date of the end of the project, is shown in

the graph.

Figure 33. The Puertollano IGCC Plant Project Progress

Following the start-up activities, the first gas turbine switch-over from natural gas to synthetic gas was

carried out successfully on 20th March 1998. After this test, modifications and adjustments were made to

the system in order to improve the IGCC operation of the plant, particularly in the gasification area:

- coal preparation, coal and petcoke mixing, milling and conveying.

-

PROGRESS OF THE PROJECT

0

20

40

60

80

100

120

ene-

92

abr-9

2

jul-9

2

oct-9

2

ene-

93

abr-9

3

jul-9

3

oct-9

3

ene-

94

abr-9

4

jul-9

4

oct-9

4

ene-

95

abr-9

5

jul-9

5

oct-9

5

ene-

96

abr-9

6

jul-9

6

oct-9

6

ene-

97

abr-9

7

jul-9

7

oct-9

7

dic-

97

Prog

ress

%

Construction Start

TG Synchronization First Syngas

67

3.3.2. BASIC PROJECT DATES

The basic dates in the development of the Puertollano IGCC Power Plant project are as follows:

• The ELCOGAS company for the construction and exploitation of the plant was incorporated in

April 1992.

• Project activities started with the award of the contracts for the supply of main equipment and for

the engineering in July 1992.

• Construction of the plant at the Puertollano site started in April 1993.

• Gas Turbine was delivered in October 1994

• The DCS was energised in September 1995

• The Combined cycle start up with burning natural gas occurred in September 1996.

• First ignition in the gasifier was achieved in December 1997.

• The performance test of the gasification with synthetic gas from local coal and pet-coke was carried

out in March 1998.

• First operation of the gas turbine with coal gas and, in consequence, integrated operation of the

combined cycle, air separation unit and gasification was achieved in March 1998. The period

between first ignition in the gasifier and the first coal gas operation in the gas turbine was three

months. In September 1998, 98% of the nominal output of the plant with gasification was reached.

68

3.3.3. PROJECT BUDGET AND FINANCING

3.3.3.1. Project Budget

Project Budget in constant currency of October 1991, date of the initial Project Budget, discounting the

amounts with the rate of variation of the Consumer Price Indexes in Pesetas and Deutsche Marks, and

converting DM to PTA at the rate of exchange in force at that time of 63 PTA/DM, shows that it amounts

to: 85,486.30 Million Pesetas. This amount compared with the amount of the initial project budget in

October 1991, implies an increase of 9.8%. This increase in Project Budget was due basically to the

design changes carried out in the gasification systems and to the extension of the start up programme

owing to its complexity. Breakdown of the Project Budget in constant currency October 1991 is as

follows:Million PTA91 %

GASIFICATION 30,799.55 36.03%

AIR SEPARATION UNIT 4,283.63 5.01%

COMBINED CYCLE 20,520.13 24.00%

FUEL HANDLING PLANT 1,717.65 2.01%

BALANCE OF PLANT 8,536.18 9.99%

WATER SUPPLY 1,808.15 2.12%

CONTROL SYSTEM 1,964.88 2.30%

GENERAL 15,390.33 18.00%

TOTAL PROJECT 85,020.51 99.46%

TECHNOLOGY GROUP 465.79 0.54%

TOTAL 85,486.30 100.00%1 DM = 63 PTA (October 1991)

Table 19. Project Budget constant currency Base 1991

Figure 34. Project Budget distribution. Constant currency October 1991

GENERAL18,0%

GASIFICATION36,0%

TECHNOLOGY GROUP

0,5%

AIR SEPARATION5,0%COMBINED

CYCLE24,0%

BALANCE OF PLANT10,0%

FUEL HANDLING2,0%

WATER SUPPLY2,1%

CONTROL SYSTEM

2,3%

69

3.3.3.2. Capital costs

Capital costs of the plant, not including interests during construction, come to almost 269,000 PTA91/kW,

equivalent to 1,850 $91/kW

Forecast on the economics of the IGCC's costs, as per US DOE estimations, indicate that these costs will

decrease in the coming years while its efficiency will increase significantly by 2015. The table shows this

capital cost forecast, including interest during construction, for a typical IGCC unit.

Year

Capital costs

US$/kW Efficiency (HHV,%)

1997 1,450 39.6

2000 1,250 42

2010 1,000 52

2015 850 >60Source: US DOE. Office of Fossil Energy. Federal Energy Technology Centre

Table 20. IGCC's Capital costs forecast

Figure 35. IGCC's Capital costs forecast

IGCC's Capital costs forecast

0

500

1000

1500

1997 2000 2010 2015

US$

/kW

70

3.3.3.3. Project Financing

The Puertollano IGCC Project has been financed with the partners’ contribution to the company capital,

the subordinated debt with the owners of the plant, the THERMIE Programme subventions, as well as

other subsidies that may be obtained and the rest through a Project Financing programme.

The project has been financed with a share of 35% own assets and 65% others assets. The subsidies

received to date represent a 5.8% of the total funds.

The Project Financing system was based on limited resources and was established according to the

expected cash-flow generated from the economical unit as a source of repayment (principal + interest),

and the Spanish Electrical Sector Remuneration System (Marco Legal Estable) as the main guarantee for

the loan. In 1998, upon the modification of the competitive market, the project finance was replaced by a

Bridge Loan supported by the shareholders guarantee.

71

3.4. AUTHORIZATIONS AND LICENSES

The following principal authorizations and licenses for the plant have been obtained:

Puertollano Municipal Construction Authorization

The Puertollano Municipal Construction Authorization covering all the works in the plant was granted on

June, 23th, 1993.

Cooling and Supply Water

Water Concession: The concession by the Confederación Hidrográfica del Guadalquivir, Ministerio de

Obras Públicas y Transportes of water for cooling and supply to the plant, in January 1994.

Water Pipeline Construction: The Construction Water Pipeline Authorization in January 1995 from

Diputación Provincial de Ciudad Real

Water Disposal Authorization: The Water Disposal Authorization in February 1996, from the

Confederación Hidrográfica del Guadalquivir.

Project Authorization and Declaration of Public Interest by the Dirección General de la Energía

In May 1994 the Dirección de Política Ambiental of the Ministerio de Obras Públicas y Medio Ambiente,

issued a positive Declaración de Impacto Ambiental (Environmental Impact

Declaration) for the plant.

In June 1994, the Dirección General de la Energía issued the Project Authorization and Declaration of

Public Interest.

Combine Cycle Start Up Act

In September 1996, the Delegación Provincial de Ciudad Real, Consejería de Industria y Trabajo, of the

Junta de Comunidades de Castilla-La Mancha, issued the Start Up Act for the Combined Cycle with

natural gas, the first phase of the start up of the plant.

Authorization for waste production activity

In November, 1998, the Consejería de Agricultura y Medio Ambiente of the Junta de Comunidades de

Castilla-La Mancha granted to ELCOGAS the Authorization for waste production activity.

72

4. PLANT OPERATION

4.1. OPERATION ORGANIZATION

The organization for plant Exploitation is established in Puertollano. At the end of August 2000, this

organization comprises 138 people.

The Operation organizational chart in Puertollano for the commercial operation of the plant is the

following:

Figure 36. Operation Chart

The shift operation personnel is composed by five teams, each one with a shift supervisor, three operators

and seven assistant operators.

OPERATION MANAGER

MAINTENANCE & TECHNICAL SERVICES

CHEMICAL, SAFETY & ENVIRONMENT

QUALITY ASSURANCE

OPERATION ADMINISTRATION PUERTOLLANO

EXTERNAL RELATIONS

ENGINEERING

73

4.2. PLANT OPERATION ASSESSMENT AND DATA

4.2.1. ASSESSMENT OF THE TOTAL PLANT PERFORMANCE

4.2.1.1. Plant status update

The plant start-up has been organized, since the project’s conception, into two steps to take advantage of

an earlier natural gas operation of the combined cycle before burning syngas generated in the Gasification

Island. The high degree of integration of the major plant blocks, as a result of the selected design concept,

requires integrated and stable operation of the combined cycle and the air separation unit, which has

impacted on the timely completion of the gasification start and tests.

Integrated operation of combined cycle, air separation unit and Gasification Island has been accomplished

and the plant concept has demonstrated its feasibility.

The following list gives the most relevant figures corresponding to the operational phase up to December

31th, 2000:

• Number of gasifier runs: 190.

• Hours with gasifier operation: 6,024.

• Longest gasifier run in hours: 688.

• Hours with gas turbine on coal gas: 4,788

• Gasifier maximum load: 106 %, (Run 139).

• GT maximum load on coal gas operation in MWh: 197.6 (Run 139).

74

The facts below summarise the plant status.

Milestones and main operational stops Date

FIRST IGNITION OF GAS TURBINE. April 1996

HRSG drums. Undersized level control system modification. July 1996

COMMERCIAL OPERATION OF COMBINED CYCLE WITH

NATURAL GAS.

October 1996

Loose part in GT. Blades damage repair. October 1996

FIRST AIR EXTRACTION. January 1997

PERFORMANCE TEST OF AIR SEPARATION UNIT. June 1997

Undersized steam system for NOx control in NG and GT syngas burners

modifications.

June 1997

FIRST IGNITION OF GASIFIER. December 1997

FIRST SWITCH OVER FROM NATURAL GAS TO SYNGAS. March 1998

Waste nitrogen compressor motor (20MW) damage. May 1998

GT syngas burners modification after first IGCC tests. July-August 1998

Gasifier burner overheated. October 1998

FIRST BASE LOAD OF GT WITH SG. November 1998

Gasifier combustion chamber cooling system leak. January 1999

Modification of internal part at GT rotor. March-May 1999

FIRST 100 HOURS CONTINUOUS OPERATION AS IGCC. August 1999

High degree of fouling at gasifier cooling surfaces and candle filters damaged. August 1999

FIRST PRODUCTION OF SOLID SULPHUR. August 1999

START-UP OF RECYCLE COMPRESSOR. February 2000

500,000 MWH OF ELECTRIC PRODUCTION WITH SYNGAS. GAS

TURBINE GUARANTEE TEST ON SYNGAS.

March 2000

GT 25,000 equivalent operation hours overhaul. April/June 2000

Slag pipe and gasifier reaction chamber blocked by slag. July 2000

Table 21. Main milestones of operation.

75

The following figures show hours of operation per quarter up to November 2000.

Figure 37. Accumulated gasifier and IGCC run time.

Figure 38. Gasifier and IGCC run time.

����� ���� �������������

���������������

����������������

��������������������

������������������������

�����������������������������������

Accumulated Gasifier and IGCC Run Time

0

1000

2000

3000

4000

5000

6000H

ours Gasifier���

IGCC

����� ���� �����

��������������������

������������������������

������������������������������ �����

����������������������������������������

������������������������

Gasifier and IGCC Run Time

0200400600

800100012001400

Hou

rs Gasifier����IGCC

76

The following figures show IGCC and natural gas (NGCC) availability factor per quarter up to November

2000.

Figure 39. IGCC and NGCC availability factor.

To sum up, it can be said that, since September 1999, after the initial periods where corrective actions

were the predominant activities, the plant is in a phase of real optimisations and operational learning

during which it has started significantly to increase availability and production using syngas.

����������

����������

���������������

������������

����������

���������������

����������

�����������������������������������

������������������������������������

�������������������������

�����������������������������������

������������������������

������������������������������

����������������������������������������

������������

�����������������������������������

���������������������������������������������

�����������������������������������

������������������������������������������������

����������������������������������������

IGCC and NGCC Availability factor

0

10

20

30

40

5060

70

80

90

100

%

NGCC

���IGCC

77

4.2.1.2. Main operation interruptions and type of failures

The following figures show operation interruptions classified by type of failure up to August 2000. Main

interruptions have been caused by process design1 (36%).

PROCESS DESIGN

36%

OPERATING FAULT

12%

EQUIPMENT FAULT

20%

ERECTION FAULT

4%

SCHEDULED4%

CONTROL LOGIC

24%

Figure 40. Gasifier stoppages classified by type of failure.

1 Process design fault is understood as a forced stoppage because systems or equipment did not permit operation

when they were installed and operated as they were designed.

78

EQUIPMENT FAULT22% SCHEDULED

16%

ERECTION FAULT0%

OPERATING FAULT5%

CONTROL LOGIC9%

PROCESS DESIGN48%

Figure 41. Gas turbine syngas operation interruptions classified by type of failure.

79

4.2.1.3. Lessons learned

When conducting an overall assessment of the lessons learned during the commissioning and operational

phases of the Puertollano IGCC, the main comments to be made are the following:

♦ Significant know-how has been gathered and demonstrated up to the present situation. The planning

issues with greatest impact have been:

∗ The management of interfaces between the various Engineering companies involved and the

Suppliers, in order to minimise the overlap of project, Construction and Commissioning

activities in a demonstration plant such as this. No one of the main suppliers is responsible

for the whole plant and the detailed engineering co-ordination has taken a long time.

∗ The phased construction schedule, due to the need to reach two commercial operations, has

resulted in a longer Project duration.

∗ The unique nature of the plant has led to the introduction of a high number of design

corrections during start-up and first operational periods. It has required a great deal of

operation and reengineering to analyse, find out and define the problem and the solution.

♦ The scope and extent of changes have been mostly related to optimisation of design. Largest

modifications involved problems of equipment capacity not being related to concept modifications.

♦ The complex and innovative technology requires a high level of skills from the operators and

maintenance staff.

80

4.2.2. ASSESSMENT OF THE PERFORMANCE OF INDIVIDUAL EQUIPMENT

4.2.2.1. Main operation interruptions classified by areas

The following figures show operation interruptions up to August 2000 classified by areas. Main stoppages

have been caused by the Gasification Island (58%).

Others (BOP)3%

Asu15%

Combined Cycle23%

External1%

Gasification58%

Figure 42. Gasifier stoppages classified by areas.

81

Others (BOP)3%

Asu8%

Combined Cycle45%

External0%

Gasification44%

(Gas turbine 91%)

Figure 43. Gas turbine syngas operation interruptions classified by areas.

82

4.2.2.2. Gasification Island

The following figures show operation interruptions up to August 2000 classified by gasification systems.

Among Gasification Island stoppages, most interruptions have been caused by the Slag Extraction System

(31%).

START-UP BURNER & FLAME MONITORS

10%

SULPHUR RECOVERY & TAIL GAS RECYCLE

3%

QUENCH GAS RECIRCULATION

7%

WATER STEAM SYSTEMS & BOILERS

8%

MIXING & GRINDING PLANT

6%

GAS WET TREATMENT4%

SLAGS31%

DRY DEDUSTING & FLY ASH SYSTEM

1%

DUST FUEL CONVEYING & FEEDING

30%

Figure 44. Gasifier stoppages classified by Gasification Systems.

83

GAS WET TREATMENT4% SULPHUR RECOVERY &

TAIL GAS RECYCLE2%

WATER STEAM SYSTEMS & BOILERS

2%

START-UP BURNER & FLAME MONITORS

0%

MIXING & GRINDING PLANT20%

SLAGS44%

QUENCH GAS RECIRCULATION

0%

DUST FUEL CONVEYING & FEEDING

28%

DRY DEDUSTING & FLY ASH SYSTEM

0%

Figure 45. Gas turbine syngas operation interruptions classified by Gasification Systems.

84

4.2.2.2.1. Coal dust preparation

Demonstration of equipment scale-up has been a major achievement while economies of scale advise the

use of just one train. However, availability and load changes flexibility of the grinding plant are other

factors to be taken into account.

The main experience of this system are:

• Robustness is key in obtaining an acceptable performance.

• Automatic control is complex and has required operational experience to develop it.

• Performance flexibility of roller mills is not high enough for three materials with different hardness

(coal, coke and limestone) at the same time.

4.2.2.2.2. Coal dust conveying, sluicing and feeding

High-pressure (over 25-bar) transport and feeding has been accomplished through different methods.

Main experiences of these systems during operation are the following:

• In the coal dust sluicing system, coal dust had to fall by gravity from one vessel into the vessel

underneath; however, coal discharge presents many problems and high nitrogen consumption to

improve capacity of sluicing systems has been necessary. Some modifications were implemented in

the original discharge procedure. The concrete tower where the system is placed could be

simplified.

• Damages in the sintered metal of lock hopper discharge cones were often found. These pieces were

replaced and a new design was manufactured to increase their porosity.

• Coal dust flow measure at high density has sometimes displayed erratic behaviour. This measure is

based on coal dust velocity measuring devices. These devices show problems with high coal dust

densities (> 400 kg/m3) and unstable flow conditions. As a result of these wrong measurements,

oxygen flow may increase more than permitted limits and damage gasifier burners. To improve

these measurements, some line modifications and installation of field sensors were carried out.

• These systems require improvements to the equipment parts relating to homogeneous dilution of

the fuel dust and pressure control systems.

85

4.2.2.2.3. Gasifier

A very positive experience, shown by the results of the tests, is that the gasification process itself is not

too sensitive to the operational parameters that may be changed under normal operation. This results in

reliable operation in spite of the usual variations that are present at coal/coke ratios, combustion

temperatures, cold gas recycling flow, purity of oxygen, operational pressure and so on.

From the reaction chamber the following experiences are worth highlighting:

• Low reliability of flame monitoring system. This requires a different monitoring concept.

• During the first operation runs, gasifier burners were blocked with foreign particles (oversize

material of coal and limestone), resulting into a high pressure drop in the coal dust feeding lines.

For line cleaning by back-blowing from the gasifier to the atmosphere, stoppage of the gasifier is

required.

• Auxiliary burners to control slag blockage have been dismounted.

• The igniter and start-up burner system affects to the availability, since full depressurization is

required to start ignition.

4.2.2.2.4. Waste Heat Recovery System

During the first long term Gasifier operation, high gas outlet temperatures at the HP-Boiler, which were

limiting the gasifier load, were noticed. After discussing the operating results, the following reasons for

the increase of fouling in the HP- Evaporators were considered:

• Low velocities in the bundles.

• Fly ash composition and fly ash grain size distribution different to the design.

• Limited function of the rapping devices due to blockages inside the housing.

To solve this problem, it was decided to increase the velocity of the lower HP bundle. This decision was

based on the following aspects, which were observed during operation and inspections of the plant:

• The HP bundles undergo fouling in a similar order of magnitude as the IP bundles shortly after

start-up of the gasifier.

• The gas velocity in the IP bundles is higher than in the HP bundles (approx. 30-50%).

• No accumulation and blockages of raw gas paths were found during the inspections.

86

• The fly ash is very fluffy.

• After a special inspection, accumulation of fly ash in the fin areas of the HP bundles, which could

not be removed by actuating the rappers during operation, was confirmed.

• During the last phase of inertization, which is required after any gasifier stoppage, the gas velocities

inside the HP bundles are higher than during the normal operation, which can lead to a cleaning of

the HP heating surface.

Experience on similar designed heat exchangers revealed a significant impact of the raw gas velocity on

fouling. Unfortunately, these studies became known after the design and installation of the Waste Heat

Boiler in the Puertollano Plant.

Rehabilitation of some rapping devices (no blockages in the rapper housing) was necessary. Rappers were

checked and repaired. Additionally, several actions were carried out:

• Test with different limestone content in the feedstock.

• Tests with different pet-coke/coal ratios in the feedstock.

• Characterisation of the fly ash deposits in different laboratories: ECN (Netherlands), University of

Stuttgart (Germany) and UCLM (Spain).

• Assessment of the CABRE II project fouling model with actual data from the plant. CABRE (Coal

Ash Behaviour in Reducing Environment) II is a project that began in 1996 and it was funded by an

international consortium of industrial and governmental agencies.

• Assessment of the actual fouling evolution with a fouling calculation model.

Fouling was one of the main operation parameter and its trend was followed in every run. The following

figure shows the improvement in fouling behaviour from run No. 114 (September 1999) up to run No.

169 (August 2000). Fouling in the HP II evaporator has decreased considerably even with a higher

gasifier load.

87

0,0000,0020,0040,0060,0080,0100,0120,0140,0160,0180,020

0 8 16 24 32 40 48 56 64 72 80 88 96 104

112

120

128

136

144

152

160

168

176

184

192

200

208

222

Operation hours

Foul

ing

(m2 K

/W)

0102030405060708090100

Gas

ifier

load

(%)

HP II fouling (Run 169) HP II fouling (Run 114) HP I fouling (Run 169)HP I fouling (Run 114) Load (Run 169) Load (Run 114)

Figure 46. Comparison of fouling behaviour between September 1999 and August 2000.

88

4.2.2.2.5. Slag handling

Low reliability of slag valves and slag fine filters are the main reason of the unscheduled gasifier

stoppages:

• Some problems are due to the higher production of fine slag than expected. Fine slag can block the

slag water filters. Temporary reservoirs for settling this fine slag, operating as a bypass to the slag

water filter, were sometimes used as back up. The cleaned water overflow of the settling tanks was

pumped back to the system and the settled sludge removed via a mobile filter press.

• New automatic system to fill, pressurize and discharge supervision was installed to increase

reliability of operations.

• Pump components exposed to high speed can suffer erosion and corrosion beyond the acceptable

limits and need to be replaced by a more resistant material. Slag extractor speed was decreased to

reduce the mechanical wear of the chain assembly and associated parts and improve the settling of

the slag particles.

• The complexity of the system (removal of solid slag with a system of pressure lock hoppers filled

with water and a supposed amount of fines) has made the operation and analysis of malfunctions

too complex and diffuse.

89

4.2.2.2.6. Dry dedusting system and quench gas compressor

Candle filter elements are of ceramic-type material, made of silicium carbide and manufactured in Europe

by Schumacher. The selected type of candle filter were Dia-Schumalith F40 which consists of a porous

support body of clay-bonded silicon carbide (SiC). The basic design of the Dia-Schumalith is an

asymmetric filter ceramic material with a thin outer fine filtering ceramic membrane. The operating life of

the filter elements should not be less than 8000 hours of operation.

In order to maintain a high efficiency filtration, the candle filters have to be cleaned semi-continuously

without taking them out of operation. The pressure drop from the raw gas inlet to the dedusted gas outlet

of the candle filter vessel, which is controlled, must not exceed 200 mbar an the cleaning frequency

depends on that value.

During a inspection in July 1998, an excessive accumulation of ash was observed between the two levels

of candles in both filter vessels, but no broken candles were found. However, after a 100 hours run of

operation (August 1999) most of the candles were broken. This was due to the following reasons:

• During the previous operation, pressure drop in the filters was higher than that specified in the

design.

• Some of the filter cleaning valves were in bad conditions. These valves use nitrogen for cleaning

the filters.

Several actions were carried out to avoid breakage of candle filters:

• Filter cleaning valves were checked and repaired and some of their parts were changed. A new

material, different from the specified one, was used in the new parts.

• Pressure drop in the filters is followed in every run and controlled to be lower than the design

value.

During Gas Turbine scheduled outage corresponding to 25,000 equivalent operation hours, in April 2000,

a new type of candle filter (DS 10-20 supplied by Schumacher) was installed in the dry dedusting system.

Approximately half of the candle filters were substituted by this new model.

However, cleaning dedusting is still one of the critical systems in the plant and monitoring of the cleaning

dedusting process is carried out during the operation by two parameters:

90

• The candle filter fouling factor.

• The solids in Venturi water measured in the laboratory.

91

The following figure shows the main data of the candle filter operation.

0,00

0,25

0,50

0,75

1,00

1,25

1,50

1,75

2,00

2,25

2,5072

0

920

1120

1320

1520

1720

1920

2120

2320

2520

2720

2920

3120

3320

3520

3720

3920

4120

4320

4520

Accumulated hours

Foul

ing

fact

or

0

500

1000

1500

2000

2500

3000

3500

Solid

s in

Ven

turi

(ppm

)

Candle filter fouling factor Candle filter fouling factorCandle filter fouling factor Candle filter fouling factorSolids in Venturi (ppm)

August 99 candles breakage

Jan./Feb. 2000 2nd/3rd

cleaning off

Dec. 99 1st

cleaning off

Candle filter change

Valves blockage

Figure 47. Candle filter fouling factor and solids in Venturi during operation.

The cleaning system needs to be improved. Alternative filter elements should be evaluated.

92

4.2.2.2.7. Fly ash recycling and handling

Fly ash recycling to the gasifier had as main targets the transformation of fly ash in environmental inert

slag, and achievement of a high carbon conversion rate. However, the present carbon conversion rate is

very high without recycling and this system is not used. The design carbon content was in the range of 10-

40%, but the actual values are bellow 5%.

The feed bin was designed to have a higher pressure than the gasifier in order to return fly ash to the

gasifier. The system for recycling fly ash is not necessary.

In the design, only a small part of the fly ash flow was not recycled to the gasifier. This part was

transported via discharge vessels to the fly ash bunker to be stored before being taken away. The designed

mass flow rate of fly ash to discharge was 150 kg/h (100 kg/h on a dry basis) at full load. However, in the

actual operation all fly ash is discharge (about 2000 kg/h) and the bunker, where fly ash is stored, does not

have enough capacity. Trucks have to take away fly ash too frequently.

The fly ash bunker is emptied by means of the fluidisation device located in the bottom of the bunker

using LP nitrogen to fluidise the fly ash. However, discharge and handling of fly ash presents several

difficulties due, mainly, to a smaller fly ash size distribution than predicted in the design.

FLY ASH SIZE DISTRIBUTION

1

10

1001 10 100

%

Design lower limit (%) Design higher limit (%)Sample 1 Sample 2Sample 3 Sample 4Sample 5 Sample 6

>

2

50

5

20

>> µm µmµm

Figure 48. Fly ash size distribution.

93

As observed in the previous figure, more than 6% of the design particles had to be bigger than 30 µm,

however actual particles are below this design value. Fly ash particles are finer than expected and only 2-4

% of them are above 60 µm.

ELCOGAS has participated in the ECSC project No. 7220-ED/072: “Valorisation of IGCC Power Plant

by-products as secondary raw materials in construction”, completed in December 1999, and currently fly

ash is being used in civil construction and geotechnical works. New uses of fly ash are being studied by

our Research Group in co-operation with the Research Organism UCLM, CSIC and AICIA.

4.2.2.2.8. Wet scrubbing and gas stripping

Performance of these systems has been satisfactory and main experiences to report are:

• Wrong engineering design of the system. Installed controlling filters are not necessary with the

actual concept of dry dedusting.

• Overfill of the separator downstream of the Venturi Scrubber.

• Difficulties in pH control of the stripping of the raw gas washing water due to poor detailed design

and lack of robustness.

4.2.2.2.9. Desulphurization system

Specified clean gas composition is within reach. An exhaustive gas sampling campaign was carried out

within the ECSC project 7220-ED/754: “Improved IGCC Plant performance with coal/pet-coke

coprocessing” and the good performance of the desulphurization system was demonstrated. The following

table shows the actual and forecast raw gas and clean gas composition.

Actual average Design Actual average Design

CO (%) 59,26 61,25 CO (%) 59,30 60,51

H2 (%) 21,44 22,33 H2 (%) 21,95 22,08

CO2 (%) 2,84 3,70 CO2 (%) 2,41 3,87

N2 (%) 14,32 10,50 N2 (%) 14,76 12,5

Ar (%) 0,90 1,02 Ar (%) 1,18 1,03

SH2 (%) 0,83 1,01 SH2 (ppmv) 3 6

COS (%) 0,31 0,17 COS (ppm) 9 6

HCN (ppmv) 23 38 HCN (ppmv) LDO (*) 3

Concentrations are expressed in volume on a dry basis(*) LDO: Low of detection limit.

Raw gas Clean gas

Table 22. Raw gas and clean gas composition

94

It has been noticed that raw gas, from the water separator of the wet scrubbing system, can carry out acid

condensates and cause piping corrosion and COS catalyst deterioration.

A first study into corrosion problems was carried out within the THERMIE project No. SF-200-95

ES/IT/FR: “Materials performance monitoring through a state of reference program”. Follow up of

corrosion problems is studied in new projects.

A Desalting Pilot Unit was installed within the THERMIE project No. SF-200-95 ES/IT/FR. This unit

removes the MEDEA formates from the MEDEA, stemming from the reaction of the MDEA and the

hydrogen cyanide (HCN) contained in the raw gas. The Desalting Unit performance is within expected

and an extension of this unit is envisaged to achieve full operational performance.

In general, MDEA system behaviour is good and MDEA consumption is bellow the foreseen

consumption.

4.2.2.3. Air Separation Unit (ASU)

4.2.2.3.1. Interfaces ASU-Combined Cycle-Gasifier

Main experiences during operation related to this system are:

• Development of procedures for air, O2, coal gas, waste N2, condensate recovery, and water/steam

interfaces, which lead to more effective operation, in terms of cost, than those formerly issued

during the design phase.

• The duration of the plant start-up procedure is mainly conditioned, in the Puertollano design, by the

availability of the gaseous products from ASU. ASU is the critical path during the Plant start-up.

For cold starts, it takes 5 days and for hot starts 6 hours to reach the required conditions for the

gasifier ignition.

Nevertheless, this system has a good availability. ASU control is very sophisticated but highly reliable.

95

4.2.2.3.2. Nitrogen network

The economic impact of nitrogen consumption during operation needs to be looked at closely:

• The design concept of the project was that the pure nitrogen was a surplus by-product of the

oxygen distillation and that it could be used without restrictions. In normal steady state operation

this criteria is acceptable, but in transients and, specially, in stop and start operations, the

availability of pure nitrogen is a restraint which should be avoided.

• During IGCC operation commissioning, N2 consumption is high. This is an aspect that should be

considered in new IGCC designs.

96

4.2.2.4. Combined Cycle

A first Acceptance Test of Combined Cycle operating with synthetic gas (IGCC operation) was carried

out on March 20th. The main results are summarised in the following table:

Parameters of Guarantee Measured valueson the test

Guarantee valuesadapted for thetest conditions1

Guaranteevalues for design

conditionsPower (MW) 315.6 312.7 317.7Gas turbine (MW) 178.4 174.5 182.3Steam turbine (MW) 137.2 138.2 135.4Gross efficiency (%) 50.84 50.15 52.55Auxiliary consumption (kW) 3720 4307 4307NOx emissions (mg/Nm3, 15% O2 dry) 43 60 60Saturation water (kg/s) 6.09 5.29 5.29Noise (dB(A)) 85/100 85/100 85Air to ASU (kg/s) 103.3 103.3 97.0

1 Environmental and boundary conditions have been taken into account trough predictive models.

Table 23. Main results of the Acceptance Test.

The Acceptance Test shows a better gas turbine performance than that related to the design conditions.

However, a worse performance of the steam turbine was also observed due to the IP section. Main

conclusions at the moment are:

• Total power and gross efficiency of the Combined Cycle working in IGCC mode is higher than

those of the design conditions.

• Saturator water flow required for NOx is higher than the designed one due to the need to improve

gas turbine burner performance.

Nevertheless, the analysis of this test is not completed as of the date of this report.

4.2.2.4.1. Gas turbine

Some overheating problems and acoustic oscillations phenomena (humming) was detected during coal

gas combustion since June 1998. After this, coal gas burner design was modified several times. Further

tests were required to achieve humming-free stable flame during start up with natural gas and switchover

operations and to solve overheating problems.

97

Some evaluations of the different design modifications of the V94.3 hybrid burners were carried out by

the University of Twente in Cupertino with ELCOGAS and Siemens. For these studies, numerical

calculations regarding flame behaviour and acoustic data were performed. A small scale burner was also

manufactured.

Switch Over

0

100

200

300

400

500

60025

/9/0

0 21

:20

25/9

/00

21:2

1

25/9

/00

21:2

2

25/9

/00

21:2

3

OTC

(ºC

) and

hum

min

g

0

20

40

60

80

100

120

140

GT

Pow

er (M

W) a

nd v

alve

and

IGV'

s po

sitio

ns

RCC Humming LCC Humming OTC (ºC) GT Power (MW)WN2 control valve CG control valve NG valve position IGV's

Figure 49. Main gas turbine parameters to control the “switch over”.

Switch Back

0

100

200

300

400

500

600

25/9

/00

21:2

5

25/9

/00

21:2

6

25/9

/00

21:2

7

25/9

/00

21:2

8

25/9

/00

21:2

9

OTC

(ºC

) and

hum

min

g

0

20

40

60

80

100

120

140G

T Po

wer

(MW

) and

val

ve a

nd IG

V's

posi

tions

RCC Humming LCC Humming OTC (ºC) GT Power (MW)WN2 control valve CG control valve NG valve position IGV's

Figure 50. Main gas turbine parameters to control the “switch back”.

98

4.2.2.4.2. Heat Recovery Steam Generator

In this system, the drums are a critical availability point. Their volume must be optimised.

4.2.2.5. Auxiliary systems (Balance of Plant)

• Adjustment of the strippers’s pH-operation value: In order to reduce the acid elements as CN and S

of the stripped water sent to the waste water plant, the pH value of the water leaving the strippers of

the Waste Water Pre-treatment was reduced from 8 to 6.

• The cooling tower should stop when the Plant is stopped. Auxiliary cooling should be independent.

99

4.2.3. PROCESS DATA

4.2.3.1. Fuel heat rate. Year 2000

To the end of November 2000, the plant burnt 87,344 t of coal, 84,237 t of pet-coke and 3,407 t of

limestone. The fuel heat rate, coal and pet-coke 50% weight, to August 2000 is shown in the figure.

Figure 51. Fuel heat rate

4.2.3.2. Auxiliary power. Year 2000

Power consumed by the auxiliary systems of the plant per hour of operation to November 2000 is shown

in the figure.

Figure 52. Plant auxiliary power

Plant Auxiliary Power. Year 2000

15

20

25

30

35

40

45

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov

Mw

h/h

Fuel Heat Rate. Year 2000

1000

1200

1400

1600

1800

2000

2200

Jan Feb M ar A pr M ay Jun Jul A ug Sep O ct N ov

Kca

l(HH

V)/K

wh

100

4.2.3.3. Consumption of consumables and catalysers

The following table shows the consumption of consumables and catalysers in the operation of the plant

during 2000.

Consumption (kg/month) year 2000

Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov

Sulphuric Acid 36897 42771 66303 2919 6174 30118 32814 31148 9587 48741 63103

Caustic Soda 60591 50486 105172 3953 11696 32296 120536 112615 70199 130229 107329

Coagulant 2516 4265 7590 1080 2819 3288 2057 5251 6554 7236 4913

Poly-electrolyte 25 100 50 6 15 22 75 50 50 25 14

Hydrazine 813 276 96 0 437 347 893 894 504 126 1624

Ammonia 336 597 105 30 522 342 1063 403 582 885 672

Anticorrosive 1885 1068 2128 188 2165 4125 3806 3319 2384 2215 1853

Hypochloride 5734 3050 6734 200 5136 9235 18349 24261 2401 695 671

Calcium Chloride 5189 13331 37988 0 0 10380 14883 25954 17730 3350 10329

MDEA 0 1631 0 0 0 0 5419 0 174 0 0

Catalysers 0 0 0 0 50 0 0 0 0 10000 0

Table 24. Plant operation consumables.

101

4.2.3.4. Generation of electricity

4.2.3.4.1. IGCC Plant generation of electricity

Accumulated

Historic yearly electricity gross output records of the Puertollano IGCC plant up to November 2000 are

shown in table and graph.

IGCC Gross Output

MWh

1998 8867

1999 334937

2000 (Nov.) 723241

Table 25. IGCC Plant electricity gross output. Accumulated

Figure 53. IGCC Plant yearly electricity generation records

The Puertollano plant was built and started up in two phases, the first one fuelling the combined cycle

with natural gas, which was achieved in September 1996. The plant operated with natural gas from this

date to the adjustment of the combined cycle systems and supported start up of the gasification system in

1998.

IGCC Gross Output. MWh

0

100.000

200.000

300.000

400.000

500.000

600.000

700.000

800.000

1998 1999 2000 (Nov.)

MW

h

102

Year 2000

Monthly and accumulated electricity gross output Puertollano IGCC Plant with syn-gas for 2000 up to

November is shown in table and figure.

IGCC GROSS OUTPUT MWh

2000 Monthly Accumulated

January 34494 34494

February 75850 110344

March 108183 218526

April 0 218526

May 0 218526

June 2987 221513

July 83709 305222

August 118816 424039

September 97195 605101

November 118140 723241

Table 26. IGCC Plant electricity gross output. Year 2000

Figure 54. IGCC Plant Monthly electricity gross output. Year 2000

A scheduled shutdown took place from April to the end of June 2000 to perform an overhaul of the gas

and steam turbines in the combined cycle and to do some modifications in the gasification area to improve

systems performance.

IGCC Gross Output year 2000. MWh

0

100000

200000

300000

400000

500000

600000

700000

800000

0

20000

40000

60000

80000

100000

120000

140000

103

The best monthly gross output with IGCC was reached in August with a production of 118,816 MWh. In

general, performing of the IGCC plant and electricity generation evolved positively, increasing along

2000, with the exception of the shutdown period and the subsequent start up phase which affected

negatively the electricity production of June.

4.2.3.4.2. Generation of electricity. Total plant

Accumulated

Total plant's yearly gross power output and distribution by fuel used, syn-gas (IGCC) or natural gas (NG),

is shown in table and figure.

Total Gross Output

MWh

1996 178295

1997 959685

1998 752493

1999 720521

2000 (Nov.) 1341876

Table 27. Total Plant yearly electricity gross output.

Figure 55. Total plant yearly gross output

Total plant Gross Output. MWh

150000

400000

650000

900000

1150000

1400000

1996 1997 1998 1999 2000(Nov.)

MW

h IGCC GrossOutput

NG GrossOutput

104

Year 2000

Regarding performance of the total Puertollano plant, gross output for 2000 up to November is the

following:

Total Gross Output MWh

2000 Monthly Accumulated

January 147205 147205

February 139922 287127

March 168826 455954

April 8451 464405

May 0 464405

June 100801 565206

July 159492 724698

August 170833 895531

September 142917 1179335

November 162541 1341876

Table 28. Total Plant electricity gross output.

The figure shows the monthly gross output and distribution by fuel used, syn-gas (IGCC) or natural gas

(NG), of the total plant for 2000 up to November.

Figure 56. Total Plant monthly electricity gross output. Year 2000

The best monthly gross output of the plant was reached in August with 170,833 MWh of electricity

produced this month.

Gross Output 2000 MWh

0

20.000

40.000

60.000

80.000

100.000

120.000

140.000

160.000

180.000

MW

h

IGCC GrossOutput

NG GrossOutput

105

Plant availability

Plant availability for 2000 up to November is shown in the figure.

Figure 57. Plant availability for 2000 (up to November)

Total plant (IGCC + NGCC) availability reached 58%. Availability resulting in energy generated resulted

a 50%. Non scheduled availability was only a 5% of the total.

Plant availability year 2000

Availability58%

Scheduled unavaliablity

37%

Non Scheduled unavaliablity

5%

106

4.2.4. FINANCIAL DATA

4.2.4.1 Production Costs

The budget for operational costs of the plant for year 2000 amounts to 7,900 million PTA. 49% of this

operational costs are variable costs, including coal, pet-coke, limestone, consumables and cooling water

costs.

The variable costs are the result of the plant operation costs in the different operation modes, each of them

representing very different unitary variable costs. Thus, in natural gas operation mode, the variable cost

was forecasted 4.57 PTA/kWh, while in IGCC operation mode this cost drops to 2.06 PTA/kWh. The

unitary costs obtained are higher in other transient operation modes required to reach the normal IGCC

operation mode.

During 2000, the operation unitary costs have been higher than forecasted due to the increase experienced

in the international fuel markets. By the opposite, the fixed operation costs are kept in lower levels than

those estimated in the budget.

107

4.2.4.2. Operation Income

In the new deregulated electricity market, in force in Spain since 1 January 1998, ELCOGAS obtains its

incomes from the electricity sold to the market pool plus a Capacity Payment depending on the

availability of the plant.

In ELCOGAS budget 2000, a mean income of 5.43 PTA/kWh was forecasted, 4.50 PTA/kWh from this

corresponding to the payment for energy sold to the market Pool.

During 2000, payment by the Pool has been higher than forecasted due to the increase experimented in

fuel prices, transferred by the electric utilities to the price of the energy sold. The mean price obtained by

ELCOGAS sales reached 5.83 PTA/kWh. From this price, 5.07 PTA/kWh come from energy sales to the

Pool and 0.76 PTA/kWh come from Capacity Payments. The amount obtained from this Capacity

Payments has been lower than forecasted due, by one side, to a slightly lower availability of the plant

than forecasted and, by the other side, to the lower price fixed by the Spanish Ministry of Economy for

payments under this concept.

108

4.2.5. ENVIRONMENTAL DATA

4.2.5.1. Absolute environmental data

Environmental behaviour of the Puertollano IGCC Plant has been satisfactory, despite of the fact that

there has not been a complete continuity of operations with synthetic and natural gas due to technical

problems. The effect of the pollutant emissions has been well below the limits set for ELCOGAS for

operation with synthetic or natural gas, in particular for SO2 and particulate emissions. Regarding NOx,

emissions, an improved level of performance with synthetic gas is noted, reaching less than a 50% of the

authorised emission limit. This confirms the trend forecasted, which could improve in the future, once the

optimum plant operative parameters have been reached.

In accordance with Spanish environmental regulation R.D. 649/91, yearly atmospheric pollutant

emissions measures were carried out with satisfactory results.

Continuing with on the development of the ELCOGAS Environmental Management System, the system’s

new design, integrating Quality, should be highlighted. This system is aimed at achieving the jointly

Quality and Environmental Management certification process, as soon as possible, as per ISO 14001 and

9002 quality standards, initiated previously.

A natural barrier made of trees suited to the land was designed and implemented around the perimeter of

the coal yard, with the aim of minimising impact on the landscape and as a wind-barrier to avoid coal dust

dispersion, in accordance with the requirements of the Declaration on Environmental Impact.

109

4.2.5.2. Emission data

Emission data for 2000 up to October are as follows:

SO2 (6% O2) NOx (6% O2) Particulate (6% O2)

Concen-

tration

Total

emission

Specific

emission

Concen-

tration

Total

emission

Specific

emission

Concen-

tration

Total

emission

Specific

emission

MONTH mg/Nm3 t/month g/kWh mg/Nm3 t/month g/kWh mg/Nm3 t/month g/kWh

January 11.0 1.2 0.0334 78.6 8.2 0.2383 0.02 0.002 0.0001

February 17.2 3.9 0.0522 78.1 17.7 0.2364 0.47 0.106 0.0014

March 17.3 5.5 0.0511 62.6 20.0 0.1845 0.42 0.135 0.0012

April

May

June 3.8 0.0 0.0080 63.1 0.4 0.1330 0.78 0.005 0.0016

July 11.9 2.9 0.0345 74.9 18.2 0.2169 2.38 0.577 0.0069

August 40.9 13.7 0.1153 146.7 49.1 0.4135 2.19 0.732 0.0062

September 33.0 8.0 0.0954 138.2 33.5 0.3996 2.69 0.653 0.0078

October 26.9 7.8 0.0805 99.1 28.9 0.2963 0.04 0.011 0.0001

MEAN TOTAL MEAN MEAN TOTAL MEAN MEAN TOTAL MEAN

24.3 43.0 0.0712 99.5 176.0 0.2912 1.26 2.221 0,0037

Table 29. IGCC Plant emission data for 2000

Evolution of emissions of the different pollutants for 2000 are shown in the following graphs.

110

Figure 58. NOx emission mg/Nm3 for 2000

Figure 59. Specific NOx emission g/kWh for 2000

Emission of nitrogen oxide for 2000

78 63

147 13899

7579 63

0

100

200

300

400

500

600

janua

ry

februa

rymarc

hap

rilmay jun

e july

augu

st

septe

rmbe

r

octob

er

nove

mber

dece

mber

mg/

Nm

3 6

% d

e O

2

EU emission limit

Specific emission of NOx for 2000

0,24 0,22

0,41 0,400,30

0,130,180,24

0,00,10,20,30,40,50,60,70,80,91,01,11,2

janua

ry

februa

rymarc

hap

rilmay jun

e july

augu

st

septe

rmbe

r

octob

er

nove

mber

dece

mber

g/kWh

111

Figure 60. SO2 emission mg/Nm3 for 2000

Figure 61. Specific SO2 emission g/kWh for 2000

Emission of sulphur dioxide for 2000

11,0 17,2 17,3 3,8 11,940,9 33,0 26,9

0

100

200

300

400

janua

ry

februa

rymarc

hap

rilmay jun

e july

augu

st

septe

rmbe

r

octob

er

nove

mber

dece

mber

mg/

Nm

3 6

% d

e O

2EU emission limit

Specific emission of SO2 for 2000

0,030,05 0,05

0,01

0,03

0,120,10

0,08

0,0000,0200,0400,0600,0800,1000,1200,140

112

Figure 62. Particulate emission mg/Nm3 for 2000

Figure 63. Specific particulate emission g/kWh year 2000

Emission of particulates for 2.000

0,02 0,47 0,42 0,78 2,38 2,19 2,690,04

0

10

20

30

40

50

janua

ry

februa

rymarc

hap

rilmay jun

e july

augu

st

septe

rmbe

r

octob

er

nove

mber

dece

mber

mg/

Nm

3 6%

de

O2

EU emission limit

Specific emission of particulate for 2.000

0,0001

0,0014 0,00120,0016

0,00690,0062

0,0078

0,0001

0,000

0,002

0,004

0,006

0,008

0,010

janua

ry

februa

rymarc

hap

rilmay jun

e july

augu

st

septe

rmbe

r

octob

er

nove

mber

dece

mber

g/kWh

113

4.2.5.3. By-products and waste data

By-products generated at the plant for 2000 up to August are the following:

Material Jan-00 Feb-00 Mar-00 Apr-00 May-00 Jun-00 Jul-00 Ago-00 Oct-00 Oct-00 TotalFly ashes (t) 686 697 1,354 96 604 1,491 1,242 1,242 7,135Slag (t) 6,583 7,181 60 2,848 102 7,112 14,000 7,297 7,297 52,226Filter cake (t) 121 171 501 243 999 1,400 756 756 4,690Sulphur (exits, t) 401 762 992 403 467 611 611 4,185

Official inspections and controls of the liquid effluent to the Ojailén river, carried out by the

Confederación Hidrográfica del Guadalquivir, confirmed compliance with the requirements imposed by

the provisional liquid effluent authorization. For the final authorization, ELCOGAS submitted the final

technical report with the analytical characterization of the effluent.

Regarding production of solid wastes, ELCOGAS complied strictly with the requirements established in

the official solid waste authorization, sending the vitrified slag to the Encasur coal mine as a matter of

course, but it has recently valued as a by-product to be used in the fabrication of ceramic products and it

has been agreed to sell the slag to a local ceramic workshop for next year.

Fly ashes have been also valued as a by-product to be used as an additive for concrete and are being used

by local cement and concrete industries as a component in the manufacture of concrete.

Other normal industrial wastes produced in the plant were managed by entities duly authorised by the

Environmental Authority.

114

Waste data for year 2000 until October are as follows:

Material Jan-00 Feb-00 Mar-00 Apr-00 May-00 Jun-00 Jul-00 Ago-00 Sep-00 Oct-00 TotalProcess wasteEffluent slurry (m3) 30 66 30 5 5 10 15 15 20 30 226Coal mills waste (t) 56 40 123 30 72 90 81 67 559Waste water (m3) 36,375 35,365 55,672 14,303 4,737 36,462 50,544 44,595 44,300 49,000 371,353MDEA wastes (kg) 5,000 5,000Acid contaminated absorbent (kg) 1,200 1,200MDEA contaminated absorbent (kg) 2,400 2,400Oil contaminated absorbent (kg) 1,000 600 1,600Other wasteUrban solid waste (m3) 125 146 146 135 125 125 125 146 125 145 1,342Paper and clothes (m3) 6 6 12 6 84 12 12 12 12 6 168Wood (kg) 27,480 27,480Plastics and miscellaneous (m3) 6 6 6 12 6 15 30 6 15 102Steel (t) 72 134 206Inert industrial waste (kg) 17,920 3,920 21,840Used oil (kg) 1,820 2,000 1,600 1,420 6,840Used batteries (barrels 150 l) 0Used batteries (kg) 500 300 800Fluorescent lamps (kg) 200 200Laboratory packs (kg) 2 200 202Contaminated industrial packs (kg) 1,000 200 1,200Obsolete laboratory reactive chems (kg) 40 10 50Organic halogen solver (kg) 75 75Obsolete paintings (kg) 2,850 2,850

Table 30. IGCC Plant waste data for 2000

115

4.2.5.4. Trace element mass balance

Major, minor and trace metallic elements are emitted both by natural processes and human activities. Fuel

contains many of the elements of the periodic table and metal trace elements appear in coals, at different

concentrations, according to regional and local scales, as a result of the complex (and, generally, random)

way they originally entered the coal. Even, coals from different parts of the same seam can contain

different trace element contents. In addition, petroleum wastes, as coke, can present different trace

element content depending on the original petroleum and the refining process.

Trace elements in ELCOGAS feedstock (input) and in by-products (output) have been studied within the

ECSC project No. 7220-ED/754: “Improved IGCC plant performance with coal/pet-coke coprocessing”.

Sampling trials have been carried out and main results from them are summarised in the following figures:

Trace distribution in feedstock

0%

20%

40%

60%

80%

100%

Zn Pb As Sb Cd Cu V Be Hg Ni Co Mn Cr

Coal Coke Limestone

Figure 64. Trace distribution in feedstock.

In general, most of the trace elements from the Puertollano coal. Pet-coke from REPSOL refinery is rich

in Vanadium, Nickel (Cr, Cu and Zn also appear in the pet-coke).

116

Trace distribution in by-products

0%

20%

40%

60%

80%

100%

Zn Pb As Sb Cd Cu V Be Hg Ni Co Mn Cr

Slag Filter cake Fly ash

Figure 65. Trace distribution in by-products.

The relative enrichment of metal trace elements in smaller particles is explained by a

volatilisation/condensation mechanism. During gasification, volatile types are vaporised. Later, as the

temperature falls, these types can condense out of the vapour phase on to the surface of ash particles. The

smallest particles represent a large fraction of the overall available surface area although they are only a

small part of the total mass. Therefore, on a mass basis, there appears to be preferential enrichment of the

smallest particles.

Measurements in raw and clean gas did not detect Hg.

117

4.3. ASSESSMENT OF OPERATION WITH DIFFERENT FUELS

4.3.1. INTRODUCTION

After starting the demonstration phase, ELCOGAS proceeded to perform series of tests with different fuel

mixtures. This commitment of ELCOGAS is stated in the contract number SF 337/91 ES (THERMIE

programme).

These tests were carried out according to the specification explained in the document PO-YHA-TFX-

ELX-00038, sent to the Directorate-General for Energy of the European Commission on March 7th, 2000

in the letter reference MT-LB/040.

The tests were carried out over several months, taking into account the preparation of the facilities for

each fuel used in accordance with the programme in the aforementioned document. Four of these tests

were chosen for this report.

118

4.3.2. FUEL CHARACTERIZATION

One feature of the Puertollano gasification process is its flexibility with different kinds of feedstocks. The

plant is designed to be able to gasify the following fuel ranges.

Min. Max.

Higher heating value MJ/kg) 20.90 29.32

Ash 3 25

N (%) - 3

S (%) - 4

Volatile matter (%) 13 40

Cl (%) * - 0.5(*) Plant operation is limited by restrictions resulting from high chlorine operation, i.e. wet scrubbing, stripper system and water consumption

Table 31. Fuel range designation.

Coal and coke mixtures permit to modify the composition and characteristics of the feedstock.

Four tests were envisaged to demonstrate the flexibility of the Puertollano gasification process, the

theoretical composition of which is shown in the following table:

Mixture 1 Mixture 2 Mixture 3 Mixture 4

Coal % Coke % Coal % Coke % Coal % Coke % Coal % Coke %

39 61 45 55 54 46 58 42

Ash %

Fixed Carbon %

Volatile matter

Sulphur %

Nitrogen

Chlorine %

HHV MJ/kg

Hardgrove index (º)

17.9

65.3

16.8

4.0

1.13

0.029

27.92

60.7

20.5

62.1

17.1

3.7

1.09

0.031

26.84

60.3

24.5

57.4

18.2

3.3

1.06

0.034

25.22

59.8

26.2

56.2

18.5

3.1

1.01

0.036

24.49

59.5

Water free analysis (% in weight)

Table 32. Fuels selected for demonstration tests.

119

The four tests were carried out with different coke and coal mixtures. Comparison between the predicted

theoretical composition and actual composition of the mixtures appears in the following table:

Feedstock composition

Mixture

1

Mixture

2

Mixture

3

Mixture

4

Coal % 39 45 54 58

Coke % 61 55 46 42

Actual 0.75 1.04 1.29 0.93Moisture wt. %

Predicted 2 2 2 2

Actual 68.8 65.61 62.76 60.66C wt. % (mf)

Predicted 70.51 67.79 65.52 61.89

Actual 3.36 3.68 3.15 3.24H wt. % (mf)

Predicted 3.17 3.11 3.06 2.98

Actual 1.89 2.69 3.36 3.68O (by

difference)

wt. % (mf)

Predicted 3.3 3.8 4.2 4.8

Actual 1.52 1.3 1.49 1.27N wt. % (mf)

Predicted 1.13 1.09 1.06 1.01

Actual 3.82 3.47 3.28 3.0S wt. % (mf)

Predicted 4.0 3.7 3.3 3.1

Actual 722 685 482 524Cl ppm (mf)

Predicted 290 310 340 360

Actual 20.67 23.69 25.95 28.21Ash wt. % (mf)

Predicted 17.9 20.5 24.5 26.2

Actual 16.33 17.44 18.25 18.42Volatile matter wt. % (mf)

Predicted 16.8 17.4 18.2 18.5

Actual 26.89 25.53 24.69 23.61H. H. V. MJ/kg (mf)

Predicted 27.92 26.84 25.22 24.49

Table 33. Actual and predicted composition of the mixtures tested.

120

Coal and coke composition for each mixture is the following:

Mixture 1 Mixture 2 Mixture 3 Mixture 4 Mixture 1 Mixture 2 Mixture 3 Mixture 4

Moisture (%) 10.79 8.96 12.81 9.12 6.07 8.7 5.34 5.47

Ash (wt.% mf) 45.31 47.32 42.58 44.43 0.6 0.49 0.43 0.68

Volatile matter (wt.% mf) 22.17 21.97 22.52 22.81 12.59 13.52 12.99 12.93

Fixed carbon (wt.% mf) 32.53 30.31 34.9 32.74 87.08 85.99 86.58 86.38

C (wt.% mf) 42.04 39.96 43.94 42.7 87.94 88.16 87.8 87.15

H (wt.% mf) 2.82 2.68 2.86 2.88 3.7 3.63 3.7 3.65

N (wt.% mf) 0.75 0.7 1.04 1.08 1.59 1.43 1.53 1.66

O (wt.% mf) 8.27 8.44 8.69 7,98 0.06 0.25 0.09 0.34

S (wt.% mf) 0.81 0.9 0.89 0.93 6.23 6.04 6.45 6.52

16,554 15,675 17,283 16,745 34,861 34,969 34,986 34,787

15,947 15,358 16,667 16,126 34,074 34,200 34,198 34,009

H.H.V (kJ/kg)

L.H.V (kJ/kg)

COAL COKE

Prox

imat

e an

alys

isU

ltim

ate

anal

ysis

Table 34. Coal and coke composition during the tests.

121

4.3.3. ASSESSMENT OF TESTS AND EXPERIENCE WITH DIFFERENT FUELS

4.3.3.1. History of test operation

Gasification tests of different feedstock in Puertollano IGCC plant were carried out from February 20th,

2000. Four periods were chosen as representative of these tests.

Selected test runs and conditions are listed in the following table in chronological order. In both cases the

Puertollano plant had been operating on the previous fuel and was then switched to the next feedstock.

Test run Mixture No. Coal-coke composition Period of Balance

1 3 54%-46% 26/02/00 16:00-20:00

2 4 58%-42% 07/03/00 17:23-21:20

3 2 45%-55% 21/03/00 12:00-16:00

4 1 39%-61% 23/03/00 16:28-20:16

Table 35. Main test conditions.

Approx. 12,185 tons of feedstock were gasified in 138 operating hours, during the first test; 8,883 tons of

feedstock in 130 operating hours, during the second test; 11,656 tons of feedstock in 136 operating hours,

during the third test and 9,960 tons of feedstock in 121 operating hours, during the last one, i.e. 525

operating hours altogether.

The following figures show the records of the main process data for the tests. These figures include

information about operation under load change conditions, effect of O/C ratio control and other operating

conditions.

122

MIXTURE No. 1

0

20

40

60

80

100

120

23/3

/00

16:2

5

23/3

/00

16:3

5

23/3

/00

16:4

5

23/3

/00

16:5

5

23/3

/00

17:0

5

23/3

/00

17:1

5

23/3

/00

17:2

5

23/3

/00

17:3

5

23/3

/00

17:4

5

23/3

/00

17:5

5

23/3

/00

18:0

5

23/3

/00

18:1

5

23/3

/00

18:2

5

23/3

/00

18:3

5

23/3

/00

18:4

5

23/3

/00

18:5

5

23/3

/00

19:0

5

23/3

/00

19:1

5

23/3

/00

19:2

5

23/3

/00

19:3

5

23/3

/00

19:4

5

23/3

/00

19:5

5

23/3

/00

20:0

5

23/3

/00

20:1

5

23/3

/00

20:2

5

Period of test

Feed

stoc

k (t/

h), O

2 pur

ity (%

) and

gas

ifier

pr

essu

re (b

ar)

0

7000

14000

21000

28000

35000

42000

49000

56000

63000

70000

O2 (

Nm

3 /h) a

nd s

team

(kg/

h) to

bur

ners

Gasifier pressure (bar)

O2 to burners (Nm3/h)

Steam to burners (kg/h)

Feedstock (t/h)O2 purity (%)

Figure 66. Main process input data during the tests. Mixture 1

MIXTURE No. 2

0

20

40

60

80

100

120

21/3

/00

12:0

0

21/3

/00

12:1

0

21/3

/00

12:2

0

21/3

/00

12:3

0

21/3

/00

12:4

0

21/3

/00

12:5

0

21/3

/00

13:0

0

21/3

/00

13:1

0

21/3

/00

13:2

0

21/3

/00

13:3

0

21/3

/00

13:4

0

21/3

/00

13:5

0

21/3

/00

14:0

0

21/3

/00

14:1

0

21/3

/00

14:2

0

21/3

/00

14:3

0

21/3

/00

14:4

0

21/3

/00

14:5

0

21/3

/00

15:0

0

21/3

/00

15:1

0

21/3

/00

15:2

0

21/3

/00

15:3

0

21/3

/00

15:4

0

21/3

/00

15:5

0

21/3

/00

16:0

0

Period of test

Feed

stoc

k (t/

h), O

2 pur

ity (%

) and

gas

ifier

pr

essu

re (b

ar)

0

7000

14000

21000

28000

35000

42000

49000

56000

63000

70000

O2 (

Nm

3 /h) a

nd s

team

(kg/

h) to

bur

ners

Gasifier pressure (bar)

O2 to burners (Nm3/h)

Steam to burners (kg/h)

Feedstock (t/h)

O2 purity (%)

Figure 67. Main process input data during the tests. Mixture 2

123

MIXTURE No. 3

0

20

40

60

80

100

120

26/2

/00

16:0

0

26/2

/00

16:1

0

26/2

/00

16:2

0

26/2

/00

16:3

0

26/2

/00

16:4

0

26/2

/00

16:5

0

26/2

/00

17:0

0

26/2

/00

17:1

0

26/2

/00

17:2

0

26/2

/00

17:3

0

26/2

/00

17:4

0

26/2

/00

17:5

0

26/2

/00

18:0

0

26/2

/00

18:1

0

26/2

/00

18:2

0

26/2

/00

18:3

0

26/2

/00

18:4

0

26/2

/00

18:5

0

26/2

/00

19:0

0

26/2

/00

19:1

0

26/2

/00

19:2

0

26/2

/00

19:3

0

26/2

/00

19:4

0

26/2

/00

19:5

0

26/2

/00

20:0

0

Period of test

Feed

stoc

k (t/

h), O

2 pur

ity (%

) and

gas

ifier

pr

essu

re (b

ar)

0

7000

14000

21000

28000

35000

42000

49000

56000

63000

70000

O2 (

Nm

3 /h) a

nd s

team

(kg/

h) to

bur

ners

O2 to burners (Nm3/h)

Feedstock (t/h)

O2 purity (%)

Gasifier pressure (bar)

Steam to burners (kg/h)

Figure 68. Main process input data during the tests. Mixture 3

MIXTURE No. 4

0

20

40

60

80

100

120

7/3/

00 1

7:20

7/3/

00 1

7:30

7/3/

00 1

7:40

7/3/

00 1

7:50

7/3/

00 1

8:00

7/3/

00 1

8:10

7/3/

00 1

8:20

7/3/

00 1

8:30

7/3/

00 1

8:40

7/3/

00 1

8:50

7/3/

00 1

9:00

7/3/

00 1

9:10

7/3/

00 1

9:20

7/3/

00 1

9:30

7/3/

00 1

9:40

7/3/

00 1

9:50

7/3/

00 2

0:00

7/3/

00 2

0:10

7/3/

00 2

0:20

7/3/

00 2

0:30

7/3/

00 2

0:40

7/3/

00 2

0:50

7/3/

00 2

1:00

7/3/

00 2

1:10

7/3/

00 2

1:20

Period of test

Feed

stoc

k (t/

h), O

2 pur

ity (%

) and

gas

ifier

pr

essu

re (b

ar)

0

7000

14000

21000

28000

35000

42000

49000

56000

63000

70000

O2 (

Nm

3 /h) a

nd s

team

(kg/

h) to

bur

nersO2 to burners (Nm3/h)

Feedstock (t/h)

O2 purity (%)

Gasifier pressure (bar)

Steam to burners (kg/h)

Figure 69. Main process input data during the tests. Mixture 4

124

MIXTURE No. 1

0

20

40

60

80

100

120

140

160

180

200

220

240

23/3

/00

16:2

5

23/3

/00

16:3

5

23/3

/00

16:4

5

23/3

/00

16:5

5

23/3

/00

17:0

5

23/3

/00

17:1

5

23/3

/00

17:2

5

23/3

/00

17:3

5

23/3

/00

17:4

5

23/3

/00

17:5

5

23/3

/00

18:0

5

23/3

/00

18:1

5

23/3

/00

18:2

5

23/3

/00

18:3

5

23/3

/00

18:4

5

23/3

/00

18:5

5

23/3

/00

19:0

5

23/3

/00

19:1

5

23/3

/00

19:2

5

23/3

/00

19:3

5

23/3

/00

19:4

5

23/3

/00

19:5

5

23/3

/00

20:0

5

23/3

/00

20:1

5

23/3

/00

20:2

5

Period of test

Gas

ifier

load

(%),

HP

and

IP s

team

pro

duce

d in

the

gasi

fier

and

turb

ine

pow

er (M

W)

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

200000

Cle

an g

as fl

ow (N

m3 /h

)

Clean gas flow

HP steam flow

Gas turbine power

Steam turbine power

Gasifier load

IP steam flow

Figure 70. Main process output data during the tests. Mixture 1

MIXTURE No. 2

0

20

40

60

80

100

120

140

160

180

200

220

240

21/3

/00

12:0

0

21/3

/00

12:1

0

21/3

/00

12:2

0

21/3

/00

12:3

0

21/3

/00

12:4

0

21/3

/00

12:5

0

21/3

/00

13:0

0

21/3

/00

13:1

0

21/3

/00

13:2

0

21/3

/00

13:3

0

21/3

/00

13:4

0

21/3

/00

13:5

0

21/3

/00

14:0

0

21/3

/00

14:1

0

21/3

/00

14:2

0

21/3

/00

14:3

0

21/3

/00

14:4

0

21/3

/00

14:5

0

21/3

/00

15:0

0

21/3

/00

15:1

0

21/3

/00

15:2

0

21/3

/00

15:3

0

21/3

/00

15:4

0

21/3

/00

15:5

0

Period of test

Gas

ifier

load

(%),

HP

and

IP s

team

pro

duce

d in

th

e ga

sifie

r an

d tu

rbin

e po

wer

(MW

)

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

200000

Cle

an g

as fl

ow (N

m3 /h

)

Clean gas flow

HP steam flow

Gas turbine powerSteam turbine power

Gasifier load

IP steam flow

Figure 71. Main process output data during the tests. Mixture 2

125

MIXTURE No. 3

0

20

40

60

80

100

120

140

160

180

200

220

240

26/2

/00

16:0

0

26/2

/00

16:1

0

26/2

/00

16:2

0

26/2

/00

16:3

0

26/2

/00

16:4

0

26/2

/00

16:5

0

26/2

/00

17:0

0

26/2

/00

17:1

0

26/2

/00

17:2

0

26/2

/00

17:3

0

26/2

/00

17:4

0

26/2

/00

17:5

0

26/2

/00

18:0

0

26/2

/00

18:1

0

26/2

/00

18:2

0

26/2

/00

18:3

0

26/2

/00

18:4

0

26/2

/00

18:5

0

26/2

/00

19:0

0

26/2

/00

19:1

0

26/2

/00

19:2

0

26/2

/00

19:3

0

26/2

/00

19:4

0

26/2

/00

19:5

0

26/2

/00

20:0

0

Period of test

Gas

ifier

load

(%),

HP

and

IP s

team

pro

duce

d in

th

e ga

sifie

r an

d tu

rbin

e po

wer

(MW

)

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

200000

Cle

an g

as fl

ow (N

m3 /h

)

IP steam flow

Gasifier load

Steam turbine power

Gas turbine power

HP steam flow

Clean gas flow

Figure 72. Main process output data during the tests. Mixture 3

MIXTURE No. 4

0

20

40

60

80

100

120

140

160

180

200

220

240

7/3/

00 1

7:20

7/3/

00 1

7:30

7/3/

00 1

7:40

7/3/

00 1

7:50

7/3/

00 1

8:00

7/3/

00 1

8:10

7/3/

00 1

8:20

7/3/

00 1

8:30

7/3/

00 1

8:40

7/3/

00 1

8:50

7/3/

00 1

9:00

7/3/

00 1

9:10

7/3/

00 1

9:20

7/3/

00 1

9:30

7/3/

00 1

9:40

7/3/

00 1

9:50

7/3/

00 2

0:00

7/3/

00 2

0:10

7/3/

00 2

0:20

7/3/

00 2

0:30

7/3/

00 2

0:40

7/3/

00 2

0:50

7/3/

00 2

1:00

7/3/

00 2

1:10

7/3/

00 2

1:20

Period of test

Gas

ifier

load

(%),

HP

and

IP s

team

pro

duce

d in

the

gasi

fier

and

turb

ine

pow

er (M

W)

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

200000

Cle

an g

as fl

ow (N

m3 /h

)Clean gas flow

HP steam flow

Gas turbine power

Steam turbine power

Gasifier load

IP steam flow

Figure 73. Main process output data during the tests. Mixture 4

126

MIXTURE No. 1

0

25

50

75

100

125

150

23/3

/00

16:2

5

23/3

/00

16:3

5

23/3

/00

16:4

5

23/3

/00

16:5

5

23/3

/00

17:0

5

23/3

/00

17:1

5

23/3

/00

17:2

5

23/3

/00

17:3

5

23/3

/00

17:4

5

23/3

/00

17:5

5

23/3

/00

18:0

5

23/3

/00

18:1

5

23/3

/00

18:2

5

23/3

/00

18:3

5

23/3

/00

18:4

5

23/3

/00

18:5

5

23/3

/00

19:0

5

23/3

/00

19:1

5

23/3

/00

19:2

5

23/3

/00

19:3

5

23/3

/00

19:4

5

23/3

/00

19:5

5

23/3

/00

20:0

5

23/3

/00

20:1

5

23/3

/00

20:2

5

Period of test

CO

(%) a

nd H

2 (%

)

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

200000

Cle

an g

as fl

ow (

Nm

3 /h)

H2 in clean gas CO in clean gas Clean gas flow

CO

H2

Clean gas flow

Figure 74. Main gas composition data during the tests. Mixture 1

MIXTURE No. 2

0

25

50

75

100

125

150

21/3

/00

12:0

0

21/3

/00

12:1

0

21/3

/00

12:2

0

21/3

/00

12:3

0

21/3

/00

12:4

0

21/3

/00

12:5

0

21/3

/00

13:0

0

21/3

/00

13:1

0

21/3

/00

13:2

0

21/3

/00

13:3

0

21/3

/00

13:4

0

21/3

/00

13:5

0

21/3

/00

14:0

0

21/3

/00

14:1

0

21/3

/00

14:2

0

21/3

/00

14:3

0

21/3

/00

14:4

0

21/3

/00

14:5

0

21/3

/00

15:0

0

21/3

/00

15:1

0

21/3

/00

15:2

0

21/3

/00

15:3

0

21/3

/00

15:4

0

21/3

/00

15:5

0

21/3

/00

16:0

0

Period of test

CO

(%) a

nd H

2 (%

)

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

200000

Cle

an g

as fl

ow (

Nm

3 /h)

H2 in clean gas CO in clean gas Clean gas flow

CO

H2

Clean gas flow

Figure 75. Main gas composition data during the tests. Mixture 2

127

MIXTURE No. 3

0

25

50

75

100

125

150

26/2

/00

16:0

0

26/2

/00

16:1

0

26/2

/00

16:2

0

26/2

/00

16:3

0

26/2

/00

16:4

0

26/2

/00

16:5

0

26/2

/00

17:0

0

26/2

/00

17:1

0

26/2

/00

17:2

0

26/2

/00

17:3

0

26/2

/00

17:4

0

26/2

/00

17:5

0

26/2

/00

18:0

0

26/2

/00

18:1

0

26/2

/00

18:2

0

26/2

/00

18:3

0

26/2

/00

18:4

0

26/2

/00

18:5

0

26/2

/00

19:0

0

26/2

/00

19:1

0

26/2

/00

19:2

0

26/2

/00

19:3

0

26/2

/00

19:4

0

26/2

/00

19:5

0

26/2

/00

20:0

0

Period of test

CO

(%) a

nd H

2 (%

)

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

200000

Cle

an g

as fl

ow (N

m3 /h

)

H2 in clean gas CO in clean gas Clean gas flow

H2

CO

Clean gas flow

Figure 76. Main gas composition data during the tests. Mixture 3

MIXTURE No. 4

0

25

50

75

100

125

150

7/3/

00 1

7:20

7/3/

00 1

7:30

7/3/

00 1

7:40

7/3/

00 1

7:50

7/3/

00 1

8:00

7/3/

00 1

8:10

7/3/

00 1

8:20

7/3/

00 1

8:30

7/3/

00 1

8:40

7/3/

00 1

8:50

7/3/

00 1

9:00

7/3/

00 1

9:10

7/3/

00 1

9:20

7/3/

00 1

9:30

7/3/

00 1

9:40

7/3/

00 1

9:50

7/3/

00 2

0:00

7/3/

00 2

0:10

7/3/

00 2

0:20

7/3/

00 2

0:30

7/3/

00 2

0:40

7/3/

00 2

0:50

7/3/

00 2

1:00

7/3/

00 2

1:10

7/3/

00 2

1:20

Period of test

CO

(%) a

nd H

2 (%

)

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

200000

Cle

an g

as fl

ow (N

m3 /h

)

H2 in clean gas CO in clean gas Clean gas flow

Clean gas flow

CO

H2

Figure 77. Main gas composition data during the tests. Mixture 4

The plant was operated successfully with the different feedstock, however some mechanical and

operational difficulties were observed during the tests.

128

4.3.3.2. Individual analysis of performance op processing parts

4.3.3.2.1 . Slag extraction system

During Test No. 1 (Mixture No. 3), slag collector level increased by twice the permitted level for a correct

operation (3400 mm). A trip on February 25th was caused by this problem due to the high ash

concentration in the feedstock.

During Test No. 2 (Mixture No. 4), the slag collector level was also quite high on two occasions.

However, the problem was controlled by operation parameters (mainly by decreasing the gasifier load to

85%).

In Test No. 3 (Mixture No. 2) and No.4 (Mixture No. 1), problems relating to the slag extraction system

did not appear, because of lower ash concentrations in the feedstock.

The following figures show the behaviour of the slag extraction system during the four tests. Main

parameters: slag collector level and slag crusher intensity have been registered.

129

THERMIE TEST No. 1

0

500

1000

1500

2000

2500

3000

3500

4000

20/2

/00

4:00

20/2

/00

17:2

0

21/2

/00

6:40

21/2

/00

20:0

0

22/2

/00

9:20

22/2

/00

22:4

0

23/2

/00

12:0

0

24/2

/00

1:20

24/2

/00

14:4

0

25/2

/00

4:00

25/2

/00

17:2

0

26/2

/00

6:40

26/2

/00

20:0

0

27/2

/00

9:20

27/2

/00

22:4

0

28/2

/00

12:0

0

Period of test

Slag

col

lect

or le

vel (

mm

)

0

20

40

60

80

100

120

140

160

180

200

Slag

cru

sher

inte

nsity

(A) a

nd h

eat f

lux

dens

ity

in re

actio

n ch

ambe

r (kW

/m2 )

Allowed level < 3400 mm

Slag crusher intensity

Slag collector level

Heat flow density in reaction chamber

Figure 78. Main data of the slag extraction system during the tests. Test 1.

THERMIE TEST No. 2

0

500

1000

1500

2000

2500

3000

3500

4000

6/3/

00 5

:00

6/3/

00 1

0:00

6/3/

00 1

5:00

6/3/

00 2

0:00

7/3/

00 1

:00

7/3/

00 6

:00

7/3/

00 1

1:00

7/3/

00 1

6:00

7/3/

00 2

1:00

8/3/

00 2

:00

8/3/

00 7

:00

8/3/

00 1

2:00

8/3/

00 1

7:00

8/3/

00 2

2:00

9/3/

00 3

:00

9/3/

00 8

:00

9/3/

00 1

3:00

9/3/

00 1

8:00

9/3/

00 2

3:00

10/3

/00

4:00

10/3

/00

9:00

10/3

/00

14:0

0

10/3

/00

19:0

0

11/3

/00

0:00

11/3

/00

5:00

Period of test

Slag

col

lect

or le

vel (

mm

)

0

20

40

60

80

100

120

140

160

180

200

Slag

cru

sher

inte

nsity

(A) a

nd h

eat f

lux

dens

ityin

reac

tion

cham

ber (

kW/m

2 )

Allowed level < 3400 mm

Slag crusher intensity

Slag collector level

Heat flow density in reaction chamber

Figure 79. Main data of the slag extraction system during the tests. Test 2

130

THERMIE TEST No. 3

0

500

1000

1500

2000

2500

3000

3500

4000

14/3

/00

22:3

0

15/3

/00

3:30

15/3

/00

8:30

15/3

/00

13:3

0

15/3

/00

18:3

0

15/3

/00

23:3

0

16/3

/00

4:30

16/3

/00

9:30

16/3

/00

14:3

0

16/3

/00

19:3

0

17/3

/00

0:30

17/3

/00

5:30

17/3

/00

10:3

0

17/3

/00

15:3

0

17/3

/00

20:3

0

18/3

/00

1:30

18/3

/00

6:30

18/3

/00

11:3

0

Period of test

Slag

col

lect

or le

vel (

mm

)

0

20

40

60

80

100

120

140

160

180

200

Slag

cru

sher

inte

nsity

(A) a

nd h

eat f

lux

dens

ityin

reac

tion

cham

ber (

kW/m

2)

Allowed level < 3400 mm

Slag crusher intensity

Slag collector level

Heat flow density in reaction chamber

Figure 80. Main data of the slag extraction system during the tests. Test 3

THERMIE TEST No. 4

0

500

1000

1500

2000

2500

3000

3500

4000

19/3

/00

6:00

19/3

/00

16:0

0

20/3

/00

2:00

20/3

/00

12:0

0

20/3

/00

22:0

0

21/3

/00

8:00

21/3

/00

18:0

0

22/3

/00

4:00

22/3

/00

14:0

0

23/3

/00

0:00

23/3

/00

10:0

0

23/3

/00

20:0

0

24/3

/00

6:00

24/3

/00

16:0

0

25/3

/00

2:00

25/3

/00

12:0

0

25/3

/00

22:0

0

26/3

/00

9:00

26/3

/00

19:0

0

27/3

/00

5:00

Period of test

Slag

col

lect

or le

vel (

mm

)

0

20

40

60

80

100

120

140

160

180

200

Slag

cru

sher

inte

nsity

(A) a

nd h

eat f

lux

dens

ity

in re

actio

n ch

ambe

r (kW

/m2)

Allowed level < 3400 mm

Slag crusher intensity

Slag collector level

Heat flow density in reaction chamber

Figure 81. Main data of the slag extraction system during the tests. Test 4

131

4.3.3.2.2. Waste Heat Boiler

During the first long gasifier operation run (August 99), high gas outlet temperatures at HP-Boiler, which

were limiting the gasifier load, were noticed. These temperatures (higher than the design ones) indicate

that a boiler is fouling. The monitoring of the fouling is carried out by a computing model. This model

solves energy balances, for every heat exchanger in HP and IP boiler, obtaining the fouling factor (F) from

the overall heat transfer coefficient (U):

( ) Fh

1AA

eφπλeA

h1

AA

1U

outout

t

text

tt

inin

t +×+−××

×+×

= /2/

Fouling factors in every test were registered and compared, however no influence of different fuels was

observed in fouling behaviour. In every test, fouling factor increases with the operation time. The

following figure shows fouling behaviour during the tests.

132

THERMIE TEST No. 1

0,000

0,002

0,004

0,006

0,008

0,010

20/0

2/00

4:0

0

20/0

2/00

16:

00

21/0

2/00

4:0

0

21/0

2/00

16:

00

22/0

2/00

4:0

0

22/0

2/00

16:

00

23/0

2/00

4:0

0

23/0

2/00

16:

00

24/0

2/00

4:0

0

24/0

2/00

16:

00

25/0

2/00

4:0

0

25/0

2/00

16:

00

26/0

2/00

4:0

0

26/0

2/00

16:

00

27/0

2/00

4:0

0

27/0

2/00

16:

00

28/0

2/00

4:0

0

28/0

2/00

16:

00

Foul

ing

(m2 K

/W)

0

20

40

60

80

100

Load

(%)

HP II Fouling HP I Fouling Load

Figure 82. Fouling data during the tests. Test 1.

THERMIE TEST No. 2

0,000

0,002

0,004

0,006

0,008

0,010

06/0

3/00

5:0

0

06/0

3/00

17:

00

07/0

3/00

5:0

0

07/0

3/00

17:

00

08/0

3/00

5:0

0

08/0

3/00

17:

00

09/0

3/00

5:0

0

09/0

3/00

17:

00

10/0

3/00

5:0

0

10/0

3/00

17:

00

11/0

3/00

5:0

0

Foul

ing

(m2 K

/W)

0

20

40

60

80

100

Load

(%)

HP II Fouling HP I Fouling Load

Figure 83. Fouling data during the tests. Test 2.

133

THERMIE TEST No. 3

0,000

0,002

0,004

0,006

0,008

0,010

14/0

3/00

22:

30

15/0

3/00

10:

30

15/0

3/00

22:

30

16/0

3/00

10:

30

16/0

3/00

22:

30

17/0

3/00

10:

30

17/0

3/00

22:

30

18/0

3/00

10:

30

18/0

3/00

22:

30

Foul

ing

(m2 K

/W)

0

20

40

60

80

100

Load

(%)

HP II Fouling HP I Fouling Load

Figure 84. Fouling data during the tests. Test 3.

THERMIE TEST No. 4

0,000

0,002

0,004

0,006

0,008

0,010

19/0

3/00

6:0

0

20/0

3/00

6:0

0

21/0

3/00

6:0

0

22/0

3/00

6:0

0

23/0

3/00

6:0

0

24/0

3/00

6:0

0

25/0

3/00

6:0

0

26/0

3/00

6:0

0

27/0

3/00

6:0

0

Foul

ing

(m2 K

/W)

0

20

40

60

80

100

Load

(%)

HP II Fouling HP I Fouling Load

Figure 85. Fouling data during the tests. Test 4.

134

4.3.3.2.3. Cleaning dedusting system

Cleaning dedusting is one of the critical systems in the Plant. Monitoring of the cleaning dedusting

process is carried out during the operation by the two following parameters:

1. The candle filter fouling factor:

actefref

actef

ref NQCNQTPkP

CCfatorfoulingfiltercandle

/*)/(*)/(* 2−∆

==

Where:

∆p is the differential pressure across the filters,

k is 5.11E-7 K/(m3/h)2,

P and T are the pressure and temperature of the gas respectively,

Nact is the number of active sectors,

Cref 1.389E-4 bar/(m3/h)

and Qef is given by:

15.273*01325.1* T

PQQ nef =

2. The solids in Venturi water which are measured in the laboratory

During these tests, no influence of different fuels was observed in the candle filter behaviour. However,

the candle filter fouling factor increased from the first test to the last one, due mainly to the accumulation

of operation hours.

The following figure shows the performance of this system.

135

THERMIE TEST No. 1

0,0

0,4

0,8

1,2

1,6

2,0

2,4

20/2

/00

4:00

20/2

/00

16:0

0

21/2

/00

4:00

21/2

/00

16:0

0

22/2

/00

4:00

22/2

/00

16:0

0

23/2

/00

4:00

23/2

/00

16:0

0

24/2

/00

4:00

24/2

/00

16:0

0

25/2

/00

4:00

25/2

/00

16:0

0

26/2

/00

4:00

26/2

/00

16:0

0

27/2

/00

4:00

27/2

/00

16:0

0

28/2

/00

4:00

28/2

/00

16:0

0

Period of test

Can

dle

filte

r fou

ling

fact

or

0

40

80

120

160

200

240

Solid

s in

Ven

turi

(ppm

)

Fouling factor candles Solids in Venturi (ppm)

Figure 86. Candle filter performance during the tests. Test 1

THERMIE TEST No. 2

0,0

0,4

0,8

1,2

1,6

2,0

2,4

6/3/

00 5

:00

6/3/

00 1

7:00

7/3/

00 5

:00

7/3/

00 1

7:00

8/3/

00 5

:00

8/3/

00 1

7:00

9/3/

00 5

:00

9/3/

00 1

7:00

10/3

/00

5:00

10/3

/00

17:0

0

11/3

/00

5:00

Period of test

Can

dle

filte

r fou

ling

fact

or

0

40

80

120

160

200

240

Solid

s in

Ven

turi

(ppm

)

Fouling factor candles Solids in Venturi (ppm)

Figure 87. Candle filter performance during the tests. Test 2

136

THERMIE TEST No. 3

0,0

0,4

0,8

1,2

1,6

2,0

2,4

14/3

/00

22:3

0

15/3

/00

3:30

15/3

/00

8:29

15/3

/00

13:2

9

15/3

/00

18:2

8

15/3

/00

23:2

8

16/3

/00

4:27

16/3

/00

9:27

16/3

/00

14:2

6

16/3

/00

19:2

6

17/3

/00

0:25

17/3

/00

5:25

17/3

/00

10:2

4

17/3

/00

15:2

4

17/3

/00

20:2

4

18/3

/00

1:23

18/3

/00

6:23

18/3

/00

11:2

2

Period of test

Can

dle

filte

r fou

ling

fact

or

0

40

80

120

160

200

240

Solid

s in

Ven

turi

(ppm

)

Fouling factor candles Solids in Venturi (ppm)

Figure 88. Candle filter performance during the tests. Test 3

THERMIE TEST No. 4

0,0

0,4

0,8

1,2

1,6

2,0

2,4

19/3

/00

6:00

19/3

/00

18:0

0

20/3

/00

6:00

20/3

/00

18:0

0

21/3

/00

6:00

21/3

/00

18:0

0

22/3

/00

6:00

22/3

/00

18:0

0

23/3

/00

6:00

23/3

/00

18:0

0

24/3

/00

6:00

24/3

/00

18:0

0

25/3

/00

6:00

25/3

/00

18:0

0

26/3

/00

6:00

26/3

/00

18:0

0

27/3

/00

6:00

Period of test

Can

dle

filte

r fou

ling

fact

or

0

40

80

120

160

200

240

Solid

s in

Ven

turi

(ppm

)

Fouling factor candles Solids in Venturi (ppm)

Figure 89. Candle filter performance during the tests. Test 4.

137

4.3.3.3. Fuel consumption and other consumables

Data of fuel consumption and other consumables for each test mixture is shown in the table.

Mixture 1 Mixture 2 Mixture 3 Mixture 4(39%coal–61%coke) (45%coal–55%coke) (54%coal–46%coke) (58%coal–42%coke)

Operation hours 4 4 4 4

Gasifier load (%) 84.5 93.1 91.2 85.0

Streams to burners

Fuel (t) 361.1 392.0 391.7 362.1

Limestone (t) 8.36 8.62 8.63 8.03

Oxygen (Nm3) 233,077 247,277 239,587 219,745

HP steam (kg) 40,253 43,068 34,162 28,214

Nitrogen (Nm3) 116,006 124,315 117,416 111,388

Process water

Demineralised water 93.45 86.14 71.91 70

Other consumables

NaOH (kg) 1,829 1,872 2,024 2,264

H2SO4 (kg) 8.19 8.20 6.08 11.38

Table 36. Fuel consumption and other consumables.

138

4.3.3.4. Electricity, by-products and wastes production

Mixture 1 Mixture 2 Mixture 3 Mixture 4(39%coal–61%coke) (45%coal–55%coke) (54%coal–46%coke) (58%coal–42%coke)

Gasifier load (%) 85.5 93.1 91.2 85.0

Operation hours 4 4 4 4

Power

Gas turbine (MWh) 698.2 707.8 664.5 562.1

Steam turbine (MWh) 496.5 531.6 504.9 449.1

By-products

Fly ash (t) 11.95 12.1 11.23 9.50

Slag (t) 61.34 78.62 82.08 101.66

Sulphur (t) 12.9 12.92 11.96 10.2

Wastes

Filter cake (t) 3.89 6.05 4.89 1.58

Table 37. Electricity, by-products and wastes production.

139

4.3.3.5. Gasification behaviour of feedstock

The tests with different feedstock were designed to examine the effect of the different fuels and major

process parameters (oxygen/carbon ratio and steam addition) on the gasification performance.

The tests were carried out using an oxygen purity of 85% and a pressure in the Puertollano gasifier of

approx. 25 bar.

The results of the gasification tests are shown in the following figures.

4.3.3.5.1. Carbon conversion

Carbon conversion achieved during the tests is shown in the following table.

Mixture 1 Mixture 2 Mixture 3 Mixture 4

O2/C feedstock 0.76 0.75 0.73 0.72

C conversion 98.8 98.4 98.5 99.7

Table 38. Carbon conversion during tests.

The best combination of carbon conversion and oxygen consumption was attained with mixture No. 4

(Maximum coal composition). A carbon conversion value of 99.7 was attained with just 0.72 of

O2/feedstock.

140

4.3.3.5.2. Cold Gas Efficiency

Based on the studies carried out in the University of Ulster /1/, the influence of feedstock properties on the

Techno-Economic Performance of IGCC was assessed.

70

72

74

76

78

80

0,7 0,72 0,74 0,76 0,78 0,8

O2/feedstock (m.a.f.) ratio

Col

d G

as E

ffici

ency

(%)

Figure 90. Cold Gas efficiency against O2/ feedstock ratio

70

72

74

76

78

80

60 62 64 66 68 70

Carbon content of the fuel (%)

Col

d G

as E

ffici

ency

(%)

Figure 91. Cold Gas Efficiency against fuel carbon content.

141

70

72

74

76

78

80

20 22 24 26 28 30

Ash content of the fuel (%)

Col

d G

as E

ffici

ency

(%)

Figure 92. Cold Gas Efficiency against fuel ash content.

70

72

74

76

78

80

16 17 18 19

Volatile matter of the fuel (%)

Col

d G

as E

ffici

ency

(%)

Figure 93. Cold Gas Efficiency against fuel volatile matter.

A series of correlation studies was performed to try to identify which of the fuel properties was having the

most significant effect on efficiency. It was found out that the fuel ash content, carbon content and volatile

matter are some of the most significant fuel properties with regard to efficiency.

142

The last graphs show the decrease in efficiency when increasing fuel ash content and volatile matter and

the increase when increasing O2/feedstock ratio, as well as the increase in efficiency by increasing fuel

carbon content. This tendency holds true for the simulation models based on the Shell gasifier and

therefore it can be concluded that for entrained flow gasification systems fuels with a higher carbon

content display the best performance.

143

4.3.3.5.3. Thermal Efficiency

Thermal efficiency refers to the part of the heating value of the fuel (HHV) which is transferred in the

process to other forms of usable energy (heating value of cold gas and enthalpy of the steam produced).

In the tests, values of 90.43% were obtained during the first test, 91.17% during the second test, 90.51%

during the third test and 91.35% during the last one.

4.3.3.5.4. Slag/ash split

The term slag/ash split is defined as the fraction of the fuel ash leaving the Puertollano gasifier as molten

slag through the slag hole. It is desirable to have a high slag/ash split because slag is an inert, vitreous

material and therefore exhibits optimum leachable quality.

In the gasification tests slag/ash splits of between 86.5% and 90.1% were achieved. This ratio increases

with the O2/feedstock ratio and with the ash content in feedstock, as the following figure shows.

80

82

84

86

88

90

92

20 22 24 26 28 30Ash in feedstock (%)

Slag

/ash

spl

it (%

)

Figure 94. Slag/ash split.

144

4.3.3.6. Main data on emissions and by-products

4.3.3.6.1. Emissions during the tests

During all of the tests, emissions figures were well within EEC and Spanish limits. This demonstrates the

excellent environmental performance of the Puertollano plant.

0

50

100

150

200

250

300

350

400

450

500

mg/Nm3

SO2 NOx Particulate emission(x100)

MIXTURE No. 1

EEC 88/609 ELCOGAS average

0

50

100

150

200

250

300

350

400

450

500

mg/Nm3

SO2 NOx Particulate emission(x100)

MIXTURE No. 2

EEC 88/609 ELCOGAS average

0

50

100

150

200

250

300

350

400

450

500

mg/Nm3

SO2 NOx Particulate emission (x100)

MIXTURE No. 3

EEC 88/609 ELCOGAS average

0

50

100

150

200

250

300

350

400

450

500

mg/Nm3

SO2 NOx Particulate emission(x100)

MIXTURE No. 4

EEC 88/609 ELCOGAS average

Figure 95. Emission data during fuel tests.

145

g/kWh

Dust 0.1 NOx 0.4Dust 0.02

BASIS

Feedstock (3.2 % S, 20.7 % Ash and HHV = 23.12 MJ/kg) Gross production 320 MW Gross efficiency (HHV) 37.5 % (PC and AFBC), 46% (IGCC)

LNB (50%)ESP (99.2%)

AFBCCyclone filters (96%)

PULVERIZED COALNo gas treatment

PULVERIZED COALDeSOx (90%)

IGCC PUERTOLLANOSulphur removal (99.9%)

SO2 25.3

NOx 4.5

Dust > 40

PC PC AFBC IGCC

Dust 0.3SO2 1.4NOx 0.8

SO2 2.5NOx 2.3

SO2 0.07

NOx 0.240 NOx 0.239 NOx 0.633 NOx 0.111Dust 0.0013 Dust 0.0010 Dust 0.0001 Dust 0.0002

Mixture No. 1

IGCC PUERTOLLANOIGCC PUERTOLLANO

Mixture No. 3 Mixture No. 4

IGCC PUERTOLLANO IGCC PUERTOLLANO

SO2 0.057

Mixture No. 2

SO2 0.027SO2 0.036 SO2 0.039

Figure 96. Comparison of emission levels during fuel tests.

146

4.3.3.6.2. Mass balance and trace elements in the by-products

The following table shows the main figures in terms of by-product composition.

Test 1 Test 2 Test 3 Test 4

Slag Fly

ash

Filter

cake

Slag Fly

ash

Filter

cake

Slag Fly

ash

Filter

cake

Slag Fly

ash

Filter

cake

Carbon wt. % mf 2.13 2.84 34.56 0.35 2 33.56 0.23 3.3 33.77 0.62 6.13 52.11

Total sulphur wt. % mf 0.29 0.89 2.13 0.25 0.91 2.48 0.28 1.11 2.09 0.32 1.37 3.03

Ash wt. % mf 97.91 96.15 66.24 99.83 97.02 66.17 99.98 95.59 67.36 99.32 92.08 47.12

Ash Analysis

Fe2O3 wt. % 4.41 4.82 7.38 6.17 4.92 8.80 5.78 4.82 8.26 4.31 4.72 9.51

SiO2 wt. % 64.40 63.41 61.83 57.72 62.99 56.27 55.04 61.43 56.76 58.89 63.66 54.92

Al2O3 wt. % 22.29 22.57 22.78 26.85 22.87 26.55 28.17 23.86 26.56 24.80 21.39 26.14

CaO wt. % 5.42 3.13 4.15 5.31 3.02 3.26 6.72 3.36 3.28 7.90 4.12 4.77

MgO wt. % 0.77 0.73 0.77 1.06 0.79 0.85 1.00 0.73 0.86 1.10 0.83 0.92

Na2O wt. % 0.30 0.48 0.38 0.41 0.45 0.40 0.33 0.54 0.41 0.35 0.58 0.47

K2O wt. % 1.78 3.70 2.01 1.86 3.75 3.01 2.16 3.95 3.04 1.95 3.65 2.39

TiO2 wt. % 0.56 0.64 0.60 0.71 0.64 0.72 0.70 0.64 0.72 0.63 0.58 0.72

P2O5 wt. % 0.03 0.48 0.06 0.03 0.55 0.07 0.04 0.63 0.06 0.02 0.43 0.11

MnO wt. % 0.03 0.04 0.04 0.06 0.04 0.07 0.06 0.04 0.06 0.05 0.04 0.06

Table 39. Composition of solid residues.

147

The following figure shows the distribution of trace elements among different by-products.

MIXTURE No. 1

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Zn Sb V Cr Sn Ni Cu Cd Pb As

Filter cake Slag Fly ash

Figure 97. Distribution of trace elements among by-product streams. Mixture 1

MIXTURE No. 2

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Zn Sb V Cr Sn Ni Cu Cd Pb As

Filter cake Slag Fly ash

Figure 98. Distribution of trace elements among by-product streams. Mixture 2

148

MIXTURE No. 3

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Zn Sb V Cr Sn Ni Cu Cd Pb As

Filter cake Slag Fly ash

Figure 99. Distribution of trace elements among by-product streams. Mixture 3

MIXTURE No. 4

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Zn Sb V Cr Sn Ni Cu Cd Pb As

Filter cake Slag Fly ash

Figure 100. Distribution of trace elements among by-product streams. Mixture 4

149

Feedstock ash is recovered mainly as an inert, vitreous material named slag. Slag/ash ratio increases with

the ash content in feedstock, as observed before (Slag/ash split).

Distribution of fuel ash in the solid outlet streams

0

20

40

60

80

100

(%)

Fly ash 15 13 11 8Slag 85 87 89 92

Mixture No.1 Mixture No.2 Mixture No.3 Mixture No.4

Figure 101. Distribution of ash among by-product streams.

150

4.3.3.6.3. Wash and Venturi water composition

The following table shows the main figures for wash and Venturi water .

Mixture 1 Mixture 2 Mixture 3 Mixture 4

Washwater

Venturiwater

Washwater

Venturiwater

Washwater

Venturiwater

Washwater

Venturiwater

pH 10.6 7.5 11.9 7.4 9.8 7.4 10.2 8.4

F- mg/l 430 708 395 625 619 695 400 342

Cl- mg/l 2,862 4,385 2,338 3,714 5,7 6,189 3,169 2,764

NH3+ mg/l 28 422 46.6 584 77.1 838 1,341 749

S2- mg/l 35 216 51 243 19 99 2,91 3,822

SO4- mg/l 266 - 205 - 187 - 143 230

HCOO- mg/l 182 283 211 263 548 577 512 581

CN- total mg/l 1 8.8 0.8 9.3 2.4 15 8.3 3.4

Solid content mg/l 90 209 55 87 25 25 32 41

Table 40. Composition of wash and Venturi water.

151

4.3.3.7. Thermo-economic diagnosis

The Thermo-economic analysis has been carried out by TDG system, a tool specifically developed for

ELCOGAS and co-financed by the THERMIE programme (Contract no. SF-0200-95 ES/IT/FR:

Puertollano project activities to improve the efficiency, availability and economics of the current and

future IGCC). TDG, used as an engineering analysis calculator, permits a relative comparative analysis

between different working scenarios.

In the following tables, main performance input and output data are listed for test balances. The raw gas

composition is taken at the outlet of the Puertollano gasifier and includes the nitrogen from fly ash filter

cleaning.

Mixture 1 Mixture 2 Mixture 3 Mixture 4

Input Data 16/03/00 11:00 24/03/00 12:25 25/02/00 12:00 7/03/00 11:00

Feedstock composition

Moisture wt. % 0.75 1.04 1.29 0.93

Carbon wt. % mf 68.8 65.61 62.76 60.66

Hydrogen wt. % mf 3.24 3.19 3.11 3.13

Oxygen (by difference) wt. % mf 1.89 2.69 3.36 3.68

Nitrogen wt. % mf 1.52 1.3 1.49 1.27

Sulphur wt. % mf 3.82 3.47 3.28 3.0

Chlorine ppm mf 722 685 482 524

Ash wt. % mf 20.64 23.69 25.95 28.21

Higher heating value kJ/kg mf 26,891 25,536 24,699 23,612

Table 41. Performance Input Data.

152

Mixture 1 Mixture 2 Mixture 3 Mixture 4

Output Data 16/03/00 11:00 24/03/00 12:25 25/02/00 12:00 7/03/00 11:00

Gasification temperature ºC 1,706 1,735 1,746 1,797

Gasifier pressure bar 25.1 23.87 24.87 23.54

Raw gas composition (dry)

H2 vol. % mf 20.8 20.83 20.8 19.45

CO vol. % mf 61.14 60.1 59.38 59.65

CO2 vol. % mf 1.76 2.69 2.81 3.75

N2 + Ar vol. % mf 15.09 15.22 15.87 16.07

H2S + COS vol. % mf 1.21 1.16 1.13 1.07

H2O vol. % 3.22 4.26 4.36 3.4

CH4 ppm 62.36 56.09 47.17 42.25

Clean gas composition

H2 vol. % mf 21.11 21.17 21.14 19.8

CO vol. % mf 62.06 61.1 60.36 60.7

CO2 vol. % mf 1.43 2.19 2.29 3.05

N2 + Ar vol. % mf 15.34 15.47 16.14 16.36

H2S + COS vol. % mf 0 0 0 0

H2O vol. % 0.07 0.07 0.07 0.08

Low Heat Value kJ/kg 9,911 9,751 9,646 9,355

O2/feedstock ratio tpu 0.70 0.71 0.72 0.73

H2O/feedstock ratio tpu 0.14 0.15 0.12 0.11

Carbon conversion % 98.8 98.4 98.5 99.7

Cold gas efficiency (HHV) % 76.07 74.5 74.19 74.07

Thermal efficiency (HHV) % 91.35 90.51 90.43 91.17

Slag/ash split % 84.7 88.4 86.5 90.1

Gasifier load % 84.5 93.1 91.2 85.0

Total power MW 290.2 303 287.8 247.5

Gas turbine power MW 168.7 173.0 163.0 137.8

Steam turbine power MW 121.5 130.0 124.8 109.7

IGCC gross efficiency % 46.12 46.06 46.21 44.64

CC gross efficiency % 50.25 50.7 50.77 48.86

Auxiliary power MW 39.95 41.73 37.3 38.11

Table 42. Performance Output Data.

153

4.3.3.7.1. Mass balances

The following table shows mass balances of the test. Mass balances incorporate data from around the

Puertollano gasifier after quenching.

Input streams

Mixture 1 Mixture 2 Mixture 3 Mixture 4

Feedstock kg/s 24.06 26.53 25.98 24.22

C (feedstock) wt. % 68.29 64.43 61.96 60.2

Oxygen to the gasifier kg/s 22.35 23.67 22.89 20.92

Steam to the gasifier kg/s 2.74 2.93 2.33 1.91

Nitrogen to the gasifier kg/s 7.07 7.12 6.65 7.25

Total in kg/s 56.22 60.25 57.85 54.3

Output streams

Raw gas, dry kg/s 50.87 53.52 51.04 46.48

Slag, dry kg/s 4.26 5.46 5.7 7.06

Fly ash, dry kg/s 0.83 0.84 0.78 0.66

Filter cake, dry kg/s 0.27 0.42 0.34 0.11

Total out kg/s 56.23 60.24 57.86 54.31

Table 43. Mass balances.

154

4.3.3.7.2. Heat balances

The following table shows the heat balances for the tests.

Gasifier Energy Balance Mixture 1 Mixture 2 Mixture 3 Mixture 4

Feedstock to burners kW 649,578 680,155 644,560 574,648

Oxygen to burners kW 3,933 4,161 4,027 3,680

Steam to burners kW 7,679 8,210 6,536 5,362

Nitrogen to burners kW 120 126 127 120

Total in kW 661,310 692,652 655,250 583,810

Raw gas kW 638,872 661,844 628,386 557,478

Slag + Filter cake kW 5,548 8,854 7,987 2,251

Energy extracted from the

combustion chamber

kW 9,825 10,194 7,994 10,573

Energy extracted from the slag kW 8,084 10,364 12,146 12,586

Total out kW 662,329 691,256 656,513 582,888

Table 44. Heat Balances.

155

4.3.3.7. 3. Financial costs

For the purposes of this study, the following scenario has been set:

Cost PTA/t Euro/t

Coal 5592 33.6

Pet-coke 2701 16.2

Limestone 1528 9.2

Demi-water 160 0.96

Table 45. Cost fixed for the financial study.

The following table shows the main figures related to financial costs obtained from the fuel tests.

Parameters Mixture 1 Mixture 2 Mixture 3 Mixture 4

Feedstock consumption t/h 91.3 100.9 98.7 92

Feedstock cost pta2/t 4,074 4,094 4,083 4,106

Syngas cost pta/th 0.829 0.895 0.914 0.964

Gas Turbine energy cost pta/kWh 1.29 1.39 1.42 1.56

Steam Turbine energy cost pta/kWh 2.31 2.41 2.47 2.53

Net power sent to the grid MWh 250.2 261.3 250.6 209.4

Net energy cost pta/kWh 1.81 1.92 1.95 2.1

Table 46. Financial costs.

A summary of these results is given in the following figures.

2 1 Euro = 166.386 pta.

156

Figure 102. Test No. 1 (Mixture 3).

157

Figure 103. Test No. 2 (Mixture 4).

158

Figure 104. Test No. 3 (Mixture 2).

159

Figure 105. Test No. 4 (Mixture 1).

160

4.3.4. REFERENCES

/1/ Evans, R. H.; Huang Ye; Millar S.; McMullan J.T. and Williams B. C. The influence of feedstock

properties on the techno-economic performance of coal fired IGCC. University of Ulster, Energy

Research Centre, Cromore Road Coleraine Co. Londonderry N. Ireland, UK BT52 1SA. Gasification 4

The Future, 11-13 April 2000.

/2/ Evaluation of the performance of a coal/petroleum coke mixture in the PRENFLO coal gasification

process. ENDESA, KRUPP KOPPERS. October 1992.

/3/ U.S. coal test at the PRENFLO demonstration plant. EPRI. May 1989.

/4/ Demonstration and industrial pilot projects in the field of energy (EEC regulation No 3640/85). EUR

13091 EN. 1990.

161

5. IMPROVEMENTS FOR FUTURE IGCC PLANTS

5.1. ASSESSMENT OF THE GLOBAL OPERATION RESULTS FOR FUTURE IGCC

PLANTS

In terms of design principles and components, the Puertollano power plant is the most advanced IGCC

concept with the highest level of efficiency of the IGCC plants currently in operation or under

construction. Nevertheless, when comparing the state of technology at the time of the design of this plant

with the present status, it can be seen that a degree of technical progress has been achieved in the

meantime.

Based on the design principles of the Puertollano power plant, an advanced IGCC concept named “IGCC

98” was drawn up as part of the JOULE III Programme project “Contract JOF3-CT95-0004”, financed by

the European Commission. The tasks of this project were to investigate the potential efficiency

improvements and the potential reduction in cost for manufacturing and assembly (plant delivery price) of

a Puertollano type IGCC power plant and to assess the economical and environmental impact.

Besides the Universities of Essen and Ulster and the Netherlands Energy Research Foundation ECN, the

companies Krupp Uhde and Siemens companies participated in this project. They manufactured and

supplied major components for the Puertollano IGCC power station. Siemens has also delivered the

combined gas and steam turbine plant for the Buggenum IGCC power station. They channelled the

knowledge gained from the engineering of these plants into this project and will also use the design

principles and know-how brought together in the JOULE project for subsequent IGCC power plants.

The “IGCC 98” concept is based on qualified available materials and proven processes. It is characterised

by an increase in efficiency and reduced capital requirements compared with former IGCC plants. The

influence of several process parameters and changes in the design were investigated. Also, the efficiency

potential of future IGCC concepts with more advanced components and process parameters was studied.

Nevertheless, IGCC 98 improvements, based on the experience gained from actual operation in the

Puertollano Power plant up to August 2000, have led to the ELCOGAS advanced IGCC concept: “IGCC

2000”.

162

Several process modifications based on actual operation experience, aiming at higher efficiency as well as

at cost reduction have been performed and have led to the IGCC 2000 concept (following figure).

Mixedfuel

Coalpreparation

IP

HP

Gasifier

Slag

O2

IP

N2CoalFeed

Raw gas

Waste WaterTreatment

Venturi

Improvedcandlefilter

Clean gassaturator

COSHydrolysis

Clean gas

Dedustinggas

MDEA ClausPlant

Sulphur

Air

QuenchGas

AirSeparation

Unit

O2 N2

DiluentN2

Diluent N2Saturator

Fuel Gas

Exhaust Gas

GasTurbine

Air

G

Flue Gas

Heat RecoverySteam

Generator

GLPIPHP

Make-upwater

BFWTank

Condensate

LP

Saturation WaterPreheat

IP

HP

Reheat

SteamTurbine CondenserFly

ash

Filter cakeIP

Figure 106. IGCC 2000 simplified flow diagram.

163

5.2. ASSESSMENT OF THE DIFFERENT PROCESS PARTS

5.2.1. PROCESS OPTIMISATION AND ADJUSTMENT

5.2.1.1. Coal dust preparation

The Puertollano IGCC Power Plant was designed for a coal-coke mixture (1:1) as fuel. Nevertheless,

based on results from the THERMIE tests carried out with different fuel mixtures (described above), the

Puertollano gasifier allows variations of up to 10% of coal/coke composition in the mixture without

significant changes into the process. Fuel mixing does not require an extremely high precision, thus fuel

can be mixed in the Coal Yard, so improving control problems and saving on investment in equipment.

The coal is ground in mills using nitrogen for drying. The drying circuit is heated up to about 250 ºC by

IP-steam and additional burning of natural gas. As a result of cost optimisations, no LP-steam is

consumed for heating. IP-steam and natural gas cost is quite well balanced, although drying circuit

availability for start-up and shutdown operation is worse with IP-steam than burning natural gas. A dual

drying circuit using only natural gas and the produced syngas could be studied.

Currently two circuits with two mills are installed in the plant, a system with two circuits and three mills

or three circuits and four mills could be studied. Availability of the drying circuits has to be improved by

increasing their robustness.

According to the European trend, new “green” fuels are being studied (biomass, wastes, etc.) for mixing

in small quantities to the original mixture.

5.2.1.2. Coal dust conveying, sluicing and feeding

The main problem in the coal sluicing and feeding system is the dilution of N2 in the fuel. A better

mechanic design has to lead to a N2 consumption reduction and to an improvement of this system

availability. Bridging in the equipment cones and density transient period in the feed bin and lock hoppers

discharge have to be avoided.

164

The prepared coal dust, with a residual moisture content of about 1.2% wt, could be transported

pneumatically under high pressure in dense phase flow with conveying vessels to the coal feed bin. High

pressure and high-density pumps could be studied. In this way, lock hopper system would be necessary

and the weight of the gasification building could be reduced considerably. A large concrete building may

not be necessary.

5.2.1.3. Gasifier and gas quenching

In the Puertollano plant, the gasifier is started with an atmospheric pressure igniter. After a trip the

gasification system has to reduce its pressure down to atmospheric one before starting-up again. To avoid

this loss of time, an igniter, able to work at high pressure, integrated either with the start-up burner or with

one of the gasifier burners would have to be designed. Flame and combustion performance must be

monitored. Pyrometry and spectrometry studies need to be carried out for this purpose.

Inside the gasification chamber, the fuel is converted to mainly to CO and H2. The gas residence time is

only a few seconds. The raw gas leaves the gasification chamber at a temperature of about 1300 ºC. At the

outlet, the raw gas is quenched by recycled cold gas to a temperature below 800 ºC. A study into this

optimum temperature value should be carried out.

Auxiliary burners could be removed from a new plant design.

5.2.1.4. Waste Heat Recovery System

One of the main process problems of the Puertollano plant is the fouling in the Waste Heat Recovery

System produced by fly ash deposition. Fouling in HP surfaces leads to an increase of temperatures above

permitted limits for some of the materials.

The cleaning system is performed by rappers. Rapping system versus blowing system, vibration effects

and rapper layout have to be assessed. This fouling can be mitigated with higher velocities of the gas. A

new boiler design would have to confer suitable velocities of the gas to avoid fly ash deposits.

A better selection of materials for the economiser and HP/IP heat transfer surface distribution and design

is necessary in a new plant design. Increasing HP surface has to be studied.

165

5.2.1.5. Slag handling

The main problem of the slag handling system is fine slag filtration. Filters could be replaced by a settling

system while, in addition, the slag water circuit could be simplified.

The produced filter cake has a high carbon content and it can be recycled to the gasifier.

Only one slag sluicing line and one slag extractor are necessary for discharging. One of the slag lock

hoppers and one of the slag extractors could be removed in a new plant design.

5.2.1.6. Dry dedusting system

Compared with a combined dry/wet dedusting system consisting of a cyclone (coarse dust) and a Venturi

scrubber (fine dust), the net plant efficiency is 0.45% point higher when a dry dedusting system is applied,

due mainly to the lower pressure drop in the smaller Venturi scrubber, reducing losses due to a higher

temperature of the recycled gas. The dry dedusting system also has economic advantages compared with

the wet dedusting system.

The dedusting system is one of the critical systems in the Puertollano plant. This system consists of two

candle filter devices. In new plant designs (IGCC 98), a cyclone separator is included before a candle

filter to remove and recycle coarse fly ash with high carbon content. However, due to the Puertollano fly

ash characteristics (very low carbon content and very small particle size) nor cyclone separator neither

recycling is advised for future designs.

In order to maintain a high efficiency filtration, the cleaning of candle filters must be improved. An

assessment of different filtering elements and materials need be carried out for a new plant design.

The system for recycling fly ash is not necessary owning to the poor carbon content of the fly ash. The fly

ash handling system can be greatly simplified and its cost reduced by removing the fly ash recycling

system. The feed bin was designed to have a higher pressure than the gasifier in order to return fly ash to

the gasifier. The fly ash feed bin, distributor and discharge vessels can be removed, discharging fly ash

directly from the lock hoppers to the fly ash bunker.

166

In the design, only a small part of the fly ash flow was not recycled to the gasifier. This part was

transported via discharge vessels to the fly ash bunker to be stored before being taken away by truck. The

designed mass flow rate of fly ash to discharge was 150 kg/h (100 kg/h on a dry basis) at full load.

However, in the actual operation all fly ash is discharged (about 2000 kg/h) and the bunker, where fly ash

is stored, does not have enough capacity. Trucks have to take away fly ash too frequently. For a new plant

design, a fly ash bunker, with at least one-week storage capacity, should be designed.

5.2.1.7. Wet scrubbing and gas stripping

The downstream Venturi scrubber is only designated for the removal of water-soluble gaseous pollutants.

This system displays a correct behaviour, although an improvement to materials (to avoid corrosion)

could increase its availability. Studies into surface treatments of pipes could be carried out.

Controlling filters had to remove solids present in the wash water stemming from the wet scrubbing

process. However, these filters can be removed due to the high degree of efficiency of the candle filters

and their poor capacity of filtration in case of candle filter failure.

5.2.1.8. Desulphurization system

This system presents an excellent performance. After the good performance in formate removing

demonstrated for the pilot Desalting Unit, an industrial Desalting Unit should be considered in new plant

designs.

The new MDEA-α type (with COS removing capacity), Super Claus plant (efficiency of 99.8%) and

recycling compressor should be assessed technically, economically and environmentally (taking into

account new environmental standards) before a new plant design.

5.2.1.9. Air separation unit (ASU)

This system has shown a good performance during operation of the Puertollano plant. Nevertheless, some

improvements could be carried out.

167

The liquid N2 storage capacity could be increased. A start-up low capacity (30%) compressor improves

the availability of this unit. A more flexible control range in oxygen purity should be considered and

oxygen storage would not be necessary.

5.2.1.10. Saturator

The clean coal gas from the sulphur removal unit has to be moistened and heated prior to its injection in

the gas turbine. In the clean gas moistening system, saturation of the clean gas with water takes place, in

order to reduce NOx formation during gas combustion reducing the flame temperature. The waste nitrogen

from the air separation unit is used to control NOx formation by fuel gas dilution – further completed with

saturation – and to increase the gas turbine power output.

Research areas to improve this process would be: mixing the waste nitrogen with the clean gas before or

after saturation, saturation of the waste nitrogen only and vapour injection for the dilution of the gas.

5.2.1.11. Gas turbine

Overheating and acoustic oscillations phenomena observed in the combustion chamber during the

commissioning are presently expected to be solved.

In the IGCC concept, where gasifier is integrated with the gas turbine and the gasifier is a piece of

equipment with no oscillations for ambient temperature changes, the gas turbine should absorb

oscillations due to changes in ambient temperatures. A pre-cooler could be installed in the gas turbine.

5.2.1.12. Auxiliary systems (Balance of Plant)

The condenser of the cycle is cooled by means of a system with wet cooling tower system. The circulation

system cools two open circuits, one for the gasification and air separation and the other for the combined

cycle equipment. The pumping station comprises two semiaxial flow pumps, each with a 60% capacity of

the nominal circulating water flow. The cooling water system could be split for each island, avoiding

overly high pumps for Plant start-up or isolated system working.

168

5.2.1.13. Control system

ELCOGAS plant has a Distributed Control System (DCS), which is highly integrated with most of the

systems. The performance and suitability of the DCS have generally been good but the following

improvements should be considered in future IGCC plants:

• Local control systems with “black box“ philosophy to communicate with the DCS are

creating avoidable setbacks and delays during OLM. It is clearly preferable to integrate these

local controls into the main DCS.

• Quality and finished grade of detail engineering has an important effect in installation costs,

start-ups and OLM’s. Detail engineering must be defined more consistently in the project

phase, particularly in:

• Equipment with complex control: Gas turbine control. (ELCOGAS has modified

approximately the 80% of gas turbine control diagrams).

• Alarms engineering: Structured, co-ordinated and user-friendly.

5.2.1.14. General layout

The general layout of ELCOGAS is as shown in figure 108. Of definite importance in ELCOGAS’s

experience is the location of the Sulphur recovery circuit, which is better located to the west of the

gasifier, rather than to the east, together with the balance of the by-product handling systems.

169

Figure 107. General layout of ELCOGAS plant.

170

171

5.3. CONCLUSIONS FOR FUTURE IGCC PLANTS

Some aspects of IGCC technology such as excellent emissions records, high efficiency and flexibility to

use a wide range of fuels including wastes, are already accepted. Other aspects, such as Plant availability

and reliability are still to be improved over the next few years at the existing IGCC Demonstration Plants.

Based on the operating experience at Puertollano IGCC Plant, some improvements, summarised in the

following table, could be carried out.

System/equipment Potential efficiency improvements Reduction in cost for manufacturing,

assembly and operation

Coal dust preparation - Elimination of mixing equipment.

Coal dust conveying,

sluicing and feeding

N2 saving. Elimination of concrete building for coal

storage and lock hopper system.

Gasifier Recycling of filter cake. Removing auxiliary burners.

Waste Heat Recovery

System

Improvement of cleaning system.

Increasing HP surfaces.

-

Slag handling Replacement of filtering system by

settling system.

Simplification of slag water circuit.

Elimination of one slag lock hopper and

extractor.

Dry dedusting filter Improvement of candle filter cleaning

system. Improvement of candle filter

material and design.

Elimination of fly ash feed bin, distribution

and discharge vessels (Recycling system).

Wet scrubbing and gas

stripping

- Controlling filter removing.

Desulphurization

system

Assessment of a Super Claus Plant. -

Air Separation Unit Oxygen storage removing Increase of liquid N2 storage capacity.

Gas turbine Installation of a pre-cooler. New higher

efficiency gas turbines.

-

Auxiliary Systems Cooling water system split

Control systems Integrate local control systems with

“black box” into main DCS.

General arrangement Location of Sulphur Recovery Unit. -

Table 47. Summary of the main system improvements based on the experience in Puertollano.

172

However, if this type of technology is to compete successfully with other clean electricity generation

technologies, plant investment cost must be reduced to around 1,000 US$/kW. This goal will be achieved

by a joint effort between Technology suppliers and Utilities. In order to get this lower price, plant

suppliers must design:

• Improved coal-feeding systems.

• More efficient boilers.

• Improved slag removal systems.

• More efficient ceramic filters.

• Improved gas turbines.

• Improved materials.

In the Combined Cycle and ASU areas, some sub-systems such as the gas turbine, steam power system

and Air Separation Unit are offered today at considerably lower prices than when the Puertollano plant

was ordered. This is partly due to a new generation of gas turbines of greater size and efficiency and

improvements to the materials development of Steam Power Plants.

Over the past few years, major advances have been made in the area of gas turbine development, such as

more efficient blade cooling, higher-temperature materials, lower-loss flow paths and lower-pollution

combustion processes.

Siemens is working on further increasing gas turbine inlet temperature by further improving component

cooling, materials and protective and thermal barrier coatings. Improvements are also underway for

compressor and turbine aerodynamics. The higher turbine inlet temperature and component efficiencies

made possible by these advances have significantly increased gas turbine efficiency and output. These

improvements, in combination with a bottoming steam cycle, have in turn led to the highest rates of

efficiency of all fossil-fuel power plants. Next figure shows the expected IGCC efficiency potential.

173

Puertollanoplant

Net plantefficiency

46

48

50

52

%

54

Efficiencydependingon the coal

used

with low ash bituminous coal and GT inlettemperature 1150ºC (ISO)

with low ash bituminous coal and GT inlettemperature 1120ºC (ISO)

2.4 %

GT inlettemperature

1190ºC (ISO)

0.7 %

GT inlettemperature

1250ºC (ISO)

0.7 %

Higher steamconditions

0.7 %

Improvement ofpower plantcomponents

1.0 %

Dry hot gascleaning

Fuel: Pittsburgh # 8Ambient conditions: 15ºC / 1.013 bar / f = 60%

Condenser pressure: 0.04 bar

State of the art Future development

Figure 108. Expected IGCC Efficiency Potential(*)

Efficiency improvements and cost reductions in coal-based IGCC power plants are important tasks. The

IGCC technology can be competitive compared with modern PC steam power plant. The co-gasification

of coal and biomass in IGCC is a further possibility of reducing CO2 emission and of preserving non-

regenerative fuels.

IGCC technology still has a considerable enhancement potential over the existing demonstration plants,

and possibilities for a second generation of IGCC plants to compete with other clean electricity generation

technologies in the near future appear realistic.

(*) Source: Optimized IGCC Cycles for Future Applications. Siemens AG)

174

During the coming years, competition between types of power systems and fuel resources will continue

and, as long as natural gas remains readily available and relatively inexpensive, natural-gas-based power

systems are likely to be the technology of choice. As natural gas becomes more expensive, lower-cost

energy resource options such as coal and alternative fuels will become increasingly common choices.

Gasification will then prove to be the best technology for providing efficient power and synthetic gas

conversion technologies.

The capital cost for a natural-gas combined cycle is currently well under one-half the cost of a coal IGCC

plant. IGCC is capital intensive; it needs economies of scale and fuel cost advantages to be an attractive

investment option. However, IGCC costs can be lowered when integrated synergistically with industrial

applications. For example, gasifiers can operate on low-cost opportunity feedstocks; can be used to

convert hazardous waste into useful products, reducing or eliminating waste disposal costs; and can co-

produce power, steam, and high value products for use in the market. IGCC will become more

competitive in the long term if, as is happening at present, the natural gas prices increase.

Technical trends will help gasification, include improving gas turbines and poly-generation. Each increase

in combined cycle efficiency directly reduces the size and cost of the gasification facility required to fire

that combined cycle. Advanced intercooled, recuperated, reheat gas turbines have the potential of power-

to-cogeneration heat ratio that is an order of magnitude higher than that possible with steam turbines.

For the future, IGCC will play a role as an alternative for electric energy supply due to this costs levelling

characteristics from the uses of different feedstocks, particularly coal, which are available in most

countries. The present rise in natural gas prices shall trigger this tendency,

On medium terms, the necessity for CO2 emissions control will need to be faced. The IGCC will represent

the best choice for CO2 removal, among all the fossil fuelled technologies, according to the EPRI

assessments made at the last Gasification Technologies Conference of San Francisco (California).

Europe, being a basically energy import area, shall urgently face a decision on this in order to demonstrate

his political and technical leadership and, in the first hand, to benefit from a Super Clean Coal

Technology.

December 2000

ELCOGAS

ACHIEVEMENTS OF THE EUROPEAN IGCCPLANT AT PUERTOLLANO

ACHIEVEMENTS OF THE EUROPEAN IGCCPLANT AT PUERTOLLANO

December 2000

4

THE PROJECTTHE PROJECT

December 2000

5

ELCOGASELCOGAS

European Company incorporated in April 1992 toundertake the planning, construction,management and operation of a 335MW IGCCplant located in Puertollano (Spain)

December 2000000

6

ELCOGAS LOCALIZATIONELCOGAS LOCALIZATION

December 2000

7

SHAREHOLDERSSHAREHOLDERS

EDF

ENDESAIBERDROLASEVILLANACANTABRICOB.W.ESPAÑOLA

EDP

ENEL

NATIONALPOWER KRUPP KOPPERS

SIEMENS

December 2000

8

ELCOGASELCOGAS

ENDESAENDESA

37.9337.93

KRUPP UHDEKRUPP UHDE

1.001.00SIEMENSSIEMENS

2.342.34BWEBWE

2.502.50NATIONAL POWERNATIONAL POWER

4.004.00ENELENEL

4.004.00

EDPEDP

4.004.00

CANTABRICOCANTABRICO

4.004.00

EDFEDF

29.1329.13

IBERDROLAIBERDROLA

11.1011.10

EQUITY SHARE in %EQUITY SHARE in %

December 2000

9

ELCOGAS AN EUROPEAN PROJECTELCOGAS AN EUROPEAN PROJECT

Gasification Unit: Prenflo® Process from KruppKoppersCombined Cycle Unit: SiemensAir Separation Unit: Air LiquideDistributed Control System: SiemensGeneral engineering: Initec and shareholders’engineering departments

December 2000

10

ELCOGAS PROJECT SCHEDULEELCOGAS PROJECT SCHEDULE

PUERTOLLANO IGCC PROJECT BASIC PLAN

ACTIVITY

AWARD OF MAIN EQUIPMENT & ENGINEERING

ENGINEERING AND DESIGN

SITE PREPARATION

GASIFICATION PLANT MANUFACTURING AND SUPPLY

COMBINED CYCLE MANUFACTURING AND SUPPLY

CIVIL WORKS

COMBINED CYCLE ERECTION AND START UP

GASIFICATION ERECTION AND START UP

19971992 1993 1994 1995 1996

December 2000

11

OBJECTIVES AND IMPLEMENTATIONIGNACIO MENDEZ VIGO - ALEJANDRO MUÑOZOBJECTIVES AND IMPLEMENTATIONIGNACIO MENDEZ VIGO - ALEJANDRO MUÑOZ

December 2000

12

PROJECT OBJECTIVESPROJECT OBJECTIVES

Build up and operate an IGCC power plant, takingcare of the following characteristics:

– Development of European technology for IGCC

– Environmentally friendly

– Demonstration of a commercial size IGCC plant

December 2000

13

PROJECT OBJECTIVES:EUROPEAN TECHNOLOGYPROJECT OBJECTIVES:EUROPEAN TECHNOLOGY

Development of the IGCC European technologyfor poor quality and complex fuels (high ash andsulphur content)Scaling up of the existing plant size of theEuropean Gasification technologyHighly integrated IGCC plant using Europeantechnology:– Krupp Koppers. Gasification– Siemens. Combined cycle– Air Liquide. Air separation unit

Collaboration among European utilities &engineering suppliers for the project development

December 2000

14

PROJECT OBJECTIVES: ENVIRONMENTALLYFRIENDLYPROJECT OBJECTIVES: ENVIRONMENTALLYFRIENDLY

Very low gaseous emission levelsSolid wastes:– Inert vitrified slag– High carbon content fly ash recycled to the gasifier

Low level of treated liquid effluents

December 2000

15

PROJECT OBJECTIVES:COMMERCIAL OPERATIONPROJECT OBJECTIVES:COMMERCIAL OPERATION

Competitiveness: low production costs– Fuel cost: < 359 pta/Gj (2.16 €/GJ)– Water cost: 37.31 pta/m3 (0.22 €/m3)

Plant efficiency:– CC gross efficiency/LHV (%): 50.15– IGCC gross efficiency/LHV (%): 47.12

High availability, 6500 full load equivalent hoursof operationDissemination of the results

December 2000

16

PROJECT IMPLEMENTATIONSPROJECT IMPLEMENTATIONS

Plant construction data and budget

Commissioning of the plant

Plant operation data

Conclusions and future developments

December 2000

17

PROJECT IMPLEMENTATIONS:CONSTRUCTION DATAPROJECT IMPLEMENTATIONS:CONSTRUCTION DATA

Main contracts in 1992-1993

Start of civil works at site 1993

First ignition of gas turbine April 1996

Project on budget

December 2000

18

PROJECT IMPLEMENTATIONS:COMMISSIONINGPROJECT IMPLEMENTATIONS:COMMISSIONING

Commercial operation with natural gas in October1996Acceptance of the Air Separation Unit in June1997First gasifier ignition in December 1997First electricity production with syngas in March1998Gas turbine acceptance test with syngas carriedout in March 2000

December 2000

19

PROJECT IMPLEMENTATIONS:PLANT OPERATIONPROJECT IMPLEMENTATIONS:PLANT OPERATION

Plant operation experience with differentfeedstock demonstrates:– Efficient use of poor quality and complex fuels through

an European technology

– Environmentally friendly behaviour of this technology

– Commercial operation viability

December 2000

20

USE OF POOR QUALITY AND COMPLEXFUELSUSE OF POOR QUALITY AND COMPLEXFUELS

Mixture 1 Mixture 2 Design Mixture 3 Mixture 4

Coal Coke Coal Coke Coal Coke Coal Coke Coal Coke

Feedstockcomposition

39% 61% 45% 55% 50% 50% 54% 46% 58% 42%

Moisture wt. % 0.75 1.04 2.00 1.29 0.93

C wt. % (mf) 68.8 65.61 61.68 62.76 60.66

H wt. % (mf) 3.36 3.68 2.92 3.15 3.24

O (bydifference)

wt. % (mf) 1.89 2.69 3.45 3.36 3.68

N wt. % (mf) 1.52 1.3 1.42 1.49 1.27

S wt. % (mf) 3.82 3.47 3.34 3.28 3.0

Cl ppm (mf) 722 685 200 482 524

Ash wt. % (mf) 20.67 23.69 25.17 25.95 2288..2211

H. H. V. MJ/kg(mf)

26.89 25.53 24.09 24.69 23.61

December 2000

21

400

650

50

150

7,5250,9

94

16

109

10 0,223

68

0,0418

340,10

100

200

300

400

500

600

700

SO2 NOx Particulate emission

mg/Nm3, dry gas. 6% O2

EEC 88/609 Design value Mixture No. 1 Mixture No. 2Mixture No. 3 Mixture No. 4

ENVIRONMENTALLY FRIENDLY:EMISSIONSENVIRONMENTALLY FRIENDLY:EMISSIONS

December 2000

22

* Low Limit Detection

** PCDD/FS: Polychlorinated dibenzo-p-dioxins and furans I-TEQ: International Toxicity Equivalent Concentration

(EN1948:1996 < 100 pg/Nm3)

ENVIRONMENTALLY FRIENDLY:EMISSIONSENVIRONMENTALLY FRIENDLY:EMISSIONS

Hg emissions < L.L.D.*PCDD/FS (I-TEQ)** < L.L.D.)

December 2000

23

g/kWh

Dust 0.1 NOx 0.4Dust 0.02

SO2 0.07SO2 2.5NOx 2.3Dust 0.3

SO2 1.4NOx 0.8

SO2 25.3NOx 4.5

Dust > 40

PULVERIZED COAL

No gas treatment

PULVERIZED COAL

DeSOx (90%)

IGCC PUERTOLLANO

Sulphur removal (99.9%)LNB (50%)ESP (99.2%)

AFBC

Cyclone filters (96%)

BASIS Feedstock (3.2 % S, 20.7 % Ahs and HHV = 23.12 MJ/kg) Gross production 320 MW Gross efficiency (HHV) 37.5 % (PC and AFBC), 46% (IGCC)

ENVIRONMENTALLY FRIENDLY:EMISSIONSENVIRONMENTALLY FRIENDLY:EMISSIONS

December 2000

24

ENVIRONMENTALLY FRIENDLY:EMISSIONS (Cont.)ENVIRONMENTALLY FRIENDLY:EMISSIONS (Cont.)

NOx 0.240 NOx 0.239 0.196 NOx 0.111Dust 0.0013 Dust 0.0010 Dust 0.0001 Dust 0.0002

MIXTURE NO. 1

SO2 0.039SO2 0.036 0.067

MIXTURE NO. 2

SO2 0.027

MIXTURE NO. 3 MIXTURE NO. 4

NOx

SO2

IGCC Puertollano NOx 0.4Dust 0.02

SO2 0.07

DESIGN

December 2000

25

ENVIRONMENTALLY FRIENDLY:BY-PRODUCTSENVIRONMENTALLY FRIENDLY:BY-PRODUCTS

More than 85% of fuel ash is inert vitreous slag.Uses:– Roads, construction material manufacturing (cements,

bricks and tiles) and return to the mine as fillerDue to its low carbon content, fly ash is notrecycled, but it is suitable for:– Construction material and additive for concrete

manufacturingSmall portion of high carbon content filter cakefor:– Recycling to the gasifier after dry, additive for

construction material and energetic by-product

December 2000

26

ENVIRONMENTALLY FRIENDLY:EFFLUENTSENVIRONMENTALLY FRIENDLY:EFFLUENTS

ELCOGASvalues

Spanish standard limits(R.D. 927/1988)

Al <1 1As 0.025 0.5Ba <0.2 20B 1.78 5Cd <0.001 0.2

Cr VI <0.050 0.2Fe 1.16 3Mn <0.050 3Ni 0.047 3Hg <0.002 0.05Pb 0.030 0.2Se <0.02 0.03Sn <0.100 10Cu 0.016 0.5Zn 0.172 10

Suspended solids (mg/l)

December 2000

27

ELCOGASvalues

Spanish standard limits(R.D. 927/1988)

CN- <0.05 0.5Cl- 1240 2000S2- <0.2 1F- 0.87 8

NH 4+ 9.13 50P total 0.68 20

Detergents (LAS) 0.13 3

ENVIRONMENTALLY FRIENDLY:EFFLUENTS (Cont.)ENVIRONMENTALLY FRIENDLY:EFFLUENTS (Cont.)

Suspended solids (mg/l)

December 2000

28

PROJECT IMPLEMENTATIONS:COMMERCIAL OPERATIONPROJECT IMPLEMENTATIONS:COMMERCIAL OPERATION

Competitiveness: Low production costs

– Heat rate (gross, LHV): 7894 kJ/kWh

– Raw water consumption: 3 hm3/year

High Plant efficiency

High availability

December 2000

29

Scenario Variable cost3rd quarter 2000

Cost pta/t €/t

Coal 5592 33.6

Pet-coke 2701 16.2

Limestone 1528 9.2

Demi-water 160 0.96

ParametersNo. 1 No. 2 No. 3 No. 4

Feedstock consumption t/h 91.3 100.9 98.7 92

Feedstock cost pta/t 4,074 4,094 4,083 4,106

Syngas cost pta/Th 0.829 0.895 0.914 0.964

Gas Turbine energy cost pta/kWh 1.29 1.39 1.42 1.56

Steam Turbine energy cost pta/kWh 2.31 2.41 2.47 2.53

Net power sent to the grid MWh 250.2 261.3 250.6 209.4

pta/kWh 1.81 1.92 1.95 2.1Net energy variable cost

€/MWh 10.88 11.54 11.72 12.62

COMPETITIVENESS:LOW PRODUCTION COSTSCOMPETITIVENESS:LOW PRODUCTION COSTS

Mixture

December 2000

30

CC IGCC

Design gross efficiency (%) 50.15 47.12

Acceptance test gross efficiency (%) 50.13 45.67

Auxiliary power (MW) 4.3 35

Acceptance test auxiliary power (MW) 3.72 42.64

Design Power (MW) 317.7

Acceptance test Power (MW) 320.6

PLANT EFFICIENCY:IGCC ACCEPTANCE TESTSPLANT EFFICIENCY:IGCC ACCEPTANCE TESTS

December 2000

29

Total accumulative production

December 2000

January-Novemb 2000

Total 1999

187,972MWh

MWh

MWh 334,937

723,241

Total 1998 MWh 8,867

MWh 1.255,017

IGCC GROSS PRODUCTION

COMPETITIVENESS:PRODUCTIONCOMPETITIVENESS:PRODUCTION

�������������������������

�������������������������

�������������������������

�������������������������

�������������������������

�������������������������

�������������������������

�������������������������

�������������������������

�������������������������

�������������������������

MWh

0

200.000

400.000

600.000

800.000

1.000.000

1.200.000

1.400.000

Producción bruta GICC

dic 00

2000 Ene-Nov�������� 1999

����

1998

December 2000

30

LAST 12 MONTHSACCUMULATED IGCC PRODUCTIONLAST 12 MONTHSACCUMULATED IGCC PRODUCTION

Gross Output IGCC cumulated last 12 months

0100.000200.000300.000400.000500.000600.000700.000800.000900.000

1.000.000M

Wh

December 2000

31

IMPROVING AVAILABILITYIMPROVING AVAILABILITY

���������������

��������������������������������

��������� ����������������

����������������

�����������������

���������

�����������������

����������������

����������������

����������������

����������������

���������������

��������������

��������������

��������������

��������������

���������������

����������������

����������������

����������������

����������������

����������������

����������������

����������������

����������������

����������������

����������������

����������������

����������������

����������������

����������������

����������������

���������������

��������������

��������������

��������������

��������������

��������������

������� �����������������

���������

���������

���������

���������

���������

���������

���������

���������

���������

�����������������

����������������

����������������

����������������

����������������

����������������

����������������

���������������

��������������

��������������

��������������

��������������

���������������

����������������

����������������

����������������

����������������

����������������

����������������

����������������

����������������

����������������

����������������

����������������

����������������

Availability IGCC & Natural Gas

01020

3040506070

8090

100

%

Gas natural

������ GICC

December 2000

32

YEAR 2000 IGCC AVAILABILITYAND UNAVAILABILITYYEAR 2000 IGCC AVAILABILITYAND UNAVAILABILITY

�������������������������

�������������������������

�������������������������

�������������������������

�������������������������

�������������������������

�������������������������

�������������������������

�������������������������

�������������������������

���������������������������������������������������������������������������

���������������������������������������������������������������������������

���������������������������������������������������������������������������

���������������������������������������������������������������������������

���������������������������������������������������������������������������

���������������������������������������������������������������������������

���������������������������������������������������������������������������

���������������������������������������������������������������������������

���������������������������������������������������������������������������

���������������������������������������������������������������������������

���������������������������������������������������������������������������

���������������������������������������������������������������������������

���������������������������������������������������������������������������

���������������������������������������������������������������������������

���������������������������������������������������������������������������

���������������������������������������������������������������������������

���������������������������������������������������������������������������

�����������������������������

�����������������������������

�����������������������������

�����������������������������

�����������������������������

�����������������������������

�����������������������������

�����������������������������

�����������������������������

��������������������������������������������������������������������������

��������������������������������������������������������������������������

��������������������������������������������������������������������������

��������������������������������������������������������������������������

��������������������������������������������������������������������������

��������������������������������������������������������������������������

��������������������������������������������������������������������������

��������������������������������������������������������������������������������������������

������������������

������������������

������������������

������������������

��������������������������������������������������

��������������������������������������������������

��������������������������������������������������

��������������������������������������������������

��������������������������������������������������

��������������������������������������������������

��������������������������������������������������

��������������������������������������������������

�������������������������������������������������� A S U1 2 ,0 %

Ga s if ic a t io n1 7 ,7 %

Inte g ra t io n4 ,5 %

A v a ila bility3 8 ,2 %

C o m bine d C yc le2 7 ,6 %

% hours

December 2000

36

Mixedfuel

Coalpreparation

IP

HP

Gasifier

Slag

O2

IP

N2CoalFeed

Raw gas

Waste WaterTreatment

Venturi

Improvedcandlefilter

Clean gassaturator

COSHydrolysis

Clean gas

Dedustinggas

MDEA ClausPlant

Sulphur

Air

QuenchGas

AirSeparation

Unit

O2 N2

DiluentN2

Diluent N2Saturator

Fuel Gas

Exhaust Gas

GasTurbine

Air

G

Flue Gas

Heat RecoverySteam

Generator

GLPIPHP

Make-upwater

BFWTank

Condensate

LP

Saturation WaterPreheat

IP

HP

Reheat

SteamTurbine CondenserFly

ash

Filter cakeIP

PROJECT IMPLEMENTATIONS:CONCLUSIONSPROJECT IMPLEMENTATIONS:CONCLUSIONS

€ million

December 2000

37

System/equipment Potential efficiency improvements Reduction in cost for manufacturing,

erection and operation

Coal dust preparation - Elimination of mixing equipment.

Coal dust conveying,

sluicing and feeding

N2 saving. Elimination of concrete building, coal

storage and lock hopper system.

Gasifier Recycling of filter cake. Removing auxiliary burners.

Waste Heat Recovery

System

Improvement of cleaning system.

Increasing HP surfaces.

-

Slag handling Replacement of filtering system by

settling system.

Simplification of slag water circuit.

Elimination of one slag lock hopper and

extractor.

Dry dedusting filter Improvement of candle filter cleaning

system. Improvement of candle filter

material and design.

Elimination of fly ash feed bin,

distribution and discharge vessels

(Recycling system).

PROJECT IMPLEMENTATIONS (cont.)PROJECT IMPLEMENTATIONS (cont.)

December 2000

38

System/equipment Potential efficiency improvements Reduction in cost for manufacturing,

erection and operation

Wet scrubbing and gas

stripping

- Controlling filter removing.

Desulphurisation

system

Assessment of a Super Claus Plant. -

Air Separation Unit Oxygen storage removing Increase of liquid N2 storage capacity.

Gas turbine Installation of a precooler. New higher

efficiency gas turbines.

-

Auxiliary Systems Cooling water system split

Control systems Integrate local control systems with

“black box” in main DCS.

General arrangement Location of Sulphur Recovery Unit. -

PROJECT IMPLEMENTATIONS (cont.)PROJECT IMPLEMENTATIONS (cont.)

December 2000

39

ELCOGAS : SIEMENS CONTRIBUTIONJORGE WIENHOLZELCOGAS : SIEMENS CONTRIBUTIONJORGE WIENHOLZ

December 2000

40

CONSORTIUM SIEMENS/BWESCOPE OF SUPPLYCONSORTIUM SIEMENS/BWESCOPE OF SUPPLY

BWE Scope of Supply– Heat recovery steam generator and GT flue gas duct– Piping system water/steam cycle– Condenser

Siemens Scope of Supply– Gas turboset V94.3 (GT)– Steam turboset KN (ST)– Instrumentation and control for turbosets– Turbine house cranes (GT + ST)– Heat exchangers (cooling air cooler, saturator water

and clean gas preheater)– Saturator system for clean gas– Electrical equipment– Engineering– Overall plant control system

December 2000

41

CONSORTIUM SIEMENS/BWESCOPE OF SUPPLY (Cont.)CONSORTIUM SIEMENS/BWESCOPE OF SUPPLY (Cont.)

Supplementary Orders for Siemens– Design of heat exchangers for the air/nitrogen system

connecting gas turbine and air separation unit– Optimisation study

Background information for the final plant designStart-up and shut down concept for the overall plantEngineering support for integration aspects and the design ofthe overall plant control concept

December 2000

42

Syngas-proven operation40

38

36

34

32

30

281970 1980 1990 2000

%

Gross Efficiency *

Year

Model V84.3A / V94.3A

Model V93

Model V84.3 / V94.3

Lünen

Buggenum, Priolo Gargallo

Puertollano

* Related to natural gas operation, including generator losses

Model V84.2 / V94.2

in IGCC plants

V93

V94.2

V94.3

DEVELOPMENT OF EFFICIENCY LEVELSFOR V-TYPE GAS TURBINESDEVELOPMENT OF EFFICIENCY LEVELSFOR V-TYPE GAS TURBINES

December 2000

43

Basic Definition ⇒ Syngas Diffusion BurnerBasic Design Parameter ⇒ Syngas Dilution (NOx value, flame stability)

Fuel oil(diffusion)

Natural gas+ steam(diffusion)

Air

Siemens Syngas Burner

Syngas

Air

Air

Natural gas(premix)

Fuel oil(premix)

Natural gas(diffusion)

Siemens Hybrid Burner

SYNGAS COMBUSTIONSYNGAS COMBUSTION

December 2000

44

SYNGAS BURNER DESIGN PARAMETERSSYNGAS BURNER DESIGN PARAMETERS

Syngas pressure drop Definition of min. Gas Turbine load in syngas operation Flame stability reason and suppression of pressureoscillations Definition of syngas passage capacity

Syngas swirl angle (recirculation zone) Stable burning conditions without flame blow off or burneroverheating condition

Cross-sectional area of syngas nozzle Adjustment of syngas outlet velocity slightly abovecorresponding air outlet velocity

Swirl perturbators ⇒ Lessons learned fromBuggenum and implemented in Puertollano

Suppression of flame induced pressure oscillations

December 2000

45

GAS TURBINE FUEL GAS AND AIREXTRACTION SYSTEMGAS TURBINE FUEL GAS AND AIREXTRACTION SYSTEM

IGCC - specific feature of Combined CycleapplicationsTasks:– Syngas dilution control (ensuring heating value range)– Optimal heat flow recovering

– Syngas preheating and extracted air cooling– Low temperature utilisation by syngas saturation

– Flushing and inertisation procedures

December 2000

46

GAS TURBINE FUEL GAS AND AIREXTRACTION SYSTEM PUERTOLLANOGAS TURBINE FUEL GAS AND AIREXTRACTION SYSTEM PUERTOLLANO

December 2000

47

3.9 – 5.1MJ/kg

Puertollano

4 – 6 MJ/kg

Buggenum

around 8.6MJ/kgOperational Heating valuerange

ISAB

OPERATIONAL EXPERIENCEOPERATIONAL EXPERIENCE

Initial Combustion Problems in Buggenum andPuertollano are solved and a wide operating rangeestablished

Gas Turbine syngas commissioning period in ISABreduced to 1 MonthDemonstration of new control features for integratedoperation in Puertollano to increase IGCC plant reliabilityPerformance Test procedure with extended scope ofmeasurements and new complex calculationcarried out in Puertollano

31/10/2000

48

Plant/Project ElectricalOutput (net)

GasTurbine

Main Features Start-up

Hörde Steelworks(Germany)

8 MW VM5 Blast-furnace-gas-fired,gas turbine as mechanical drive

1960

U. S. Steel Corp.(Chicago, USA)

20 MW CW201 Blast-furnace-gas-fired gas turbine 1960

Kellermann(Lünen,Germany)

163 MW V93 First CC plant in the world with integratedLURGI coal gasification (hard coal)

1972

Plaquemine(Lousiana, USA)

208 MW 4) 2 x W 501D5 CC plant with integratedDOW coal gasification

1987

Buggenum 1)

(Netherlands)253 MW V94.2 CC plant with integrated

SHELL coal gasification (hard coal)1993 3)

1994/95

Puertollano 1)

(Spain)300 MW V94.3 CC plant with integrated PRENFLO coal

gasification (coal and petroleum coke blend)1996 3)

1997/98

ISAB(Priolo, Italy)

521 MW 2 x V94.2K CC plant with integratedTEXACO heavy-oil gasification (asphalt)

1998 2)

1999

Servola(Italy)

180 MW V94.2K CC plant with steel-making recovery gas 2000

1) Demonstration plant 2) Oil firing 3) Natural-gas firing 4) 160 MW from syngas and 48 MW from natural gas

CC = Combined-cycle V94.2K = V94.2 with modified compressor

APPLICATION OF SIEMENS GAS TURBINETECHNOLOGY FOR UTILISATION OF SYNGASAND STEEL-MAKING RECOVERY GASES

APPLICATION OF SIEMENS GAS TURBINETECHNOLOGY FOR UTILISATION OF SYNGASAND STEEL-MAKING RECOVERY GASES

December 2000

December 2000

49

ELCOGAS : KRUPP UDHE CONTRIBUTIONWOLFGANG SCHELLBERGELCOGAS : KRUPP UDHE CONTRIBUTIONWOLFGANG SCHELLBERG

December 2000

50

IGCC POWER PLANT AT PUERTOLLANOIGCC POWER PLANT AT PUERTOLLANO

Consortium Krupp Uhde (Koppers) andBabcock & Wilcox Española was responsiblefor the gas island– Coal preparation

– PRENFLO ® Gasification

– Desulphurisation

– Claus unit

December 2000

51

Oxygen

Nitrogen

Raw fuel Coalpreparation

PRENFLOgasification

Desul-phurisation

Claus unit

Boiler feed water Sulphur

Claus gas

Recycle gas

Raw gasCoaldust

Clean gas

Steam

GASIFICATION ISLANDGASIFICATION ISLAND

December 2000

52

PRENFLO® PLANT INFÜRSTENHAUSEN/GERMANYPRENFLO® PLANT INFÜRSTENHAUSEN/GERMANY

December 2000

53

Oxygen

Coaldust

Boilerfeed water

1

2

3 4

5

6

7

8

9

10

11

12

13

Steam

Raw gas

Slag

Washwater

1 Cyclone filter2 Lock hopper3 Feed bin4 PRENFLO gasifier5 Slag crusher/collector

6 Slag lock hopper7 Waste heat boiler8 Steam drum9 Filter

10 Fly ash lock hopper11 Fly ash feed bin12 Scrubber13 Quench gas compressor

PRENFLO® ProcessPRENFLO® Process

December 2000

54

ERECTION OF PRENFLO® GASIFIERAND HP-BOILER AT PUERTOLLANO, SPAINERECTION OF PRENFLO® GASIFIERAND HP-BOILER AT PUERTOLLANO, SPAIN

December 2000

55

CO2

COH2

N2 + ArH2S + COS

Total

3.960.522.113.512

100.0

vol. % vol. %vol. % vol. % ppmv

vol. %

1.960.0 22.315.812

100.0

Design Actual

CLEAN GAS COMPOSITION OFPUERTOLLANOCLEAN GAS COMPOSITION OFPUERTOLLANO

December 2000

56

LESSONS LEARNEDLESSONS LEARNED

Scale-up of PRENFLO® Gasification including burnersfrom demonstration plant without problemsDedusting of raw gas with ceramic candles possible,which leads to higher efficiencyProblems with coal dust lock hopper system could besolved (capacity restrictions)Clean coal gas quality is excellent for gas turbineLow environmental impact of total gas islandFly ash and sulphur are saleable productsFull integration of the gas island with air separation andpower block was successful

December 2000

57

SULPHUR STORAGE AREASULPHUR STORAGE AREA

December 2000

59

COMPETITIVENESS FACTORSANDRES FERNANDEZ LOZANOCOMPETITIVENESS FACTORSANDRES FERNANDEZ LOZANO

31/10/2000

60

COST COMPETITIVENESS OFELCOGAS IGCC PLANTCOST COMPETITIVENESS OFELCOGAS IGCC PLANT

High investment cost due to the innovative project technology and theplant demonstration nature

High potential cost reduction for future project investment

Fuel cost less than those of other technologies (except nuclear) owing to:High energy efficiency (higher than other coal plants)Use of low cost fuel (mixture of refinery residuals -coke- and high ashcoal)

Operational and maintenance cost higher than those of a conventionalplant due to the innovative project nature:

Use of sophisticated technology (equipment, material, processes) High plant integration Commercial demonstration phase

INVESTMENT

FUEL

O&M

December 2000

December 2000

61

COST COMPETITIVENESS OFELCOGAS IGCC PLANTCOST COMPETITIVENESS OFELCOGAS IGCC PLANT

Total cost of the electricity generated byELCOGAS IGCC (using syngas) is lower than thecost of generation through nuclear plants andcomparable to conventional domestic coal-firedgeneration plantsVariable cost is lower compared to conventionalgeneration plants, coal- or gas-fired, in thedomestic market

December 2000

62

ELCOGAS IGCC OTHER GENERATION SYSTEMS

High investment cost of theproject (technological investmentcost) compared to othertechnologies.

Cost of IGGC plants will bereduced in the future due to theexperience acquired.

Mature technologies, with a lowerpotential to reduce investmentlevels in the future.

In conventional plants, theinvestment per kW tends to growdue to the addition ofenvironmental investments(desulphurisation).

MAIN ASPECTS OF ELECTRICITY COSTINVESTMENTMAIN ASPECTS OF ELECTRICITY COSTINVESTMENT

December 2000

63

ELCOGAS IGCC OTHER GENERATION SYSTEMS

Uses a cheap mixture of fuel(0.134 € cents/MJ) competitiveagainst imported coal due to theuse of refinery residuals.

High energy efficiency of theproject.

Flexibility to use other fuels(natural gas with a 50.5%efficiency).

Imported coal price slightly higherthan ELCOGAS mixture, fired inconventional PC plants with aworst efficiency.

Lower nuclear fuel cost by kWh.

Higher energy efficiency ofCombined Cycles but with ahigher volatility on natural gasprice.

MAIN ASPECTS OF ELECTRICITY COSTFUELMAIN ASPECTS OF ELECTRICITY COSTFUEL

December 2000

64

MAIN ASPECTS OF ELECTRICITY COSTOPERATIONAL & MAINTENANCEMAIN ASPECTS OF ELECTRICITY COSTOPERATIONAL & MAINTENANCE

ELCOGAS IGCC OTHER GENERATION SYSTEMS

Operational and maintenance costsof this “first of its kind” plant shouldbe reduced in the near future(learning curve).

Higher operational andmaintenance costs due to itsdemonstration plant nature.

Lower operational andmaintenance cost of conventionalplants due to the simplicity of itsprocess and the experienceacquired.

Other power plants belongs tobigger companies witch deliverscommon services, and does nothave a demonstration plant nature.

December 2000

65

TOTAL COST OF ELECTRICITY FORELCOGAS IGCC (€ cents/kWh)TOTAL COST OF ELECTRICITY FORELCOGAS IGCC (€ cents/kWh)

Discount rate: 6.00%Annual Production: 6,500 Full Load Equivalent Hours.High investment cost

Lower fuel cost than other technologies

Higher operational and maintenance costs than conven-tional plants due to the innovative nature of the project

Lower cost than nuclear plants, in the samerange of domestic coal plants

INVESTMENT3.15

FUEL1.13

O&M0.90

5.18

December 2000

66

OPERATION IN A COMPETITIVESCENARIOOPERATION IN A COMPETITIVESCENARIO

NGCC – Price scenario

IGCC Low Medium High

Fuel Cost (€ cent/kWh) 1.13 2.06 2.74 3.43

% hours in which pool price > fuel cost

199819992000 (1/1 to 26/10)

99.799.9

100.0

77.678.880.6

35.042.554.2

8.211.734.3

December 2000

67

YEAR CAPITAL COSTSUS$/ kW

EFFICIENCY (HHV ,%)

1997200020102015

145012501000850

39,6 %42 %52 %

> 60 %

Source :US DOE. Office of Fossil Energy. Federal Energy Technology Centre

TOTAL COST OF ELECTRICITY FORIGCC PROJECTIONSTOTAL COST OF ELECTRICITY FORIGCC PROJECTIONS

IGCC´s CAPITAL COSTS FORECAST

0

500

1.000

1.500

1997 2000 2010 2015

IGCC´s CAPITAL COSTS FORECAST

0

500

1.000

1.500

1997 2000 2010 2015

Forecast on the economics of the IGCC´s costs, as per US DOE estimations, indicate that these costs willdecrease in the coming years, while its efficiency will increase significantly by 2015. The table shows thiscapital cost forecast, including interest during construction, for a typical IGCC unit.

December 2000

68

TOTAL COST OF ELECTRICITY FORIGCC PROJECTIONSTOTAL COST OF ELECTRICITY FORIGCC PROJECTIONS

0

1

2

3

4

5

6

c€ /k

Wh

1997 2000 2010 2015

O&MFUELINVES TMENT

0

1

2

3

4

5

6c€

/kW

h

1997 2000 2010 2015

O&MFUELINVES TMENT

Decrease of Investment cost as per US DOE projections Efficiency increase from 42% to 50% Slight reduction of operational and maintenance costs

5.184.67

4.033.61

December 2000

69

COST COMPETITIVENESS OF ELCOGAS VISA VIS OTHER GENERATION SYSTEMSCOST COMPETITIVENESS OF ELCOGAS VISA VIS OTHER GENERATION SYSTEMS

InitialInvestment

O&M Fuel Total“strict costs”

Environmentalcosts

Total costs in a“broad sense”

Nuclear ++//--Advanced coalgenerationsystems

= =

Conventionaldomestic coalgeneration

=

Conventionalforeign coalgeneration

=

Combinedcycle

Costs of each type ofpower station comparedto ELCOGAS

Higher= Comparable

Lower

December 2000

70

ECONOMIC FACTORSECONOMIC FACTORS

December 2000

71

PERFORMANCE AGAINST GOALSPERFORMANCE AGAINST GOALS

Goal:– Demonstrate, with a commercial size Plant, the

virtues of this clean coal technologyFacts:– The capital expenditure that was required is out

of range in a liberalised market– Variable costs are competitive and stable (low

volatility)– Excellence on environmental matters

December 2000

72

Project Development– From 1992 up to 1998

1992 ELCOGAS’ incorporation1993 Bridge Loan plus Sub. Debt1994 Project Finance

Operation– From 1998 up to now

1998 Refinancing the Project Finance with aShareholders Guarantied Loan

FINANCIAL PROJECT PHASESFINANCIAL PROJECT PHASES

December 2000

73

0

100

200

300

400

500

600

700

800

92 93 94 95 96 97 98

Other AssetsCAPEX

€ million

PROJECT DEVELOPMENT. ASSETSPROJECT DEVELOPMENT. ASSETS

December 2000

74

0

100

200

300

400

500

600

700

800

92 93 94 95 96 97 98

SubsidiesOther LiabilitiesLoanSub DebtEquity

€ million

PROJECT DEVELOPMENT. LIABILITIESPROJECT DEVELOPMENT. LIABILITIES

December 2000

75

EXTERNAL SERVICES

0,6%

OTHER3,7%

LABOUR5,2%

TRAVEL & RELATED

0,3%

MATERIALS90,2%

TOTAL 669,6 € million

PROJECT DEVELOPMENT.TOTAL ELIGIBLE COSTS THERMIE contract

PROJECT DEVELOPMENT.TOTAL ELIGIBLE COSTS THERMIE contract

December 2000

76

OPERATIONOPERATION

Plant working as a natural gas CC since the endof 1996– Recognition under the former Spanish

electricity legal framework (standard costs +recognised margin)

– Profit in 1997 fiscal year (1.64 € million)New legal framework: Liberalisation– Competition in generation– Stranded costs and new accounting system

December 2000

77

OPERATION (cont.)OPERATION (cont.)

Competition in generation– Pool price determined by the market– Technical incidences due to:

New technology (first of it’s kind)Learning curve

Stranded costs and new accounting system– Main part of them depending on actual

production– Transitory period: 10 years– Very aggressive amortisation path

December 2000

78 0

100200

300

400

500600

700

800

1998 1999 2000

Other AssetsCAPEX

OPERATION . ASSETSOPERATION . ASSETS

These facts have caused ELCOGAS to incur inlosses in the following years:

€ million

December 2000

79

0100200300

400500600700800

1998 1999 2000

SubsidiesOther LiabilitiesLoanSub DebtEquity

€ million

OPERATION . LIABILITIESOPERATION . LIABILITIES

December 2000

80

OPERATION (cont.)OPERATION (cont.)

Added difficulties for the company: the recognitionof the stranded costs in Spain is under review bythe EC Commission as State-aidELCOGAS’ viability now depends on the finalapproval of the recognised stranded costs