Catalytic tar reforming of biomass-derived synthesis gas: Influence of the catalyst, gas composition and sulfur poisoning

Catalytic reforming of tarry by-products in product gases derived from gasification of biomass is considered a possible alternative to scrubbing processes. Despite a large number of publications in the last years there are still a lot of problems to be solved for regarding the long-term application of catalysts in large scale processes. In our project, several different commercially-available and recently-developed catalysts were tested for the reforming of model tar compounds and methane in a simulated producer gas from allothermal biomass gasification in a laboratory scale test rig. Bulk nickel based catalysts showed lower resistance to sulphur poisoning than precious metal based, confirming the common literature. The performance of monolithic precious metal based catalysts is highly dependent on the ratio of different precious metals. Down to 800 °C it is possible to convert a considerable amount of tar components even with high tar load and H2S present in the gas mixture. In the final phase of the project, details about the reaction kinetics shall be investigated. Additionally, combinations of nickel and precious metal based catalysts will be tested.