Hydrogen Storage in Liquid Organic Hydride: Producing Hydrogen Catalytically from Methylcyclohexane

Abstract

Hydrogen storage for stationary and mobile applications is an expanding research topic. One of the more promising hydrogen storage techniques relies on the reversibility and high selectivity of liquid organic hydrides, in particular, methylcyclohexane (MCH). The use of liquid organic hydrides in hydrogen storage also provides high gravimetric and volumetric hydrogen density, low potential risk, and low capital investment because it is largely compatible with the current transport infrastructure. Despite its technical, economical, and environmental advantages, the concept of hydrogen storage in liquid organic carriers has not been commercially established because of technical limitations related to the amount of energy required to extract the hydrogen from liquid organic hydride and the insufficient stability of the dehydrogenation catalyst. This paper provides a review for the effort that has been directed toward the development of this concept over the past few decades and mainly focuses on the catalytic production of hydrogen from MCH. The topics that have been covered are the kinetics of MCH dehydrogenation over Pt/Al2O3 and Pt–Re/Al2O3 catalysts, the kinetics of catalyst deactivation, the thermodynamic equilibrium in MCH dehydrogenation, and the sulfur impact on the MCH dehydrogenation reaction.

Assessing Uncertainties of Well-To-Tank Greenhouse Gas Emissions from Hydrogen Supply Chains

“…Notably, Cresswell and Metcalfe demonstrated a MCH dehydrogenation system in which the reaction heat was supplied by waste heat from a solid oxide fuel cell [108]. R&D that focuses on improving the dehydrogenation catalysts is also important for advancing the process efficiency [109,110]. In this manner, catalysts that facilitate the dehydration using low-quality waste heat have been reported by Chaouki and Klvana [111] and Hodoshima et al [112].…”

Catalytic Ammonia Decomposition over High-Performance Ru/Graphene Nanocomposites for Efficient COx-Free Hydrogen Production

“…On the other hand, although hydrogen can be stored in porous materials via adsorption under mild conditions [5][6][7][8][9], the relatively low hydrogen storage capacity of various sorbents seems to be an insurmountable obstacle for practical applications. A great deal of attention has been paid to the chemical storage of hydrogen, and various types of hydrogen storage systems have been intensively studied based on different hydrogen carriers such as metal and organic hydrides [10][11][12][13][14]. Ammonia [15][16][17][18][19][20] has recently been widely accepted as a very promising and important hydrogen carrier owing to its fascinating properties.…”

Bulk Storage Vessels for Compressed and Liquid Hydrogen

“…These approaches include representatives of the reversible solid-state hydrogen storage group such as clathrate hydrates [6][7][8] and cryoadsorbing storage systems [3] as well as some irreversible chemical hydrogen storage concepts such as the methylcyclohexane-toluene-hydrogen cycle [9,10], benzene-water systems [11], and aqueous hydrogen peroxide [12]. This shows that very different storage methods are conceivable for the purpose of bulk storage.…”

“…This shows that very different storage methods are conceivable for the purpose of bulk storage. However, these methods still require further improvement before they can be put into practice [5,6,9].…”