Thermodynamic and economic analysis of new coupling processes with large-scale hydrogen liquefaction process and liquid air energy storage

Abstract

Liquid hydrogen serves as an environmentally friendly energy carrier, playing a crucial role in alleviating greenhouse effects. In order to tackle the challenges concerning energy consumption and economic costs, it becomes imperative to develop an efficient and cost-effective large-scale hydrogen liquefaction process (LHLS). This study integrates of LHLS with liquefied air energy storage (LAES) and introduces three liquefaction processes to reduce the economic cost associated with hydrogen liquefaction. By coupling LAES, electricity generated during off-peak hours can be stored and subsequently utilized in LHLS operations during peak hours, leading to a reduction in electricity costs. Furthermore, utilizing the surplus cooling capacity of LAES can enhance the efficiency of LHLS. A genetic algorithm is used to optimize the coupling processes. The calculated total annual cost (TAC) of the most economically viable coupling process amounts to 12271.8 k$/year, representing in a 20.91 % reduction compared to the independent LHLS. This indicate a clear economic advantage with the coupling process. The levelized cost of hydrogen (LCOH) and the payback period (PBP) for this particular coupling process are 2.523 $/kg and 4.56 years, respectively. A sensitivity analysis reveals that the economic benefits of the coupling processes escalate with higher electricity prices and greater liquefaction capacity.