Performance analysis of the proton-conducting solid oxide electrolysis cell coupling with dry methane reforming

Abstract

The proton-conducting solid oxide electrolysis cell (H-SOEC) is a clean technology for syngas production from H2O and CO2 through electrochemical and chemical reactions. However, it gives low CO2 conversion and produces syngas product with high H2O content. Therefore, the H-SOEC coupling with a dry methane reforming process (H-SOEC/DMR) is proposed to improve its performance. The process flowsheet of the H-SOEC/DMR is developed by using Aspen Plus and used to evaluate the performance of H-SOEC/DMR. The performance analysis of the H-SOEC/DMR shows that under the temperature range of 1073-1273 K, the %CO2 and %CH4 conversions of higher than 90% and 80% are observed, and the syngas product with low H2O content is obtained. The amount of syngas product increases with an increase in operating current density and the number of cells. The energy analysis is also performed, and the result indicates that the H-SOEC/DMR (500 cells) gives the highest energy efficiency of 72.80% when it is operated at temperature of 1123 K, pressure of 1 atm, and current density of 2500 A m–2. Based on a pinch analysis, the heat exchanger network is applied to the H-SOEC/DMR process, and its energy efficiency is increased to 81.46%. The exergy analysis shows that the H-SOEC/DMR unit gives the lowest exergy efficiency as high-temperature exhaust gas is released.