Benefits of current and future policies on emissions of China's coal-fired power sector indicated by continuous emission monitoring

• Published in: Environmental pollution (1987) Vol. 251; pp. 415 - 424
• Main Authors: Zhang, Yan, Bo, Xin, Zhao, Yu, Nielsen, Chris P.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2019
• Subjects: CEMS; Coal-fired power plant; Emission control; Ultra-low emission policy; Coal-fired power plant; Ultra-low emission policy; Emission control; CEMS
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2019.05.021

Emission inventories are critical to understanding the sources of air pollutants, but have high uncertainties in China due in part to insufficient on-site measurements. In this study, we developed a method of examining, screening and applying online data from the country's improving continuous emission monitoring systems (CEMS) to reevaluate a “bottom-up” emission inventory of China's coal-fired power sector. The benefits of China's current national emission standards and ultra-low emission policy for the sector were quantified assuming their full implementation. The derived national average emission factors of SO2, NOx and particulate matter (PM) were 1.00, 1.00 and 0.25 kg/t-coal respectively for 2015 based on CEMS data, smaller than those of previous studies that may not fully recognize improved emission controls in recent years. The annual emissions of SO2, NOx and PM from the sector were recalculated at 1321, 1430 and 334 Gg respectively, 75%, 63% and 76% smaller than our estimates based on a previous approach without the benefit of CEMS data. The results imply that online measurement with proper data screening can better track the recent progress of emission controls. The emission intensity (the ratio of emissions to economic output) of Northwest China was larger than that of other regions, attributed mainly to its less intensive economy and industry. Transmission of electricity to more-developed eastern provinces raised the energy consumption and emissions of less-developed regions. Judged by 95 percentiles of flue-gas concentrations measured by CEMS, most power plants met the current national emission standards in 2015 except for those in Northwest and Northeast China, while plants that met the ultra-low emission policy were much scarcer. National SO2, NOx and PM emissions would further decline by 68%, 55% and 81% respectively if the ultra-low emission policy can be strictly implemented, implying the great potential of the policy for emission abatement. [Display omitted] •The method for estimating emissions from power sector was improved incorporating CEMS data.•Application of CEMS data could better capture the recent progress on emission abatement.•The “in compliance” rate of units depended on selection of criterion.•Emission reduction potential was limited under current standard but large for ultra-low emission policy. The method for estimating power sector emissions is improved incorporating CEMS data, and it effectively captures the progress on emission controls for China's power sector.