A novel hydrogen liquefaction process based on LNG cold energy and mixed refrigerant cycle

Abstract

• A novel hydrogen liquefaction cycle using LNG cold energy and mixed refrigerant cycle is proposed. • Energy, exergy, and economic analyses are performed. • Take advantage of using LNG cold energy of the regasification system in the hydrogen liquefaction cycle. • The proposed cycle is compared and analyzed with other cycles. • COP, SEC, and FOM are investigated for the proposed hydrogen liquefaction cycle. A novel hydrogen liquefaction cycle with a capacity of 369 tons per day has been proposed. Given the fact that the process integration and appropriate design can reduce the power consumption of the light gas liquefaction cycle, wasted cold energy of a natural gas regasification system is integrated into the pre-cooling part of the liquid hydrogen production. In this study, after being evaporated in the pre-cooling part of the hydrogen liquefaction cycle, the liquefied natural gas (LNG) enters the steam methane reforming (SMR) to feed the hydrogen liquefaction process by hydrogen gas. Energy, exergy, and economic analyses are carried out to investigate the process. The mixed refrigerant method is implemented in the proposed model. The specific energy consumption (SEC) of the proposed process is 19.90% less than that of the similar cycles mentioned in the literature. The economic analysis results illustrate that the total annual cost of the proposed model is 13.43% less than that of the base model. A comparison between the proposed and other hydrogen liquefaction cycles is made to verify feasibility and efficiency. The minimum selling price of the liquid hydrogen is $ 2.07 k g − 1 in a payback time of three years, making it economically viable.