Exergy-aided environmental sustainability assessment of an ethylene dichloride–vinyl chloride production process

Abstract

Vinyl chloride is a carcinogen and ethylene dichloride is a toxic chemical besides the high-energy demand of their production process, which can also cause environmental impacts. This paper presents an exergy-aided LCA to pinpoint the avoidable key cause of the unsustainability in the period of energy transition, and enhance the sustainability as much as achievable. The electricity generation system is pinpointed as the main source of the unsustainability of the ethylene dichloride–vinyl chloride production process under the strict process constraints imposed by the energy transition. Then, a set of possible scenarios supported by Monte Carlo simulation are defined, resulting in reducing environmental impacts from 5.19 to 5.15MJ equivalent of nonrenewable energy sources according to CExD or from dimensionless normalized results of 2.47E-04 to 1.36E-04 according to ReCiPe, thus paving the way towards sustainable ethylene dichloride–vinyl chloride production process. In addition, LCA is advantageous to quantify precisely the environmental impacts of each chemical component, showing that CO2 has much more adverse impacts than the hazardous substances on human health. Moreover, LCA reveals that natural gas can even be less sustainable than residual fuel oil in terms of freshwater ecotoxicity, marine ecotoxicity, terrestrial acidification, human toxicity, particulate matter formation, and fossil depletion impacts.