Performance improvement of the proton-conducting solid oxide electrolysis cell coupled with dry methane reforming

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 provides a low C(O)2 conversion and produces a syngas product with a high H2O content. To improve the H-SOEC for syngas production, H-SOEC coupled with a dry methane reforming process (H-SOEC/DMR) was proposed in this work. The process flowsheet of the H-SOEC/DMR was developed and further used to evaluate the performance of the H-SOEC/DMR process. From the performance analysis of the H-SOEC/DMR process, it was found that the CO2 and CH4 conversions were higher than 90% and 80%, respectively, when the process was operated in the temperature range of 1073-1273 K. In addition, the result showed that a syngas product with a low H2O content could be obtained. Energy efficiency was then considered and the results indicated that the highest energy efficiency of 72.80% could be achieved when the H-SOEC/DMR process was operated at a temperature of 1123 K, pressure of 1 atm, and current density of 2500 A m(-2). Based on a pinch analysis, a heat exchanger network was applied to the H-SOEC/DMR process that improved the energy efficiency to 81.46%. Finally, an exergy analysis was performed and showed that the HSOEC/DMR unit had the lowest exergy efficiency as a high-temperature exhaust gas was (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The combination of proton-conducting solid oxide electrolysis cell (H-SOEC) with dry methane reforming process (H-SOEC/DMR) was proposed to improve the efficiency and water content of syngas production. Performance analysis of the H-SOEC/DMR process showed that CO2 and CH4 conversions exceeded 90% and 80%, respectively, at temperatures ranging from 1073 to 1273 K, resulting in a syngas product with low water content. The highest energy efficiency of 72.80% was achieved at a temperature of 1123 K, pressure of 1 atm, and current density of 2500 A m(-2), which increased to 81.46% with the application of a heat exchanger network. Exergy analysis revealed that the H-SOEC/DMR unit had the lowest exergy efficiency.