A System-Level Analysis for Long-Distance Hydrogen Transport Using Liquid Organic Hydrogen Carriers (LOHCs): A Case Study in Australia-Korea

Abstract

The toluene (TOL)-methylcyclohexane (MCH) system is one of the viable solutions because of its high stability and high hydrogen storage capacity (6.2%). However, the high volatilities of TOL and MCH and the accumulative byproducts make it difficult to transport hydrogen. Considering these limitations, we developed a new strategy introducing an extraction column and pressure swing adsorption with heat integration to reduce the required energy utilities. Furthermore, a comprehensive system-level analysis was conducted through an application example of the transport of hydrogen from Australia to Korea. The minimum transport cost of hydrogen was determined to be $2.17/kg-H-2 via techno-economic analysis. Sensitivity and uncertainty analyses revealed the influence of the economic and process parameters. Finally, a life cycle assessment was conducted to compare the environmental impact (EI) of each part. Although dehydrogenation is more energy-demanding than hydrogenation, hydrogenation has larger EIs for some factors including fossil resource scarcity (13% larger) and water consumption (746% larger), due to the toluene and hydrogen makeup. Furthermore, we compared changes in the EIs in the energy sources. This study can provide insights into the optimization and decision-making of hydrogen supply chains to revitalize the hydrogen economy.