Performance evaluation and economic feasibility of a PAFC-based multi-energy hub system in South Korea

In this study, a MW-scale fuel-cell-based multi-energy hub system is simulated to maximize microgrid flexibility. The system was designed to deliver electricity, heat, and H2 with a high energy efficiency, which can be realized through the integration of the exothermic phosphoric acid fuel cell and endothermic turboexpander generator modules. To extract additional useful work during the depressurization process in the natural gas supply chain, this multi-energy system is currently under construction on a pilot basis in South Korea. Based on a natural gas flow rate of 28,000kg/h, we analyze the performance of the system and its economic effects under different load demands and operating conditions. The system simulation results show that the total electrical power generated by the turboexpander generator and phosphoric acid fuel cell modules is approximately 3.395–3.539MWe, while the H2 yield is 19.94–40.00kg/h. In addition, an economic assessment of the multi-energy hub system is conducted based on the current natural gas, electricity, and H2 prices in South Korea. Assuming a life span of 20 years for the turboexpander generator and phosphoric acid fuel cell modules, the payback period is estimated to be between 7.09 and 10.05 years.