| China’s energy structure is dominated by coal, meanwhile coal-fired electricity industry consumes nearly50%of the total coal consumption. Coal-fired power plants have been considered as one of the major emission sources of regional atmospheric haze and acid rain. Environmental influence researches of coal-fired power plants have important implications for air pollution control, energy structure adjustment and social stability. A unit-based inventory compilation method of coal-fired power plants was applied in this paper, which greatly reduced uncertainties of emission inventory. Meanwhile, emission projection of SO2, NOx, particulate matter (PM) and PM2.5was developed based on unit-based emission inventory for the year2011. The main contents are as follows:(1) Methods of literature review and data investigation are combined to build database of unit-based activity levels. Meanwhile, emission factor database of main pollutants are built based on field measurement. Estimated total emissions of SO2, NOx, PM and PM2.5in2011were7251kt,8067kt,1433kt and622kt, respectively. Units larger than300MW consumed75%coal, while emitting46%SO2,58%NOx,55%PM and63.2%PM2.5. Compared with estimation results of2005, contamination status of Chinese power plants in2011showed a remarkable turnaround. SO2, PM and PM2.5emissions of coal-fired power plants respectively decreased by58%,28%and10%, whereas NOx increased by21%. It should be noted that national coal consumption of the electricity industry in2011was1804Mt, increased by71%compared with2005. Significant reduction was found in SO2inventory, which mainly attributed to the high installation ratio of gas desulphurization facilities. NOx emission had a21%growth rate largely due to the low installation rate of SCR or SNCR.(2) Monte Carlo simulation was adopted to evaluate uncertainties of unit-based emission inventory in this paper, and results showed that uncertainties (expressed as95%confidence interval around the central value) at unit level of SO2, NOx, PM and PM2.5were estimated to be-10.1%～+5.4%,-2.1%～+4.6%,-5.7%～+6.9%and-4.3%～+6.5%, respectively. Also sector-based simulation was applied. Uncertainties at sector level were calculated to be-26.8%～+27.6%,-16.8%～+34.1%,-68.1%～+141.4%and-68.6%～+147.6%, respectively. Uncertainties at sector level were overestimated because diversity of emission characteristics in a given source category should not be neglected. The large number of plants narrowed unit-based uncertainties when comparing these two methods. Sector-based uncertainty analysis well depended on detailed source classification when comparing uncertainties at provincial level.(3) Electricity elasticity coefficient method was applied in this paper to forecast future electric energy production and coal consumption in China. Baseline scenario, middle scenario and strict scenario were set for emission projection, and middle scenario was regarded as the best-available situation for the projection in China. Results showed that all emissions increased obviously in baseline scenario while significant emission reduction performance was found in middle scenario. Results of middle scenario showed that in2017emissions of SO2, NOx and PM were estimated to be3116kt,3068kt and594kt, decreased by57%,62%and59%compared with2011, respectively; In2030emissions of SO2, NOx and PM were estimated to be797kt,1138kt and114kt, decreased by89%,86%and92%compared with2011, respectively. Small units were remediated in strict scenario. Results showed that in2017emissions of SO2, NOx and PM were estimated to be2552kt,2090kt and486kt; In2030emissions of SO2, NOx and PM were estimated to be517kt,690kt and91kt, decreased by92.9%,91.4%and93.6%compared with2011, respectively. |
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