Staged Biomass Gasification by Autothermal Catalytic Reforming of Fast Pyrolysis Vapors

Abstract

A novel staged gasification process aiming to produce heat and power from biomass residue materials has been investigated. The process comprises a fast pyrolysis reactor, coupled with an autothermal catalytic reformer to convert the pyrolysis vapors into a clean fuel gas. Because of the relatively low temperature in the first stage, inorganic contaminants are retained in the fast pyrolysis char byproduct, enabling the use of catalysts in the second stage to produce a virtual tar free product gas. The char byproduct is combusted in the pyrolysis system at moderate temperature, thus preventing potential ash-melt problems. The influence of the air-fuel ratio and mixing behavior, the catalyst composition, and the biomass composition on the process performance were determined using a 1–5 kg/h experimental setup. Six biomass materials ranging from clean wood to sewage sludge were converted without any operational problems. Tar concentrations below 10 mg/Nm3 could be obtained, which is sufficiently low for direc...