Calculating The Emission Inventories And Assessing The Reduction Potential Of Atmospheric Heavy Metal Pollution Of Coal-fired Power Plants In China From The Perspective Of Production And Consumption

Atmospheric heavy metal pollution threatens China’s ecological environment security and human health,and coal-fired power plant(CFPP)is an important sources of atmospheric heavy metal emissions in China.Reducing heavy metal emissions from CFPPs is an important part of China’s implementation of the Minamata Convention and control of heavy metal emissions comprehensively and effectively.However,there are a large number of coal-fired power plants in China,which are widely distributed and have significant technical differences.How to formulate atmospheric heavy metal emission reduction strategies for different regions and even different coal-fired power plants has become a key scientific issue to effectively control atmospheric heavy metal pollution caused by coal-fired power.Thus,a high-precision long-term atmospheric heavy metal emission inventory from the perspective of production and consumption was compiled,a regional emission responsibility allocation model was constructed,the key driving factors affecting emission changes were identified,and the synergistic emission reduction potential of air pollution and carbon reduction policies for heavy metals in the atmosphere of CFPPs was evaluated.The study expands the data base,decision-making tools and theoretical system of heavy metal control in CFPPs,and have great practical significance for realizing clean utilization of CFPPs in China.By using emission factor model,a long time-series atmospheric heavy metal emission inventory of CFPPs in China from the perspective of production was compiled.It is found that the total atmospheric heavy metal emissions from coal-fired power plants in China decreased from 12 869.8 t in 2005 to 8 801.0 t in 2020.The emissions of small coal-fired power plants with installed capacity under 300 MW decreased by 90.9% due to the upgrading of pollution control equipment and the elimination of small thermal power plants,while the emissions of large coal-fired power plants(> 1200 MW)increased by almost three times due to the significant increase in installed capacity during the study period.Through the combination of multi-regional input-output model and production-based emission inventory,this dissertation calculates the embodied emissions at the provincial level from the perspective of consumption and reveals the emission flow rules among regions.It is found that the main contributors of embodied emissions from the perspective of consumption are the coastal developed provinces.From the perspective of emission flow,developing regions with large amount of coal consumption are the main net emission outflow areas,while developed regions are the main net emission inflow areas.By constructing a "shared responsibility" model coupling the emission inventory from the perspective of production and consumption,this dissertation takes atmospheric mercury emission as an example,and clarifies the division mechanism of provincial emission reduction responsibility.The results show that provinces with large emissions from the perspective of consumption and provinces with large emissions from the perspective of production should bear higher emission reduction responsibilities under the principle of "shared responsibility".Logarithmic Mean Divisia Index and Structural Decomposition Analysis was used to identify the driving factors and their evolution process of atmospheric mercury emissions from the perspective of production and consumption.The results found that from the perspective of production,the most obvious emission reduction effects are energy intensity and emission intensity,but the economic scale growth offsets the above emission reduction effects to a certain extent.From the perspective of consumption,the emission factor is the biggest driving factor of emission reduction,while the increase of per capita consumption greatly promotes the growth of embodied emissions.A scenario analysis model was used to simulate the impact of pollution and carbon reduction policies on heavy metal emissions from coal-fired power plants in China,and to assess the emission reduction potential of coal-fired power plants in China under different policy combinations in the future.The results show that the total amount of heavy metal emissions under the most stringent policy scenario is 38.7 Kt,which was only 17.6% of that under the baseline scenario.Rapid elimination of small self-owned power plants with high emission intensity and low power generation efficiency and gradual increase of coal washing proportion are effective measures to reduce atmospheric heavy metal emissions in the future.