Case Study #1
Turning hydrogen into a liquid vehicle fuel
At a glance
Companies: Umicore and Anglo American
Challenge: Reducing the pressure and temperature needed for dehydrogenation of a liquid organic hydrogen carrier
Response: New catalysts
Status: Early stages of development
Hydrogen is one of the fuels of the future. Hydrogen-powered fuel-cell vehicles emit no carbon dioxide, only a thin trail of water. Unlike electric cars, they can be refueled in minutes. And while H2 is created mostly from methane today, proponents see a future when green hydrogen is generated cheaply by water electrolysis that uses energy from the wind and the sun.
But hydrogen is also an extremely light molecule that must be compressed for shipping and storage. The infrastructure to get it into fuel-cell vehicles or power plants exists in just a few places.
Umicore and Anglo American, two big players in precious metals, have formed an R&D venture to advance a novel solution to the compression problem: the liquid organic hydrogen carrier, or LOHC.
The idea behind the LOHC is to chemically bind hydrogen to a stable liquid carrier. This bound hydrogen can be loaded into a standard fuel tank just like a conventional liquid fuel, eliminating the need for compression, both in the fuel-loading lines and the vehicle itself.
For a hypothetical future vehicle to make use of the hydrogen, the hydrogen-loaded LOHC would pass through a reactor containing a dehydrogenation catalyst. Hydrogen would then be released and supplied to the fuel-cell stack of the vehicle, be it a car, truck, or train. The spent LOHC would be removed during the next fueling so it could be reloaded with more H2.
Umicore and Anglo American formed their partnership in April, building on Anglo American’s earlier investment in Hydrogenious LOHC Technologies, a German LOHC start-up cofounded by Peter Wasserscheid, a chemist at Friedrich Alexander University Erlangen-Nuremberg. The partners’ focus is the dehydrogenation catalyst.
Some investors have warmed to the LOHC concept. In September, Hydrogenious LOHC raised close to $60 million from investors including Chevron to further develop LOHCs. The firm is building a test facility in Dormagen, Germany, where it will store hydrogen in an LOHC and test shipping it to customers.
Hydrogenious LOHC and Umicore agree that the best current LOHC candidate is benzyltoluene, owing to its combination of high heat capacity and storage density and low viscosity and surface tension. The molecule has long been an important heat-transfer fluid. In July, Hydrogenious LOHC signed an agreement to purchase benzyltoluene from Eastman Chemical, which makes it in Marl, Germany.
But Umicore and Anglo American say more work needs to be done on the catalyst that dehydrogenates the LOHC. In an April 26 online presentation to stock analysts to explain the research effort, An Steegen, Umicore’s chief technology officer at the time, said dehydrogenation with the current catalyst system requires pressures and temperatures too high to be practical for vehicle use.
Umicore’s role in the partnership is to develop a new heterogeneous catalyst—specifically, a precious metal fixed on an inorganic support material—that permits dehydrogenation at lower pressures and temperatures. The company cautions that the project is still at the early stages of development and that it will take 5–10 years before an efficient LOHC could be commercialized.
In the April 26 presentation, some analysts questioned the need for an alternative to compressed hydrogen for H2 fuel systems. Alex Stewart of Barclays Investment Bank pointed out that “99% of the rest of the market is investing in the—sort of—old technology, which is getting pure hydrogen to the hydrogen fuel cells.”
And while the hydrogen vehicle market is nascent, it does exist in places such as California, which has 47 hydrogen fueling stations. Eric McFarland, chief technology officer of the carbon-free hydrogen start-up C-Zero, says he was once skeptical about filling a vehicle with compressed H2. But McFarland has been driving the hydrogen-powered Toyota Mirai in California and says he’s become comfortable with the fueling process, which isn’t much different from a traditional gasoline fill-up.
Responding to Stewart, Steegen acknowledged that compressed hydrogen is the incumbent fuel-cell vehicle fuel. But she noted that the safeguards needed to make hydrogen-powered vehicles safe—sensors, alarms, special seals in the event of leakage, and a high-tech pressurized tank—add significantly to the vehicles’ cost.
Moreover, California’s experiment aside, converting the world’s existing fossil fuel transportation and storage infrastructure to hydrogen has yet to happen and would be a costly undertaking. Transitioning to a hydrogen-loaded LOHC would allow the existing infrastructure to stay mostly in place, Steegen said.
“That said,” she added, “LOHC is still in an early stage of development. We still need to work on the catalyst for dehydrogenation to make it compatible with onboard dehydrogenation. Also, the efficiency needs to improve. But nevertheless, it has the potential to basically be a very efficient hydrogen carrier towards the future.”