Regenerable Manganese-Based Sorbent for Cleanup of Simulated Biomass-Derived Syngas

Abstract

During biomass gasification, sulfur contained in the feedstock is converted primarily to hydrogen sulfide. Conventional technologies for sulfur removal such as amine scrubbing and ZnO sorption operate at much lower temperatures than those of gasification and tar reforming and are thus thermally inefficient for cleanup of biomass-derived syngas. This work aims to develop options for high-temperature sulfur removal. In this research, we focus our investigation on the regeneration chemistry of a manganese-based sorbent for sulfur removal at the high temperature, high steam conditions (700 °C and up to 68% steam) used for biomass gasification and subsequent syngas conditioning. We found that regeneration conditions that have a small amount of air or steam in combination with air would allow for equal sulfidation and regeneration time. We also demonstrated the effectiveness of both fresh and regenerated sorbents in protecting downstream tar and methane reforming catalysts.