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Proceedings of the 27th National and 5th International ISHMT-ASTFE Heat and Mass Transfer Conference December 14-17, 2023, IIT Patna, Patna-801106, Bihar, India
December, 14-17, 2023, Bihar, India

Understanding the Thermodynamic and Kinetic behavior of the Dehydrogenation process of Liquid Organic Hydrogen Carrier (Methylcyclohexane-Toluene) at high pressure

Get access (open in a dialog) DOI: 10.1615/IHMTC-2023.1320
pages 815-820


Fossil fuels are limited in nature and cause pollution when burn for electricity production and vehicle power generation. This necessitates an alternative renewable energy source to achieve a net-zero emission system. Hydrogen stands out as a potential energy source with a high gravimetric energy density of approximately 120 MJ/kg. However, the storage of hydrogen presents a major challenge, hindering its use as an alternative energy source for vehicles. Even though it can be stored as compressed gas or liquid, but this requires specific pressure and temperature conditions. Maintaining these conditions in turn necessitate energy-intensive heaters, chillers, and pumps. For instance, storing hydrogen as a liquid at -252°C and atmospheric pressure consumes 30% of its lower heating value. A promising technology called Liquid Organic Hydrogen Carrier (LOHC) has emerged as a solution to store hydrogen at atmospheric pressure. LOHC allows repeated hydrogenation and dehydrogenation, with the former being an exothermic process and the latter being endothermic. This technology provides a safe and efficient means of transporting and storing hydrogen for a long time and it is non-toxic and non-flammable. Due to its superior safety for hydrogen storage, LOHC should be considered as an alternative to the current fossil fuels used in light vehicles, which can leverage the existing infrastructure of petrol and diesel. This paper focuses on understanding the thermodynamic and kinetic behavior of the dehydrogenation process of LOHC (Methylcyclohexane to toluene) at high pressure by varying its pressure and temperature under limits. It is found that 90.9% dehydrogenation takes place at 300°C with 10 bar pressure which is not even possible at 450°C with 1 atm pressure at the same molar flow rate. This reduces the power required to heat the feed by almost 34%.