Role of Liquid Hydrogen Carriers in Deeply Decarbonized Energy Systems

Abstract

Hydrogen can be valuable for deep decarbonization of electricity systems as well as energy end-uses where direct electricity is challenged. While most hydrogen supply chain analyses focus on storing hydrogen as compressed gas hydrogen (CGH 2 ) storage, hydrogen storage systems with lower capital cost of storage capacity such as liquefied hydrogen (LH 2 ) and liquid organic hydrogen carriers (LOHC) may provide a differentiated value for energy system decarbonization. However, the latter systems have disadvantages (e.g., higher capital cost of charge/ discharge capacity, boil-off, high energy requirement for conversion/ reconversion) that could impede their deployment. In this study, we expand upon a previously developed electricity-hydrogen infrastructure planning model, DOLPHyN, to explore the value of liquid hydrogen solutions for energy storage and transport in a deeply decarbonized energy system. First, we show that TOL-LOHC (i.e., toluene-based LOHC) and LH 2 are beneficial as seasonal energy storage systems, while CGH 2 is more suitable for shorter-duration storage (e.g., weekly) cycling. The addition of LH 2 and LOHC enables more efficient utilization of deployed electric generation and power-to-hydrogen generation infrastructures. Second, we show that LH 2 is more favorable than LOHC for providing long-term storage for the power sector because its primary capital costs and energy penalty for conversion are incurred during charging periods, which typically correspond to when renewable energy is more abundant. Cost effectiveness of LH 2 is based on accounting for boil-off rates of largescale LH 2 systems. Third, we show that commercial viability of LOHC is strongly tied to the ability to lower the energetic consumption of the dehydrogenation process as well as its capital cost.

Molecular Insights into the Impact of Surface Chemistry and Pressure on Quartz Wettability: Resolving Discrepancies for Hydrogen Geo-storage

“…1,2 However, H 2 is highly compressible, explosive, and volatile, posting challenges for large-scale surface storage techniques. 3,4 Alternatively, subsurface formations, e.g., salt deposits, aquifers, and depleted hydrocarbon reservoirs, show great promise for large-scale hydrogen storage. 5−7 The wettability of the porous formations is vital in ensuring storage safety, efficiency, and capacity.…”

High performance of visible-light driven hydrogen production over graphdiyne (g-CnH2n−2)/MOF S-scheme heterojunction

“…Therefore, the development of renewable energy is imminent. [5][6][7][8][9][10][11] As we all know, hydrogen has high burning value and efficient cleaning, and solar energy possesses the merits of being inexhaustible, non-polluting, and regenerative. [12][13][14] To meet the requirements of low carbon and environmental protection, research on efficient hydrogen production materials has attracted considerable attention for development and utilization around the world.…”

Uncovering novel liquid organic hydrogen carriers: a systematic exploration of chemical compound space using cheminformatics and quantum chemical methods

“…Both systems, however, require methods to isolate N 2 or CO 2 at the end stages of the catalytic dehydrogenation process and are prone to release mixtures of gases instead of pure H 2 . 12 Various hydrogen-lean liquid organic hydrogen carriers (LOHCs) 3,13,14 have been proposed as alternative, more promising carrier molecules.…”

“…Both systems, however, require methods to isolate N 2 or CO 2 at the end stages of the catalytic dehydrogenation process and are prone to release mixtures of gases instead of pure H 2 . 12 Various hydrogen-lean liquid organic hydrogen carriers (LOHCs) 3,13,14 have been proposed as alternative, more promising carrier molecules. LOHCs are unsaturated organic molecules that can chemically trap (hydrogenation) and then release (dehydrogenation) H 2 molecules, with the hydrogenation/dehydrogenation cycles mediated by a catalyst under specific reaction conditions.…”