Liquid organic hydrogen carriers: Final report

None of the today’s energy storages are feasible to serve the revolution from fossil to renewable energy due to their limited storage times and capacities. Liquid organic hydrogen carrier (LOHC) concept is promising solution to safely carry hydrogen with flexible storage times and capacities, and being compatible with the existing infrastructure for liquid fuels. LOHC liquid can be reversibly hydrogenated and dehydrogenated using catalysts, however, at relatively high temperature (e.g. 300 °C). Development needs identified were tackled in the LOHC-NESS project with focus on LOHC system based on dibenzyl toluenes (DBT) already on market. In the feasibility screening, the logistics of by-product hydrogen from chlorate and chlor-alkali plants to light industry was identified as a possible low-hanging fruit for the LOHC con-cept to enter the markets. LOHC could also be a feasible option for large-scale import of re-newable hydrogen. In the catalyst development, Pt on a titania nanopowder catalyst was found to be active for dehydrogenation of H18-DBT at lower temperature than reported ear-lier. This catalyst was tested in reactor and in own proof-of-concept station, which confirmed that catalyst wash coated on a tube was active. However, in the own station, hydrogen re-leased from H18-DBT was modest, possibly due to lower actual than set temperatures. A commercial LOHC release plant was leased from Hydrogenious GmbH for demonstration in several operation points, and for the long-term stability of operation. The largest degree of de-hydrogenation (72%) was achieved with the highest temperature (310 °C) and lowest flow tested. The decomposition of LOHC liquid in product gas and in outlet liquid was substantial in own station and in leased unit. Recovering benzene/MCH would improve economy of system. Fuel cell operation was studied with different toluene levels, also together with CO. According to these results, hydrogen from dehydrogenation of H18-DBT requires purification system, if hydrogen is used in automotive PEMFC.