Gasification of different biomasses in a dual-bed gasifier system combined with novel catalysts with high energy efficiency

Abstract

Syngas has been produced from the gasification of various biomasses such as jute stick, bagasse, rice straw, and saw dust of cedar wood using a dual-bed gasifier combined with a novel catalyst. The gasification conditions were 150 mg/min of biomass feeding, ER=0.25, catalyst (3 g) at temperature range of 823–923 K. The carbon conversion to gas and yield of useful gases such as CO, H2, and CH4 were dependent on the properties of biomass. In terms of the formation rate of useful gases, the biomass quality was in the order of cedar wood > jute stick > bagasse > rice straw. Although the rice straw gasification is comparatively difficult in a single-bed gasifier due to its high ash content (22.6%), it becomes possible in a dual-bed reactor system. The dual-bed gasifier using Rh/CeO2/SiO2 catalyst that has been developed gave higher conversion to gas and higher yield of CO+H2+CH4 than did the single-bed gasifier. In the case of cedar wood gasification, although a small amount of coke was formed on the catalyst surface, the tar was not formed at all even at 823 K. However, in the case of other biomass, especially for rice straw, a significant amount of coke on the catalyst surface and tar was formed even at the high temperature (923 K).