Dual fluidized bed biomass steam gasification combined with catalytic gas cleaning

Biomass gasification has a big potential for advanced biomass-to-electricity technologies due to ist great flexibility and the high electrical as well as the overall efficiencies. Although a great deal of research and development work has been carried out during the past decade the commercial breakthrough for this technology is still far away. One problem that has not been completely solved so far is the tar content in the product gas, which can cause plugging in the colder parts of the plant. Among the possible gas cleaning methods, catalytic hot gas cleaning is rather promising. To explore long-term activities of a catalyst, developed at Fraunhofer Institute, a 100 scm/h partial stream reactor at the biomass CHP Güssing ws designed and erected summer 2006. Commissioning has been finished in April 2007. The producer gas contaminated with tar is sucked off from the freeboard of the gasifier, fed into the catalytic reactor, and discharged back to the product gas line between the gasifier and the gas cooler. Tar amounts and composition, gas composition, and ammonia can be measured before and after the reformer. 4 000 hours of continuous operation are planned.