One dimensional solid oxide electrolyzer-fuel cell stack model and its application to the analysis of a high efficiency system for oxygen production

This paper presents a finite difference one dimensional (1D) model of a single unit SOFC-SOEC stack, a novel technology based on the integration of a solid oxide fuel cell (SOFC) and solid oxide electrolyzer (SOEC), and a promising candidate for the high efficiency production of oxygen and/or hydrogen, especially for small scale applications. The model is applied to determine the performance of a SOFC-SOEC integrated system for oxygen production which has been previously analysed by means of a simplified zero-dimensional or lumped volume approach. The improved 1D model is used to explore the impact of different system configurations and operating conditions. It is shown that the simplified approach previously used overestimates the performance of the system by up to 60%. Despite this, the results presented here show an electricity consumption in optimized conditions in the range of 0.35-0.5 kWh/kgO2, still significantly lower than that of state of the art technology for small scale oxygen production systems.