Hydrogen-rich synthesis gas production from biomass catalytic gasification

Abstract

Hydrogen-rich synthesis gas (syngas, CO+H2) production from renewable woody biomass via steam gasification technology appears as a promising option in the existing energy context towards a green and sustainable future. The biomass is pyrolysed in the first stage of the reaction system, followed by the catalytic steam reforming process of derived products in the second stage, which appears as one of the economically viable methods for hydrogen-rich syngas production. The objective of this work is to present a viability assessment for catalytic steam reforming of derived products from pyrolysis of biomass into hydrogen-rich syngas in a two-stage fixed bed reaction system by using co-precipitated supported NiO-ZnO-Al2O3 and NiO-Fe2O3-Al2O3 metal oxide catalysts. The effect of catalyst on H2 yield, gas yield and composition, H2 to CO and CO to CO2 ratio, and coke deposition are investigated in this work. In general, the particle size in a nano scale and high stability characteristics are obtained from the metal oxide catalysts. With the utilization of catalysts, both gas and hydrogen yields are elevated by decreasing the tar amount. In addition, the H2 composition of total gas increases, while both CH4 and C2-C4 compositions are decreased. Besides, CO and CO2 compositions vary from the utilization of different catalysts. Very limited (<2wt.%) coke deposition is generated, which can be treated as negligible. The highly efficient conversation of renewable biomass resource to hydrogen-rich syngas indicates that it is a positive method to produce hydrogen-rich syngas from biomass catalytic gasification with co-precipitated supported NiO-ZnO-Al2O3 and NiO-Fe2O3-Al2O3 metal oxide catalysts via a two-stage fixed bed reaction system towards a clean energy development.