Progress in carbon capture and impurities removal for high purity hydrogen production from biomass thermochemical conversion

Abstract

Renewable hydrogen production from biomass thermochemical conversion is an emerging technology to reduce fossil fuel consumptions and carbon emissions. Biomass-derived hydrogen can be produced by pyrolysis, gasification, alkaline thermal treatment, etc. However, the removal of impurities from biomass thermochemical conversion products to improve hydrogen purity is currently technical bottleneck. It is important to assess and investigate the types and properties of impurities, the difficulty of separation, and the impact on downstream utilization of hydrogen in the biomass-derived hydrogen production process. The key objectives of this comprehensive review are: (1) to reveal the current status and necessity of developing biomass-derived hydrogen production; (2) to evaluate the types, devices and impurities distribution of biomass thermochemical conversion; (3) to explore the formation pathways and removal technologies of typical impurities of tar, CO₂, sulfides, and nitrides in hydrogen production process; and (4) to propose future insights on the separation technologies of typical impurities to promote the gradual substitution of biomass-derived hydrogen for fossil-derived energy.