Exergy Drying Systems · - Works as heat sink for power plants . ... MVR 15-100 kWh/m3 Vacuum evaporation (MVR) 15-100 kWh/m3 Evaporation - Heat input ... Forced Recirculation Evaporator

www.swedishexergy.com

Conversion of Coal fired Power Plant to Biomass using Exergy Steam Drying Technology – A Case Study

Swedish Exergy AB

Gamla Rambergsvägen 34

SE-417 01 Gothenburg

Sweden

Tel: +46 31 51 3990

Fax: +46 31 51 7960

Email: [email protected]


Stalowa Wola – Power Plant • The power plant is located in the town of Stalowa Wola,

Poland.

• There are three boilers and turbines.

• Coal is used as fuel.

• One of the boilers is converted from coal to bio-mass fuel.

• All required bio-mass shall be pre-treated, dried to 90% dry solids and fine milled before firring to wood dust burners. All coal dust burners have been replaced with wood dust burners.

• Stalowa chose most efficient drying system availabe in the market – Exergy Drying System.

• The project is in final stage.

• This presentation is about this project and Exergy drying technology.


Stalowa Wola Power Plant, Poland

• Conversion of coal boiler to bio-mass

• 50tons/hour bio-mass drying

• Two stage drying – Exergy Air Stream Dryer followed by Exergy Steam Dryer – single line capacity 45 ton/hour bio-mass with 50% moisture content

• Turn-key delivery – 2012.


Schematic for Stalowa Wola Plant

Exergy Steam Dryer

Generator Dry Product Silo

1 Pre-treatment 2 Chip Silo 3 Pre-Milling 4 Feeder 5 Exergy Air Stream Dryer

Flu

e ga

ses

~

13

12

3

10

Raw bio-mass

11

CW

Wood Dust

Steam Boiler

Steam Condensate

6 Feed/Discharge 7

11 Boiler 8 12 Heat Recovery system 13 Steam Turbine 14

7

Exergy Steam Dryer

chips

4

2

Flash Steam

Generated Steam

MP Steam

1

Dry

ing

Air

Exhaust Air

Recipient

6

Flash bin

5

Exergy Air stream Dryer

6

Dried Product

8

9

14

10 Air fan 9 Fine Milling


Comparision of Boiler-fuels

1

3

9

12

10

5

2,7 2,5

0

2

4

6

8

10

12

14

Fuel Oil Pellets Fire Wood Wood chips

Vo

lum

e, m

3

Volume/10 MWh

MWh/ton


Buy or Produce Bio-Fuel Advantages of production of bio-fuel at Power Plant: 1. Lower Price of produced bio-fuel compared to

wood pellets – better economy 2. Flexibility 3. Only one transport cost from green field/forest

to place of use. 4. This reduces use of diesel for transport and

thus lower CO2 emission. 5. Independence from wood pellet market price

variations.


Different factors at the combustion of moist fuels.

higher moisture

content

lower combustion temperaturemore excess air

larger fluegas amount

more uncombusted

material

larger flue gas refining

equipmentlarger furnace larger flue gas duct

greater investmentinferior efficiency


Distribution of losses and useful energy at the combustion of moist and dried fuel respectively (1 KG combustible dry substance)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

21% losses with water steam

14% losses with dry flue gases

from completely dry fuel

65% absorbed in the boiler

20 MJ

150°

150°

2%

13%

85%

Boiler

Boiler

60% moisture

50% excess air

10% moisture

20% excess air


Distribution of losses and useful energy at the combustion of moist fuel and flue gas dried fuel respectively

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

21%

14%

65%

20%

12%

68%

100°C 150°C

Boiler

20% excess air

60% moisture

50% excess air

Boiler

Dryer

60% moisture


Why Dry Bio-fuels?

•Less air and water vapour from furnace •Reduced CO2 emission •Reduced fuel consumption •Higher boiler capacity •Less combustible material remains in ash

Wet Dry Dry

Moisture % 60 30 10

Heat value

MJ/kg DS 15 17,5 20

Excess air % 60 20 10

Flue gas flow

m3/kg DS

10 8 6

Flue gas flow

m3/MJ

0,7 0,45 0,3

Boiler capacity,

% 100 150 230

Water does not burn!!


Fuel Moisture Content & CO2 emission


EXERGY – COMPANY/ TECHNOLOGIES/ APPLICATIONS


Exergy Location Map

Head Office

Subsidiary

Sales office/agent


What is Exergy?

Exergy

Anergy

Energy

Exergy = Energy - Anergy (losses)


Products and Services

• Exergy Steam Dryer

• Exergy Air Stream Dryer

• Exergy Bed Dryer

• Project Management

• Design and Engineering

• Manufacturing

• Installation

• Testing and commissioning

• Consulting services

• Pilot Testing

• Feasibility studies

• Turn-key supply

• Key-part and engineering

• On-site services

• Spare parts

• After Sales Service


The Main Applications

• Bio-mass

• Wood waste

• Animal Feed

• Spent grains

• Heat Treatment

• Pulp and fibres

• Industrial/ Municipal Sludge

• Tobacco


Why Exergy Drying?

• Super-heated steam • Pressurized atmosphere • Closed-loop • In-direct heating • Compact installation • Efficient heat transfer • Low energy consumption • Overall plant efficiency 96-

98%

• High Energy recovery 80-90% • No emissions (particles or

VOCs) to the atmosphere and thus no negative effect on environment

• No fire and/or explosion risk • Precision dryness control • Small footprint • Cooking/Sterilisation • Total cost of production lower

than conventional dryers

Quick, Clean and Sterilized!


Exergy Dryer Energy Consumption

Unit

Exergy Dryer

with Energy

Recovery

Open Air

Dryer excl

RTO

Exergy Steam

and Bed dryer -

combination

Energy consumption

Heat kWh/ton Evap 760 1130-1350 450

Electrical kWh/ton Evap 40-60 30-50 40-60

Energy recovery

Heat kWh/ton Evap 610 0 (210)

Recovery % 80 0 (40)

Net consumption

Heat kWh/ton Evap 150 1130-1350 450

Electrical kWh/ton Evap 40-60 30-50 40-60

Total kWh/ton Evap 190-210 1160-1400 490-510


Bio-Fuel Production with Exergy System

• CHP plants and bio-pellets

• Wood Powder/Saw dust for combustion

• Coal/lignite/peat

• Boiler fuels such as agro waste, sludge etc.

• Bio-gas/Bio-ethanol/Bio-Diesel

• Bagasse/Straw

• Other bio-mass


Modern Energy Plant


Some large plants delivered recently with Exergy Steam Drying Technology Project Location Capacity Year Remarks

Hedensbyn Bio-combine

Sweden 50 tons/h saw dust drying

1996 2,5 MWe power from steam dervived from bio-mass in Exergy Steam dryer

DONG bio-pellet plant

Denmark 50 tons/h wood chip drying

2003 Potential to produce 2,5 MWe power from dryer steam

BioStor - Biocombine

Sweden 42 tons/h biomass drying

2007 120 000 tons/year wood pellet, 8 MWe Power and 50 GWh/year district heat

BioWood Norway 135 tons/h wood chips

2010 450 000 tons/year wood pellet prodcution

Stalowa Wola Poland 50 tons/h bio-mass drying

2012 Plant ready for commissning


Sludge Drying and Incineration


Dried municipal sludge Granulated, pellets and powder


VOC Treatment – Exergy Steam Drying


Final design Rockhammar

CTMP dryer


Rockhammar Pulp mill

Rockhammar, Sweden

10 ton evaporation/hour


Sedamyl, DDGS Application


Exergy Bed Dryer

Low cost and robust dryer for boiler fuel drying: - Using low grade heat - Works as heat sink for power plants


Exergy Bed Dryer-CHP application


ENA Energi


Rockhammar Bed Dryer


Why Exergy Evaporation?

• Proven Technology.

• No chemicals required.

• Effective volume reduction.

• Lower operating costs.

• Low maintenance costs.

• Environmently friendly technology.

• All heavy metals and other contaminants conatined in small concenrate volume.


Heat input •Direct heated 750 kWh/m3

•Multiple effect 150-500 kWh/m3

•Steam recompression, MVR 15-100 kWh/m3 Vacuum evaporation (MVR) 15-100 kWh/m3

Evaporation - Heat input

Steam

Condensate

Water

Steam

Steam 125

Condensate

Water Steam 150

Condensate

Steam 100

Steam 110

Condensate

Water

Steam 100

Steam 80

Condensate

Water

Steam 70

Vacuum


Forced Recirculation Evaporation

• Controlled heating without evaporation

• Large Flash chamber

• Tubular heat exchanger

• High flowrates

• Turbulent flow

• Steam or MVR

• Process integration

• No fouling

• High concentration

• High suspended solids

• Viscous fluids

• Batch or continuous

• Low energy consumption

Main Features Benefits


Forced Recirculation Evaporator Hoogoven, The Netherlands

1 ton water evaporation/hour


Forced Recirculation Evaporator SAKAB Waste Handling, Sweden 2 ton water evaporation/hour


Forced Recirculation Evaporator Volvo Aero, Trollhättan, Sweden



Forced Recirculation Evaporator SKF, Ovako Steel, Hofors, Sweden



Forced Recirculation Evaporator NSR Waste Handling, Helsingborg,

Sweden,0,5 ton water evaporation/hr


2-effect Forced Recirculation Evaporator Orchid Chemicals, India

2*1,2ton water evaporation/hour


Exergy integrated modern energy plant


Exergy integrated modern energy plant

1 Feed Conditioning 2 Feed Bin 3 Exergy Dryer 4 Evaporator 5 Mixer

Flu

e ga

s

9

5 6

Bio-mass

4

Syngas To:

Dried Bio-mass

6 Gasifier 7 FT liquids

3

Exergy Dryer

8

2

Flash Steam Steam

1

4-33%DS

7

Flash bin

PYROLYSIS REDUCTION OXIDATION

Air

Ash

Flue gas

~

FT liquids

Bio-chemicals

Clean gas Bio-El.

DSW 60%

Steam

Condensate

DSW

Steam Condensate

Steam

Bio-Chemicals 9 Gas Turbine 8


THANK YOU FOR YOUR ATTENTION!

QUESTIONS?

Contact Details:

Swedish Exergy AB

Gamla Rambergsvägen 34

SE-417 01 Gothenburg, Sweden

Tel: +46 31 51 3990

Fax: +46 31 51 7960

Email: [email protected]

Documents

Exergy Drying Systems · - Works as heat sink for power plants . ... MVR 15-100 kWh/m3 Vacuum evaporation (MVR) 15-100 kWh/m3 Evaporation - Heat input ... Forced Recirculation Evaporator