Techno-economic analysis of hydrogen production electrically coupled to a hybrid desalination process

Abstract

Climate change and resource scarcity have gained prominence with an increase in the world's population, necessitating the replacement of fossil fuels with eco-friendly alternatives. Here, to produce hydrogen sustain-ably, a combination of hybrid desalination with water electrolysis, to simultaneously produce hydrogen and pure water (with 4 MW plant capacity), has been proposed. The desalination produces additional electricity, which is used for high-temperature steam electrolysis (HTSE) using a solid oxide electrolysis cell (SOEC), and water electrolysis using an alkaline electrolysis cell (AEC). Reducing the electricity price, which accounts for almost the entire cost of hydrogen production, could decrease the cost of producing hydrogen. The system was verified by process simulation and optimization, along with economic and sensitivity analyses. The levelized cost of pure water was $1.08-1.86 per ton of water (reasonable compared to previous studies); the levelized cost of hydrogen ($1.75-5.32 and $0.63-2.35 per kg of H-2 in SOEC and AEC, respectively) was significantly low, using the electricity generated by desalination. Therefore, this new small-scale paradigm producing pure water and hydrogen simultaneously could be an alternative to distributed hydrogen production, considering the difficulties of hydrogen storage and transportation.