Story by: Tyler Campbell, Managing Editor

The Sustainable Energy Council (SEC) and the U.S. Department of Energy (DOE) hosted the second Hydrogen Americas Summit in Washington DC (United States). At the summit, the H₂ Tech Series featured presentations on various hydrogen (H₂) projects, equipment and services to progress the H₂ economy. Robert Schneider, Senior Technical Advisor, Downstream and New Technologies for Chiyoda International Corp., delivered a presentation titled “Hydrogen value chain: LOHC–MCH for energy transition.”

Chiyoda is a global engineering company and has worked on various engineering, procurement and construction (EPC) contracts, including petrochemical and liquified natural gas (LNG) facilities. The company has since included battery storage and H₂ projects. The presentation focused on the company’s commercially proven technology, SPERA (Latin for HOPE), used to transport H₂ via the global supply chain.

In the process described, toluene—containing three double bonds—is hydrogenated to methylcyclohexane (MCH) using three hydrogen molecules. MCH is capable of being transported short and long distances and dehydrogenated back to toluene with three hydrogen molecules, making it a liquid organic H₂ carrier (LOCH).

According to Schneider, SPERA transports MCH by whatever means is deemed most appropriate (e.g., tanker, rail line, pipeline) from the point of production to end use. The H₂ is then recovered through dehydrogenation. Chiyoda then uses its proprietary catalyst, providing high conversion, selectivity and long-term stability; the toluene is transported back to the H₂ production point and recycled, thus making it a circular carrier.

“Looking at the process from an overall perspective, we can consider the energy content of the H2 to be transported, hydrogenation conversion energy required, energy recovered from the hydrogenation exothermic reaction, energy used to transport the MCH and toluene and the energy required for dehydrogenation (an endothermic reaction),” Schneider said. “Considering these factors, we estimate an overall process efficiency of around 60%.”

When comparing LOHCs with ammonia (NH₃) and liquid H₂ (LH₂), LOHCs can be transported at ambient temperatures, while NH₃ and LH₂ have more restrictions due to being cryogenic liquids. With MCH, H₂ content is about 1/500 of the equivalent volume of gaseous H₂, while the H₂ contained volume in NH3 is 1/1300. MCH can also provide H₂ at a purity above 99.8% (further cleaning will be required for it to reach fuel cell grade).

“In the case of NH₃, H₂ used as a fuel requires no further treatment, but for H₂ recovery applications, NH₃ cracking and subsequent purifications would be required,” Schneider said. “There is no question that NH₃ cracking is possible; however, there are no large-scale NH₃ cracking facilities in commercial operation.”

Schneider continued by showing a chart of the costs of producing H₂ in South America and shipping it to the Port of Rotterdam in different forms—LH₂, NH₃, MCH, methanol and dibenzyltoluene (DBT). The chart shows that the shipping costs are not the primary issue and pale in comparison to H₂ production, storage and other various supply chain costs.

To demonstrate the efficiency of SPERA, the company transported H₂ from Brunei Darussalam to Japan (about 3,000 mi) in iso containers, where the H₂ was recovered as a purified gas and used in a gas turbine electric power generator. Over the year of the demonstration, 210 metric t of H₂ were successfully transported.