Efficient integration of SOFC and gasification system

In the presented work a medium sized integrated system based on the Güssing gasification plant concept and Solid Oxide Fuel Cells (SOFC) is introduced, simulated and validated in Aspen Plus. Suitable feedstocks for such fluidized bed gasification systems are for example waste and biomass, especially wood. During an allothermal fluidized bed gasification process high temperature heat at around 800°C (1073K) is necessary to drive the endothermic gasification reactions. In the Güssing gasifier this heat is produced in an additional combustion chamber by burning a share of about 20-25% of the generated product gas and transported into the gasifier via circulating bed material. At the same time SOFC produce excess high temperature heat. Thus, the scope of the presented system integration approach is to use the heat generated in the SOFC for the gasification process to reduce the amount of valuable fuel for the combustion process and increase the efficiency. For this purpose the normal steam and air streams to the gasifier are replaced with the anode and cathode outlets of the SOFC, respectively. Like this the exhaust streams carry SOFC waste heat into the gasifier. Furthermore, since the steam is replaced by the anode exhaust residual fuel is recycled into the gasifier. The gasifier model used in this work has been validated against data from the Güssing plant. The SOFC model applied is a thermodynamic model, which has been developed in the frame of SOFCOM and already described in detail in other works. A case study is conducted, from which an optimal exergy efficiency of 71.89% is found for the case where the SOFC power output as small as possible, so that the heat transported into the gasifier via the SOFC exhausts and the combustion process is just high enough to eliminate the necessity for additional fuel.      «

In the presented work a medium sized integrated system based on the Güssing gasification plant concept and Solid Oxide Fuel Cells (SOFC) is introduced, simulated and validated in Aspen Plus. Suitable feedstocks for such fluidized bed gasification systems are for example waste and biomass, especially wood. During an allothermal fluidized bed gasification process high temperature heat at around 800°C (1073K) is necessary to drive the endothermic gasification reactions. In the Güssing gasifie...     »