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 H 2 O and CO 2 through electrochemical and chemical reactions. However, it provides a low CO 2 conversion and produces a syngas product with a high H 2 O 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 CO 2 and CH 4 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 H 2 O 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 H-SOEC/DMR unit had the lowest exergy efficiency as a high-temperature exhaust gas was released. [Display omitted] • The syngas production from H-SOEC is improved by incorporating with DMR. • The obtained syngas product has a high H/C molar ratio of 2 with less amount of H 2 O. • Increasing temperature can reduce the cell voltage and enhance syngas product. • The implementation of heat exchanger network can enhance the energy efficiency to 81.46%. [ABSTRACT FROM AUTHOR]