Sector-based volatile organic compound emission characteristics and reduction perspectives for coating materials manufacturing in China

Coating materials manufacturing, with heavy use of organic raw materials and excipients, has become an important industrial source of ambient volatile organic compounds (VOCs). Effective control measures must be developed which rely on a complete understanding of both the current emission characteristics and future emission projections. Thus, a comprehensive whole-process method was proposed and local investigations and measurements were conducted to acquire the material balance-based emission factors (EFs) and sector-based VOC emission characteristics in China. Then, its historical emission trends were evaluated and future reduc-tion perspectives were also projected. The results indicate that: (1) the non-controlled VOC EFs for different coatings were 80 g/kg solvent-based paint, 11 g/kg water-based paint, 49 g/kg varnish, 9 g/kg others (pigment, dyestuff, auxiliary), and 70 g/kg ink, respectively. (2) The VOC emissions increased from 0.34 Gg in 1949 to 872.72 Gg in 2018, and solvent-based paint was always the largest contributor (69-83%). Guangdong attributed the highest emissions (24.1%) in 2018, followed by Jiangsu (10.7%) and Sichuan (10.5%) provinces. The most abundant species were aromatics. (3) Disposal facility efficiency and VOC collection rate together determined the total process treatment efficiency. The disposal efficiency of adapted facilities could reach 90-99%, but the unmaintained or unsuitable facilities are more general and greatly reduced in efficiency. The collection rate could be up to >90% but only averaged about 40%. (4) Improving the treatment efficiency and expanding the market for green paint are the main pathways to reducing VOC emissions, and three scenarios were hereby set with increasing intensities. Compared to the non-controlled scenario, if basic or stringent control measures were fully implemented in China in 2030, the VOC emissions would be reduced by 70% or 81%, respectively.