Technical Analysis of Dehydrogenation Process of Liquid Organic Hydrogen Carriers (LOHC’s) for Hydrogen Storage

Abstract

Hydrogen as a clean-energy carrier has gained great attention in the current times while its storage, transportation and dehydrogenation are the stumbling blocks in fulfilment of a hydrogen backed clean economy. The efficiency of storage that is hydrogenation has been achieved significantly but dehydrogenation efficiency still needs improvement in order to increase the efficiency of the overall Hydrogen storage technique. Liquid organic hydrogen carrier (LOHC) could be one of the replacements, provided appropriate conditions are given for its storage, transportation and its dehydrogenation that is the removal of hydrogen from the LOHC thus contributing to the clean fuel idea in coming years. In this study, a parametric and simulation-based research was carried out for the storage and release of hydrogen for three different LOHC’s. Specifically, the dehydrogenation reaction was assessed over three catalysts for the temperature range of 300–450 °C and a pressure range of 1–3 bar to select the best catalyst and LOHC under optimum operating conditions. Likewise, the effects of hydrogen addition in the feed mixture were also investigated as functions of operating conditions. Hydrogen addition in the feed not only reduced the percentage conversion but also enhanced catalyst’s stability. It avoids the coke formation on the catalyst surface. The results were compared for maximum LOHC conversion in the required conditions. The optimum operating conditions selected for the dehydrogenation process were 360 °C and 1.8 bar. In order to perform the simulation, Aspen Plus simulation software was utilized to carry out different simulations under different temperature and pressure conditions. The conversion percentage trends were observed with increasing temperature and pressure on the graphs which shows their impact on the conversion percentage.