Steam Reforming of Biomass Tar Using Iron-based Catalysts

Abstract

Gasification of biomass is an important process for utilization of production of chemicals and fuels. During the gasification, biomass is converted with oxygen,air or steam into a gas mixture such as CO, CO2, H2, H20 etc. Besides the gases, a number of low, volatile hydrocarbons (mostly CH4) are obtained, together with tars. The tar represents a complex mixture of components, usually polyaromatic that are difficult to deal with in the downstream processes that accompany gasification as well as in utilization technologies. The gasification technology for biomass conversion is still in the development stage and cannot be considered as proven technology for small and medium scale applications. The main technical barrier remains the efficient removal of tar from the produced gases in gasification systems. The purpose of this work is to identify an appropriate catalyst that can be used as an active in-bed material for removal of biomass tar to increase the efficiency processing. Novel nano char-supported iron catalysts were prepared, tested for the steam reforming of biomass tar and their performances were compared with ilmenite catalyst. The activity of char-supported iron catalysts toward steam tar reforming process was investigated under different operational conditions. The experimental data show that catalysts have activity in steam tar reforming process. At low temperature, the tar was mainly converted into coke using iron carbon catalyst , whereas, at high temperature, the tar was primarily reformed into gas using ilmenite. The specific reactivity of the char-supported iron catalyst changed significantly after the steam reforming at different temperatures because of the changes in the properties of the char and the iron-containing species in the catalyst.