CO₂ capture and storage(CCS) are required for coal‐fired power plants, which are major sources of anthropogenic CO₂ emission. In this study, energy, exergy, environment, and economic (4E) analyses were performed for a 500‐MW_e oxy‐coal ultra‐supercritical circulating fluidized‐bed (CFB) power plant with CO₂ capture. The effect of the location of flue‐gas recirculation (FGR) on the 4E values was investigated for wet FGR (wFGR) at 170°C, dry FGR (dFGR) at 68°C, and 80% wet and 20% dry FGR (wdFGR). The net electricity efficiencies of the wFGR and dFGR power plants were 37% and 36%, respectively. The exergy loss was the largest in the combustor and boiler area, where process improvement was possible. The levelized cost of electricity was approximately 60 $/MWh. The return on investment was 6.7% and 6.1%/y for the wFGR and dFGR plants, respectively. The CO₂ emission rate decreased by 90% (from 690 to 76 kg‐CO₂/MWh) in the oxy‐coal power plants with CO₂ capture. Relative to the wFGR, the dFGR was advantageous for preventing material corrosion because of the lower sulfur content in the FGR stream. For the wdFGR power plant, the process performance was intermediate, that is, between that of the wFGR plant and that of the dFGR plant. The study provided an effective tool for identifying the technological and economic effects of the FGR location for the oxy‐coal power plant with CCS via 4E analyses.

中文翻译：

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烟气再循环对带有CO2捕集的氧煤循环流化床电厂的能源，火用，环境和经济的影响

燃煤电厂需要CO ₂捕集和封存（CCS），这是人为CO ₂排放的主要来源。在这项研究中，对具有CO ₂的500兆瓦_e氧煤超超临界循环流化床（CFB）电厂进行了能源，火用，环境和经济（4E）分析捕获。对于170°C的湿FGR（wFGR），68°C的干FGR（dFGR），80％的湿FGR和20％的干FGR，研究了烟气再循环（FGR）位置对4E值的影响（ wdFGR）。wFGR和dFGR电厂的净电力效率分别为37％和36％。火用损失在燃烧器和锅炉区域最大，可以进行工艺改进。平均的电费约为60美元/兆瓦时。wFGR和dFGR工厂的年投资回报率分别为6.7％和6.1％。的CO ₂排放率下降90％（从690到76千克的CO ₂在氧-煤发电厂/兆瓦）用CO ₂捕获。相对于wFGR，由于FGR流中的硫含量较低，dFGR有利于防止材料腐蚀。对于wdFGR电厂，其过程性能是中等的，即介于wFGR电厂和dFGR电厂之间。该研究提供了一种有效的工具，可通过4E分析确定具有CCS的燃煤电厂FGR位置的技术和经济影响。