Aiming at issues on flue gas des-ulfurization facing coal-fired power plants inChina, such as process selection, whetheradopting flue gas desulfurization (FGD) or not,qualification of flue gas desulfurization en-ginee...Aiming at issues on flue gas des-ulfurization facing coal-fired power plants inChina, such as process selection, whetheradopting flue gas desulfurization (FGD) or not,qualification of flue gas desulfurization en-gineering company, the localization of technicalequipment, charge for SO2 emission andnormalized management, this article makes acomprehensive analysis and puts forwardconstructive suggestions. These will providesome references for those being engaged in fluegas desulfurization in coal-fired power plants.[展开更多
Three gas separation technologies,chemical absorption,membrane separation and pressure swing adsorption,are usually applied for CO2 capture from flue gas in coal-fired power plants.In this work,the costs of the three ...Three gas separation technologies,chemical absorption,membrane separation and pressure swing adsorption,are usually applied for CO2 capture from flue gas in coal-fired power plants.In this work,the costs of the three technologies are analyzed and compared.The cost for chemical absorption is mainly from $30 to $60 per ton(based on CO2 avoided),while the minimum value is $10 per ton(based on CO2 avoided).As for membrane separation and pressure swing adsorption,the costs are $50 to $78 and $40 to $63 per ton(based on CO2 avoided),respectively.Measures are proposed to reduce the cost of the three technologies.For CO2 capture and storage process,the CO2 recovery and purity should be greater than 90%.Based on the cost,recovery,and purity,it seems that chemical absorption is currently the most cost-effective technology for CO2 capture from flue gas from power plants.However,membrane gas separation is the most promising alternative approach in the future,provided that membrane performance is further improved.展开更多
The Ontario Hydro Method （OHM） recommended by the United States Environmental Protection Agency （EPA） was used to determine mercury speciation in the combustion flue gas across wet FGD systems. Four coal-fired uni...The Ontario Hydro Method （OHM） recommended by the United States Environmental Protection Agency （EPA） was used to determine mercury speciation in the combustion flue gas across wet FGD systems. Four coal-fired units with wet FGD systems were chosen to evaluate mercury speciation and mercury removal efficiencies through these wet FGD systems. Chlorine content in coal had been suggested as a main factor that affects mercury speciation in flue gas. It is shown that the higher the chlorine concentration in coal is, the higher the percentage of oxidized mercury （Hg2＋） is removed in wet FGD systems, which can increase overall mercury removal efficiencies through wet FGD systems. The selective catalyst reduction （SCR） system has a function of oxidizing ele- mental mercury （Hg0） to oxidized mercury. A higher percentage of oxidized mercury in the total vapor mercury at the FGD inlet is observed when SCR is in service. Therefore, higher overall mercury removal efficiencies through wet FGD are attained. Because of different wet FGD operating conditions, there are different mercury removal efficiencies in different units. Elemental mercury reemission took place when a fraction of oxidized mercury absorbed in the slurry is reduced to elemental mercury, and Hg2＋ is reemitted from stack, which results in decreases in mercury removal efficiencies through wet FGD systems.展开更多
The numerous environmental protection equipments for desulfuration,denitration,and precipitation have been installed in the domestic coal-fired power plants,while the investment and energy consumption of the units inc...The numerous environmental protection equipments for desulfuration,denitration,and precipitation have been installed in the domestic coal-fired power plants,while the investment and energy consumption of the units increase correspondingly.To reduce the operational cost and initial investment as much as possible,the working processes of the environmental protection equipments are optimized in the design and some new technologies are adopted for energy saving.These technologies include the SCR,SNCR,combined SCR and SNCR for denitration device,system without gas-gas heater design for desulfuration,desulfuration system without bypass,booster fan and induced draft fan integrated,stack and cooling tower integrated and so on.However,such measures may cause some new problems during the operation of the equipment.The problems are summarized and analyzed thoroughly and the feasible methods are provided to solve them,which could decrease the operational risk of units.The present discussion can also improve the further design of environmental protection equipments to ensure the long-term steady operation of the units.展开更多
For Finland, carbon dioxide mineralisation was identified as the only option for CCS （carbon capture and storage） application. Unfortunately it has not been embraced by the power sector. One interesting source-sink ...For Finland, carbon dioxide mineralisation was identified as the only option for CCS （carbon capture and storage） application. Unfortunately it has not been embraced by the power sector. One interesting source-sink combination, however, is formed by magnesium silicate resources at Vammala, located -85 km east of the 565 MWe coal-fired Meri-Pori Power Plant on the country＇s southwest coast. This paper assesses mineral sequestration of Meri-Pori power plant CO2, using Vammala mineral resources and the mineralisation process under development at Abo Akademi University. That process implies Mg（OH）E production from magnesium silicate-based rock, followed by gas/solid carbonation of the Mg（OH）2 in a pressurised fluidised bed. Reported are results on experimental work, i.e., Mg（OH）2 production, with rock from locations close to Meri-Pori. Results suggest a total CO2 fixation capacity -50 Mt CO2 for the Vammala site, although production of Mg（OH）2 from rock from the site is challenging. Finally, as mineralisation could be directly applied to flue gases without CO2 pre-capture, we report from experimental work on carbonation of Mg（OH）2 with CO2 and CO2-SO2-O2 gas mixtures. Results show that SO2 readily reacts with Mg（OH）2, providing an opportunity to simultaneously capture SO2 and CO2, which could make separate flue gas desulphurisation redundant.展开更多
文摘Aiming at issues on flue gas des-ulfurization facing coal-fired power plants inChina, such as process selection, whetheradopting flue gas desulfurization (FGD) or not,qualification of flue gas desulfurization en-gineering company, the localization of technicalequipment, charge for SO2 emission andnormalized management, this article makes acomprehensive analysis and puts forwardconstructive suggestions. These will providesome references for those being engaged in fluegas desulfurization in coal-fired power plants.[
基金Supported by the National High Technology Research and Development Program of China (2007AA03Z229)the Fundamental Research Funds for the Central Universities (2009ZM0185)
文摘Three gas separation technologies,chemical absorption,membrane separation and pressure swing adsorption,are usually applied for CO2 capture from flue gas in coal-fired power plants.In this work,the costs of the three technologies are analyzed and compared.The cost for chemical absorption is mainly from $30 to $60 per ton(based on CO2 avoided),while the minimum value is $10 per ton(based on CO2 avoided).As for membrane separation and pressure swing adsorption,the costs are $50 to $78 and $40 to $63 per ton(based on CO2 avoided),respectively.Measures are proposed to reduce the cost of the three technologies.For CO2 capture and storage process,the CO2 recovery and purity should be greater than 90%.Based on the cost,recovery,and purity,it seems that chemical absorption is currently the most cost-effective technology for CO2 capture from flue gas from power plants.However,membrane gas separation is the most promising alternative approach in the future,provided that membrane performance is further improved.
文摘The Ontario Hydro Method （OHM） recommended by the United States Environmental Protection Agency （EPA） was used to determine mercury speciation in the combustion flue gas across wet FGD systems. Four coal-fired units with wet FGD systems were chosen to evaluate mercury speciation and mercury removal efficiencies through these wet FGD systems. Chlorine content in coal had been suggested as a main factor that affects mercury speciation in flue gas. It is shown that the higher the chlorine concentration in coal is, the higher the percentage of oxidized mercury （Hg2＋） is removed in wet FGD systems, which can increase overall mercury removal efficiencies through wet FGD systems. The selective catalyst reduction （SCR） system has a function of oxidizing ele- mental mercury （Hg0） to oxidized mercury. A higher percentage of oxidized mercury in the total vapor mercury at the FGD inlet is observed when SCR is in service. Therefore, higher overall mercury removal efficiencies through wet FGD are attained. Because of different wet FGD operating conditions, there are different mercury removal efficiencies in different units. Elemental mercury reemission took place when a fraction of oxidized mercury absorbed in the slurry is reduced to elemental mercury, and Hg2＋ is reemitted from stack, which results in decreases in mercury removal efficiencies through wet FGD systems.
文摘The numerous environmental protection equipments for desulfuration,denitration,and precipitation have been installed in the domestic coal-fired power plants,while the investment and energy consumption of the units increase correspondingly.To reduce the operational cost and initial investment as much as possible,the working processes of the environmental protection equipments are optimized in the design and some new technologies are adopted for energy saving.These technologies include the SCR,SNCR,combined SCR and SNCR for denitration device,system without gas-gas heater design for desulfuration,desulfuration system without bypass,booster fan and induced draft fan integrated,stack and cooling tower integrated and so on.However,such measures may cause some new problems during the operation of the equipment.The problems are summarized and analyzed thoroughly and the feasible methods are provided to solve them,which could decrease the operational risk of units.The present discussion can also improve the further design of environmental protection equipments to ensure the long-term steady operation of the units.
文摘For Finland, carbon dioxide mineralisation was identified as the only option for CCS （carbon capture and storage） application. Unfortunately it has not been embraced by the power sector. One interesting source-sink combination, however, is formed by magnesium silicate resources at Vammala, located -85 km east of the 565 MWe coal-fired Meri-Pori Power Plant on the country＇s southwest coast. This paper assesses mineral sequestration of Meri-Pori power plant CO2, using Vammala mineral resources and the mineralisation process under development at Abo Akademi University. That process implies Mg（OH）E production from magnesium silicate-based rock, followed by gas/solid carbonation of the Mg（OH）2 in a pressurised fluidised bed. Reported are results on experimental work, i.e., Mg（OH）2 production, with rock from locations close to Meri-Pori. Results suggest a total CO2 fixation capacity -50 Mt CO2 for the Vammala site, although production of Mg（OH）2 from rock from the site is challenging. Finally, as mineralisation could be directly applied to flue gases without CO2 pre-capture, we report from experimental work on carbonation of Mg（OH）2 with CO2 and CO2-SO2-O2 gas mixtures. Results show that SO2 readily reacts with Mg（OH）2, providing an opportunity to simultaneously capture SO2 and CO2, which could make separate flue gas desulphurisation redundant.
