Economic and environmental impact of long-term voltage degradation in solid oxide CO2/H2O co-electrolysis on synthetic Fischer-Tropsch fuel production

Abstract

Solid oxide electrolysis (SOEL) has achieved not only inherently high thermodynamic and kinetic efficiencies, but also high system thermal efficiency through integration with thermochemical processes. However, the impact of long-term voltage degradation within overall integrated systems has not been addressed, despite being one of the major factors that may challenge the widespread deployment of long-term SOEL operation for producing valuable chemicals. Therefore, in this study, the voltage degradation mechanisms of SOEL are investigated and mathematically modeled using MATLAB. The degradation model is then connected into a synthetic Fischer-Tropsch (FT) fuel production process modeled in Aspen Plus to evaluate the economic and environmental impacts of voltage degradation on the overall synthetic FT fuel production system. Considering the economic impact of voltage degradation on the overall system, SOEL exhibited optimal economic performance at an operating temperature of 708 ◦C, with the unit production cost of synthetic FT fuel estimated at 420.45 $ GJ−1. Moreover, a decrease in the purchased cost of SOEL system is shown to mitigate the economic impact of voltage degradation. Regarding the environmental impact, the results show that the overall environmental performance is not significantly affected by voltage degradation. Based on both economic and environmental results, this study proposes a strategy for integrating SOEL with thermochemical processes to produce valuable chemicals. © 2025 Elsevier B.V.