Analysis of Liquid Organic Hydrogen Carrier Systems

Liquid organic hydrogen carriers (LOHCs) provide attractive opportunities for hydrogen storage and transportation. In this study, a detailed examination of the most prominent LOHCs is performed, with a focus on their properties and scope for successful process implementation, as well as catalytic materials used for the hydrogenation and dehydrogenation steps. Different properties of each potential LOHC offer significant flexibility within the technology, allowing bespoke hydrogen storage and transportation solutions to be provided. Among different LOHC systems, dibenzyltoluene/perhydro-dibenzyltoluene has been identified as one of the most promising candidates for future deployment in commercial LOHC-based hydrogen storage and transport settings, based on its physical and toxicological properties, process conditions requirements, availability and its moderate cost. PGM-based catalysts have been proven to catalyse both the hydrogenation and dehydrogenation steps for various LOHC systems, though base metal catalysts might have a potential for the technology.

Potential Deployment and Integration of Liquid Organic Hydrogen Carrier Technology within Different Industries

The deployment of hydrogen as an infrastructure fuel and an energy vector across a range of industries is expected to aid with meeting decarbonisation goals and achieving net zero emissions. For the transition towards a low carbon hydrogen economy, not only the production of hydrogen needs to be addressed, but also its transportation and storage. Liquid organic hydrogen carriers (LOHCs) are an attractive solution for the storage and transportation of hydrogen to allow a reliable and on-demand hydrogen supply, enabling industrial decarbonisation. This work describes the potential deployment and integration of LOHCs within different industries. These include: the transportation sector; steel and cement industries; the use of stored hydrogen to produce fuels and chemicals from flue gases, and a system integration of fuel cells and LOHCs for energy storage.

Dielectric barrier discharge plasma grafting carboxylate groups on Pt/Al2O3 catalysts for highly efficient hydrogen release from perhydro-dibenzyltoluene

The key issues for the use of dibenzyltoluene (DBT) as a Liquid Organic Hydrogen Carrier (LOHC) are the high dehydrogenation temperature and the sluggish hydrogen releasing rate. Therefore, highly active...

Thermodynamic analysis of electrochemical synthesis of ammonia in solid-state proton-conducting electrochemical reactors with considering interfacial potential steps

Ammonia (NH3) as a carbon-free hydrogen carrier shows great potential as fuel and its production at mild conditions is desired. NH3 synthesis at atmospheric pressure can be realized in solid-state...

Development of Ammonia Fueled Solid Oxide Fuel Cells

Solid oxide fuel cells (SOFCs) can generate electricity through an electrochemical conversion of the chemical energy of fuels including hydrogen, hydrocarbons, and biogas because of high operation temperatures. Ammonia has recently been considered as a promising hydrogen carrier that is relatively convenient to store and transport and can be decomposed into hydrogen and nitrogen with no carbon emission via catalytic cracking. Thus, much effort has been made to utilize ammonia as a clean fuel to SOFCs for power generation at high efficiency. This review is aiming at delivering the current progress of developing high temperature ceramic fuel cells fed with ammonia, particularly more focused on the achievements of a direct ammonia fueled SOFC (DA-SOFC) to shed light on the challenges of degrading the performance and durability. The problems are primarily attributed to a lack of rational catalysts, thermal imbalance, and the evolution of nitrides on the components including the Ni based anode, Ni mesh as current collector, and stainless steels of metallic interconnect that are exposed to the ammonia fuel environment incurring microstructural deformations and electrical and electrochemical deteriorations. Lastly, strategic pathways to overcome the inadequate performance and the instability are suggested to accomplish a commercialization of DA-SOFCs.

Recent Advances in Homogeneous/Heterogeneous Catalytic Hydrogenation and Dehydrogenation for Potential Liquid Organic Hydrogen Carrier (LOHC) Systems

Here, we review liquid organic hydrogen carriers (LOHCs) as a potential solution to the global warming problem due to the increased use of fossil fuels. Recently, hydrogen molecules have attracted attention as a sustainable energy carrier from renewable energy-rich regions to energy-deficient regions. The LOHC system is one a particularly promising hydrogen storage system in the “hydrogen economy”, and efficient hydrogen mass production that generates only benign byproducts can be applied in the industry. Therefore, this article presents hydrogenation and dehydrogenation, using homogeneous or heterogeneous catalysts, for several types of LOHCs, including formic acid/formaldehyde/ammonia, homocyclic compounds, nitrogen- and oxygen-containing compounds. In addition, it introduces LOHC system reactor types.