Iron-loaded activated carbon as a tar cracking/reforming catalyst in the production of clean producer gas from oil palm biomass

The conversion of abundantly available and renewable biomass, e.g. oil palm waste, into combustible gas mixture provides good opportunities for reducing the greenhouse gas effect and the reliance on fossil fuel in energy sector. The use of catalyst in the reforming/cracking of tarry materials, e.g. biomass-derived bio-oil or tar in the gasification outlet gas, helps to achieve the required gas quality for various energy and power generation applications. Catalyst deactivation which leads to shortened catalyst lifetime, however, limits the application of many commercial catalysts in the production of clean producer gas from biomass, especially for a large-scale system, contributing to the increase in operating expenditure and creating waste management issue arising from the disposal of spent catalyst. It is therefore important to develop an environmentally-friendly low-cost catalyst that can efficiently convert biomass tarry materials into clean burnable gas for practical application. This paper reports some of our recent studies on the development and testing of tar cracking/reforming catalyst for the production of low-tar, highly burnable gas from oil palm biomass. Iron-loaded activated carbon was prepared using a stepwise impregnation method that allows high loading of iron without severe deterioration on catalyst dispersion and porosity of the catalyst support. The catalyst was tested in the lab-scale bio-oil reforming as well as in the pilot-scale biomass gasification. Results indicate that this low-cost practical catalyst can reduce tar content in the producer gas with performance comparable to other commercial catalysts.