Gas Extraction and Gas Cleaning from a Novel Biomass Conversion Plant Based on Updraft Gasification

The EU Horizon Europe project Clean bioenergy for industry (CBE4I) aims at the development of a novel, fuel-flexible biomass updraft gasification based technology for a highly energy efficient, almost zero emission and zero waste process heat supply for flexible implementation at industrial settings. Among others, this technology shall provide process heat and a clean product gas for utilisation in industrial gas burners for direct heating. This paper focuses on the latter application. Approximately 45% of the product gas derived from an air-blown, fixed-bed updraft gasifier is extracted directly from above the fuel bed, while the remaining portion is combusted in a multi-stage gas burner. To remove tars present in the extracted product gas, a combination of thermal tar reforming and high-temperature catalytic tar reforming is applied. For the latter a novel high-temperature tar reforming catalyst based on wire mesh substrates, an Al-oxide based washcoat and Pt as active element has been developed. The entire system has been implemented at a 350 kW (fuel power based on NCV) testing plant. Test runs with woody biomass fuels have revealed that with the new technology an almost tar and soot free product gas with an NCV of about 5.1 MJ/Nm³ can be achieved which is well suitable for application in industrial gas burners.