Perspective on Decarbonizing Long-Haul Trucks Using Onboard Dehydrogenation of Liquid Organic Hydrogen Carriers

Abstract

Decarbonization of long-haul trucks, which are the backbone of global supply chains, is necessary to meet climate goals. Currently, battery electric and conventional hydrogen powertrains are not cost-competitive solutions against diesel. Liquid Organic Hydrogen Carriers (LOHCs) are a promising fuel option that benefits from synergies with existing retail fuel distribution infrastructure, providing a cost-effective way to transport hydrogen energy. LOHCs are now used to deliver hydrogen gas to refueling stations, where it is then compressed and used to fuel trucks. However, this approach incurs ∼50% energy loss from the endothermic dehydrogenation and compression of hydrogen. We discuss an alternative concept based on onboard hydrogen release to address these pain points. We highlight recent advances in dehydrogenation reactor design, catalyst technologies, and hydrogen combustion engines that are relevant to the proposed system. Deficiencies in current technologies are discussed, along with potential research directions to address them. Initial analysis shows that the LOHC option, charged with blue hydrogen, achieves rough cost parity with diesel. The estimated well-to-wheel greenhouse gas emissions for this option are approximately one-third of diesel. Based on our analysis, LOHC-powered trucks featuring onboard dehydrogenation are a promising option to decarbonize long-haul trucking. However, making this option a reality will require dedicated study and development of core components for the power-dense, efficient, and robust onboard release of hydrogen from LOHCs along with efficient heat integration between the engine and the dehydrogenation reactor.

Comprehensive Review of Hydrogen Leakage in Relation to Fuel Cell Vehicles and Hydrogen Refueling Stations: Status, Challenges, and Future Prospects

“…From a macroscopic perspective, in open or well-ventilated environments, gaseous hydrogen can quickly mix with air and dilute, potentially reducing explosion risks but also expanding the range of potential danger zones. On the other hand, liquid hydrogen rapidly vaporizes upon leakage, forming cold liquid pools on the ground . The rapid evaporation from these pools can create combustible gas clouds that maintain high hydrogen concentrations for a period of time, thereby increasing explosion risks.…”

Perspectives and Potential of Liquid Organic Hydrogen Carriers in the German Energy Scenario

“…al. describe the potential of LOHC for mobility applications by suggesting long-haul trucks with on-board dehydrogenation [58].…”

A nature-inspired solution for water management in flow fields for electrochemical devices

“…9 On the contrary, PEMFC technology is expected to dominate freight transportation (ships, trains, heavy lorries) soon, since its power output can be easily scaled up via an increase of the size of the stack or the hydrogen tank at a lower additional weight cost than a lithium-ion battery, 10 with PEMFC powered prototypes gradually infiltrating the market. 4,10–12…”

“…9 On the contrary, PEMFC technology is expected to dominate freight transportation (ships, trains, heavy lorries) soon, since its power output can be easily scaled up via an increase of the size of the stack or the hydrogen tank at a lower additional weight cost than a lithium-ion battery, 10 with PEMFC powered prototypes gradually infiltrating the market. 4,[10][11][12] However, the current PEMFC technology is not mature enough to meet the 80 000 h and 8000 h durability targets (2020-2025) for stationary and transportation applications, respectively. 13 This lack of durability is associated with the degradation of the key component of PEMFC, namely the membrane electrode assembly (MEA), and is related to the operating conditions: load cycling between open-circuit potential of 1 V vs. reversible hydrogen electrode (RHE) and optimum operating point (0.5-0.7 V vs. RHE), and 20-60% relative humidity (RH).…”