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Energy Policy 34 (2006) 3124–3136

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Refurbishment priorities at the Russian coal-fired power sector forcleaner energy production—Case studies

P. Grammelisa,b,�, N. Koukouzasa, G. Skodrasa, E. Kakarasa,b,A. Tumanovskyc, V. Kotlerc

aCentre for Research and Technology Hellas/Institute of Solid Fuels Technology and Applications (CERTH/ISFTA), 4 km N.R. Ptolemaida-Kozani,

P.O. Box 95, Ptolemaida 50200, GreecebLaboratory of Steam Boilers and Thermal Plants, Mechanical Engineering Department, National Technical University of Athens, Athens, Greece

cVTI All Russia Thermal Engineering Institute, Russia

Available online 22 July 2005

Abstract

The paper aims to present the current status of the coal-fired power sector in Russia, the prospects for renovation activities based

on Clean Coal Technologies (CCT) and two case studies on potential refurbishment projects. Data were collected for 180

thermoelectric units with capacity higher than 100MWe and the renovation needs of the power sector, among the retrofitting,

repowering and reconstruction options, were estimated through a multi-criteria analysis. The most attractive system to renovate a

power plant between the Supercritical Combustion (SC) and the Fluidized Bed Combustion (FBC) technologies was evaluated. The

application of each of the aforementioned technologies at the Kashirskaya and Shaturskaya power plants was studied and their

replication potential in the Russian coal-fired power plant park was examined.

Nowadays, the installed capacity of coal-fired power plants in the Russian Federation is 29.3GWe, while they account for about

19% of the total electricity generation in the area. The low efficiency and especially the advanced age are the determinant factors for

renovation applications at the Russian units. Even in the more conservative modernization scenario, over 30% of the thermoelectric

units have to be repowered or reconstructed. Concrete proposals about the profitable and reliable operation of two Russian

thermoelectric units with minimized environmental effects were elaborated. A new unit of 315MWe with supercritical steam

parameters and reburning for NOx abatement is envisaged to upgrade Unit 1 of Kashirskaya power station, while new Circulating

Fluidized Bed (CFB) boilers of the same steam generation is the most promising renovation option for the boilers of Unit 1 in

Shaturskaya power station.

r 2005 Elsevier Ltd. All rights reserved.

Keywords: Renovation; EU–Russia partnership on energy; Environmental performance

1. Introduction

Russia has 4.6% of the total world-proved oilreserves, 30.7% of the natural gas reserves, 15.9% ofthe coal reserves and 14% of the uranium world reserves(BP Statistical Review of World Energy, 2002; Russia—

e front matter r 2005 Elsevier Ltd. All rights reserved.

pol.2005.06.009

ng author. Centre for Research and Technology Hellas/

Fuels Technology and Applications (CERTH/ISFTA),

maida-Kozani, P.O. Box 95, Ptolemaida 50200, Greece.

53842; fax: +302463053843.

ess: [email protected] (P. Grammelis).

Energy Overview, 2000). The primary energy consump-tion is dominated by natural gas whereas oil followswith 19% of the total energy consumption. Coal’s shareis 18%, while nuclear and hydroenergy represent 5%and 6%, respectively, of the total primary energyconsumption, Fig. 1.

Coal plays also a dominant role in the powergeneration mix in Russia. In the last decade the coalproduction and consumption in Russia followed thegeneral trend in power generation showing a decrease inthe beginning of the 90s till 1998. Currently, the annualcoal production is about 120mtoe. Despite the increased

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Power Generation Mix [GWel / %]

122.319%

335.452%

114.618%

30.95%

39.86%

Oil

Natural Gas

Coal

Nuclear Energy

Hydro-electricity

Fig. 1. Russia’s primary energy consumption distributed by fuel type.

P. Grammelis et al. / Energy Policy 34 (2006) 3124–3136 3125

utilization of natural gas in the power sector in Russia(approximately 62–65%), it is projected that the coalshare in the fuel balance throughout the country will beincreased, in the near future (Martynova, 2001;CERTH/ISFTA, 2004). This is mostly attributed tothe forecasts for the significant cost increase of naturalgas purchase compared to coal. As for 2000, natural gaswas purchased by the Russian energy utilities at $11/thousand m3, which when recalculated to the fuelequivalent turned out to be 1.5 times cheaper withreference to coal. Combined with the increased accessi-bility and its valuable user properties, natural gas wasconsidered at that time the most attractive fuel sourcefor the Russian utilities. However, a new and ratherpositive trend has been observed recently and its coststarts to increase abruptly. In 2003, the average naturalgas purchase cost was 20 $/thousand m3 and it isexpected to increase in 2006 up to about 40$/thousandm3 and in 2010 from 59 to 64 $/thousand m3. In themeantime, the coal price will also increase, but atconsiderably lower levels.

At the moment, the electricity generated in WesternSiberia, Urals and European part of the country isprovided mainly by natural gas. A remarkable numberof the power plants in the region operate on natural gas,although they were designed to use coal. In Central andEast Siberia the resources are hydro and coal and finallyin the North-West and the Far East the resources arenuclear power and coal, respectively, with the exceptionof some large power plants in the natural gas productionareas of West Siberia. Modernization measures mainlyfocusing on the reduction of emitted pollutants havebeen implemented in the recent years in many Russianpulverized coal-fired boilers, as well as in gas- and oil-fired boilers. Better results were obtained in gas- and oil-fired boilers when introducing simultaneously three orfour technological methods, while more complicatedproblems are raised in the coal-fired boilers. Towardsthe enhancement of such rehabilitation activities inRussia and the enforcement of the EU–Russia partner-ship on energy, the current status and future prospectsof the Russian coal-fired power sector were investigated.For this purpose, a multi-criteria analysis which is based

on three different approaches was used. Namely, themodernization needs of the power production sectorwere determined, providing indications for the mosteffective application among the retrofitting, repoweringand reconstruction options. Then, the potential for theinstallation of additional flue gas treatment systems wasquantified and, finally, the most attractive technologybetween the Supercritical Combustion (SC) and theFluidized Bed Combustion (FBC) was evaluated for allreconstruction prospects. The rehabilitation of the twopower stations, i.e. Kashirskaya and Shaturskaya, withnew boilers was investigated and the technical aspects ofthe Russian sector’s renovation needs are presented inaccordance with the targets set in the dialogue with theEuropean Commission on energy-related issues.

2. Rehabilitation of the Russian coal-fired power sector

2.1. Russian coal-fired power plant park

The total installed capacity of all the power plants inRussia amounts to 215GWe, including:

(a)
148.2GWe of thermal power plants (TPP), i.e.natural gas-, coal- and oil-fired units,
(b)
44.3GWe of hydroelectric plants, and (c) 22.7GWe of nuclear power plants (NPP).
The ratio among the above sources for the electricitygeneration has been kept for a long time at the samelevel, viz., TPP—60%, hydropower—20.5%, andNPP—10.5%. All large, medium and the majority ofsmall TPP and hydroelectric plants are integrated intothe RAO ‘‘UES of Russia’’, whose government share-holdings are 52.5%. The RAO ‘‘UES of Russia’’ and theJoint Stock Company (JSC) subsidiaries possess122GWe of the TPP—over 83% of the total TPPinstalled capacity—and 26.2GWe of the hydroelectricplants—59% of the total hydroelectric plants installedcapacity.

The Russian coal-fired power plants are subdividedinto 96 thermal power stations or 848 units of totalcapacity 50.5GWe. RAO ‘‘UES of Russia’’ operates thelargest units of total capacity 20.5GWe, while theremaining are integrated into 39 territorial verticallyintegrated power companies with their own electricalnetworks and electricity/heat sales enterprises. Investi-gations in this work are focused only on the thermo-electric units with capacity larger than 100MWe, whichcount for 25 thermal power stations (180 units) of totalcapacity 29.3GWe (CERTH/ISFTA, 2004). Fig. 2illustrates the distribution of these Russian coal-firedunits and the capacity in the regions where the powerstations are located. More than half of the capacity isinstalled in five regions as illustrated in Fig. 2. More-

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Fig. 2. Distribution of Russian coal-fired power plants.

55

52

27

49

36

0

5

10

15

20

25

30

35

40

0-10 10-20 20-30 30-40 40-50 >50

Years

Per

cent

age

of T

otal

Ins

talle

d C

apac

ity

[%]

0

10

20

30

40

50

60

70

80N

o of

Uni

ts

Percentage of Electric Capacity [%] Number of Units

Fig. 3. Classification of units according to their age.

Fig. 4. Weighted average age of the Russian coal-fired power plants.

P. Grammelis et al. / Energy Policy 34 (2006) 3124–31363126

over, the installed capacity per unit of about one-thirdof the Russian coal units is between 100 and 200MWe.Approximately half of the total installed capacitycorresponds to units within the range of200–300MWe. Thirty units have 300MWe capacity,which is the most preferable boiler dimension.

The Russian coal-fired power plants are already at anadvanced age. More than 50% of the installed capacitycorresponds to units older than 30 years, while about aquarter of the fleet’s capacity is in the range of 20–30years. As far as the number of units is concerned, morethan 60% are over 30 years old while about 20% rangebetween 20 and 30 years, Fig. 3.

In order to have more detailed information regardingthe age and also the obsolescence level of the coal-firedpower plants, the Weighed Average Age was estimatedfor all the coal-fired power plants through the followingformula:

WAA ¼

PiniMWiP

iMWi

, (1)

where i denotes a coal-fired unit and n is the age of theunit (CERTH/ISFTA, 2000). Fig. 4 illustrates theWeighted Average Age (WAA) of the Russian coal-fired power plants. The calculated results indicate

statistically which power plants should extend theirlifetimes, as one of the most cost-effective options tomeet their future energy requirements. Half of the powerplants have ‘‘WAA’’ values between 20 and 40 years,while five of them seem to urgently need lifetimeextension measures. WAA of the whole Russian coal-fired power plant park equals 31.22 years which isrelatively high compared to the values calculated forEU-15 and new or candidate EU member countries.WAA for the majority of the EU countries rangesbetween 15 and 30 years, while the respective calculatedresults of the new or candidate EU member states arebetween 20 and 32 years. The Russian WAA value ismore close to those of Belgium, United Kingdom,France in the EU-15 and Estonia, Hungary andSlovenia in the EU-25, indicating that urgent renovationmeasures should be applied (CERTH/ISFTA, 2000).

The Russian coal-fired power plants show low-efficiency values mainly because of their advanced age.Total efficiency varies between 27% and 33% for mostof the thermoelectric units, as represented in Fig. 5.However, efficiency is mostly influenced from the mainoperating parameters, such as the share of the heat loadand steam characteristics and less on the commissioningdate of the unit, as well as the service life and coalquality. More specifically, combined heat and powerproduction power plants operate at efficiencies higherthan 33% and up to 38%. This is valid especially forpower plants that were constructed in the ’60s and ’70sand their efficiencies exceed 33%. Taking into accountthe heat production, total efficiency of TPP may reachenhanced values, up to 80%. Leaving aside the heat loadand estimating only the electricity efficiency, then thelatter correlates in direct proportion to the operatingparameters of the thermoelectric units. For example, thelast phase of construction of the Vorkutinskaya CHP-2,the first phase of the Chitinskaya CHP-1 and the Yuzno-Uralskaya CHP-1 operating at 90 atm. and 540 1C, haveelectricity generation efficiencies varying from 23.73%

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25

30

35

40

45

1940 1950 1960 1970 1980 1990 2000 2010Commissioning Year

Eff

icie

ncy

(%)

Fig. 5. Efficiency of the Russian units versus the commissioning year.

0

20

40

60

80

100

1950 1960 1970 1980 1990 2000Commissioning Year

Ava

iliab

ility

(%

)

Fig. 6. Availability of the Russian units versus the commissioning

year.

Fig. 7. Environmental performance of the Russian coal-fired power

sector (2003).

Scrubber & Cyclone

3%

Scrubber & ESP17%

Cyclone25%

Scrubber24%

ESP31%

Fig. 8. De-pollution equipment of the Russian power sector.


to 27.49%. In TPPs with steam parameters of 140 atmand 545 1C—Neryungrinskaya TPP Unit No. 1, 200MW units of the Schekinskaya and Yuzno-UralskayaTPPs—the efficiency is considerably higher, i.e. from33.93% and 35.39%. Even higher can be the electricitygeneration efficiency in the supercritical units. Namely,at the third phase of the Troitskaya TPP, the efficiency is36.22%, whereas at the Berezovskaya TPP—with asmall share of the heat load—the efficiency equals39.1%.

The availability of the Russian coal-fired power plantsis also considered to be very low. In Fig. 6, theavailability of the Russian coal-fired Units is illustratedas a function of their commissioning year, showing thatmost of the Units are in the range of 30–70%. However,it should be noticed that many Russian units operateonly in specific periods each year at the peak demand.This is due to the lower gas cost on Gcal basis comparedto coal. Therefore, the availability of the coal-fired TPPis mostly defined by the contribution of natural gas inthe power sector. Also, the heat loads demand andsubsequently the weather conditions influence theavailability values, since significant number of theexisting cogeneration units are used to generate elec-tricity in order to meet the heat supply requirements.

Regarding the environmental performance of theRussian coal-fired power plants, the emitted pollutants

(NOx, SO2, dust, CO2) of each power plant wereinvestigated. Fig. 7 illustrates the total amount of thesepollutants emitted during 2003 in Russia, including gas-and oil-fired Units. The Russian legislation for theenvironmental protection in force today consists of theState Standard GOST P 50831 for the new boilers andthe Law of the Russian Federation ‘‘On the Environ-mental Protection’’. The latter demands the implemen-tation of the technical norms for the atmosphericpollutant emissions from the existing power plants.The technical norms do not substitute the establishedsystem of regulating norms and are used to set up thetemporary agreed emission limits, accounting not onlyfor the overall ecological situation, but also for thetechnical capability of the equipment to limit theatmospheric pollutant emissions.

Ash content of coal used in over 25% of the RussianTPP exceeds 40 (%, wt), which makes the particulatematter retention in the flue gas a rather urgent problem.In the Russian coal-fired power plants, the de-pollutionequipment for fly ash collection mainly consists ofElectrostatic Precipitators (ESP), Cyclones, Scrubbersand combinations of the aforementioned equipment,Fig. 8. Cyclones feature low efficiencies, between 75%and 85 %, and remain in operation only for old boilers,installed in the ’50–’60s. More recently constructed

ARTICLE IN PRESSP. Grammelis et al. / Energy Policy 34 (2006) 3124–31363128

boilers, employ wet scrubbers (Z ¼ 92297%) or ESP(Z ¼ 94299%). In general, the fly ash collectionefficiency at the power industry-wide level is 95.5%.The fabric filters and wet fly ash collection emulsifiersare in the designing phase.

Nowadays, the problems with SO2 emissions at themajority of power stations are solved through thecombined combustion of coal and gas or with theaddition of low-sulphur coal. This is the case in theRyzan and the Cherepet TPP, in which low-sulphurbrown coal and sulphur-free natural gas are used,respectively, to substitute the bituminous coal with highsulphur content. To meet the up-to-date SO2 emissionrequirements, the boilers that burn high-sulphur coalsfrom the Pechora and the near-Moscow deposits oranthracite from the Eastern Donbas region, should beequipped with 82–95% efficiency sulphur removalsystems.

The restrictions about the NOx emissions reduction atthe Russian coal-fired TPP are met by implementing theprimary, in-furnace suppression, methods. Amongthem, the two-stage combustion measure (OFA),various options of three-stage combustion (reburning),concentric combustion in the tangentially fired furnacesand low-NOx burners (LBN) are most widely applied.The method of high-density pulverized coal transport isused, capable of reducing NOx emissions by 20–40%, inthe indirect-fired pulverized systems. The pulverized coalpreheating is being developed, while the flue gas cleaningsystems using ammonia—based on the well-knownSNCR method—are installed in two boilers of theTolliatti CHP. The best results obtained at the Russiancoal-fired TPPs are as follows: 350–400mg/m3 (dry, 6%O2) in firing high volatile bituminous coal and250–300mg/m3 in brown coal-fired units.

Considering the high obsolescence level and lowefficiency values, a high demand for new capacity isforecasted over the coming years. It is expected that thereplacement or retrofitting of some of the old powerplants with Clean Coal Technologies (CCTs) will beamong the preferred technical options for the utilities(Grigori, 1999; Tumanovski, 2001).

2.2. Multi-criteria analysis

The quantification of the renovation prospects in acoal-fired system is a complex affair, closely related withthe regional criteria concerning inter alia the fuelavailability, the environmental aspects, the technologi-cal background and the financial resource, which set theenergy strategy of a country. Aiming to determine themodernization requirements in the Russian powerproduction sector, a multi-criteria analysis was per-formed. The latter includes widespread concepts inorder to estimate the renovation needs of the electricitygeneration sector under conditions that maintain or

improve the effective and the environment-friendlyoperation. Its governing parameters are experienceddata related to the system performance and the fuelquality and availability. Towards this purpose, threedifferent and progressive approaches are examined andapplied (Kakaras et al., 2002). Firstly, the demand of thepower production system for modernization was deter-mined providing also indication for the most effectiveapplication among the retrofit, repowering and recon-struction options. The demand for the application of thespecial flue gas treatment (denitrification and desulpur-ization) was afterwards quantified. Finally, the mostattractive system between the SC and the FBCtechnology was evaluated for each reconstructionprospect. Towards this purpose, three different andprogressive approaches were examined:

�
Retrofitting–repowering–reconstruction prospects, � Flue gas treatment prospects, � Technologies for repowering or reconstruction.
The governing parameters of this analysis are datarelated to the power plant performance and the fuelquality and availability (Kakaras, 1999).

2.2.1. Retrofitting– repowering– reconstruction

The renovation need for a power production system,was determined, providing indications for the mosteffective application among the retrofitting, repoweringand reconstruction options (Kakaras et al., 2002).Retrofitting is used when individual or set of modifica-tions and/or improving activities of units’ componentstargeting to the enhancement of the effective andenvironmental friendly operation is carried out. Repow-ering is the replacement of the boiler with modernCCTs’ technologies (SC or Circulating Fluidized Bed(CFB)), which is usually accompanied with retrofittingmeasures in other primary components. Reconstructionis the replacement of the entire unit with a modern one.Two scenarios were applied during this analysis. In thefirst more conservative scenario, low modernizationneeds and consequently low investment cost is consid-ered and retrofitting prevails against repowering and/orreconstruction options. On the contrary, the secondscenario of higher renovation needs and investment costincludes more dynamic options, in which reconstructionor repowering is the most favourite concept.

As already mentioned in the WAA index description,the age of a plant is regularly used to be the primaryparameter of determining the possible needs for apply-ing modernization activities on a power plant. In orderto quantify the average potential for each of the threepossibilities, the above two scenarios were applied. As itis obvious in Table 1, certain probabilities (Ai) of anyaging classification are considered for retrofitting,repowering and reconstruction in both scenarios. Even

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Table 1

Renovation options depending on the plant age

Age (years) Renovation probability (%)—percentage of plants with renovation needs

First scenario Second scenario

A1 A2 A3 A1 A2 A3

Retrof. Repower Recons. Total Retrof. Repower Recons. Total

o10 0 0 0 0 20 0 0 20

10–20 20 0 0 20 40 10 0 50

20–30 40 10 0 50 40 20 10 70

30–40 40 20 10 70 20 40 30 90

440 20 40 30 90 0 40 60 100

Table 2

Weighting factors based on the net plant efficiency

Plant net efficiency (%) Weighting of renovation options

f1 f2 f3Retrofitting Repowering Reconstruction

o29 0.1 0.5 0.4

29–33 0.3 0.4 0.3

33–37 0.5 0.3 0.2

37–41 0.7 0.2 0.1

4 41 0.9 0.1 0


though these probabilities are somewhat arbitrarilyelected, they are fully in compliance with the commonfeeling for renovation from technical, financial andeconomic viewpoint.

In addition to the plant age, a second parameter thatplays an important role in designing a specific renova-tion strategy is the net efficiency. Hence, the technicalfeasibility and the economical viability of a retrofittingproject would be more promising if the unit operatesalready with an increased efficiency. The opposite isvalid for a low-efficiency plant, where the repowering oreven the reconstruction may be much more economic-ally competitive actions, due to the great achievableefficiency gain. In order to take into account also thisparameter, the weighting factors shown in Table 2 areintroduced when estimating the potentiality of the threerenovation options. Considering the current efficiencydata of all the operating plants in comparison to theirage, the weighting values (fi) are estimated in severalefficiency ranges. The efficiency range should be higherin few years due to the expected increase of efficiencystandards that should be gained both by the accom-plishment of renovation works in several existing unitsand through operating modern power plants of ad-vanced performance.

Combining the above parameters, the renovationpotentiality (R) for a power plant can be calculatedfrom the relationship:

Ri ¼f iAiðA1 þ A2 þ A3Þ

f 1A1 þ f 2A2 þ f 3A3, (2)

where i ¼ 1; 2, or 3 corresponds to the retrofitting,repowering or reconstruction option, respectively. In-tegrating the above expression over a group of powerplants, after multiplying by the known capacity of eachplant, the cumulative fraction of the installed capacity(W) that may be subjected to renovation actions isobtained via:

W i ¼

PjRi;jNjP

jNj

, (3)

where j ¼ 12n, with n the number of plants in thegroup, Nj is the capacity (MWe) of the plant j, andi ¼ 1; 2, or 3 corresponds again to the retrofitting,repowering or reconstruction option, respectively.

2.2.2. Flue gas treatment prospects

Coal-specific characteristics and to some extent theimplemented combustion system seriously determine theflue gas treatment needs in a power plant. SOx emissionswere considered and their adequate reduction dependson the incorporation of new desulphurization technol-ogies. The primary measures include spray-dry, low Scoals or mixtures, and extra cleaning and controlsystems, whereas the secondary desulphurization pro-cess is usually performed by wet FGD units. Theprimary techniques can be implemented at a lower costbut their reduction efficiency is quite smaller comparedto the more expensive and difficult to install secondarysystems. For this reason, desulphurization probability isevaluated through two scenarios. The first low-cost onerepresents the application of primary measures, whereasthe second higher-cost scenario gives rise to the use ofmore efficient secondary systems. From another point ofview, these two scenarios can also represent a less ormore stringent environmental legislation, respectively.

The DeSOx probabilities that were used during theanalysis are presented in Table 3.

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Table 3

Desulphurization options depending on the coal type

SO2 formation

tendency of the fuel

DeSOx systems probability (%)—percentage of

plants needing a specific desulphurization

process


D1 D2 D1 D2

Primary Secondary Primary Secondary

Low 70 0 70 30

Moderate 50 50 30 70

High 0 100 0 100

Table 4

Reconstruction options depending on the fuel availability

Coal reserves

(years)

Reconstruction probability (%)—percentage of

plants to be reconstructed


R1 R2 R1 R2

SC CFBC SC CFBC

440 70 30 50 50

20–40 50 50 30 70

o20 30 70 10 90

Table 5

Weighting factors based on the emissions

Secondary depollution

needs

Weighting of reconstruction options

f1 (SC) f2 (CFBC)

Low 0.6 0.4

Medium 0.45 0.55

High 0.3 0.7


The total percentage of the installed capacity thatneeds desulphurization equipment is calculated throughthe following relationship:

W i ¼

PjDi;jNjP

jNj

, (4)

where Di,j is the probability number of Table 3corresponding to the system i�1 for primary and 2 forsecondary systems—to be used in the plant j havingcapacity Nj.

2.2.3. Repowering and reconstruction technologies

In addition to the determination of the renovationrequirements in the power generation sector, indicationsabout the most effective CCTs’ application betweenCirculating Fluidized Bed Combustion (CFBC) and SCarised. The main advantages of the SC over the CFBCtechnology are its well-known potential and perfor-mance, with many operating units of large capacityworldwide, as well as the competitive construction andmaintenance costs. On the contrary, CFB technologyhas been adopted in fewer thermal units of smaller tomoderate capacity. However, the latter concentratesseveral important strengths, such as the compactstructure, the increased fuel flexibility and the excellentenvironmental performance. Fuel availability and de-pollution requirements were adopted as controllingparameters in order to estimate the potentiality of usingeach of the two technologies for reconstruction orrepowering (Kakaras, 1999; Grammelis et al., 2005).Enhanced economically recoverable reserves of the sameindigenous fuel support the use of SC plants, whereaslow resources of the single fuel give rise to the use ofCFB boilers. The effect of fuel availability is quantifiedin Table 4 via two different scenarios. The existence ofcoal reserves for more than 40 years secures theutilization of the same fuel type for almost the entirelifetime of the new unit, thus a SC boiler should bepreferably selected. On the contrary, small reserves, i.e.below 20 years, encourage the CFB boiler selection in

order to keep operating the plant when the reserves areconsumed, even with a quite different coal type, whichwould then exhibit the best availability cost compro-mise. Also, strict de-pollution requirements of both NOx

and SO2 emissions in SC plants offer an advantage tothe CFBC applications. The effect of this parameter isconsidered through the weighting values (fi), given inTable 5.

Taking into account the above parameters, theprobability, P, of using either the SC or the CFBCtechnology for reconstruction of an old plant, iscalculated through the following equation:

Pi ¼

Pj ½ðf i;jRi;jðR1;j þ R2;jÞÞ=ðf 1;jR1;j þ f 2;jR2;jÞNj�

PjNj

, (5)

where the subscript i denotes the technology—1 for theSC and 2 for the CFBC—and the sum includes all the j

mines of a country.

2.3. Results and discussion

Calculations in each of the above multi-criteriaanalysis steps were performed and useful conclusionsabout the most promising refurbishment actions weredrawn. The results are estimated and presented in thefollowing paragraphs.

2.3.1. Retrofitting– repowering– reconstruction

The evaluation of retrofitting, repowering and recon-struction was performed considering both age and

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0%

20%

40%

60%

80%

100%

Scenario 1 cenario 2

Per

cent

age

of In

stal

led

Cap

acity

FGD

Primary

Nomeasure

Fig. 11. Potentiality for implementing desulphurization process in

Russia.


efficiency. Figs. 9 and 10 represent the calculated resultsfor the whole Russian coal-fired power plant park,referred on number of units and installed capacity,respectively. Based on both scenarios, renovationactivities should be applied in units that represent morethan half of the installed capacity, rising up to 80% inthe more dynamic scenario. Reconstruction or repower-ing are the less favourite options compared to retro-fitting. Boiler replacement is recommended for unitscorresponding to 22–41% of the total installed capacity.Conclusively, the market potential of new combustionapplications in Russia ranges between 6.5 and 12GWe.The high potentiality of renovation applications at theRussian thermoelectric units is mostly attributed to theiradvanced age.

2.3.2. Flue gas treatment prospects

The accumulated results of desulphurization needs areillustrated in Fig. 11. The application of primarydesulphurization measures prevails in both scenarios,while no desulphurization measure is needed in 30% ofinstalled capacity, in the more conservative scenario.

ReconstructionRepoweringRetrofit Nothing

Fig. 9. Modernization prospects based on the aging and the

experienced performance (referred on number of units).

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

Retrofit Repowering Reconstruction Nothing

Perc

enta

ge o

f in

stal

led

capa

city

of

Rus

sia

Scenario 1 Scenario 2

Fig. 10. Modernization prospects based on the aging and the

experienced performance (referred on installed capacity).

The outlook of the Russian coal-fired power plantslooks alike with the prevailing situation in the new orcandidate EU member states, showing that severemeasures should be implemented for SO2 control(Kakaras et al., 2002). Namely, all the Russian powerplants must undertake modernization measures to meetthe environmental standards for SO2 reduction in themore dynamic scenario and the same was ascertainedfor the new or candidate EU member states. However,the need for installation of FGD systems in this case isconsiderably lower corresponding to more than 20% ofinstalled capacity, while the respective percentage isaround 55% in the new or candidate EU member states(Kakaras et al., 2002).

2.3.3. Repowering and reconstruction technologies (SC

and CFBC)

The results representing the potentiality of the twoCCTs’ applications in Russia are presented both for theconservative (1) and the dynamic (2) scenarios in Fig.12, in case that reconstruction is selected. SC technologyis more preferable in scenario (1), while the oppositeoccurs in the dynamic scenario. SC technology prevailsover CFBC either when repowering of the thermo-electric unit is performed in the more conservativescenario, Fig. 13. When the dynamic probability iscalculated, no obvious precedence between the twotechnologies is taken. In general, the selection of themost appropriate CCT depends mostly on the assump-tions made and the particularities for every specific testcase. The particularities of each coal-fired unit should betaken into consideration, while reaching a final decisionabout future modernization applications.

3. Modernization scenarios of Russian coal-fired plants

Despite the promising market potential of renovationin the Russian power sector, strongly rational-dependedparameters may sometimes determine the modernizationstrategies. Within the framework of this paper, two

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Reconstruction Options

0.0%

0.5%

1.0%

1.5%

2.0%

2.5%

3.0%

3.5%

4.0%

4.5%

SC CFBCClean Coal Technologies

Per

cent

age

of t

otal

inst

alle

d ca

paci

ty (

%)

1st Conservative Scenario 2nd Dynamic Scenario

Fig. 12. Comparison of alternative scenarios for reconstruction

options in Russia.

Repowering Options

0.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

SC CFBCClean Coal Technologies

Per

cent

age

of t

otal

inst

alle

dca

paci

ty (

%)

1st Conservative Scenario 2nd Dynamic Scenario

Fig. 13. Comparison of alternative scenarios for repowering options in

Russia.


representative Russian units—Kashirskaya and Sha-turskaya power plants—were examined. The necessarytechnological measures towards their renovation aredescribed below. The modernization measures designedto take place in these two case studies could bereplicated in similar units over the Russian Power PlantPark.

3.1. Refurbishment of Kashirskaya thermal power plant

with SC technology

The Kashirskaya TPP is located in the Moscowregion and is owned by JSC ‘‘UES of Russia’’. The plantconsists of three coal-fired units with two boilers of slagtap removal and one single reheat. The advanced age ofthe unit and the increased cost of coal delivered fromKuznetsk basin in Western Siberia, are expected to leadto the reconstruction of a new unit with supercritical

steam parameters, accompanied with all the systems forminimum gas pollutant emissions. A new unit of315MWe with steam parameters of 300 bar pressure,600/600 1C temperatures and reburning technology forNOx abatement is envisaged for upgrading the existingunit. The main retrofitting actions are focused on thefurnace and burners upgrade, reburning process, flue gascleaning and steam/water path.

The furnace configuration of the boiler remainsunchanged, i.e. prismatic shape with narrowing, rectan-gular section and liquid slag removal, using finepulverized coal with R90 ¼ 6% and resulting in stableignition and combustion with low NOx emissions. Thefurnace outlet gas temperature is 1155 1C. The combus-tion chamber is fully screened with finned-tube platens,divided in two sections. In view of high NOx concentra-tion for the above boiler type, the combination ofseveral technologies of NOx emissions reduction isadopted, which are reburning process, flue gas recircula-tion and overfire air. Exactly 85% of the fuel is fired inthe furnace chamber, the excess air being 1.05–1.1. Theremaining fuel is fed with the recirculation gases to the‘‘injectors’’, located above the combustion chambernarrowing, where the excess air is 0.9–0.95. The tertiaryair nozzles provide 25% of the total air to the reducingzone and are located at 21.5m elevation. The advantageof the method lies on requiring no furnace chambermodifications, while the efficiency of NOx reduction isabout 50%. Further to the application of the reburningprocess, the excess air ratio is reduced from 1.2 to 1.05.

The technical solutions calculated for the furnaceensu0re moderate loss of unburned carbon at minimumexcess air, no-slagging operation of the screens andplatens at the furnace outlet, as well as ignition stabilityof the pulverized coal flame at a low level. As concernsthe flue gas cleaning, the technical measures for the flyash collection and DeSOx of the SC unit include theinvestigations of the ESP for simultaneous reduction ofSO2 and fly ash. The process is accompanied by flue gaswet conditioning prior to ESP cleaning.

In designing the hydraulic circuits of the steam/waterpath of the SC boiler, it is very important to apply thevertical screen heating surfaces with upward flow of thefluid, including load-changing operations at slidingpressure in the entire boiler path. The selection of themass velocities in the heating surfaces is defined byensuring reliable temperature conditions and constantflows in sliding pressure startups. Based on thepredictive temperature range analysis inside the ultrasupercritical boiler, the tubes of the lower and higherradiation section can be constructed of high-chromecontent steels. The outlet section of the convectivesuperheater, wherein the steam is superheated to 600 1C,shall be made of highly alloyed steels that have beentested in 30MPa and 650 1C for 200,000 operatinghours.

ARTICLE IN PRESS

Table 6

Heat losses and boiler efficiency when using the different fuels

Peat Lignite Bituminous coal

Flue gas losses (%) 7.5 6.4 5.1

Combustible losses (%) 1.2 2.3 1

Entrainment losses (%) 0.6 1.5 1

Ambient losses (%) 0.4 0.4 0.4

Boiler efficiency (%) 90.4 89.4 92.5

Fuel consumption (t/h) 220.3 202.4 173.5


3.2. Refurbishment of Shaturskaya thermal power plant

to a peat-fired CFB boiler

The Shaturskaya TPP is located in the Moscow regionand is also owned by the JSC ‘‘UES of Russia’’ (federalsubmission) under the management of the JSC Mose-nergo. Three lignite-fired units of 200MWe each areinstalled in the power station. Each unit consists of twoboilers with steam capacity of 320 t/h and one singlereheat steam turbine, the steam parameters being140 bar, 5451/545 1C.

In the recent years, local peat has been the base fuel,in mass percentage close to 70 (%wt). The remainingthermal input is covered by brown coal from Moscowregion. The fuels to be used in the future at the powerplant are peat, Near-Moscow lignite, Kuznetsk andKarakansk bituminous coals. Due to the foreseendiversity of supplied fuel as well as the ageing of theUnits, the repowering of the two boilers in Unit No. 1with a new CFB boiler of the same steam production isconsidered a very promising renovation prospect. As aresult, the increase of the availability and the effectiveoperation of the unit at an environmentally acceptableway will be achieved.

The heat balance diagram of the Shaturskaya newunit is illustrated in Fig. 14. The main operating

Fig. 14. Heat balance diagram of the new

parameters and the characteristics of the water/steamare represented in the same figure. The electrical outputof the unit equals 225MWe whilst the heat capacity is484MWth. Furthermore, the heat rate is 7721KJ/KWhand the power plant efficiency rises up to 39.5%.

Based on the heat losses and boiler efficiency whenusing different fuels, the lowest values of boilerefficiency are obtained for lignite and the highest whenbituminous coal is used. The combustible loss data wereconsidered when calculating the heat losses, boilerefficiency and fuel consumption, Table 6. In addition,the long-term requirements on the emissions of SO2,NOx and fly ash were estimated and the calculated dataare represented in Table 7. The SO2 flue gas concentra-tions in flue gas were calculated, neglecting CaO capture

Power = 225,1 MWe

Boiler's Efficiency=90,4%

Plant's Efficieny=39,5%

Heat Rate= 1844 Kcal/KWh

unit at the Shaturskaya power plant.

ARTICLE IN PRESS

Table 7

Calculated data for SO2, NOx and fly ash

Peat Lignite Kuznetsk coal Peat/lignite blend Peat/ Kuznetsk coal blend

Limestone (t/h) 0 30 2 6 0

SO2 (mg/m3, dry, 6% O2) 482 9290 880 1550 500

Fly ash entrainment (%) 90 50 60–65 — —

Air flow (103�mN3 /h) 660 667 612 — —

Flue gas flow (103�mN3 /h) 913 849 712 — —


in the fly ash and limestone addition. The lowest SO2

emissions are observed when peat is fired and these canbe even lower than the legislative limit of 400mg/m3,when limestone is added or another desulphurizationsystem is performed. NOx emissions are lower than200mg/m3. Fly ash concentrations in the flue gas lowerthan 30mg/m3 will be attained in case that bag filters areinstalled.

Boiler overall dimensions and design were determinedaccording to the specific features of peat and its blendswith other coals. An increased fuel quantity is expectedto convert in the freeboard due to the high volatile yieldof peat. Low ash content demands the addition of sandas inert material, while the large share of light fractionsin the as-fired milled peat may result in unburnedparticle entrainment. A relatively low furnace gasvelocity of 4.8m/s maximum will be used, along withan adequate fuel distribution and application of thesand hopper system. The overall boiler dimensionssatisfy the space requirements and the plant could beinstalled in the available area of 48� 40m2.

The boiler furnace is of the prismatic, gastight designusing finned tubes. The surface of the furnace sectionwas determined up to 200m2 based on the gas velocityof 4.8m/s at the temperature of 870 1C. The furnaceoverall dimensions are 21� 9.6m2 (width� length).Under nominal load, the primary air flow accounts for50–60% of the total air supply. Primary air is increasedwhen the load is reduced below 70% of the nominalvalue, in order to maintain the minimum permissiblefluidizing velocity (about 3m/s). Ash is removed via theholes at the bottom of the air distributor and is led tothe water-cooled screws. Following, the ash is suppliedto the existing hydraulic ash removal system or to theslag hopper.

The flue gas of high dust concentration—up to 10 kg/m3 is supplied to the separator constructed frominternally lined furnace walls. The fly ash entrained inthe separators is directed to the airlock and the ash heatexchangers of ‘‘INTREX’’ design and after cooling itreturns back to the furnace. This ash stream is regulatedand used to keep the optimum bed temperature underload-changing conditions. Next to the separator, the fluegas is cleaned and passes to the convective shaft wherethe first and second superheater sections, primary

reheater and water economizer are located. Afterwards,the gases pass through the air heater, which can be ofregenerative rotary or recuperative tubular design withgas moving in the inter-tube space. Sufficient cleaning offlue gas is achieved in the steam soot blowers and fly ashis removed to the hoppers (CERTH/ISFTA, 2004;Grammelis et al., 2005).

In both refurbishment case studies, improved resultsconcerning the operation and efficiency of the renovatedunits are anticipated. The PC boiler in the KashirskayaTPP and the Shaturskaya’s CFB unit will operate atefficiency levels of around 40%, which is state of the artfor modern power plants, while meeting in parallel thestrict environmental legislative limits of the new LargeCombustion Plants Directive.

4. EU–Russia partnership on clean coal technologies and

future trends in the coal-fired power sector

EU–Russia Energy Dialogue was launched at theSummit of 30 October 2000 in Paris in order to raise all

issues of common interest relating to the energy sector

(Commission of the European Communities, 2002).Since then several meetings of thematic groups ofexperts from the EU member states and Russia wereheld, in which the areas of common interest in theenergy sector were analysed. The latter included the co-operation on energy saving, rationalization of produc-tion and transport infrastructures, European investmentpossibilities and relations between producer and con-sumer countries.

Russian energy policy makers are still increasinglyworried about the high dependence of internal marketon natural gas. Therefore, a 75% increase in coalproduction and an increase of its share in electricitygeneration are projected in Russia’s ‘‘Energy Strategyuntil the year 2020’’ document, which in turn couldliberate more natural gas for export. It is also clear thatany effort to increase the Russian coal-fired electricitygeneration at the expense of gas-fired power productionis of concern, within the context of climate change. Theoverall objective of a global reduction in greenhouse gasemissions should only be met if efficiency improvementand energy saving measures are applied to compensate

ARTICLE IN PRESS

2002

gas66.6%

others0.3%

coal28.4%

oil4.7%

(a)

2010

gas60.9%others

0.3%

coal33.9%

oil4.9%

(b)

Fig. 15. Fossil fuels used for electricity generation in the Russian

power sector (a) in 2002 and (b) according to expectations for 2010.


for the additional natural gas imports to the EU. As aresult, the increased coal utilization for electricitygeneration in Russia should be based on the modern,efficient and cleaner coal combustion technologies.Within the scope of this concept, the EU–Russiacollaboration on the cleaner and more efficient use ofsolid fuels was established through the CARNOTprogramme. Three projects were executed towards therecording of the current situation in the Russian coal-fired power sector and the promotion of EU CCT toimprove the operational and environmental perfor-mance of the thermoelectric units (CERTH/ISFTA,2004).

In the last years, only few coal-fired power plants havebeen installed in the Russian sector, due to the transitionfrom the administrative-controlled industry to themarket economy. In the long-term perspective, RAO‘‘UES of Russia’’ in cooperation with boiler manufac-turers have decided and are preparing the refurbishmentof the power sector, considering the technology and ageof individual coal-fired TPP. The implementation ofsuch a plan is delayed due to lack in financing, althoughpreparatory works are already in progress. The mea-sures undertaken to upgrade the coal-fired boilers oflarge TPP will increase the efficiency, extend the controlcapability and ensure efficient combustion of coals withvarying characteristics. This will require improved steamparameters, application of new structural materials anddesigns of heating surfaces with external and internalfins. During the refurbishment period, the old boilersfiring low-grade coals may be replaced by CFB boilers.It is expected that the reconstruction of the coal-firedsector will lead to significant savings in the repairing andmaintenance costs, which amounted about $1 billion or12% of the primary cost of the electricity generation, in2000. At the same time, the ecological problems met inthe old design boilers will be confronted by installing theup-to-date ESP, DeNOx and DeSOx systems. Nowa-days, such difficulties are faced with increasing naturalgas share in the fuel balance for electricity generation orswitching most coal-fired power plants in the Europeanpart of Russia to exploit natural gas. This approach inconnection with the expected price increase of naturalgas are temporary measures and cannot be consideredon permanent basis.

The renewal program of RAO ‘‘UES of Russia’’ until2010 is based on the assumption that the energyconsumption in Russia at that period will be1020–1135 billion kWh, out of which 65% will begenerated at TPPs. Coal share will increase from 28%in 2001 to 34% in 2010, while natural gas contributionwill decrease from 66.6% to 61%, Fig. 15. Natural gasprice in the European part of Russia during that periodwill increase from 12 to 15 $/tfe1 to 44–77 $/tfe, whereas

11 ton of fuel equivalent (tfe) ¼ 7Gcal ¼ 29.31GJ.

the coal price will increase up to 29–48 $/t. In Siberia,the natural gas price will be lower (23–44 $/t), but thecoal will also be considerably cheaper (16–27 $/t). In theEastern regions, both natural gas and coal will be moreexpensive than in the European part of Russia.

5. Conclusions

The evaluation of the current situation of the coal-fired power sector in Russia showed that 180 units largerthan 100MWe are operating nowadays, with totalinstalled capacity equal to 29.3GWe. The Russianthermoelectric coal units are of advanced age and morethan half of the installed capacity exceeds 30 years. Mostof the units are in the range of 30–70% in terms ofavailability. Limited efficiency values are met, themajority of the units achieving total efficiencies lowerthan 30%. Taking also into account the increased needsof pollution control, the potential for modernizationactivities is high (Grammelis et al., 2004).

Retrofitting rather than repowering or reconstructionwas the most preferred renovation option, according tothe results of the multi-criteria analysis. Even in themore conservative modernization scenario, over 30% ofthe thermoelectric units have to be repowered orreconstructed. Severe desulphurization measures shouldbe performed in the more aggressive scenario aiming toimprove the environmental performance of the Russianunits. SC technology prevails over the CFBC in themore conservative scenario, both for reconstruction andrepowering options. In the dynamic scenario, CFBC ismore favourite for reconstruction, while there is noobvious precedence in repowering activities. Eventhough the renovation options are conditioned bygeneral technical, technological and financial concepts,strongly rational-depended parameters strongly influ-ence the modernization of thermoelectric units. There-fore, the decision about the renovation of a specificplant should be taken after serious consideration ofunit’s main features and local restrictions.

An in-depth analysis for the renovation of tworepresentative Russian coal-fired plants, i.e. Kashirs-kaya and Shaturskaya, was carried out. A new unit of

ARTICLE IN PRESSP. Grammelis et al. / Energy Policy 34 (2006) 3124–31363136

315MWe with supercritical steam parameters andreburning for NOx abatement is envisaged to upgradeUnit 1 of Kashirskaya power station. New CFB boilersof the same steam production (320 t/h) are the mostpromising renovation options for the two boilers of Unit1 in Shaturskaya power station, due to the foreseenvariations in fuel supply and the ageing of the units.Refurbishment actions of this kind could be undertakenin the majority of the Russian coal-fired power plants,which suffer from high obsolescence level.

Towards that direction, the EU–Russia partnershipon Energy has been established and progress is alreadyachieved in the CCTs area (Commission of theEuropean Communities, 2002). The electricity genera-tion from coal-fired power plants in a cleaner and moreefficient way will permit an increase of the natural gasexports, which is among the main priorities of Russianauthorities. Wherever possible, coal firing will beincreased and, primarily, at boilers designed to operatein this way. Nevertheless, large-scale replacement of gas-fired boilers with coal-fired ones is not foreseen becauseeven in the future the price of the former will not bemuch higher compared to coal.

Acknowledgments

The financial support of the European Union(CARNOT ACTION, Contract no. 4.1004/D/01-005/2001)) is gratefully acknowledged.

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