Liquid Organic Hydrogen Carriers (LOHCs) are gaining traction as a safe and efficient method for hydrogen transport and storage, particularly in industries where conventional hydrogen delivery methods face logistical or safety challenges. These carriers allow hydrogen to be bound to organic molecules, transported in liquid form at ambient conditions, and released when needed. This approach eliminates many of the risks associated with compressed or cryogenic hydrogen, making LOHCs a compelling alternative for industrial applications. Below, we explore their use in refineries, steel production, and chemical synthesis, along with real-world implementations where LOHCs have replaced traditional hydrogen supply methods.
### Refineries
Refineries rely heavily on hydrogen for hydroprocessing, hydrocracking, and desulfurization to produce cleaner fuels. Traditionally, hydrogen is supplied via pipelines or on-site steam methane reforming (SMR), both of which have limitations. Pipelines require extensive infrastructure, while SMR emits significant CO2. LOHCs offer a flexible and low-emission alternative by enabling hydrogen to be transported from centralized production facilities to refineries without the need for pipelines or high-pressure storage.
A notable case is the collaboration between Chiyoda Corporation and Mitsubishi Corporation in Japan, where the SPERA Hydrogen system—a proprietary LOHC technology—was deployed. The system uses toluene as a carrier to store and transport hydrogen, which is then released at the refinery site. This method has proven effective in supplying hydrogen to refineries in Yokohama, reducing both transportation costs and safety risks compared to compressed hydrogen trailers.
### Steel Production
The steel industry is under pressure to decarbonize, with hydrogen-based direct reduction of iron (H2-DRI) emerging as a key pathway. However, supplying large volumes of hydrogen to steel plants remains a challenge, especially in regions without pipeline access. LOHCs provide a viable solution by enabling hydrogen to be shipped in liquid form and released on-demand at steel production facilities.
In Sweden, HYBRIT (Hydrogen Breakthrough Ironmaking Technology) has explored LOHCs as part of its efforts to replace coking coal with hydrogen in steelmaking. While the primary focus is on electrolysis-based hydrogen production, LOHCs are being evaluated for transporting hydrogen from renewable energy hubs to remote steel plants. The use of dibenzyltoluene as a carrier has shown promise due to its stability and high hydrogen storage capacity, making it suitable for large-scale industrial applications.
### Chemical Synthesis
Hydrogen is a critical feedstock for ammonia and methanol synthesis, both of which are essential for fertilizers and industrial chemicals. Conventional hydrogen delivery for these processes often involves energy-intensive liquefaction or compression. LOHCs simplify this by allowing hydrogen to be stored and transported in a liquid organic form, which can be dehydrogenated at the production site.
In Germany, Hydrogenious LOHC Technologies has partnered with Covestro to integrate LOHCs into chemical manufacturing. The project utilizes benzyltoluene to transport hydrogen from renewable sources to Covestro’s facilities, where it is used in the production of plastics and coatings. This approach has reduced reliance on fossil-derived hydrogen and minimized transportation emissions. Another example is the HELMETH project, where LOHCs were tested for methanol synthesis, demonstrating higher efficiency compared to conventional hydrogen supply chains.
### Case Studies: Replacing Conventional Hydrogen Delivery
Several industrial projects have successfully replaced traditional hydrogen delivery methods with LOHCs:
1. **Japan’s Kawasaki Heavy Industries** implemented an LOHC-based hydrogen supply chain for industrial users, including refineries and chemical plants. The system leverages methylcyclohexane (MCH) as a carrier, enabling hydrogen to be imported from overseas and distributed without high-pressure infrastructure.
2. **The Hydrogen Transport and Storage (HySTOC) project in the Netherlands** tested LOHCs for supplying hydrogen to industrial clusters. By using perhydro-dibenzyltoluene, the project demonstrated that LOHCs could reduce costs and safety risks compared to liquid hydrogen transport.
3. **Australia’s Hydrogen Energy Supply Chain (HESC) initiative** explored LOHCs for exporting hydrogen from brown coal gasification to Japan. While the primary focus was on liquefied hydrogen, LOHCs were evaluated as a complementary method due to their lower energy requirements for transport.
### Advantages Over Conventional Methods
LOHCs offer distinct benefits for industrial applications:
- **Safety**: Transporting hydrogen in liquid organic form eliminates high-pressure risks.
- **Infrastructure Flexibility**: No need for pipelines or cryogenic equipment.
- **Scalability**: Suitable for both small-scale and large-volume hydrogen delivery.
- **Integration with Renewables**: Enables green hydrogen to be transported from remote production sites.
Despite these advantages, challenges remain, including the energy penalty during hydrogen release and the need for efficient dehydrogenation catalysts. However, ongoing research and pilot projects continue to refine LOHC technologies, making them increasingly viable for industrial adoption.
### Conclusion
LOHCs are proving to be a transformative solution for hydrogen delivery in refineries, steel production, and chemical synthesis. By addressing the limitations of conventional methods, they enable safer, more flexible, and sustainable hydrogen supply chains. Real-world implementations in Japan, Sweden, and Germany highlight their potential to decarbonize industrial processes while maintaining operational efficiency. As technology advances, LOHCs are poised to play a pivotal role in the global hydrogen economy.