Comparative tests of catalysts for reforming of tars and methane in biomass-derived synthesis gas from fuidized bed gasification

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 at Fraunhofer UMSICHT. Monolith and bulk catalysts were compared with respect to their conversion performance in a synthetic syngas in a first project step without typical poisoning substances like e.g. sulfur. Precious-metal catalysts were able to almost completely remove aromatic compounds even at 800 °C and very short residence times over 5 hours of test time. If similar conversion rates can be reached for the upcoming tests in the presence of sulfur as well, the catalysts would be applicable for allothermal gasification systems. The best of the nickel ca talysts also showed high conversion levels for both methane and aromatics, but could not totally convert all tar components. One catalyst doped with a promoting compound specifically converted the tar components without showing high activity towards methane. Some first results of the influence of added H2S as the major sulfur component in the gas are also reported here as part of detailed investigations for the most promising catalysts.