Characterizing VOCs emissions of coal chemical enterprise in China: a case study in five coal chemical enterprises.

Coal chemical-induced climate change has become a global concern. However, the dearth of comprehensive case studies and fundamental data has obstructed the accurate quantification of volatile organic compounds (VOCs) emissions. This has failed to equip coal chemical industries with the necessary guidelines to implement effective emission reduction strategies. In response to this, the present study meticulously examined and contrasted the VOCs emissions from five distinct coal chemical enterprises in China. This was achieved through the application of life cycle assessment (LCA), a tool used to discern the primary factors influencing VOCs emissions and to identify potential avenues for VOCs emissions reduction. The analysis revealed that BT exhibited the highest emission intensity (5.58E-04 tons/ton), followed by ED (4.89E-04 tons/ton), YL (4.23E-04 tons/ton), XJ (2.94E-04 tons/ton), and SM (1.74E-04 tons/ton). Among these enterprises, coal-to-olefins enterprises predominantly discharged VOCs via sewage treatment (average 69.12%), while coal-to-methanol enterprises primarily emitted VOCs during circulating water cooling (40.02%). In coal-to-oil enterprises, storage and blending emerged as the principal source of VOCs emissions (56.83%). As a result, this study advocates that coal chemical enterprises concentrate on curbing VOCs emissions from highly concentrated wastewater, regulating the concentration of purgeable organic carbon in circulating water cooling systems, and instituting effective treatment methods for methanol storage tank emissions. These findings proffer invaluable insights for devising VOCs control measures in regions affected by intensive coal chemical production.

Impact of the demolition and relocation of chemical enterprises along the Yangtze River on air quality in Jingzhou City / 公共卫生与预防医学

Objective To evaluate the impact of demolition and relocation of chemical enterprises on air quality in Jingzhou City. Methods Based on the “Ambient air quality standards” (GB3095-2012), the daily average air quality index (AQI), and the concentration changes of six pollutants in the central urban area of Jingzhou, the air quality before, during and after the demolition and relocation of chemical enterprises during the environmental governance period from 2017 to 2019 was evaluated. Results The investigation results showed that the demolition and relocation of chemical enterprises had improved the local air quality to some certain extent, especially the decrease of SO2 concentration, especially for SO2, but the concentration changes of PM10 and O3 were not noticeable. At the same time, because of the attenuation of the implementation of the long-term policy, the improvement of air quality fluctuated. Conclusion This study suggests that further improvement of air quality in Jingzhou City may face the difficulty of O3 control and insufficient implementation of long-term policies in the future. It is a long-term policy to improve the environment through the renovation of chemical enterprises, and the corresponding regulatory measures need to be updated dynamically to ensure the implementation of the policy.