Development of Liquid Organic Hydrogen Carriers for Hydrogen Storage and Transport

Abstract

The storage and transfer of energy require a safe technology to mitigate the global environmental issues resulting from the massive application of fossil fuels. Fuel cells have used hydrogen as a clean and efficient energy source. Nevertheless, the storage and transport of hydrogen have presented longstanding problems. Recently, liquid organic hydrogen carriers (LOHCs) have emerged as a solution to these issues. The hydrogen storage technique in LOHCs is more attractive than those of conventional energy storage systems like liquefaction, compression at high pressure, and methods of adsorption and absorption. The release and acceptance of hydrogen should be reversible by LOHC molecules following favourable reaction kinetics. LOHCs comprise liquid and semi-liquid organic compounds that are hydrogenated to store hydrogen. These hydrogenated molecules are stored and transported and finally dehydrogenated to release the required hydrogen for supplying energy. Hydrogenation and dehydrogenation are conducted catalytically for multiple cycles. This review elaborates on the characteristics of different LOHC molecules, based on their efficacy as energy generators. Additionally, different catalysts used for both hydrogenation and dehydrogenation are discussed.

Chemical material as a hydrogen energy carrier: A review

“…Therefore, optimization studies for LOHC-based hydrogen storage and transportation systems are actively conducted worldwide, and demonstration projects are underway to integrate LOHC systems with existing hydrogen infrastructure. However, continuous research and development efforts are needed due to the relatively low hydrogen density and availability compared to other hydrogen storage compounds (such as methanol and ammonia) [124,[128][129][130][131][132][133][134][135]. Various LOHCs based on substances including benzene and toluene have been researched, and their characteristics are summarized in Table 5 [126].…”

“…Consequently, it indicates that catalysts may exist in various carbide forms with different carbon contents under LOHC dehydrogenation conditions, and structural changes in catalyst nanoparticles are highly reversible. Other types and characteristics of LOHCs and catalysts are summarized in Table 6 [124,[131][132][135][136][138][139][140][141][142][143][144][145][146]. Additionally, a comparative analysis of the technology and economic prospects of hydrogenation systems using high-density storage technologies and liquid organic hydrogen carriers (primarily ammonia or methanol) for large-scale hydrogen storage was conducted.…”

“…Comparison of catalytic performance of reported LOHC catalysts[124,[131][132][135][136][138][139][140][141][142][143][144][145][146].…”

Green Hydrogen Energy Systems: A Review on Their Contribution to a Renewable Energy System

“…During the hydrogenation process, hydrogen molecules are chemically bonded to the LOHC molecules under elevated pressure and moderate temperatures (100-200 °C). Conversely, during dehydrogenation, the LOHC releases hydrogen when exposed to higher temperatures (200-300 °C) and lower pressure [62]. The reversible hydrogenation and dehydrogenation processes are facilitated by catalytic systems that enhance the reaction kinetics and efficiency.…”