Feasibility of gasifying mixed plastic waste for hydrogen production and carbon capture and storage

Abstract

Waste plastic gasification for hydrogen production combined with carbon capture and storage is one technology option to address the plastic waste challenge. Here, we conducted a techno-economic analysis and life cycle assessment to assess this option. The minimum hydrogen selling price of a 2000 oven-dry metric ton/day mixed plastic waste plant with carbon capture and storage is US$2.26–2.94 kg−1 hydrogen, which can compete with fossil fuel hydrogen with carbon capture and storage (US$1.21–2.62 kg−1 hydrogen) and current electrolysis hydrogen (US$3.20–7.70 kg−1 hydrogen). An improvement analysis outlines the roadmap for reducing the average minimum hydrogen selling price from US$2.60 to US$1.46 kg−1 hydrogen, which can be further lowered to US$1.06 kg−1 hydrogen if carbon credits are close to the carbon capture and storage costs along with low feedstock cost. The life cycle assessment results show that hydrogen derived from mixed plastic waste has lower environmental impacts than single-stream plastics.