Environmental Evaluation Of Chinese Clean Coal-Fired Power Systems Using Life Cycle Assessment

China has established the world’s largest clean coal power generation system,in which end-of-pipe treatment represented by ultra-low emission（ULE）technology is currently the most important means of developing clean coal power.However,ULE does not necessarily equate to no emissions.Notwithstanding the significant decrease of such main pollutants as sulphur dioxide（SO₂）,nitrogen oxide（NOx）and particulate matter（PM）,the environmental problems through the coal-fired power system are still unresolved.Carbon dioxide（CO₂）emitted from coal-fired power plants（CFPPs）is one of the important challenges that the China’s clean coal power currently faces.On the one hand,CO₂ emissions have not been included in the monitoring and technical standard systems and,on the other hand,the carbon capture and storage or utilization（CCS/CCU）technologies,considered as a vital emissions abatement technology for CFPPs,are still facing various problems,including difficulties in promotion application,consumption of energy and resources,and assessment of environment comprehensive benefit.It is imperative for further pursuit of developing clean coal power to facilitate coordination and harmonization within energy conservation,emissions reduction,water saving,and other pollutants.Therefore,it is necessary to implement systematic analysis and holistic evaluation of different coal-fired power generating systems.In view of the above,the systematic and holistic approach of life cycle assessment（LCA）is applied to evaluate the environmental impacts of traditional CFPP,CFPP with ULE technology,and CFPP with oxyfuel CCS/CCU system.A new system boundary identification method is put forward to address methodological allocation problem in multifunction system,and then a systematic framework for LCA is developed.Furthermore,Chinese factors of primary energy and abiotic depletion are introduced into the developed framework to provide a quantitative environmental evaluation of CFPPs,including primary energy depletion（PED）,abiotic depletion potential（ADP）,global warming potential（GWP）,water use（WU）,acidification potential（AP）,eutrophication potential（EP）,and respiratory inorganics（RI）.The results suggest that the application of ULE technology to CFPPs can respectively decrease the values of AP,EP,and RI by79.34%,63.49%,and 98.33%,while on the other hand an obvious increase with 38.92%is seen in WU and a slight increase of less than 2.56%in PED,ADP,and GWP.By comparison,the LCA results for oxyfuel combustion CFPP with CCS/CCU show that GWP is reduced by 59.67%/60.78%,but PED,ADP,and WU are increased by60.67%-67.73%.In addition,the differences between CCS/CCU and ULE technology are no more than 5.19%in EP,AP,and RI.Moreover,desulfurization gypsum in ULE system and CO₂ utilized in CCU are considered as valuable products that are beneficial to environment with a 0.02%-0.51%and 0.28%-9.40%potential environmental benefits,respectively.Several uncertainty sources are identified as plant efficiency,transport distance,and several important parameters associated with ULE and oxyfuel technologies.A sensitivity analysis is then performed on the above-mentioned uncertainty parameters for estimating the effects on LCA results.Thus,the reliability and representativeness of the obtained eco-profiles are strengthened,further providing the reliable and comprehensive information of environmental sustainability associated with different choice of technology road maps and facilitating the development of clean coal power in China.