(572a) Methodologies for Life Cycle Inventory Generation of Chemicals and Their Implication on the Life Cycle Impact Assessment Results

The use of industrial chemicals is prevalent in the modern society as raw materials and intermediates making them an integral part of the life cycle of several products we use every day. Growing concerns over climate change, regulations and consumer awareness have necessitated a declaration of environmental impacts of these products. Life Cycle Assessment (LCA), the most popular tool to calculate these environmental impacts require a detailed analysis of input and output flows to the various stages of production of these chemicals. However, due to the vast universe of chemicals and hurdles such as restricted access to primary data from plants, LCA practitioners are faced with a challenging task of generating life cycle inventories for chemicals based on limited data availability in the open literature.

This study comprehensively examines eight different approaches used by LCA practitioners to incorporate chemical LCIs in their analysis based on varying data availability and the uncertainties associated with them. The implications of overestimating or underestimating the chemical LCI on the overall life cycle assessment of a product has been explored using a case study of polystyrene. The study suggests that, while approaches such as, using stoichiometry to determine the inputs and outputs in a chemical process can grossly underestimate the environmental impacts such as GWP and CED, using process simulation models without appropriately accounting for heat integration etc. can lead to overestimation of these impacts. Approaches which do not consider auxiliary operations and uses indeterminate estimations for electricity consumption could lead to misleading estimates for impact categories such as Ecotoxicity and such studies should avoid publishing these impacts.