Process network modelling for the assessment of environmental impacts

Environmental databases have recently become an essential instrument in the sustainability evaluation of products. Unfortunately, these repositories still contain a limited number of chemicals and are based on fixed mass flows reflecting static industrial settings that might poorly reflect the characteristics of the facilities one wishes to analyse. To overcome these limitations, we propose a methodology to quantify the life cycle assessment (LCA) impact of chemicals based on a mathematical model of the petrochemical industry coupled with linear programming and allocation methods. Our approach was applied to a network comprising 178 processes and 144 products, generating results consistent with those available in the Ecoinvent database for widely used impact indicators such as Global Warming Potential (GWP) and ReCiPe methodology score. Our method provides estimates of the life cycle impact embodied in chemicals under varying yields and demands, even for products that are missing in standard repositories. Overall, this tool should complement existing databases, extending their capabilities and boosting the widespread use of LCA in the chemical industry by simplifying its application.