Thermodynamic property fields of hydrogen in porous materials

• Main Author: Wijaya, Thomas
• Other Authors: Anutosh Chakraborty
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering
• Online Access: https://hdl.handle.net/10356/176750
• Institution: Nanyang Technological University

Given its diverse applications in various industries such as energy, transportation, and electronics, hydrogen (H2) is poised to become a highly sought-after element in the coming years. Hydrogen can be obtained through various methods, including electrolysis of water and steam reforming of natural gas. However, for applications requiring high-purity hydrogen, such as fuel cells and ammonia production, alternative extraction methods are being explored. Hydrogen exists in different states, with the most common being diatomic molecular hydrogen (H2). While non-radioactive hydrogen is abundant in the Earth's atmosphere, other forms such as hydrogen isotopes (e.g., deuterium and tritium) are used in nuclear fusion reactions. Conventional extraction techniques often involve energy-intensive processes like steam methane reforming or electrolysis, which can be costly and environmentally taxing. To address these challenges, alternative methods utilizing adsorptive separation through materials like Metal Organic Frameworks (MOFs) are being investigated. These materials offer the potential for efficient hydrogen storage and release, making them promising candidates for various applications. This report focuses on understanding hydrogen storage in porous adsorbents, emphasizing adsorption processes and their thermodynamic properties. By deriving parameters such as entropy, enthalpy, specific heat capacity, adsorbed phase volume, and isosteric heat of adsorption, a comprehensive understanding of the hydrogen-MOF system is achieved. Using a modified Langmuir Equation (LE) proposed by Sun and Chakraborty, crucial parameters necessary for characterizing the system are extracted from experimentally measured isotherms. The project aims to provide theoretical insights into thermal energy storage in confined spaces, essential for designing efficient hydrogen storage systems. Thermodynamic property surfaces are depicted graphically, illustrating changes in pressures, temperatures, and hydrogen uptakes. Additionally, temperature-entropy maps demonstrate continuous thermal storage during the charging and discharging processes, laying the groundwork for future advancements in hydrogen storage technologies.