In recent times, Beijing, Tianjin, Hebei and surrounding regions have frequently suffered from severe air pollution and regional haze . One of the strategies considered for air pollution prevention is reduction of coal use and/or its substitution. While, historically, more efforts have been directed at the power sector, in this study we explore the potential benefits in terms of air pollutant reduction through natural gas substitution strategies in power plants, residential combustion, and industrial boilers in the Jing-Jin-Ji region. We also carried out sensitivity tests for the potential role of ammonia emissions in haze episodes. The assessment of the additional supply of natural gas is based on the newly signed Russian gas deal with China. The results should allow discussion of a rational distribution plan for the gas from this deal in the future that would take account of the impact on emissions of air pollutants and concentrations of particulate matter across the region.
The integrated assessment model GAINS  is used for scenario projection and emission estimates in response to different strategies, and the air quality in different scenarios is simulated with the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) . Emission reductions from replacing coal by natural gas were calculated using equation (1).
Coal, Gas, m, p represents baseline coal activity, scenario natural gas activity, abatement measure, and pollutant, respectively; ΔE stands for the emission reduction; ΔACoal stands for the reduction in coal activity; EFCoal,m,p and EFGas,m,p stand for emission factor of pollutant p for Coal and Gas after application of control measure m; χCoal,m,p andχGas,m,p stand for the penetration rate of control measure m for pollutant p of Coal and Gas; effCoal,m,p and effGas,m,p stand for the energy efficiency of the activity Coal and Gas.
In 2030 if the Jing-Jin-Ji region utilizes 50% of the Russian gas supply, that is, about 640 PJ, then natural gas can replace as much as 980,985, and 812 PJ of coal in the power, residential (wood as well as coal) and industry scenarios respectively, compared with the baseline scenario. The corresponding total emissions of SO2 in the power, residential, and industry scenarios will decrease by 57,332, and 302 kt, emissions of NOx in the power, residential, and industry scenarios by 124, 102 and 155 kt, and emissions of PM2.5 in the power, residential, and industry scenarios by 10,249 and 81 kt.
Application of a natural gas substitution strategy in the residential sector will achieve the highest SO2 and PM2.5 reducing potentials; application in the industrial sector will achieve the highest NOx reducing potentials; application in the power sector is the least effective way of reducing air pollutants emissions. Even though the power sector consumes a large amount of coal, making it a first target for substitution, policies addressing substitution in residential and industrial combustion sectors should be developed and evaluated, as these have a potential to achieve larger emission reductions and more significant air quality improvements in this region.
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Zbigniew Klimont and Chris Heyes, Mitigation of Air Pollution and Greenhouse Gases, IIASA
Jun Liu of the College of Environmental Sciences and Engineering, Peking University, Beijing, China, is a Chinese citizen. She was funded by IIASA’s Chinese National Member Organization and worked in the Mitigation of Air Pollution and Greenhouse Gasses (MAG) Program during the YSSP.
Please note these Proceedings have received limited or no review from supervisors and IIASA program directors, and the views and results expressed therein do not necessarily represent IIASA, its National Member Organizations, or other organizations supporting the work.
Last edited: 29 September 2015
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