Intermediate Temperature SOFC in Gas Turbine Cycles

Abstract

Operational temperature around 800°C is desirable for solid oxide fuel cells (SOFC) due to alleviation of many serious problems, associated with high temperature, i.e., high degradation rate and cost of balance of plant components along with the need for expensive ceramic interconnect. This paper is concerned with the performance of hybrid cycles employing the intermedium temperature SOFC and a gas turbine. The calculations are performed with Aspen Plus® for a system in a size of 500 kW, using methane as fuel. The simulation tool is completed by a mathematical model of the fuel cell. Cell geometry is chosen to represent the type of cells developed at Risø National Laboratory. For the stand alone SOFC, introduction of the metallic interconnect gave an overall performance improvement. A maximum electric efficiency of more than 70% for the system was calculated at low pressure ratios.