Assessment of industrial metabolisms of sulfur in a Chinese fine chemical industrial park

Abstract Substance flow analysis on the industrial park scale is confounded by the multiple sources of inputs and outputs involving raw materials, products, and emissions, and by complicated intra-firm and inter-firm flows. As a result, substance flow analysis is less frequently applied than bulk material flow analysis in the planning and implementation of eco-industrial parks. The research aims to fill the gap by applying substance flow analysis to assess the flows, utilization efficiency and associated environmental impact of the sulfur element in the Zhejiang Hangzhou Bay Shangyu Industrial Area. Based on over five-year in-depth data collection and verification, we find that only 65% of all sulfur inputs enter products while 35% of sulfur inputs end up with solid, liquid, and gaseous wastes. Instead of sulfur dioxide and sulfur-containing sewage, close to 150,000 tons of calcium sulfate waste being landfilled annually presents the most serious environmental risk. The research further examines several approaches to improve the sulfur utilization efficiency (including high-efficiency synthetic dye technologies, water-efficient work-up process, and inspissation/recycling of spent sulfuric acid) and explores the main barriers to their widespread adoption. Practically, the findings from substance flow analysis assisted by value chain analysis can better inform industry and park management of future directions of industrial restructuring and greening of fine chemical industrial parks.