Autothermal Biomass and Plastic Cogasification for Hydrogen-Rich Syngas Production: Process and Sustainability Assessment

Plastic waste and biomass cogasification in the presence of CO₂ to produce hydrogen-rich syngas offer viable pathways for power generation and chemical synthesis, but their technical feasibility and environmental implications remain underexplored. To address this gap, we present a holistic framework for this emerging technology, including gasification, water–gas shift reaction (WGSR), CO₂ capture and recycle, and life cycle assessment (LCA).

Our analysis reveals an optimized plastic-to-biomass ratio of 1:4 and a steam-to-feed ratio of 0.3:1 at 900 °C and produces syngas containing 62 mol % combined H₂ and CO, at a 1.2:1 ratio and a lower heating value of 8.6 MJ Nm^3–. Process intensification of the produced syngas via the WGSR increased the H₂/CO ratio to 2:1 while preserving its energy content, and 91% of the CO₂ in the syngas is removed via amine absorption and partially recycled to the cogasification feed stream.