Catalytic Gasification of Biomass in Dual-Bed Gasifier for Producing Tar-Free Syngas

Process development for the production of syngas by gasification of biomass, a carbon-neutral source of energy, has been researched very extensively in the recent past. One of the technical challenges in biomass gasification is to produce clean syngas with no tar. Tar removal by employing secondary bed is a solution, but it faces higher cost and reliability issues. Hence, extensive work is directed to produce syngas with no tar formation in the gasifier bed itself, by employing a suitable catalyst or other options. In the present work, a dual fluidized bed process for catalytic gasification of biomass is proposed for the production of high-quality syngas. This process employs an alkali-impregnated alumina or silica-alumina catalyst that eliminates tar formation completely while increasing the H2-to-CO molar ratio to more than 10. The catalyst is able to completely gasify the volatiles and solid char generated from biomass in the temperature range of 500–750 °C, at near-atmospheric pressure, with catalyst-...