Biofuel Could Become Hydrogen Carrier
Biofuel Could Become Hydrogen Carrier
Hydrogen gas is too voluminous—even when compressed—to be a successful replacement for liquid fuels. New research suggests biofuels could be used as an energy-dense hydrogen storage medium.
Hydrogen shows great promise as a fuel; it burns cleanly and can be used by both fuel cells and internal combustion engines. But storage has remained an issue for hydrogen. Its low density and flammability make storage and transport complex, often requiring high-pressure tanks or cryogenic systems that are both costly and technically demanding.
An international team of scientists has unveiled a new method for storing and releasing hydrogen using lignin-based jet fuel—a discovery with significant implications for the future of fuels and transportation. The researchers have demonstrated that their custom-engineered fuel can chemically bind hydrogen in a stable liquid form and then release the hydrogen when exposed to a platinum catalyst.
The results could pave the way for more efficient hydrogen storage systems that could serve as a key technology to support alternative fuels in mechanical and aerospace engineering applications.
Bin Yang is a professor in the department of biological systems engineering at Washington State University in Richland. This research was developed from Yang’s work in advanced biofuels, notably lignin-based sustainable aviation fuels.
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A type of sustainable aviation fuel (SAF), lignin-based jet fuel is derived from lignin, a complex organic polymer found in the cell walls of plants—especially in woody biomass and agricultural residues. It’s one of the most abundant natural polymers on Earth and is typically a waste byproduct in industries like paper and bioethanol production. To refine it into jet fuel, lignin is broken down into smaller hydrocarbon molecules. This involves depolymerizing the lignin and upgrading the resulting compounds through catalytic reactions to meet the energy density, volatility, and stability requirements of aviation fuel.
Yang and his team discovered that platinum nanoparticles supported on zeolite, a crystal containing aluminum and silicon, could chemically break apart the the fuel molecules. In experiments, after passing the fuel through the catalyst reactor at a temperature of 250 °C, they measured an increase in the amount of aromatic carbon rings, which indicated that hydrogen had been stripped from the long molecular chains of fuel molecules.
Because it is difficult to store hydrogen molecules densely except under cryogenic conditions, many technologists have looked to attaching the hydrogen chemically to molecules and then breaking the chemical bonds when the hydrogen was needed. Unfortunately, hydrogen is tightly bound to simple molecules such as water or ammonia, meaning it takes energy—in the form of high heat or pressure—to tear those molecules apart. The use of long molecular chains such as lignin-based jet fuels could provide a better storage option if the reactions can be performed at lower temperatures.
“The research has many potential applications in fuels and transportation (i.e., rocket engines) and could ultimately make it easier to harness hydrogen’s potential as a high energy and zero emissions fuel source," Yang said. “This innovation offers promising opportunities for compatibility with existing infrastructure, economic viability for scalable production, and creating a synergistic system that enhances the efficiency, safety, and sustainability of both SAF and hydrogen technologies.”
It this vision, SAFs would be a transport medium for hydrogen rather than a fuel itself. Because SAFs are liquid and stable at room temperature, they would be easier and less costly to store and transport than compressed or cryogenic hydrogen.
There are challenges in expanding the technology and its dependence on an expensive platinum catalyst. However, they are working around this challenge using AI.
“This process currently depends on a platinum catalyst,” Yang said. “Our next steps in this collaboration include designing an AI-driven catalyst that improves the reactions, making them more efficient and cost-effective.”
Jim Romeo is a technology writer in Chesapeake, Va.
An international team of scientists has unveiled a new method for storing and releasing hydrogen using lignin-based jet fuel—a discovery with significant implications for the future of fuels and transportation. The researchers have demonstrated that their custom-engineered fuel can chemically bind hydrogen in a stable liquid form and then release the hydrogen when exposed to a platinum catalyst.
The results could pave the way for more efficient hydrogen storage systems that could serve as a key technology to support alternative fuels in mechanical and aerospace engineering applications.
Bin Yang is a professor in the department of biological systems engineering at Washington State University in Richland. This research was developed from Yang’s work in advanced biofuels, notably lignin-based sustainable aviation fuels.
More Like This: Fly the Climate-Friendly Skies
A type of sustainable aviation fuel (SAF), lignin-based jet fuel is derived from lignin, a complex organic polymer found in the cell walls of plants—especially in woody biomass and agricultural residues. It’s one of the most abundant natural polymers on Earth and is typically a waste byproduct in industries like paper and bioethanol production. To refine it into jet fuel, lignin is broken down into smaller hydrocarbon molecules. This involves depolymerizing the lignin and upgrading the resulting compounds through catalytic reactions to meet the energy density, volatility, and stability requirements of aviation fuel.
Yang and his team discovered that platinum nanoparticles supported on zeolite, a crystal containing aluminum and silicon, could chemically break apart the the fuel molecules. In experiments, after passing the fuel through the catalyst reactor at a temperature of 250 °C, they measured an increase in the amount of aromatic carbon rings, which indicated that hydrogen had been stripped from the long molecular chains of fuel molecules.
Because it is difficult to store hydrogen molecules densely except under cryogenic conditions, many technologists have looked to attaching the hydrogen chemically to molecules and then breaking the chemical bonds when the hydrogen was needed. Unfortunately, hydrogen is tightly bound to simple molecules such as water or ammonia, meaning it takes energy—in the form of high heat or pressure—to tear those molecules apart. The use of long molecular chains such as lignin-based jet fuels could provide a better storage option if the reactions can be performed at lower temperatures.
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“The research has many potential applications in fuels and transportation (i.e., rocket engines) and could ultimately make it easier to harness hydrogen’s potential as a high energy and zero emissions fuel source," Yang said. “This innovation offers promising opportunities for compatibility with existing infrastructure, economic viability for scalable production, and creating a synergistic system that enhances the efficiency, safety, and sustainability of both SAF and hydrogen technologies.”
It this vision, SAFs would be a transport medium for hydrogen rather than a fuel itself. Because SAFs are liquid and stable at room temperature, they would be easier and less costly to store and transport than compressed or cryogenic hydrogen.
There are challenges in expanding the technology and its dependence on an expensive platinum catalyst. However, they are working around this challenge using AI.
“This process currently depends on a platinum catalyst,” Yang said. “Our next steps in this collaboration include designing an AI-driven catalyst that improves the reactions, making them more efficient and cost-effective.”
Jim Romeo is a technology writer in Chesapeake, Va.
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