The H2-Industries energy storage solution is based on two separate processes namely the loading (hydrogenation) and unloading (dehydrogenation) of a liquid energy carrier. This liquid is a Liquid Organic Hydrogen Carrier (LOHC), an organic molecule showing similar physic-chemical properties as diesel. A big advantage of the hydrogen being chemically bonded to the liquid carrier is that it can be stored under ambient conditions (p=1bar, normal temperature) without suffering any self-discharge or the loss of hydrogen. One liter of the energy carrier can store an equivalent of 1 kWh thermal energy or, after reconversion, 1 kWh electrical energy
The storage process itself is a chemical reaction under elevated temperatures (T=150 – 180°C) and pressure (p=30 bar). An electrolyzer produces hydrogen at this pressure level in the STORE eUNIT, so no additional energy consuming compression is necessary. The hydrogen is fed into a hydrogenation unit filled with the porous catalyst forming a catalyst bed. The energy carrier is subsequently rinsed over the catalyst bed at 30 bars and the reaction of hydrogen and the LOHC occurs at the active precious metal sites of the porous catalyst. The chemical binding of H2 to the molecules of the energy carrier takes place on the catalyst. This reaction is an exothermic (i.e. energy is produced) reaction, allowing to use this waste heat for other applications. The loaded energy carrier (LOHC+) will be pumped to the storage tank.