- Email: [email protected]
00747 EU clean coal technology-co-combustion of coal and biomass
15 Environment (pollution, health protection, safety) emissions when cofiring CWSF and pulverized coal as compared to firing 100% pulverized coal. The level of reduction was dependent upon the cofiring configuration, with NO, emissions being reduced by as much as 26.5%. The reduction in NO, emissions was not due to the tempering effect of the water in the CWSF, because a greater reduction in NO, occurred when cofiring CWSF than when injecting the same quantity of water at the same boiler firing rate. This paper discusses the tests in detail and the proposed reburn mechanism for the NO, reduction.
Consumption of fossil fuels. How reliable are 99199743 scenarios of anthropogenic carbon dioxide emissions? Berner, U. et al. DGMK Tagungsber., 1998, 9801, 43-47. (In German) The Bundesanstalt for Geowissenschaften und Rohstoffe (BCR), Germany carried out a reassessment of anthropogenic COz emission by combustion of fossil fuels comprising coal, natural gas, and crude oil. It was based on statistical data from the BCR data bank covering the fuel production and consumption in the period 1840-1996. The results were compared with former assessments carried out by the Intergovernmental Panel of Climate Change (IPCC). The evaluated COz emission by the BCR for the eighties was 1.0 GtC/yr lower than the emission values from the IPCC and corresponds with the ‘Missing Carbon Sink’, IPCC Report 1995. Other deviations from the evaluated COz emission were caused by unexpected changes in the world economy and their impact on the fuel consumption.
Effect of co-combustion of biomass on emissions in pulverized fuel furnaces
99100744
Spliethoff, H. and Hem, K. R. G. Fuel Process. Technology, 1998, 54, (l3), 189-205. Biomass shows a reasonable cost level in comparison to other renewable energies as well as having a considerable potential as an additional fuel source. The fuel types are both residual material from forestry and agriculture, such as wood or straw, and especially cultivated reproducible feedstocks. As single fuel, it is also considered to be sensible to utilize biomass in co-combustion in existing firing systems, such as pc-fired power stations. The European Union, in order to promote the biogenetic fuels, within the framework of the APAS Clean Coal Technology Program, has initiated a research project concerning the co-combustion of biomass in existing firing systems. The focus of the investigations in experimental and industrial-scale plants was to establish the impact of co-combusting biomass and sewage sludge in coal-fired systems with regard to combustion behaviour and pollutant formation. The task of the Institut fur Verfabrenstechnik und Dampfkesselwesen (IVD), University of Stuttgart, within the EU clean coal technology program, was to investigate the effects of cocombustion of solid biomass (Miscanthus, straw) and municipal sewage sludge together with the primary fuel hard coal. The experimental plant used was a semi-industrial pulverized fuel test rig (0.5 MW). In this publication, a synopsis is given of the outcome of the project, with special regard to the effect of co-combustion on emissions. The investigations reveal that biomass addition has a positive effect on emissions. Since biomass in most cases contains considerably less sulfur than coal, an increasing biomass share in the thermal output makes the SO* emissions decrease proportionally. As for sewage sludge, the emissions of SO2 correlate with the sulfur content of the fuel and hence rise with an increasing share of this biomass. Low NO, emissions can be achieved both by air staging and by reburning due to the high volatile content of the biomass.
Environmental emission mitigation efficient electrical appliances In Sri Lanka
99100745
Environmental impact of the energy recovery of scrap tires in a cement kiln
99100746
Carrasco, F. et al. Environ. Technology, 1998, 19, (5). 461-474. At a cement plant which produces one million tons of cement per year the study of the impact of the use of scrap tires as a fuel substitute with respect to gaseous emissions was conducted. This study was conducted through the modelling of the atmospheric dispersion of contaminants emitted with the use of the ISC-ST2 software put forth by the United States’ Environmental Protection Agency. The entry data required by this Gaussian model were the meteorological data, the characteristics of the source and the pollutants, the data relating to the buildings downwash effects and the location of the receptors. The simulation of the atmospheric dispersion of pollutants allows for the evaluation of daily and annual maximum concentrations as well as the localization of the latter, which is done just as easily at a cement kiln operating with coal only or with a combination of coal and scrap tires. The analysis of the results obtained shows whether the incorporation of tires
Fuel and Energy Abstracts January 1999
EU clean coal technology-co-combustion and biomass
99100747
of coal
Hem, K. R. G. and Bemtgen, .I. M. Fuel Process. Technology, 1998,54, (l3), 159-169. The application of regenerative energy sources should be advanced in order to reduce COz emissions in addition to a more economical use of fossil fuels. One of the alternatives considered to decrease the net emissions of CO2 are the cultivation and combustion of solid biomass, or the thermal utilization of sewage sludge. In order to achieve a noticeable COz reduction, as well as fossil fuel substitution, it is desirable to use fairly large quantities of biomass for energy production. However, an exclusive biomass utilization would consequently lead to the construction of many decentralized plants, which is time-consuming and would require high financial investments as well as large storage capacities due to the seasonal fuel availability. Co-combustion, in contrast, is considered to be a cheap option for utilizing the existing biomass resources. For these reasons, an EU-project, ‘Combined Combustion of Biomass/Sewage Sludge and Coals of High and Low Rank in Different Systems of Semi-industrial and Industrial Scale’ was launched in 1993. Partners from eight European countries investigated the effects of burning sewage sludge, agricultural residuals, such as straw and manure, as well as especially cultivated energy plants in combination with coals of vanous ranks and origin. Both the pulverized fuel and the fluidized bed mode were tested, ranging from laboratory rigs to large scale utility boilers. This paper provides an overview of the activities of the various partners involved and will, in particular, show the synergetic co-operation towards a common aim. Summarized are the results of the 2-year project.
Further experience improvement in fossil fuel combustion
99100746
for
environmental
Lazzeri, L. and De Santis, R. Proc. Am. Power Conf., 1998, 60, (l), 187195. Reviewed are the most recent Ansaldo Energia achievements in emission control via combustion modifications, with emphasis on NO., CO, and particulate emission reduction from oil-, gas-, and coal-fired boilers.
99ig9749 Gaseous pollutant emission gasification In a steam-fluldized bed. 1. Exper%% on pollutants formation and sulfur capture
s~.$
Zhao, F. et al. Huanjing Kerue Xuebao, 1998, 18, (3), 225-229. (In Chinese) On a steam fluidized bed gasifier with a diameter of 160mm the yields of the principal pollutants including hydrogen sulfide, ammonia and hydrogen cyanide were measured. The effects of operating conditions, such as grade of coal and bed temperature on the yields were determined. The sulfur capture via the HzS-CaO reaction in a reductive atmosphere with high concentration of steam in the fluidized bed was investigated. Comparisons of the yields of HzS between presence and absence of limestone was conducted to obtain the efficiency of sulfur capture. The effects of bed temperature and Ca/S ratio on the extent of sulfur capture were also determined.
potential of
Shrestha, R. M. et al. International Journal of Energy Research, 1998, 22, (lo), 923-933. Assessed in this study is the techno-economic potential of selected efficient demand-side appliances to mitigate emission of air pollutants from the power Sector of Sri Lanka. The study shows that from the technical and economic perspectives a total of about 38,646 GWh and about 25.6%, 34.2% and 34.6% of the total CO*, SO2 and NO, emission, respectively, could be avoided during 1997-2015 with the use of the efficient appliances. The generation savings from utility and user perspectives and emission mitigation potential are, however, significantly smaller as all the selected appliances are not found cost effective from these perspectives. This is mainly because electricity prices in the commercial and industrial sectors exceed the corresponding long-run marginal cost of electricity supply.
74
leads to an increase or a decrease in the concentration of pollutants: particulate matter, non-condensable gases, metals, hydrogen chloride, and semi-volatile compounds. Finally, it is possible to determine if the energy recovery of scrap tires used by a cement kiln meets environmental standards.
Greenhouse gas reduction through the use of high performance power systems (HIPPS)
99/00750
Robson, F. L. et al. (Am. Sot. Mechanical Eng.), 1997, 5, (l), 345-350. Identified were advanced high-performance power systems (HIPPS) which offer the potential of reducing greenhouse gas emissions, mainly COz, by as much as 50% compared to current coal-fired stations. The HIPPS were based on either frame-type or aerodynamic gas turbines which receive up to two-thirds of their thermal input from heat exchangers located in a coalfired high-temperature advanced furnace (HITAF). The remainder of the gas turbine energy was supplied by burning natural gas to increase the temperature from the HITAF to levels needed by modern gas turbines. Advanced HIPPS with a variety of engine configurations and power cycles were analysed for use in greenfield and repowering applications. These included conventional and intercooled gas turbines used in combined cycle and humid air turbine versions of HIPPS. Depending on cycle parameters, system power generation was 200-400 MW (or more), with efficiencies of 42-55%, based on fuel higher heating value. Emissions of COz and NO, were significantly reduced because of the increased efficiencies and advanced combustion technology used.
99l90751 ldentlfication and control of NO. emissions using neural networks f;e.2;;, J. and Feldman, E. E. J. Air Waste Manage. Assoc., 1998,48, (5), The application of two classes of artificial neural networks were investigated for the identification and control of discrete-time non-linear dynamical systems. A fully connected recurrent network is used for process identification, and a multilayer feed forward network is used for process control. The two neural networks are arranged in series for closed-loop control of oxides of nitrogen emissions of a simplified representation of a dynamical system. Plant data from one of Commonwealth Edison’s coal-
Consumption of fossil fuels. How reliable are 99199743 scenarios of anthropogenic carbon dioxide emissions? Berner, U. et al. DGMK Tagungsber., 1998, 9801, 43-47. (In German) The Bundesanstalt for Geowissenschaften und Rohstoffe (BCR), Germany carried out a reassessment of anthropogenic COz emission by combustion of fossil fuels comprising coal, natural gas, and crude oil. It was based on statistical data from the BCR data bank covering the fuel production and consumption in the period 1840-1996. The results were compared with former assessments carried out by the Intergovernmental Panel of Climate Change (IPCC). The evaluated COz emission by the BCR for the eighties was 1.0 GtC/yr lower than the emission values from the IPCC and corresponds with the ‘Missing Carbon Sink’, IPCC Report 1995. Other deviations from the evaluated COz emission were caused by unexpected changes in the world economy and their impact on the fuel consumption.
Effect of co-combustion of biomass on emissions in pulverized fuel furnaces
99100744
Spliethoff, H. and Hem, K. R. G. Fuel Process. Technology, 1998, 54, (l3), 189-205. Biomass shows a reasonable cost level in comparison to other renewable energies as well as having a considerable potential as an additional fuel source. The fuel types are both residual material from forestry and agriculture, such as wood or straw, and especially cultivated reproducible feedstocks. As single fuel, it is also considered to be sensible to utilize biomass in co-combustion in existing firing systems, such as pc-fired power stations. The European Union, in order to promote the biogenetic fuels, within the framework of the APAS Clean Coal Technology Program, has initiated a research project concerning the co-combustion of biomass in existing firing systems. The focus of the investigations in experimental and industrial-scale plants was to establish the impact of co-combusting biomass and sewage sludge in coal-fired systems with regard to combustion behaviour and pollutant formation. The task of the Institut fur Verfabrenstechnik und Dampfkesselwesen (IVD), University of Stuttgart, within the EU clean coal technology program, was to investigate the effects of cocombustion of solid biomass (Miscanthus, straw) and municipal sewage sludge together with the primary fuel hard coal. The experimental plant used was a semi-industrial pulverized fuel test rig (0.5 MW). In this publication, a synopsis is given of the outcome of the project, with special regard to the effect of co-combustion on emissions. The investigations reveal that biomass addition has a positive effect on emissions. Since biomass in most cases contains considerably less sulfur than coal, an increasing biomass share in the thermal output makes the SO* emissions decrease proportionally. As for sewage sludge, the emissions of SO2 correlate with the sulfur content of the fuel and hence rise with an increasing share of this biomass. Low NO, emissions can be achieved both by air staging and by reburning due to the high volatile content of the biomass.
Environmental emission mitigation efficient electrical appliances In Sri Lanka
99100745
Environmental impact of the energy recovery of scrap tires in a cement kiln
99100746
Carrasco, F. et al. Environ. Technology, 1998, 19, (5). 461-474. At a cement plant which produces one million tons of cement per year the study of the impact of the use of scrap tires as a fuel substitute with respect to gaseous emissions was conducted. This study was conducted through the modelling of the atmospheric dispersion of contaminants emitted with the use of the ISC-ST2 software put forth by the United States’ Environmental Protection Agency. The entry data required by this Gaussian model were the meteorological data, the characteristics of the source and the pollutants, the data relating to the buildings downwash effects and the location of the receptors. The simulation of the atmospheric dispersion of pollutants allows for the evaluation of daily and annual maximum concentrations as well as the localization of the latter, which is done just as easily at a cement kiln operating with coal only or with a combination of coal and scrap tires. The analysis of the results obtained shows whether the incorporation of tires
Fuel and Energy Abstracts January 1999
EU clean coal technology-co-combustion and biomass
99100747
of coal
Hem, K. R. G. and Bemtgen, .I. M. Fuel Process. Technology, 1998,54, (l3), 159-169. The application of regenerative energy sources should be advanced in order to reduce COz emissions in addition to a more economical use of fossil fuels. One of the alternatives considered to decrease the net emissions of CO2 are the cultivation and combustion of solid biomass, or the thermal utilization of sewage sludge. In order to achieve a noticeable COz reduction, as well as fossil fuel substitution, it is desirable to use fairly large quantities of biomass for energy production. However, an exclusive biomass utilization would consequently lead to the construction of many decentralized plants, which is time-consuming and would require high financial investments as well as large storage capacities due to the seasonal fuel availability. Co-combustion, in contrast, is considered to be a cheap option for utilizing the existing biomass resources. For these reasons, an EU-project, ‘Combined Combustion of Biomass/Sewage Sludge and Coals of High and Low Rank in Different Systems of Semi-industrial and Industrial Scale’ was launched in 1993. Partners from eight European countries investigated the effects of burning sewage sludge, agricultural residuals, such as straw and manure, as well as especially cultivated energy plants in combination with coals of vanous ranks and origin. Both the pulverized fuel and the fluidized bed mode were tested, ranging from laboratory rigs to large scale utility boilers. This paper provides an overview of the activities of the various partners involved and will, in particular, show the synergetic co-operation towards a common aim. Summarized are the results of the 2-year project.
Further experience improvement in fossil fuel combustion
99100746
for
environmental
Lazzeri, L. and De Santis, R. Proc. Am. Power Conf., 1998, 60, (l), 187195. Reviewed are the most recent Ansaldo Energia achievements in emission control via combustion modifications, with emphasis on NO., CO, and particulate emission reduction from oil-, gas-, and coal-fired boilers.
99ig9749 Gaseous pollutant emission gasification In a steam-fluldized bed. 1. Exper%% on pollutants formation and sulfur capture
s~.$
Zhao, F. et al. Huanjing Kerue Xuebao, 1998, 18, (3), 225-229. (In Chinese) On a steam fluidized bed gasifier with a diameter of 160mm the yields of the principal pollutants including hydrogen sulfide, ammonia and hydrogen cyanide were measured. The effects of operating conditions, such as grade of coal and bed temperature on the yields were determined. The sulfur capture via the HzS-CaO reaction in a reductive atmosphere with high concentration of steam in the fluidized bed was investigated. Comparisons of the yields of HzS between presence and absence of limestone was conducted to obtain the efficiency of sulfur capture. The effects of bed temperature and Ca/S ratio on the extent of sulfur capture were also determined.
potential of
Shrestha, R. M. et al. International Journal of Energy Research, 1998, 22, (lo), 923-933. Assessed in this study is the techno-economic potential of selected efficient demand-side appliances to mitigate emission of air pollutants from the power Sector of Sri Lanka. The study shows that from the technical and economic perspectives a total of about 38,646 GWh and about 25.6%, 34.2% and 34.6% of the total CO*, SO2 and NO, emission, respectively, could be avoided during 1997-2015 with the use of the efficient appliances. The generation savings from utility and user perspectives and emission mitigation potential are, however, significantly smaller as all the selected appliances are not found cost effective from these perspectives. This is mainly because electricity prices in the commercial and industrial sectors exceed the corresponding long-run marginal cost of electricity supply.
74
leads to an increase or a decrease in the concentration of pollutants: particulate matter, non-condensable gases, metals, hydrogen chloride, and semi-volatile compounds. Finally, it is possible to determine if the energy recovery of scrap tires used by a cement kiln meets environmental standards.
Greenhouse gas reduction through the use of high performance power systems (HIPPS)
99/00750
Robson, F. L. et al. (Am. Sot. Mechanical Eng.), 1997, 5, (l), 345-350. Identified were advanced high-performance power systems (HIPPS) which offer the potential of reducing greenhouse gas emissions, mainly COz, by as much as 50% compared to current coal-fired stations. The HIPPS were based on either frame-type or aerodynamic gas turbines which receive up to two-thirds of their thermal input from heat exchangers located in a coalfired high-temperature advanced furnace (HITAF). The remainder of the gas turbine energy was supplied by burning natural gas to increase the temperature from the HITAF to levels needed by modern gas turbines. Advanced HIPPS with a variety of engine configurations and power cycles were analysed for use in greenfield and repowering applications. These included conventional and intercooled gas turbines used in combined cycle and humid air turbine versions of HIPPS. Depending on cycle parameters, system power generation was 200-400 MW (or more), with efficiencies of 42-55%, based on fuel higher heating value. Emissions of COz and NO, were significantly reduced because of the increased efficiencies and advanced combustion technology used.
99l90751 ldentlfication and control of NO. emissions using neural networks f;e.2;;, J. and Feldman, E. E. J. Air Waste Manage. Assoc., 1998,48, (5), The application of two classes of artificial neural networks were investigated for the identification and control of discrete-time non-linear dynamical systems. A fully connected recurrent network is used for process identification, and a multilayer feed forward network is used for process control. The two neural networks are arranged in series for closed-loop control of oxides of nitrogen emissions of a simplified representation of a dynamical system. Plant data from one of Commonwealth Edison’s coal-