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02788 Development of regenerable desulfurization sorbent for coal gas sulfur removal below ppm level
15
Environment
(pollution, health protection,
safety)
were held responsible for these surface area increments. Thermogravimetric measurements showed by decreasing the Ca(OH)z content of the hydrated sorbent, which was assumed to be converted to calcium-containing reactive species. the surface area of the sorbent increased. The conclusion was reached that the reactivity of hydrated sorbents towards SO2 was closely related to the sorbent surface area and the presence of the reactive species in the sorbent.
Sulfur absorbing capacity was 90% of the assumed sulfidation for the first cycle, then capacity decreased number of cycles. The sorbent removed sulfur compounds 20 cycles of desulfurization test. The developed sorbents be used in removing sulfur from high temperature coal power generation systems. 99102789
stoichiometric according to the to < 1 ppm after could potentially gas for advanced
The distribution of PAHs in airborne particulates source identification In Dagang Area, Tianjin,
99102705
~hl$ollution
Accorsi, R. et al. Progr. Nucl. Energy, 1999, 34, (4), 387-411. The selection of a technology for the cleanup of a contamimated site is complicated by the involvement of multiple stakeholders with conflicting objectives. Multi-attribute decision analysis can be employed to assess the impact of the alternative technologies on a number of performance measures and to rank these alternatives according to the preferences of each stakeholder. This paper presents an approach to constructing the utility functions that decision analysis requires using stakeholder input. The proposed approach is based on the analytic hierarchy process and accounts for linguistic imprecision in the stakeholder assessments. The experience from a real case study is reported and discussed.
Zhu, T. et al. Zhongguo Huanjing Kexue, 1998, 18, (4), 289-292. (In Chinese) An investigation into the distribution and pollution sources of polycyclic aromatic hydrocarbons (PAHs) in atmospheric particulate in Dagang Area, Tianjin, China. The study of PAHs is of particular importance as some PAHs exhibit carcinogenic effects in humans. The observed ratio of BaP to other PAHs indicates that the major source of PAHs is coal-combustion pollution in the Dagang petrochemical industrial zone and oil-combustion pollution in the Dagang oil-field zone.
Developing utility functions for environmental decision making
Development of a novel chemical-looping combustion: synthesis of a looping material with a double metal oxide of COO-NiO
99102786
Jin, H. et al. Energy Fuels, 1998, 12, (6), 1272-1277. This study details possible new technology for the mitigation of greenhouse gas and more efficient use of energy, stemming from the use of a new material as a solid looping reactant for a novel chemical-looping combustion. The fundamental features of several looping materials which undergo both reduction (fuel with metal oxide) and oxidation (the reduced metal with air) were identified using a thermogravimetric reactor (TGR). A new looping material was also synthesized by synergetically combining nickel oxide with cobalt oxide, using a double 11 oxide and adding YSZ. The resulting material, Coo-NiO/YSZ, was found to perform extremely well in high reactivity, completely avoiding carbon deposition, and also has good repeatability. From the evidence, the solid reactant obtained seems a suitable looping material for application of the chemical-looping combustion. 99102707 Development of advanced sorbents for desulfurization of coal gases at elevated temperatures
Abbasian, J. et al. High Temp. Gas Clean., [Pap. Int. Symp. Exhib. Gas Clean. High Temp.], 3rd. 1996, 607-617. Edited by Schmidt, E., Institut fiir Mechanische Verfahrenstechnik and Mechanik der Universitaet Karlsruhe, Karlsruhe, Germany There has been a move to optimize technology involved in coal-based power generation. This includes sulfur compound removal from coal gases, a component of integrated gasification combined cycle (IGCC) systems Consequently reducing hydrogen sulfide to sufficiently low concentrations at elevated temperatures is recognized as crucial to the efficient, economic development of IGCC processes. Development of high temperature regenerable desulfurization sorbents has focused on using various combinations of transition metal oxides for applications >55O”C, limiting the choice of metal oxides to those which possess favourable thermodynamic equilibrium. Zinc-based sorbents, such as zinc titanates, have emerged as leading candidates. However due to problems with sorbent deterioration, further improvement is needed to minimize the overall cost of desulfurization. Recent studies on total IGCC system integration indicated that overall process efficiency gains of conducting desulfurization at ~550°C may not be sufficient to justify operation at such high temperatures. Thus optimum desulfurization temperatures appears to be 350-550°C. In this way technical viability and process efficiency seem to result in lower overall process costs. A study to develop advanced mixed-metal oxide sorbents for desulfurization of coal-derived fuel gases in a fluidized bed temperatures of 350-550°C is in progess and the results obtained are presented.
Development of regenerable desulfurization sor99102788 bent for coal gas sulfur removal below ppm level
Kobayashi, M. et al. High Temp. Gas Clean., [Pap. Int. Symp. Exhib. Gas Clean. High Temp.], 3, 1996, 618-629. Edited by Schmidt, E., Institut fiir Mechanische Verfahrenstechnik und Mechanik der Universitaet Karlsruhe, Karlsruhe, Germany. A number of sorbents containing zinc ferrite have been developed for high temperature sulfur removal from coal derived gas. The sorbent must achieve 1 ppm sulfur concentrations in purified coal gas and should be regenerable for online, repeated use in a plant. An evaluation of the performance of the sorbent during repeated desulfurization tests in a pressurized pseudo-coal gas environment was carried out. By using a homogeneous precipitation method when preparing the zinc ferrite the sulfidation rate could be accelerated, and the carbon deposits which slow down sorbent performance in a pressurized coal gas environment were avoided. The sulfur decreasing limit of the sorbent was determined by a sulfidation test in a pseudo-coal gas with fixed bed reactor operated at 723 K and 9 kg/cm’. The sorbent maintained sulfur concentrations in purified coal gas at cl ppm while introducing 1000 ppm HzS to the reactor inlet. Desulfurization cycle tests, repeating reduction, sulfidation and oxidization were used to evaluate sorbent regenerability, and found no significant decline in reaction rate, even in a cycle test under pressurized conditions.
290
Fuel and Energy Abstracts
July 1999
Ecological issues in development of brown coal deposits in the Pripyat Polessye Gledko, Y. A. Vestn. Beloruss. Gos. Univ., Ser. 2, 1998, (2), 61-65. (In
99102790
Russian) Pripyat Polessye brown coal characteristics and problems associated with their use are described. The impact that the mining of these deposits has on the natural landscapes and environment are also discussed.
Effect of Ropar thermal power plant on environment samples of Sutlej River
99102791
Sahota, H. S. and Gill, S. K. Res. J. Chem. Environ., 1998, 2, (2). 49-50. An investigation of the possible radioactive contamination of environmental samples due to coal fly ash from Ropar Thermal Power Plant. Concentrations of different radionuclides were measured in an aquatic species, potamogeton perfoliatus, from two sites on the Sutlej river. Tools of gamma-spectrometry were used. It was found that the coal fly ash causes radioactive contamination of environmental samples to some extent. Potamogeton perfoliatus is highlighted as a good indicator of radionuclide pollution.
Environmental power generation in Brazil
99102792
issues arising from the thermo-
dos Santos,
M. A. and Rodrigues, M. G. Energy Policy, 1998, 26, (14), 1065-1070. The present study is the outcome of research of the thermopower generation and it’s environmental impacts in Brazil. The idea was to establish a comparative analysis between the expansion of the power operation and the emissions of pollutants, for carrying out new prospective studies on this topic, as well as new regulatory proposal for the electricity system and the potential environmental risk related. Under the Decceniall Expansion Plan of Brazilian Government, the country’s total installed capacity will grow from 57.6 GW in 1997 to 90.2 GW in 2006, with hydroelectric share declining from 92 to 83% and thermoelectric share growing from 8 to 17% over the same period. The option of thermopower plants could be a good opportunity to open the Brazilian Electric Sector to private investors, considering that low public financial capacity of the public sector to expand the electric system. But it is important to note that the new power plants could generate large environmental impacts to the atmosphere if not controlled. This paper deals specifically with the analysis of atmospheric pollution from coal and natural gas power plants and policies related to the two fields mentioned above.
99102793 Factors affecting mercury control in utility flue gas using sorbent injection
Carey, T. R. et al. Proc., Annu. Meet. - Air Waste Manage. Assoc., [computer optical disk], 1997, 90, WA72A05/1-17. There is much interest in assessing whether cost-effective technologies exist for removing mercury from fossil-fired flue gas because of the possible impending regulatory controls. This paper focusses on one of the more promising approaches, involving the direct injection of mercury sorbents, such as activated carbon, into the flue gas. It has been proven that this method is effective at removing mercury in municipal waste incinerators, however, tests conducted on utility fossil-fired boilers show that mercury removal is much more difficult in utility flue gas. Bench-scale and pilotscale tests have been conducted by EPRI to determine the ability of different sorbents to remove mercury in simulated and actual flue gas streams. The effect of various sorbent and flue gas parameters on sorbent performance are analysed under bench-scale test conditions. Data from the tests are being used to develop a theoretical model for predicting mercury removal by sorbents at different conditions. Additionally, the possibility of regenerating and recycling sorbents is being evaluated. This paper describes the results of parametric bench-scale and pilot-scale tests investigating the removal of mercuric chloride and elemental mercury by activated carbon. Results obtained so far indicate that the adsorption capacity of a given sorbent is dependent on many factors, including the type of mercury being adsorbed, flue gas composition and adsorption temperature. Valuable insight into potential mercury adsorption mechanisms has been provided for instance the results suggest that the removal of mercury involves both physical and chemical mechanisms. It is important to understand these
Environment
(pollution, health protection,
safety)
were held responsible for these surface area increments. Thermogravimetric measurements showed by decreasing the Ca(OH)z content of the hydrated sorbent, which was assumed to be converted to calcium-containing reactive species. the surface area of the sorbent increased. The conclusion was reached that the reactivity of hydrated sorbents towards SO2 was closely related to the sorbent surface area and the presence of the reactive species in the sorbent.
Sulfur absorbing capacity was 90% of the assumed sulfidation for the first cycle, then capacity decreased number of cycles. The sorbent removed sulfur compounds 20 cycles of desulfurization test. The developed sorbents be used in removing sulfur from high temperature coal power generation systems. 99102789
stoichiometric according to the to < 1 ppm after could potentially gas for advanced
The distribution of PAHs in airborne particulates source identification In Dagang Area, Tianjin,
99102705
~hl$ollution
Accorsi, R. et al. Progr. Nucl. Energy, 1999, 34, (4), 387-411. The selection of a technology for the cleanup of a contamimated site is complicated by the involvement of multiple stakeholders with conflicting objectives. Multi-attribute decision analysis can be employed to assess the impact of the alternative technologies on a number of performance measures and to rank these alternatives according to the preferences of each stakeholder. This paper presents an approach to constructing the utility functions that decision analysis requires using stakeholder input. The proposed approach is based on the analytic hierarchy process and accounts for linguistic imprecision in the stakeholder assessments. The experience from a real case study is reported and discussed.
Zhu, T. et al. Zhongguo Huanjing Kexue, 1998, 18, (4), 289-292. (In Chinese) An investigation into the distribution and pollution sources of polycyclic aromatic hydrocarbons (PAHs) in atmospheric particulate in Dagang Area, Tianjin, China. The study of PAHs is of particular importance as some PAHs exhibit carcinogenic effects in humans. The observed ratio of BaP to other PAHs indicates that the major source of PAHs is coal-combustion pollution in the Dagang petrochemical industrial zone and oil-combustion pollution in the Dagang oil-field zone.
Developing utility functions for environmental decision making
Development of a novel chemical-looping combustion: synthesis of a looping material with a double metal oxide of COO-NiO
99102786
Jin, H. et al. Energy Fuels, 1998, 12, (6), 1272-1277. This study details possible new technology for the mitigation of greenhouse gas and more efficient use of energy, stemming from the use of a new material as a solid looping reactant for a novel chemical-looping combustion. The fundamental features of several looping materials which undergo both reduction (fuel with metal oxide) and oxidation (the reduced metal with air) were identified using a thermogravimetric reactor (TGR). A new looping material was also synthesized by synergetically combining nickel oxide with cobalt oxide, using a double 11 oxide and adding YSZ. The resulting material, Coo-NiO/YSZ, was found to perform extremely well in high reactivity, completely avoiding carbon deposition, and also has good repeatability. From the evidence, the solid reactant obtained seems a suitable looping material for application of the chemical-looping combustion. 99102707 Development of advanced sorbents for desulfurization of coal gases at elevated temperatures
Abbasian, J. et al. High Temp. Gas Clean., [Pap. Int. Symp. Exhib. Gas Clean. High Temp.], 3rd. 1996, 607-617. Edited by Schmidt, E., Institut fiir Mechanische Verfahrenstechnik and Mechanik der Universitaet Karlsruhe, Karlsruhe, Germany There has been a move to optimize technology involved in coal-based power generation. This includes sulfur compound removal from coal gases, a component of integrated gasification combined cycle (IGCC) systems Consequently reducing hydrogen sulfide to sufficiently low concentrations at elevated temperatures is recognized as crucial to the efficient, economic development of IGCC processes. Development of high temperature regenerable desulfurization sorbents has focused on using various combinations of transition metal oxides for applications >55O”C, limiting the choice of metal oxides to those which possess favourable thermodynamic equilibrium. Zinc-based sorbents, such as zinc titanates, have emerged as leading candidates. However due to problems with sorbent deterioration, further improvement is needed to minimize the overall cost of desulfurization. Recent studies on total IGCC system integration indicated that overall process efficiency gains of conducting desulfurization at ~550°C may not be sufficient to justify operation at such high temperatures. Thus optimum desulfurization temperatures appears to be 350-550°C. In this way technical viability and process efficiency seem to result in lower overall process costs. A study to develop advanced mixed-metal oxide sorbents for desulfurization of coal-derived fuel gases in a fluidized bed temperatures of 350-550°C is in progess and the results obtained are presented.
Development of regenerable desulfurization sor99102788 bent for coal gas sulfur removal below ppm level
Kobayashi, M. et al. High Temp. Gas Clean., [Pap. Int. Symp. Exhib. Gas Clean. High Temp.], 3, 1996, 618-629. Edited by Schmidt, E., Institut fiir Mechanische Verfahrenstechnik und Mechanik der Universitaet Karlsruhe, Karlsruhe, Germany. A number of sorbents containing zinc ferrite have been developed for high temperature sulfur removal from coal derived gas. The sorbent must achieve 1 ppm sulfur concentrations in purified coal gas and should be regenerable for online, repeated use in a plant. An evaluation of the performance of the sorbent during repeated desulfurization tests in a pressurized pseudo-coal gas environment was carried out. By using a homogeneous precipitation method when preparing the zinc ferrite the sulfidation rate could be accelerated, and the carbon deposits which slow down sorbent performance in a pressurized coal gas environment were avoided. The sulfur decreasing limit of the sorbent was determined by a sulfidation test in a pseudo-coal gas with fixed bed reactor operated at 723 K and 9 kg/cm’. The sorbent maintained sulfur concentrations in purified coal gas at cl ppm while introducing 1000 ppm HzS to the reactor inlet. Desulfurization cycle tests, repeating reduction, sulfidation and oxidization were used to evaluate sorbent regenerability, and found no significant decline in reaction rate, even in a cycle test under pressurized conditions.
290
Fuel and Energy Abstracts
July 1999
Ecological issues in development of brown coal deposits in the Pripyat Polessye Gledko, Y. A. Vestn. Beloruss. Gos. Univ., Ser. 2, 1998, (2), 61-65. (In
99102790
Russian) Pripyat Polessye brown coal characteristics and problems associated with their use are described. The impact that the mining of these deposits has on the natural landscapes and environment are also discussed.
Effect of Ropar thermal power plant on environment samples of Sutlej River
99102791
Sahota, H. S. and Gill, S. K. Res. J. Chem. Environ., 1998, 2, (2). 49-50. An investigation of the possible radioactive contamination of environmental samples due to coal fly ash from Ropar Thermal Power Plant. Concentrations of different radionuclides were measured in an aquatic species, potamogeton perfoliatus, from two sites on the Sutlej river. Tools of gamma-spectrometry were used. It was found that the coal fly ash causes radioactive contamination of environmental samples to some extent. Potamogeton perfoliatus is highlighted as a good indicator of radionuclide pollution.
Environmental power generation in Brazil
99102792
issues arising from the thermo-
dos Santos,
M. A. and Rodrigues, M. G. Energy Policy, 1998, 26, (14), 1065-1070. The present study is the outcome of research of the thermopower generation and it’s environmental impacts in Brazil. The idea was to establish a comparative analysis between the expansion of the power operation and the emissions of pollutants, for carrying out new prospective studies on this topic, as well as new regulatory proposal for the electricity system and the potential environmental risk related. Under the Decceniall Expansion Plan of Brazilian Government, the country’s total installed capacity will grow from 57.6 GW in 1997 to 90.2 GW in 2006, with hydroelectric share declining from 92 to 83% and thermoelectric share growing from 8 to 17% over the same period. The option of thermopower plants could be a good opportunity to open the Brazilian Electric Sector to private investors, considering that low public financial capacity of the public sector to expand the electric system. But it is important to note that the new power plants could generate large environmental impacts to the atmosphere if not controlled. This paper deals specifically with the analysis of atmospheric pollution from coal and natural gas power plants and policies related to the two fields mentioned above.
99102793 Factors affecting mercury control in utility flue gas using sorbent injection
Carey, T. R. et al. Proc., Annu. Meet. - Air Waste Manage. Assoc., [computer optical disk], 1997, 90, WA72A05/1-17. There is much interest in assessing whether cost-effective technologies exist for removing mercury from fossil-fired flue gas because of the possible impending regulatory controls. This paper focusses on one of the more promising approaches, involving the direct injection of mercury sorbents, such as activated carbon, into the flue gas. It has been proven that this method is effective at removing mercury in municipal waste incinerators, however, tests conducted on utility fossil-fired boilers show that mercury removal is much more difficult in utility flue gas. Bench-scale and pilotscale tests have been conducted by EPRI to determine the ability of different sorbents to remove mercury in simulated and actual flue gas streams. The effect of various sorbent and flue gas parameters on sorbent performance are analysed under bench-scale test conditions. Data from the tests are being used to develop a theoretical model for predicting mercury removal by sorbents at different conditions. Additionally, the possibility of regenerating and recycling sorbents is being evaluated. This paper describes the results of parametric bench-scale and pilot-scale tests investigating the removal of mercuric chloride and elemental mercury by activated carbon. Results obtained so far indicate that the adsorption capacity of a given sorbent is dependent on many factors, including the type of mercury being adsorbed, flue gas composition and adsorption temperature. Valuable insight into potential mercury adsorption mechanisms has been provided for instance the results suggest that the removal of mercury involves both physical and chemical mechanisms. It is important to understand these