Hydrogen Production by High Temperature Steam Electrolysis Coupled With a Small Modular Reactor: Cross-Comparison Between Various Thermal Architectures

Abstract This paper is part of a study on the coupling of a SMR nuclear unit to a hydrogen production process using high-temperature steam electrolysis (HTSE). Different possible coupling architectures are investigated and their energetic evaluation are performed. A numerical design of experiment is established in order to study the separate effects of the various architectural options envisaged in relation to a reference simulation configuration: with or without thermal coupling, direct or indirect steam supply, location of the extraction point in the SMR Rankine cycle, one-way or two-ways thermal coupling, internal heat recovery in the HTSE, and oxygen content. The results obtained on the reference simulation configuration show that it is possible to obtain a gain of over 13% compared with the solution involving no thermal coupling between the SMR and the HTSE process (i.e. when HTSE heat is provided through electrical heaters), with a deviation of 3% from an idealized configuration with freely available heat and no utilization constraints (“ideal waste heat configuration”). It even outperforms the heat pump solution by more than 4%. From a purely energetic point of view, and considering only the HTSE operating at atmospheric pressure, it can be seen that each optimized configuration deviates rather slightly from the reference simulation configuration: all energy performances enable gains of around 13% compared with the configuration with no thermal coupling between the SMR and the HTSE process. The solution with two-ways thermal coupling is also more efficient than the one-way coupling.