Performance evaluation of an integrated hydrogen production system with LNG cold energy utilization

Abstract

This study aims to develop a novel integrated geothermal based system by the application of different thermodynamic cycles such as Kalina, liquefied natural gas (LNG), Stirling and proton exchange membrane electrolyzer (PEME) to produce cooling, hydrogen, and electricity. Energy and exergy analyses of the system are performed to evaluate the performance of the system. Additionally, the effects of five different input variables are investigated to determine their impacts on the corresponding values of net power and cooling, exergy efficiency, hydrogen production, and sustainability index. In a defined condition, the exergy efficiency of the suggested system is computed around 43%. The cycle net generated power is 10.69 MW, which is the generated power by the Stirling, LNG, and Kalina turbines each by 8.07 MW, 1.13 MW, and 1.49 MW, respectively. The produced cooling load by the cooling unit of the LNG stream is also 6.09 MW, while the rate of hydrogen production in the electrolyzer is 204.77 kg/h by consuming all the generated power. Additionally, a sensitivity analysis is performed to study the effects of each design parameters on the system performance.