Amine Borane Based Hydrogen Carriers: An Evaluation

Abstract

Liquid organic hydrogen carriers (LOHCs) represent a new concept for energy-storage. LOHCs are able to store a considerable amount of hydrogen and release it on demand without being consumed themselves. A variety of different substances has been proposed recently. One promising group of potential carriers is amine borane based compounds. This contribution introduces the LOHC concept and gives a review over the amine borane based hydrogen carriers. An energetical evaluation using Aspen Plus was performed, and overall efficiencies were calculated. An energy storage system based on azaborines reaches efficiencies of up to 30%. This study shows that still intensive research on synthesis, regeneration, long-term stability, liquefaction, and toxicity is needed before this technique is marketable.

Recent Developments in Azaborinine Chemistry

“…The use of several 1,2‐azaborinines as hydrogen carriers, proposed and explored by Liu et al, has been critically evaluated . It appears that, although several 1,2‐azaborinines are on par with other chemical hydrogen storage systems, practical limitations, for example due to their melting points above ambient temperature, might hinder their application in the current state of research.…”

Liquid Organic Hydrogen Carriers as an efficient vector for the transport and storage of renewable energy

“…Various substances have been discussed as potential ETS candidates, e.g. methylcyclohexaneetoluene by [6], a variety of cycloalkanes [9] and ammoniaborane-based systems [8,10]. The focus of this contribution lies on heterocyclic aromatic hydrocarbons like N-ethylcarbazole [11], which e due to extensive research e are currently among the best understood LOHC systems with convenient material properties for the application as an energy carrier.…”

Alkaline‐Earth‐Catalyzed Dehydrocoupling of Amines and Boranes

“…[10] It is surprising, therefore, that, beyond an isolated example of rhodium-based dehydrocoupling,[11] the sole precedent for the coupling of an amine and a monohydrido borane arises from our earlier report of the reaction between [(HC{(CMe)(N{2,6- i Pr 2 C 6 H 3 })} 2 )Ca(NPh 2 )(thf)] and 9-BBN (Scheme 1). In this case the stoichiometric reaction took place through Ca–N/ H–B metathesis to yield the aminoborane and a calcium borohydride.…”