Evaluation of Industrially Applied Heat‐Transfer Fluids as Liquid Organic Hydrogen Carrier Systems

TLDR

LOHC systems provide an attractive method for decentralized storage of renewable excess energy. The study proposes using industrial heat‑transfer oils, such as Marlotherm, as a new class of LOHC systems. These oils are hydrogenated to perhydrogenated analogues, binding 6.2 wt % H₂. The hydrogenated oils store 6.2 wt % H₂, can be transported like diesel, dehydrogenate above 260 °C, and offer low cost, high availability, and excellent thermal stability.

Abstract

Abstract Liquid organic hydrogen carrier (LOHC) systems offer a very attractive method for the decentralized storage of renewable excess energy. In this contribution, industrially well‐established heat‐transfer oils (typically sold under trade names, e.g., Marlotherm) are proposed as a new class of LOHC systems. It is demonstrated that the liquid mixture of isomeric dibenzyltoluenes (m.p. −39 to −34 °C, b.p. 390 °C) can be readily hydrogenated to the corresponding mixture of perhydrogenated analogues by binding 6.2 wt % of H 2 . The liquid H 2 ‐rich form can be stored and transported similarly to diesel fuel. It readily undergoes catalytic dehydrogenation at temperatures above 260 °C, which proves its applicability as a reversible H 2 carrier. The presented LOHC systems are further characterized by their excellent technical availability at comparably low prices, full registration of the H 2 ‐lean forms, and excellent thermal stabilities.