Solid oxide fuel cell stack coupled with an oxygen-blown TwoStage gasifier using minimal gas cleaning

Abstract

Abstract The coupling of biomass gasification and solid oxide cell technologies is very intriguing due to its high efficiency and flexibility potential. One of the key challenges in order to realize such a system design is a clean quality gas that can meet the strict requirements of the SOFC. This study presents the result of an experimental campaign with the TwoStage Viking biomass gasifier and a Topsoe Fuel Cell SOFC stack connected via a carbon filter and a desulphurizer. The stack is operated with both air- and O2 CO2-blown product gas, at 700\u202f°C and 800\u202f°C, and tests without any gas cleaning was conducted. The study found electric efficiencies up to 40% at 69% fuel utilization and an 8–11% increase in power when raising the SOFC temperature to 800\u202f°C. The O2 CO2-blown product gas showed lower efficiencies due to lower CO performance in the SOFC. A preliminary 2-h test with no gas cleaning between the gasifier and SOFC, and a ≈1.5–2.8\u202fppm sulphur concentration showed no change in operational voltage. Hence the study finds that gasifier design can greatly simplify the demand for gas cleaning equipment.