- Email: [email protected]
03930 Anthracite firing in large utility arch fired boilers
08
Steam raising (boiler operation/design)
electricity on an hourly basis. Wind energy introduces uncertainty to the system. Relations among variables are based on three states of the world depending upon the hourly speed of the wind. Biomass is a balancing factor in the supply-demand interaction, as the production of biomass is itself at the same time consuming electricity, as an input. Conclusions are drawn on (a) the optimal combination of renewable energy sources to achieve economic viability of the system (b) effects on agricultural income and local development. and (c) evaluation of renewable energy policies. Time series models to simulate and forecast hourly 97103921 averaged wind speed in Quetta, Pakistan Kamal, L. and Jafri, Y. Z. Solar Energy, 1997, 61, (1) 23-32. Hourly average wind speeds were calculated using stochastic simulation and forecast models. Time series models take into account several basic features of wind speed data including autocorrelation, non-Gaussian distribution and diurnal non-stationarity. An ARMA @, q) process is fitted to wind speed data transformed to make their distribution approximately Gaussian and standardized to remove scattering of transformed data, for a positive correlation of consecutive wind speed observations, Diurnal variations are used to observe forecasts and its dependence on lead times. The ARMA (p, 4) model is suitable for prediction intervals and probability forecasts.
Others, including Economics
Development,
Hydropower and environment in India 97103922 Ranganathan, V. Energy Policy, 1997, 25, (4) 435-438. Renewable and harmless to the environment during operation, hydroelectric power is the cheapest source of energy. Yet environmental activism has obstructed hydrodevelopment throughout the world, and more so in India. The paper calls for a realistic economic-environmental trade-off and improvements in environmental decision making apparatus. Low-temperature ftlterability properties of alterna97103923 tive diesel fuels from vegetable oils Dunn, R. 0. and Bagby, M. 0. Liq. Fuel Ind. Prod. Renewable Resow., Edited by Cundiff, John S. Proc. Liq. Fuel Con& 3rd, 1996, 95-103. American Society of Agricultural Engineers, St. Joseph, MI. Me esters from vegetable oils are an attractive option for combustion in compression ignition (diesel) engines. Recent research has shown that the issue of cold flow properties should be resolved before Me esters are appropriate as an alternative fuel in moderate temperature climates. In North America, fuel systems powered by petroleum middle distillates develop operability problems when overnight ambient temperature drop below -15°C. In contrast, Me esters from soybean oil develop similar problems at temperature near 0°C. This work examines expected operability limits for Me esters through evaluation of their low-temperature filterabilities. Overall, the results of this work demonstrate that emphasis on reducing cloud point (CP) remains the key to developing Me ester diesel fuels with improved low-temperature flow properties. Production technology of refuse-derived fuel (RDF) 97103924 Furuhayashi, K. Kagaku Kogaku, 1997, 61, (7). 502-505. (In Japanese) RDF classification, characteristics of RDF, the manufacturing processes of RDF. and its uses are discussed. A survey: internatfonal aid for renewable energy in 97/03925 the Pacific Islands since the 1970s Yu, X. and Taplin, R. Energy Policy, 1997, 25, (5) 501-516. A survey was conducted between November 1995 and May 1996, to review the situation regarding international aid for renewable energy in the Pacific Island region,. The survey has provided some interesting information regarding bilateral and multilateral aid for renewable energy in the region from the late 70s to 1996. In this paper, the main findings of the survey are presented and discussed. In the future, international aid for renewable energy in the region could be enhanced with further financial assistance, human resources and institutional development, local community involvement, joint ventures and aid efficiency. A winning coalition of advocacy: climate research, 97103926 bureaucracy and ‘alternative’ fuels. Who is driving climate change policy? Boehmer-Christiansen, S. Energy Policy, 1997, 25, (4) 439-444. With regard to global warming, anti-coal and some investment policies are largely justified. Political analysis suggests that these policies are supported by the reinforcing interests of three powerful lobbies: scientific institutions engaged in atmospheric research and earth observation, energy corporations harmed by low fossil fuel prices or supplying ‘clean’ technologies, and numerous interlocking bureaucracies. Together they have succeeded in maintaining momentum in current climate negotiations. The scientific consensus which underpins the climate treaty is examined critically. It is argued that support for emission abatement policies is better explained with
330
Fuel and Energy Abstracts
September
1997
reference to diplomatic interest in the globalisation of energy related investments and trade than understood causality between average global surface warming and fossil fuel combustion.
08
STEAM RAISING Boiler Operation/Design
97103927 Achieving compliance with advanced coal-fired low-emission boiler systems Regan, J. W. et al. Proc. Inf. Tech. Conf: Coal Util. Fuel Syst., 1995, 20, 633-645.
The work undertaken in Phase I of the U.S. Department of Energy (DOE) project, ‘Engineering Development of Advanced Coal-Fired Low-Emissions Boiler Systems’ (LEBS), part of the DOE’s Combustion 2000 Programme, alongside descriptions for future work. The overall objective of the LEBS Project is to dramatically improve environmental performance of future coal-fired power plants without adversely impacting efficiency or the cost of electricity. Short-term technologies will be used to reduce NO, and SO2 emissions to one-third current NSPS limits and particulates to half current NSPS limits. Air toxics must be in compliance and waste must be reduced and made more disposable. The work in Phase I included concept development and evaluation of several subsystems for controlling the emission of SO*, NO,, and particulates. Evaluations were then conducted on potential technologies in various combinations, as part of complete advanced supercritical power generation systems. One system was selected for preliminary design of a commercial generating plant. Acid rain legislation challen es coal pulverizer 97103926 designers to minimize impact on boiler pe r?ormance Piepho, R. R. Proc. Int. Tech. Conf. Coal Uril. Fuel Syst., 1994. 19, 733741. Pulverizer operating flexibility to supply power stations was improved with the combined use of the dynamically controlled variable speed classifier with spring load adjuster. Alternative fuel advanced reburning 97103929 Maly, P. M. et al. Proc. Int. Tech. Conf Coal Ufil. Fuel Sysf., 1997, 22, 815826. Full scale boiler systems have successfully demonstrated reburning as a mature fuel staging NO, control technology. The Energy and Environmental Research Corporation has developed advanced reburning techniques in which reburning is coupled with injection of nitrogen agents and promoter compounds, showing potential for greater than 90% NO, reduction. Test work has shown that a wide range of fuels can effectively be used for reburning, including natural gas, pulverized coal. coal pond fines, biomass and Orimulsion. The test work was conducted at a 1 x 1Oh Btu/h boiler simulation facility. Both natural gas and bituminous coal were tested as main fuels. Efficiency of basic and advanced reburning were characterized as a function of key process variables. The amount of reburn fuel ranged from 10 to 28% of the total heat input. NO, reduction was found to increase both with increasing reburn heat input and reburn zone residence time. Reburn fuel properties found to control performance include fuel nitrogen content, volatiles, fixed carbon, and ash constituents. Advanced reburn tests were conducted in which reburning was coupled with injection of nitrogen agents and/or promoters. The most effective promoter compounds were found to he alkalis, most notably sodium compounds. While reburning with alternative fuels has the potential to cause boiler impacts, such as increased slagging with biomass, these impacts are generally minimized because the reburn fuel comprises only a small fraction of total boiler heat input. The advanced reburning techniques are flexible since they can be readily applied to a variety of waste products and off-specification fuels having low cost. By virtue of their NO, reduction capabilities and its economic efficiency, such techniques are attractive candidates for a wide range of new and retrofit power plant applications. 97103930 Anthracite firing in large utility arch fired boilers Winkin, J. P. and Garcia-Mallol, J. A. Proc. Am. Power Conf., 1997, 59, (2). 1166-1174. Foster Wheeler (FW) has sold 49 arch-fired utility type boilers for burning low volatile type coals including semi-anthracites, anthracites and blends. Forty-one of these boilers have been in operation for many years. Twentythree are in the size range over 100 MWe with a total equivalent capacity of 5130 MWe. Of particular interest to the utility industry are I2 large units in the size range from 250 to 500 MWe. Ten boilers are in operation and two are completing construction. Four of these units burn anthracite, with volatile matter as law as 5.5% on an as-received basis. These were designed to burn anthracite, but some are burning semi-anthracite blends. These boilers have up-to-date arch-firing systems and furnace designs. The boilers sustain the minimum load requirements without support fuel. The database obtained from the above operating experience over a wide range of coals is
08
a significant input into the design of large utility type boilers, particularly in the low volatile end of the range of coals. However, volatile matter by itself did not give a reliable and proper base for forecasting the ignitability and burn out characteristics, more sensitive indexes were required. Accordingly, FW has developed and uses a Reactivity Index to predict the ignition characteristics of a given coal. The application of the index is explained.
Applicability of the mixture of bituminous coal and anthracite to conventional pulverized coal firing boiler
9?/03931
Takano, S.-I. et al. Proc. Int. Tech. Conf. Coal Lltil. Fuel Syst., 1994, 19, 67682. It is predicted that high-grade coal will become difficult to obtain for Japanese power stations in the future and with this in mind, pilot scale tests of pulverized blends of bituminous coal and anthracite using a 1.2 MWt tunnel furnace were conducted. The study aimed to assess the applicability of the blends of bituminous coal and anthracite to conventional pulverized coal firing boilers. One kind of bituminous coal and two kinds of anthracite, one of low ash content and another of high ash content, were prepared for the test. Prior to pilot scale tests, coal properties and ash properties of the blends of bituminous coal and anthracite were analysed to establish the characteristics of combustion, ash deposition, etc. Combustion efficiency, NO, emission, characteristics of ignition stability and grindability changing the blend rate of anthracite were all experimentally investigated. The critical constraints on the blending rate of anthracite were unburnt carbon in fly ash and NO, emissions for coals tested. The acceptable limitation on blending rate of anthracite was 10 and 209, respectively, for two kinds of conventional pulverized coal fired boiler. Grindability worsened with increasing blending rate of anthracite.
6&W’s advanced coal-fired low-emission boiler 9?/03932 system: Preparation for and preliminary results of subsystem testing Mcdonald,
D. K.
et al.
Proc. Int. Tech. Conf. Coal Util. Fuel Syst., 1996, 21.
401-413.
The design of ‘Combustion 2000’ took into account two stages of commercialization: in the short-term, the low-emissions boiler system (LEBS) and for the longer term, the high performance power system (HIPPS). The LEBS program was designed with the objective of developing an advanced pulverized coal (PC) fired power generation system for commercial application by the year 2000. Very low emissions and high cycle efficiency at a life-cycle cost equivalent to a conventional PC plant are required from the system, meeting New Source Performance Standards. (NSPS). B&W has coupled advanced environmental control technologies capable of achieving emissions of SO,, NO,, and particulate far below current New Source Performance Standards (NSPS) with an advanced boiler equipped with improved combustion and heat transfer sub-systems to meet this goal. This paper describes B&W’s advanced generating plant design and provides current results of the subsystem testing presently in progress at B&W’s Clean Environment Development Facility (CEDF) located at the company’s Alliance Research Center.
Calculation of the output of hazardous emissions from industrial and heating boilers
9?/03933
Kotler, V. R. et al. Prom, Energ., 1997, (I), 49-52. (In Russian) Provides equations and nomograms are given for calculating the emissions of flue gases and its minor components from the combustion of fossil fuels (natural gas, fuel oil, coal, and brown coal).
Chiyoda Thoroughbred 121 process for exotic-fuel-
9?/03934
fired boilers Yanagioka, H. and Kuwahara, I. FGD Synth. Gypsum, Int. Conf. [Proc.], 1997, 10/l-12. Edited by Luckevich, L. M. et al., ORTECH: Mississauga, Ont. The Chiyoda Thoroughbred 121 flue gas desulforization (FGD) process is described. This paper discusses the treatment of flue gases generated from exotic fuels, focusing on effects of impurities. Plants examined include the Suncor FGD plant at Fort McMurray, one scheduled for completion in 1997 in the Czech Republic, and an FGD operation in Japan.
5th,
heat input was 5-10%. These tests demonstrated the performance of the fuel handling system and provided a characterization of the fuel physical and chemical properties.
Coal fired power boiler system for bottom ash removal without water
97m3937
Barsin, J. A. Proc. Int. Tech. Conf: Coal Util. Fuel Syst., 1997, 22, 351-361. Power plant operators have been forced to close ash ponds and reduce sluice water effluent to a zero discharge under the demands of recent environmental regulations in Europe. This presentation reviews how a European designed bottom ash removal system was applied to a USA power boiler located in Florida where local regulations on water usage encouraged the retrofit of a zero discharge ash removal system. Design, cost and energy comparisons to typical sluice systems are described. Initial operation, problem identification, correction and present status are also included. The system has operated for three years and world-wide systems of a similar design already have over 275 000 h of actual retrofit operation. 9?/03936 Coal reburning application on a cyclone boiler Maringo, G. J. et al. Proc. Int. Tech. Conf. Coal Util. Fuel Syst., 1994, lY, 421-431. A supplemental fuel is injected into the main furnace of a cyclone-fired boiler in cyclone reburn. It produces locally reducing conditions which convert NO, generated in the main combustion zone, to molecular nitrogen, thereby reducing overall NO, emissions. The world’s only application of the cyclone reburn technology using pulverized coal as the reburn fuel was installed at Wisconsin Power & Light’s Nelson Dewey Generating Station, Unit 2. The project was selected for demonstration under the US Department of Energy’s Clean Coal Technology Demonstration Program, Round II. The reburn system start-up was initiated on December 4, 1991 and is now fully integrated into routine operation of the unit. Up to 62% nitrogen oxide emission reduction has been demonstrated, without adverse effect on the other operating parameters of the unit. This paper describes the impacts of the reburn system operation while burning either an Illinois Basin bituminous coal or a western low sulfur, PRB coal.
Coal utilization 81 fuel systems conference, 1994 ‘advanced coal-fired slagging combustor for the low-emission boiler system’
97m3939
Diehl, R. C. et al.
Rao, 0. P. and Madhusudhan,
B.
Proc. Int. Tech. Coal Util. Fuel Sysf.,
1995, 20, 759-761.
Retrofitting of an existing thermal power plant with a coal gasification plant, a matching gas turbine and a waste heat boiler is addressed in this article. The criteria for selection of thermal power plant, choice of coal gasification process and size of retrofit plant are described. Technoeconomic analysis show that the proposal is technically and environmentally desirable. but not economically comparable with a pulverized coal fired thermal power plant, perhaps due to the small size of the retrofit plant. However, the economics are comparable with a natural gas based combined cycle plant. 97103936
Co-firing switchgrass in a 50 MW pulverized coal
boiler Aerts, D. Tests on Company operation
J. et al. Proc. Am. Power Conf., 1997, 59, (2), 1180-1185. switchgrass co-firing, conducted at Madison Gas and Electricity are presented. Five tests were run for 3-5 h, each with steady at loads of 40-47 MW. Switchgrass mass feed rate was 8-15% and
Proc. Int. Tech. Conf. Coal Util. Fuel Syst., 1994, 19, 65-
75.
‘Combustion 2000’ is a major engineering development programme initiated by the Department of Energy, Pittsburgh Energy Technology Center. The programme is geared toward advanced coal-fired electrical utility plants. The Riley Stoker Corporation is leading one of three teams developing a Low-Emission Coal-Fired Boiler System (LEBS), which will be commercially available by the year 2000. This system’s advanced pollution control goals will lower SO, and NO, emissions to 113 current New Source Performance Standards (NSPS) and particulate emissions to l/ 2 current NSPS. Riley’s LEBS has selected the 4500 psi 1100°F double reheat cycle, which will include a high efficiency, once through supercritical Benson boiler. One goal unique to the team is to develop an advanced slagging combustor system which will provide fuel flexibility, high carbon conversion, low NO, emissions, high ash removal and waste management advantages over conventional firing systems. The Textron Toroidal vortex Slagging combustor (TVC) developed under DOE funding operates at high temperature producing molten slag and can greatly reduce the amount of ash going to the boiler. This will allow the boiler to be smaller in size and have closer tube spacing, which should lead to reduced overall size and cost. This paper presents the overall status of the Riley Stoker LEBS programme along with the results of the advanced TVC slagging combustor testing performed during the Phase I of the LEBS program at TDS’s Haverhill facility.
Coal water slurry reburning low cost NO, compliance system for cyclone-fired boilers
97m3940
R. A. et al.
Ashworth,
Clean and efficient power wlth high ash coals 9?/03935 through retrofitting
Steam raising (boiler operation/design)
Proc. Int. Tech. Conf. Coal Util. Fuel Syst., 1996, 21,
51 l-522.
Coal slurry reburning is applicable in cyclone boilers which have a nearby source of waste coal fines preparation plant for reducing NO, emissions for a very low operating cost or even a saving. The lower the cost of coal fines the lower the NO, reduction cost.
Cofiring coal-water slurry in cyclone boilers: some combustion issues and considerations
97m3941 Carson,
W. R. and Tillman, D.
Proc. Int. Tech. Conf. Coal Util. Fuel Syst.,
1997, 22, 627-638.
Coal-water slurry (CWS) fuels could impact fuel cost at selected power plants and also has the potential to reduce nitrous oxides emissions (NO,) by driving specific combustion mechanisms. CWS, produced from selected fines generated during coal cleaning operations, has been fired extensively at the Seward Generating Station of General Public Utilities (GPU), and testing has been initiated at cyclone plants as well. The critical issues involved with CWS firing in cyclones are listed, based on preliminary modelling tests. Included are the impact of CWS on fuel chemistry with particular attention to that of fuel ash, the impact of CWS on combustion temperature and the impact of CWS on the formation of trace metal
Fuel and Energy Abstracts
September 1997 331
Steam raising (boiler operation/design)
electricity on an hourly basis. Wind energy introduces uncertainty to the system. Relations among variables are based on three states of the world depending upon the hourly speed of the wind. Biomass is a balancing factor in the supply-demand interaction, as the production of biomass is itself at the same time consuming electricity, as an input. Conclusions are drawn on (a) the optimal combination of renewable energy sources to achieve economic viability of the system (b) effects on agricultural income and local development. and (c) evaluation of renewable energy policies. Time series models to simulate and forecast hourly 97103921 averaged wind speed in Quetta, Pakistan Kamal, L. and Jafri, Y. Z. Solar Energy, 1997, 61, (1) 23-32. Hourly average wind speeds were calculated using stochastic simulation and forecast models. Time series models take into account several basic features of wind speed data including autocorrelation, non-Gaussian distribution and diurnal non-stationarity. An ARMA @, q) process is fitted to wind speed data transformed to make their distribution approximately Gaussian and standardized to remove scattering of transformed data, for a positive correlation of consecutive wind speed observations, Diurnal variations are used to observe forecasts and its dependence on lead times. The ARMA (p, 4) model is suitable for prediction intervals and probability forecasts.
Others, including Economics
Development,
Hydropower and environment in India 97103922 Ranganathan, V. Energy Policy, 1997, 25, (4) 435-438. Renewable and harmless to the environment during operation, hydroelectric power is the cheapest source of energy. Yet environmental activism has obstructed hydrodevelopment throughout the world, and more so in India. The paper calls for a realistic economic-environmental trade-off and improvements in environmental decision making apparatus. Low-temperature ftlterability properties of alterna97103923 tive diesel fuels from vegetable oils Dunn, R. 0. and Bagby, M. 0. Liq. Fuel Ind. Prod. Renewable Resow., Edited by Cundiff, John S. Proc. Liq. Fuel Con& 3rd, 1996, 95-103. American Society of Agricultural Engineers, St. Joseph, MI. Me esters from vegetable oils are an attractive option for combustion in compression ignition (diesel) engines. Recent research has shown that the issue of cold flow properties should be resolved before Me esters are appropriate as an alternative fuel in moderate temperature climates. In North America, fuel systems powered by petroleum middle distillates develop operability problems when overnight ambient temperature drop below -15°C. In contrast, Me esters from soybean oil develop similar problems at temperature near 0°C. This work examines expected operability limits for Me esters through evaluation of their low-temperature filterabilities. Overall, the results of this work demonstrate that emphasis on reducing cloud point (CP) remains the key to developing Me ester diesel fuels with improved low-temperature flow properties. Production technology of refuse-derived fuel (RDF) 97103924 Furuhayashi, K. Kagaku Kogaku, 1997, 61, (7). 502-505. (In Japanese) RDF classification, characteristics of RDF, the manufacturing processes of RDF. and its uses are discussed. A survey: internatfonal aid for renewable energy in 97/03925 the Pacific Islands since the 1970s Yu, X. and Taplin, R. Energy Policy, 1997, 25, (5) 501-516. A survey was conducted between November 1995 and May 1996, to review the situation regarding international aid for renewable energy in the Pacific Island region,. The survey has provided some interesting information regarding bilateral and multilateral aid for renewable energy in the region from the late 70s to 1996. In this paper, the main findings of the survey are presented and discussed. In the future, international aid for renewable energy in the region could be enhanced with further financial assistance, human resources and institutional development, local community involvement, joint ventures and aid efficiency. A winning coalition of advocacy: climate research, 97103926 bureaucracy and ‘alternative’ fuels. Who is driving climate change policy? Boehmer-Christiansen, S. Energy Policy, 1997, 25, (4) 439-444. With regard to global warming, anti-coal and some investment policies are largely justified. Political analysis suggests that these policies are supported by the reinforcing interests of three powerful lobbies: scientific institutions engaged in atmospheric research and earth observation, energy corporations harmed by low fossil fuel prices or supplying ‘clean’ technologies, and numerous interlocking bureaucracies. Together they have succeeded in maintaining momentum in current climate negotiations. The scientific consensus which underpins the climate treaty is examined critically. It is argued that support for emission abatement policies is better explained with
330
Fuel and Energy Abstracts
September
1997
reference to diplomatic interest in the globalisation of energy related investments and trade than understood causality between average global surface warming and fossil fuel combustion.
08
STEAM RAISING Boiler Operation/Design
97103927 Achieving compliance with advanced coal-fired low-emission boiler systems Regan, J. W. et al. Proc. Inf. Tech. Conf: Coal Util. Fuel Syst., 1995, 20, 633-645.
The work undertaken in Phase I of the U.S. Department of Energy (DOE) project, ‘Engineering Development of Advanced Coal-Fired Low-Emissions Boiler Systems’ (LEBS), part of the DOE’s Combustion 2000 Programme, alongside descriptions for future work. The overall objective of the LEBS Project is to dramatically improve environmental performance of future coal-fired power plants without adversely impacting efficiency or the cost of electricity. Short-term technologies will be used to reduce NO, and SO2 emissions to one-third current NSPS limits and particulates to half current NSPS limits. Air toxics must be in compliance and waste must be reduced and made more disposable. The work in Phase I included concept development and evaluation of several subsystems for controlling the emission of SO*, NO,, and particulates. Evaluations were then conducted on potential technologies in various combinations, as part of complete advanced supercritical power generation systems. One system was selected for preliminary design of a commercial generating plant. Acid rain legislation challen es coal pulverizer 97103926 designers to minimize impact on boiler pe r?ormance Piepho, R. R. Proc. Int. Tech. Conf. Coal Uril. Fuel Syst., 1994. 19, 733741. Pulverizer operating flexibility to supply power stations was improved with the combined use of the dynamically controlled variable speed classifier with spring load adjuster. Alternative fuel advanced reburning 97103929 Maly, P. M. et al. Proc. Int. Tech. Conf Coal Ufil. Fuel Sysf., 1997, 22, 815826. Full scale boiler systems have successfully demonstrated reburning as a mature fuel staging NO, control technology. The Energy and Environmental Research Corporation has developed advanced reburning techniques in which reburning is coupled with injection of nitrogen agents and promoter compounds, showing potential for greater than 90% NO, reduction. Test work has shown that a wide range of fuels can effectively be used for reburning, including natural gas, pulverized coal. coal pond fines, biomass and Orimulsion. The test work was conducted at a 1 x 1Oh Btu/h boiler simulation facility. Both natural gas and bituminous coal were tested as main fuels. Efficiency of basic and advanced reburning were characterized as a function of key process variables. The amount of reburn fuel ranged from 10 to 28% of the total heat input. NO, reduction was found to increase both with increasing reburn heat input and reburn zone residence time. Reburn fuel properties found to control performance include fuel nitrogen content, volatiles, fixed carbon, and ash constituents. Advanced reburn tests were conducted in which reburning was coupled with injection of nitrogen agents and/or promoters. The most effective promoter compounds were found to he alkalis, most notably sodium compounds. While reburning with alternative fuels has the potential to cause boiler impacts, such as increased slagging with biomass, these impacts are generally minimized because the reburn fuel comprises only a small fraction of total boiler heat input. The advanced reburning techniques are flexible since they can be readily applied to a variety of waste products and off-specification fuels having low cost. By virtue of their NO, reduction capabilities and its economic efficiency, such techniques are attractive candidates for a wide range of new and retrofit power plant applications. 97103930 Anthracite firing in large utility arch fired boilers Winkin, J. P. and Garcia-Mallol, J. A. Proc. Am. Power Conf., 1997, 59, (2). 1166-1174. Foster Wheeler (FW) has sold 49 arch-fired utility type boilers for burning low volatile type coals including semi-anthracites, anthracites and blends. Forty-one of these boilers have been in operation for many years. Twentythree are in the size range over 100 MWe with a total equivalent capacity of 5130 MWe. Of particular interest to the utility industry are I2 large units in the size range from 250 to 500 MWe. Ten boilers are in operation and two are completing construction. Four of these units burn anthracite, with volatile matter as law as 5.5% on an as-received basis. These were designed to burn anthracite, but some are burning semi-anthracite blends. These boilers have up-to-date arch-firing systems and furnace designs. The boilers sustain the minimum load requirements without support fuel. The database obtained from the above operating experience over a wide range of coals is
08
a significant input into the design of large utility type boilers, particularly in the low volatile end of the range of coals. However, volatile matter by itself did not give a reliable and proper base for forecasting the ignitability and burn out characteristics, more sensitive indexes were required. Accordingly, FW has developed and uses a Reactivity Index to predict the ignition characteristics of a given coal. The application of the index is explained.
Applicability of the mixture of bituminous coal and anthracite to conventional pulverized coal firing boiler
9?/03931
Takano, S.-I. et al. Proc. Int. Tech. Conf. Coal Lltil. Fuel Syst., 1994, 19, 67682. It is predicted that high-grade coal will become difficult to obtain for Japanese power stations in the future and with this in mind, pilot scale tests of pulverized blends of bituminous coal and anthracite using a 1.2 MWt tunnel furnace were conducted. The study aimed to assess the applicability of the blends of bituminous coal and anthracite to conventional pulverized coal firing boilers. One kind of bituminous coal and two kinds of anthracite, one of low ash content and another of high ash content, were prepared for the test. Prior to pilot scale tests, coal properties and ash properties of the blends of bituminous coal and anthracite were analysed to establish the characteristics of combustion, ash deposition, etc. Combustion efficiency, NO, emission, characteristics of ignition stability and grindability changing the blend rate of anthracite were all experimentally investigated. The critical constraints on the blending rate of anthracite were unburnt carbon in fly ash and NO, emissions for coals tested. The acceptable limitation on blending rate of anthracite was 10 and 209, respectively, for two kinds of conventional pulverized coal fired boiler. Grindability worsened with increasing blending rate of anthracite.
6&W’s advanced coal-fired low-emission boiler 9?/03932 system: Preparation for and preliminary results of subsystem testing Mcdonald,
D. K.
et al.
Proc. Int. Tech. Conf. Coal Util. Fuel Syst., 1996, 21.
401-413.
The design of ‘Combustion 2000’ took into account two stages of commercialization: in the short-term, the low-emissions boiler system (LEBS) and for the longer term, the high performance power system (HIPPS). The LEBS program was designed with the objective of developing an advanced pulverized coal (PC) fired power generation system for commercial application by the year 2000. Very low emissions and high cycle efficiency at a life-cycle cost equivalent to a conventional PC plant are required from the system, meeting New Source Performance Standards. (NSPS). B&W has coupled advanced environmental control technologies capable of achieving emissions of SO,, NO,, and particulate far below current New Source Performance Standards (NSPS) with an advanced boiler equipped with improved combustion and heat transfer sub-systems to meet this goal. This paper describes B&W’s advanced generating plant design and provides current results of the subsystem testing presently in progress at B&W’s Clean Environment Development Facility (CEDF) located at the company’s Alliance Research Center.
Calculation of the output of hazardous emissions from industrial and heating boilers
9?/03933
Kotler, V. R. et al. Prom, Energ., 1997, (I), 49-52. (In Russian) Provides equations and nomograms are given for calculating the emissions of flue gases and its minor components from the combustion of fossil fuels (natural gas, fuel oil, coal, and brown coal).
Chiyoda Thoroughbred 121 process for exotic-fuel-
9?/03934
fired boilers Yanagioka, H. and Kuwahara, I. FGD Synth. Gypsum, Int. Conf. [Proc.], 1997, 10/l-12. Edited by Luckevich, L. M. et al., ORTECH: Mississauga, Ont. The Chiyoda Thoroughbred 121 flue gas desulforization (FGD) process is described. This paper discusses the treatment of flue gases generated from exotic fuels, focusing on effects of impurities. Plants examined include the Suncor FGD plant at Fort McMurray, one scheduled for completion in 1997 in the Czech Republic, and an FGD operation in Japan.
5th,
heat input was 5-10%. These tests demonstrated the performance of the fuel handling system and provided a characterization of the fuel physical and chemical properties.
Coal fired power boiler system for bottom ash removal without water
97m3937
Barsin, J. A. Proc. Int. Tech. Conf: Coal Util. Fuel Syst., 1997, 22, 351-361. Power plant operators have been forced to close ash ponds and reduce sluice water effluent to a zero discharge under the demands of recent environmental regulations in Europe. This presentation reviews how a European designed bottom ash removal system was applied to a USA power boiler located in Florida where local regulations on water usage encouraged the retrofit of a zero discharge ash removal system. Design, cost and energy comparisons to typical sluice systems are described. Initial operation, problem identification, correction and present status are also included. The system has operated for three years and world-wide systems of a similar design already have over 275 000 h of actual retrofit operation. 9?/03936 Coal reburning application on a cyclone boiler Maringo, G. J. et al. Proc. Int. Tech. Conf. Coal Util. Fuel Syst., 1994, lY, 421-431. A supplemental fuel is injected into the main furnace of a cyclone-fired boiler in cyclone reburn. It produces locally reducing conditions which convert NO, generated in the main combustion zone, to molecular nitrogen, thereby reducing overall NO, emissions. The world’s only application of the cyclone reburn technology using pulverized coal as the reburn fuel was installed at Wisconsin Power & Light’s Nelson Dewey Generating Station, Unit 2. The project was selected for demonstration under the US Department of Energy’s Clean Coal Technology Demonstration Program, Round II. The reburn system start-up was initiated on December 4, 1991 and is now fully integrated into routine operation of the unit. Up to 62% nitrogen oxide emission reduction has been demonstrated, without adverse effect on the other operating parameters of the unit. This paper describes the impacts of the reburn system operation while burning either an Illinois Basin bituminous coal or a western low sulfur, PRB coal.
Coal utilization 81 fuel systems conference, 1994 ‘advanced coal-fired slagging combustor for the low-emission boiler system’
97m3939
Diehl, R. C. et al.
Rao, 0. P. and Madhusudhan,
B.
Proc. Int. Tech. Coal Util. Fuel Sysf.,
1995, 20, 759-761.
Retrofitting of an existing thermal power plant with a coal gasification plant, a matching gas turbine and a waste heat boiler is addressed in this article. The criteria for selection of thermal power plant, choice of coal gasification process and size of retrofit plant are described. Technoeconomic analysis show that the proposal is technically and environmentally desirable. but not economically comparable with a pulverized coal fired thermal power plant, perhaps due to the small size of the retrofit plant. However, the economics are comparable with a natural gas based combined cycle plant. 97103936
Co-firing switchgrass in a 50 MW pulverized coal
boiler Aerts, D. Tests on Company operation
J. et al. Proc. Am. Power Conf., 1997, 59, (2), 1180-1185. switchgrass co-firing, conducted at Madison Gas and Electricity are presented. Five tests were run for 3-5 h, each with steady at loads of 40-47 MW. Switchgrass mass feed rate was 8-15% and
Proc. Int. Tech. Conf. Coal Util. Fuel Syst., 1994, 19, 65-
75.
‘Combustion 2000’ is a major engineering development programme initiated by the Department of Energy, Pittsburgh Energy Technology Center. The programme is geared toward advanced coal-fired electrical utility plants. The Riley Stoker Corporation is leading one of three teams developing a Low-Emission Coal-Fired Boiler System (LEBS), which will be commercially available by the year 2000. This system’s advanced pollution control goals will lower SO, and NO, emissions to 113 current New Source Performance Standards (NSPS) and particulate emissions to l/ 2 current NSPS. Riley’s LEBS has selected the 4500 psi 1100°F double reheat cycle, which will include a high efficiency, once through supercritical Benson boiler. One goal unique to the team is to develop an advanced slagging combustor system which will provide fuel flexibility, high carbon conversion, low NO, emissions, high ash removal and waste management advantages over conventional firing systems. The Textron Toroidal vortex Slagging combustor (TVC) developed under DOE funding operates at high temperature producing molten slag and can greatly reduce the amount of ash going to the boiler. This will allow the boiler to be smaller in size and have closer tube spacing, which should lead to reduced overall size and cost. This paper presents the overall status of the Riley Stoker LEBS programme along with the results of the advanced TVC slagging combustor testing performed during the Phase I of the LEBS program at TDS’s Haverhill facility.
Coal water slurry reburning low cost NO, compliance system for cyclone-fired boilers
97m3940
R. A. et al.
Ashworth,
Clean and efficient power wlth high ash coals 9?/03935 through retrofitting
Steam raising (boiler operation/design)
Proc. Int. Tech. Conf. Coal Util. Fuel Syst., 1996, 21,
51 l-522.
Coal slurry reburning is applicable in cyclone boilers which have a nearby source of waste coal fines preparation plant for reducing NO, emissions for a very low operating cost or even a saving. The lower the cost of coal fines the lower the NO, reduction cost.
Cofiring coal-water slurry in cyclone boilers: some combustion issues and considerations
97m3941 Carson,
W. R. and Tillman, D.
Proc. Int. Tech. Conf. Coal Util. Fuel Syst.,
1997, 22, 627-638.
Coal-water slurry (CWS) fuels could impact fuel cost at selected power plants and also has the potential to reduce nitrous oxides emissions (NO,) by driving specific combustion mechanisms. CWS, produced from selected fines generated during coal cleaning operations, has been fired extensively at the Seward Generating Station of General Public Utilities (GPU), and testing has been initiated at cyclone plants as well. The critical issues involved with CWS firing in cyclones are listed, based on preliminary modelling tests. Included are the impact of CWS on fuel chemistry with particular attention to that of fuel ash, the impact of CWS on combustion temperature and the impact of CWS on the formation of trace metal
Fuel and Energy Abstracts
September 1997 331