Hydrogen Production Enhancement and Tar Reduction using New Three-Layer Annular Downdraft Air-Steam Biomass Gasifier

Abstract

This study presents experimental analysis of biomass air-steam gasification for the enhancement of H2 production in producer gas (PG). Wood pellets which are widely available in Malaysia are used in this investigation. A pilot scale downdraft gasifier based on new three-layers annular reactor design was implemented to produce hydrogen enriched PG. The reactor is initially heated using hot flue gas from LPG combustion which is switched to PG when the reactor reaches stable operation. The effect of steam to biomass (S/B) ratio from 1.1 to 1.5 on PG quality in terms of gas composition, HHV and tar contamination is studied. Maximum H2 production of 27.7% was achieved at optimum air flow rate of 75 LPM and S/B ratio of 1.2. At the optimum air flow rate, HHV and tar contamination in PG where in the range of 5.06 - 6.08 MJ/Nm3 and 187 - 30mg/m3, respectively.