Biomass integrated gasification fuel cell systems–Concept development and experimental results

The link-up of wood gasification with high temperature solid oxide fuel cells (Biomass-Integrated Gasification Fuel Cell System, B-IGFC) is a promising approach to reach high electrical efficiencies in small-scale biomass fuelled combined heat and power plants (CHP). The main technical challenge is the adjustment of the three main system components gasification, gas processing and fuel cell. A B-IGFC concept has been developed based on the findings that producer gas originating from the updraft gasification of wood can be electrochemically converted in a SOFC whereby tars are degraded to hydrogen and carbon monoxide and contribute to the electrochemical reactions and power generation. Important unit operations of the B-IGFC system were characterised experimentally. During a long-term test of the complete B-IGFC demonstration unit, the gasifier and the catalytic partial oxidation could be operated without problems, delivering a fuel gas to the SOFC system with relatively constant composition and properties. Compared to methane operation, the SOFC system delivered approx. 40% less current. With the chosen operating conditions, carbon deposition was effectively prevented. Ash deposits were identified as major obstacle for a smooth SOFC system operation.