The Environmental Performance of Mixed Plastic Waste Gasification with Carbon Capture and Storage to Produce Hydrogen in the U.K.

Abstract

Hydrogen of a high purity can be produced from the advanced gasification of nonrecyclable mixed plastic wastes (MPW). Due to the fossil nature of MPW, carbon capture and storage (CCS) capabilities need to be employed for the process to be considered a low-carbon hydrogen production route. This study analyzes the environmental performance of a semicommercial process that (a) provides an end-of-life (EoL) for MPW, (b) produces hydrogen as the main product (for sustainable manufacturing, heating, and transport applications), and (c) captures carbon dioxide emissions which are injected into geological sites for permanent sequestration. The climate change impact result is −371 kg CO2 per 1 tonne of MPW treated. The process was competitive against a similarly modeled Waste-to-Energy (WtE) plant coupled with CCS─an alternative future end-of-life scenario. WtE with CCS produced a corresponding impact of 17 kg CO2 per 1 tonne of MPW. The two technologies were also compared alongside a decarbonizing electricity grid mix.