In the quest for sustainable and efficient transportation, a team of researchers from the Massachusetts Institute of Technology (MIT) has embarked on a groundbreaking journey. They are developing a disruptive technology that not only has the potential to enhance hydrogen transport and storage but could also play a pivotal role in decarbonizing the fossil-fuel-intensive long-haul trucking sector.
The Power of Liquid Organic Hydrogen Carriers (LOHCs)
At the heart of this innovation lies the concept of Liquid Organic Hydrogen Carriers (LOHCs), a group of chemical compounds used in energy storage and transportation. LOHCs consist of hydrogen-rich organic molecules with the remarkable ability to absorb and release hydrogen gas reversibly. This unique property makes them ideal for storing and transporting molecular hydrogen, offering an attractive alternative to conventional hydrogen storage methods.
The appeal of LOHCs lies in their high hydrogen storage density coupled with reduced safety concerns compared to gaseous hydrogen. This combination has sparked significant interest in their potential for long-distance transportation and hydrogen distribution, serving applications like fuel cells and industrial processes.
Traditionally, LOHCs are deployed within existing retail fuel distribution infrastructure. They facilitate the delivery of hydrogen gas to refueling stations, where it undergoes compression before being loaded onto trucks equipped with either fuel cells or combustion engines. However, this process incurs substantial energy losses due to the energy-intensive endothermic hydrogen release and compression steps at the retail station.
MIT’s Path to Efficiency: Onboard Dehydrogenation
To overcome these efficiency challenges, MIT’s research team, led by William H. Green, is charting a new course. They are exploring a more efficient application of LOHCs, one that involves onboard dehydrogenation in LOHC-powered trucks. This innovative approach harnesses waste heat from the engine exhaust to drive the dehydrogenation process, unlocking the full potential of LOHCs in hydrogen transport.
Here’s how it works: The truck’s powertrain is modified to enable onboard hydrogen release from the LOHCs. Waste heat from the engine exhaust powers the dehydrogenation process within a high-temperature reactor. This reactor continuously receives hydrogen-rich LOHCs from the fuel storage tank.
Before reaching the engine, some of the released hydrogen is diverted to a burner, which further heats the reactor. This dual-heating approach optimizes the dehydrogenation process, leveraging both engine exhaust gases and additional burner heat.
Sayandeep Biswas, a vital member of the research team, highlights the benefits of this innovation for long-hauling. “Hydrogen, when used through LOHCs, has clear benefits for long-hauling, such as scalability and fast refueling time. There is also an enormous potential to improve delivery and refueling to further reduce cost, and our system is working to do that,” says Biswas.
A Vision for the Future of Hydrogen Transport
As the hydrogen-fueled transport industry continues its expansion, industry experts predict remarkable growth. McKinsey & Co. forecasts that by 2035, Europe could witness the presence of up to 850,000 hydrogen-fueled medium- and heavy-duty trucks on its roads. This fleet is estimated to consume a substantial 6,900 metric kilotonnes of hydrogen annually, necessitating the development of up to 4,800 hydrogen refueling stations.