Combined gasification-oxidation system for waste treatment with supercritical water: Lca and performance analysis

Abstract

In this study the environmental performance of a first-of-its-kind integrated process based on supercritical water gasification and oxidation (SCW-GcO), was evaluated using life cycle assessment (LCA). The process was applied to the treatment of carbon black and used oil as model wastes. Mass and energy balances were performed using Aspen Plus, and the environmental assessment was carried out through SimaPro. A “from cradle to grave” approach was chosen for the analysis, considering impact categories such as climate change, ozone depletion, human toxicity, particulate matter, land use, resource depletion, and other relevant indicators. The environmental profile of the SCW-GcO process was compared to other technologies for the treatment of dangerous wastes, solvent mixtures, and exhaust mineral oils by using the Ecoinvent database. It is shown that SCW-GcO allows for reduced impacts in different categories and the obtention of a favorable positive life cycle energy balance, achieving good environmental performance.