Study of hydrogen liquefaction process through modelling and simulation

Ahmad, Abdurrazzaq

Abstract

Hydrogen is viewed as a promising alternative energy source to reduce dependence on conventional fuels, helping to tackle issues such as environmental challenges (climate changes) coming especially from the energy sector. Storing and delivering hydrogen efficiently can be achieved by converting it into its cryogenic liquid form. However, producing liquid hydrogen in industrial settings is both energy-intensive and costly. Current industrial hydrogen liquefaction plants are built for relatively small-scale operations that require a substantial amount of energy to liquefy hydrogen. As the future demand for hydrogen as an energy carrier grows, there will be a need for large-capacity hydrogen liquefaction plants to meet this demand. To deliver liquid hydrogen as an energy carrier, effective and viable hydrogen liquefaction processes are required. In this view, the thesis presents a study of hydrogen liquefaction process through modelling and simulation. A thorough technical review paper was developed to evaluate the past, current, and future of hydrogen liquefaction, followed by a technical paper on the evaluation of the significance of ortho-para-hydrogen conversion in the hydrogen liquefaction process leading to the development of a novel approach. All studied process concepts were modelled and simulated in Aspen Plus, a comprehensive process simulator, under a steady-state condition. To evaluate the viability, a detailed energy and exergy estimation for the hydrogen liquefaction process (including process subsystems and the process equipment) was implemented. The implemented hydrogen liquefaction process simulation and model estimations were used for the efficient determination of the hydrogen liquefaction process for both specific energy consumption (SEC), exergy efficiency, and coefficient of performance (COP). Finally, a 100 TPD capacity of hydrogen liquefaction process was developed which adopted a Claude Cycle of high-pressure hydrogen with Joule-Brayton and Mixed-refrigerant precooling. The hydrogen liquefaction process developed reduces the SEC of an average developed hydrogen liquefaction model (like that of Linde AG Plant) by nearly 70% to about 3.263 kWh/kgLH2, increases the exergy efficiency to 95.85%, and produces a COP of 0.3878. The results presented in this work are anticipated to substantially lead to reducing the cost of hydrogen liquefaction and enable hydrogen as the fuel of the future.

Citation

Ahmad, A. (2024). Study of hydrogen liquefaction process through modelling and simulation. (Thesis). University of Hull. https://hull-repository.worktribe.com/output/4927474

• Thesis Type: Thesis
• Deposit Date: Nov 26, 2024
• Keywords: Chemical engineering
• Public URL: https://hull-repository.worktribe.com/output/4927474
• Additional Information: Chemical Engineering; School of Science and Engineering; University of Hull
• Award Date: Oct 21, 2024