Novel Optimized Low Temperature Tar Reforming Catalyst in Tablet Form for Use in Hot Gas Filters for Syngas Cleaning in Biomass Gasification

For more energy-efficient tar removal in biomass gasification as necessary technology to contribute to meet the European climate protection targets catalytic tar reforming by use of catalytic hot gas filters is a promising hot gas cleaning technology. Based on a novel steam reforming catalyst in coarse grain form for complete conversion of 13 g/Nm3 model tars from 750°C down to 650°C and an evidenced complete real tar conversion in updraft gasification with a further developed catalyst system in tablet form, two new catalysts in tablet form optimized for tar reforming at 650°C - C&CS #1450 4x4 and 5x3 - were examined at a GHSV value of 2250 h-1 and 4250 h-1 in the presence of 16 ppmv H2S at the same tar inlet content. One of these tablet systems - 4x4 - exhibiting both a 4.5 fold higher BET surface area than that of a typical commercial steam reforming catalyst, was filled into a 60/40 x 475 mm filter candle for its differential pressure determination. The measured value of 31 mbar in air at 25°C at a filtration velocity of 70.2 m/h indicates the feasibility of low temperature catalytic filtration, also with 5x3 mm tablets.