A decade advance in eco-efficiency and cost-benefits of emissions reduction targeting fine chemical manufacturers.

Fine chemical industry, characterized of small scale, large heterogeneity, and high added value, is the most technology-intensive and dynamic sub-sector in chemical industry, but also has much high environmental factor in production. This study aims to explore green development pathways of about 60 fine chemicals manufacturers in a typical fine chemical industrial park with an annual output of 15 billion USD in China. We analyzed eco-efficiency and cost-benefits of emissions reduction of the park during 2011-2019 from multiple perspectives, by integrating decoupling index, data envelopment analysis, and linear econometric model. The key findings are: (1) the fine chemical industry has witnessed a volatile paradigm of absolute decoupling between economic growth and environmental pressure during the past decade, with a decoupling index of -2.2-12.4; (2) variation of eco-efficiency between benchmark enterprises and majority of enterprises are remarkable, at an average scope of 0.23-0.35, among which 77%-85% enterprises under-performed the average; and pharmaceutics production in particular needs a leapfrog to improve its performance substantially because 84%-95% of them were below the average; (3) pollutants emission plays a decisive role in affecting enterprises' eco-efficiency, and water pollutants work more in first half decade and air pollutants overturn in the second half; and (4) the marginal effect of control investment on water pollutants reductions has declined in 2019 by 66% (chemical oxygen demand (COD)) and 70% (ammonia nitrogen compounds (NH3-N)) compared with those of 2012; however, air pollutants reductions marginal effect is still in climb stage in 2019 by 607% (sulfur dioxide (SO2)) and 17% (nitrogen oxides (NOx)) compared with those in 2018. Fine chemical manufacturers are supposed to enforce a paradigm shift from end-of-pipe to systematic emissions control due to the decline trend of marginal cost-benefits on emissions reduction subsequently.