300 MW燃煤电厂生命周期排放气态有机污染物环境影响

Environmental impact of gaseous organic pollutants emitted from 300 MW coal-fired power plant during life cycle

近年来,我国煤电生产行业环境影响评价取得了一定进展,但主要集中在评估常规污染物带来的影响,而非常规气态有机污染物的排放影响一直被忽视,导致对人体健康和生态环境的危害被低估。为研究燃煤电厂气态有机污染物排放造成的环境影响,采用生命周期评价法(LCA),利用Gabi软件建模,通过实地数据采集和文献数据调研,详细编制了我国典型300 MW超临界燃煤机组发电过程排放气态有机污染物的能耗物耗数据清单,并对其排放清单结果及生命周期环境影响进行了综合评估。结果表明,2017年某300 MW燃煤电厂生命周期排放气态有机污染物总量约为9.99×10^(-3) kg/MWh。其中,燃煤发电系统排放量为3.87×10^(-3) kg/MWh,占总排放的38.69%,燃煤发电过程中间接排放是直接排放的1.64倍,占总排放的62.16%。燃煤电厂生命周期气态有机污染物排放计算得出的光化学臭氧合成潜值(POCP)、陆地生态毒性潜值(TETP)、潜在全球变暖效应潜值(GWP)、海洋生态毒性潜值(MAETP)、人体毒性潜值(HTP)、淡水生态毒性潜值(FAETP)和臭氧消耗潜值(ODP)环境影响类型的标准化值分别是7.43×10^(-14)、9.05×10^(-17)、7.72×10^(-17)、5.21×10^(-17)、1.43×10^(-13)、4.13×10^(-16)和3.21×10^(-18)。其中,POCP和HTP是对环境危害程度最大的影响类型,分别占总环境影响潜在值的50.63%和47.82%,煤炭开采、分选和烟气净化系统分别是POCP和HTP的主要贡献者,电厂运行阶段的煤炭消耗变化量对总环境影响最大。

In recent years,the environmental impact assessment of coal power production industry in China has made some progress,but it mainly focuses on evaluating the impact of conventional pollutants,while the emission impact of unconventional gaseous organic pollutants has been neglected,resulting in underestimation of the harm to human health and the ecological environment.In order to study the environmental impact of gaseous organic pollutant emissions from coal-fired power plants,using the method of life cycle assessment(LCA),the energy and material consumption data list of gaseous organic pollutants emitted from typical 300 MW supercritical coal-fired units in China was compiled in detail by using Gabi software modeling,field data collection and literature data research,and the emission list results and life cycle environmental impact were comprehensively evaluated.The results show that the total amount of gaseous organic pollutants in the life cycle of 300 MW coal-fired power plant in 2017 is about 9.99×10^(-3) kg/MWh.Among them,the emissions from coal-fired power generation system are 3.87×10^(-3) kg/MWh,accounting for 38.69% of the total emissions.The indirect emissions from coal-fired power generation are 1.64 times of direct emissions,accounting for 62.16% of the total emissions.The standardized values of environmental impact types such as the photochemical ozone synthesis potential(POCP),terrestrial ecotoxicity potential(TETP),potential global warming effect potential(GWP),Marine ecotoxicity potential(MAETP),human toxicity potential(HTP),freshwater ecotoxicity potential(FAETP) and ozone depletion potential(ODP) cycles calculated from gaseous organic pollutant emissions of coal-fired power plants during the life cycle are 7.43×10^(-14),9.05×10^(-17),7.72×10^(-17),5.21×10^(-17),1.43×10^(-13),4.13×10^(-16) and 3.21×10^(-18),respectively.Among them,POCP and human toxicity potential(HTP) are the most harmful types of environmental impact,accounting for 50.63% and 47.82% of the total potential value of environmental impact,respectively.Coal mining and washing and flue gas purification systems are the main contributors of POCP and HTP,respectively,and the change in coal consumption during the operation phase of the power plant has the greatest impact on the overall environment.