Techno-Economic and Life Cycle Analyses of Thermochemical Upcycling Technologies of Low-Density Polyethylene Waste
Date
2023-05-08
Journal Title
Journal ISSN
Volume Title
Publisher
ACS Sustainable Chemistry and Engineering
Abstract
In this study we compare techno-economics and life cycle assessment of thermochemical depolymerization technologies, including pyrolysis, gasification, hydrocracking, hydrothermal liquefaction, and hydrogenolysis, to generate various products from low-density polyethylene (LDPE) waste. We elucidate the effects of production scale, collection cost, and concentration of LDPE in plastic waste. Pyrolysis of LDPE to olefins followed by their conversion to lubricant oils is the most profitable technology. Hydrogenolysis, producing a small fraction of lubricant oils, becomes profitable at plant sizes above 25 kt/y and produces the lowest CO2 emissions. Hydrocracking is the second most environmentally friendly technology but becomes economically competitive at sufficiently large scales, and the supply chain for collecting plastics is optimized. Gasification of LDPE to H2 produces high emissions, and the price of H2 of ∼3 $/kg is higher than current markets and recently announced goals. Similarly, hydrothermal liquefaction also gives high emissions, making carbon capture systems imperative for both technologies. Our results demonstrate that lowering the cost of sorting LDPE from plastic waste, collecting waste near big cities, building sufficiently large plants, and achieving high selectivity to value-added products are critical to successful plastic waste management.
Description
This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Sustainable Chemistry and Engineering, copyright © 2023 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acssuschemeng.3c00636. This article will be embargoed until 05/08/2024.
Keywords
plastics waste, upcycling, recycling, pyrolysis, gasification, hydrogenolysis, hydrocracking
Citation
Hernández, Borja, Pavel Kots, Esun Selvam, Dionisios G. Vlachos, and Marianthi G. Ierapetritou. “Techno-Economic and Life Cycle Analyses of Thermochemical Upcycling Technologies of Low-Density Polyethylene Waste.” ACS Sustainable Chemistry & Engineering 11, no. 18 (May 8, 2023): 7170–81. https://doi.org/10.1021/acssuschemeng.3c00636.