Abstract
•Identification of Saudi Arabia’s target for hydrogen production.•Selection of nuclear powered cogeneration system for both power and hydrogen production.•Development of deterministic model to conclude 1800 operating scenarios.•Verification and validation of the developed model.•Techno-economic analysis gives thermal energy, production rate and cost.
Recently, the Kingdom of Saudi Arabia announced plans to build a green hydrogen power plant that will run on 4 GW of renewable energy, the largest hydrogen production project in the world to date. This is a defining moment for the Kingdom's development and a key element of Saudi Vision 2030, which contributes to the strategy for clean energy and a circular economy, and nuclear cogeneration for hydrogen production can support such a pragmatic move. Therefore, the current study focuses on the production of hydrogen gas in a high-temperature gas-cooled reactor (HTGR) using the thermochemical energy of sodium iodine (SI) for water decomposition. The study investigates the performance of the HTGR cogeneration system for both electricity and hydrogen gas production under different operating scenarios. Based on the developed deterministic mathematical model, which includes 1800 operating scenarios, an energy-related cost analysis is provided. The techno-economic analysis showed that the maximization of hydrogen production for the HTGR process results in a maximum thermal exergy with an energetic efficiency of 70 % and a production rate of 105,615 m3/h at the lowest production cost of 7.7 cents/m3. The cost of electricity production from cogeneration was calculated as 3.23 cents/kWh, compared to other renewable energy sources (5 cents/kWh). This optimal operating scenario was selected to provide information needed to attract investment in Saudi Arabia for the deployment of this promising cogeneration technology based on deterministic exergy cost analysis approach.