Impact of Water-Based Coating Substitution on VOCs Emission Characteristics for the Surface-Coating Industries and Policy Effectiveness: A Case Study in Jiangsu Province, China

As solvent-based coatings are gradually phasing out in China, the volatile organic compounds (VOCs) emission characteristics of surface-coating industries have changed rapidly. Sector-based field measurements were conducted to build VOCs emission factors and source profiles of surface-coating industries in Jiangsu Province. A VOCs emission inventory was developed, and the projections for 2020 to 2030 were set. It was found that VOCs content in water-based coatings is 50.8% of solvent-based coatings on average. VOCs emission factors of solvent-based coatings ranged from 0.40 to 0.51 kg kg(-1), while those of water-based coatings ranged from 0.14 to 0.24 kg kg(-1). Compared to solvent-based coatings, the proportion of aromatics emitted from water-based coatings was 44.2% lower, while the proportion of oxygenated VOCs (OVOCs) was 11.6% higher. The results showed that VOCs emissions were about 134 Gg in Jiangsu Province in 2020, of which the solvent-based coating sources contributed 79.6% of the total. Aromatics were the main species contributing 52.9% of VOCs emissions and 85.9% of ozone formation potential (OFP). According to emission prediction results of four scenarios, the emission reduction of implementing low-content VOCs coating substitution is 8.7% higher than that of adopting the best available end-of-pipe treatment measures by 2030.