Geothermal assisted hydrogen liquefaction systems integrated with liquid nitrogen precooling; Thermoeconomic comparison of Claude and reverse Brayton cycle for liquid nitrogen supply

Abstract

Hydrogen liquefaction systems are of paramount importance in achieving a low liquid hydrogen price in developing the hydrogen supply chain. In these systems, reduction of compression work and efficient supply of liquid nitrogen for precooling purposes is essential. In this respect the present research proposes an investigation of two efficient configurations comprised of a Claude cycle for hydrogen liquefaction integrated with geothermal driven organic Rankine cycle to compensate some of the consumed power. In the proposed schemes, either the Claude or reverse Brayton cycles are employed and modeled for liquid nitrogen supply, while in most of previous research a fixed value was considered for compression work to supply the liquid nitrogen, reducing the accuracy of their reported outcomes. A comprehensive thermoeconomic assessment was implemented to determine a better scheme under various operating conditions using a parametric study. The results revealed the vital importance of integrated modeling of the liquid nitrogen supply unit with that of the hydrogen liquefaction system.