Hydrogen is a clean-burning gas that could help to tackle climate change by reducing our dependence on fossil fuels. But storing and transporting hydrogen is expensive and technically challenging, typically requiring high-pressure gas tanks or cryogenic systems that operate at very cold temperatures.

One promising alternative involves incorporating hydrogen into carbon-based molecules known as Liquid Organic Hydrogen Carriers (LOHCs), which are safer and easier to handle than the gas itself. KAUST researchers have shown that certain LOHCs could reliably store hydrogen underground in depleted oil fields, and then help to recover residual oil from those reservoirs.

“Together, these advantages make LOHCs a compelling alternative to conventional hydrogen storage technologies,” says Hussein Hoteit, who led the research team.

LOHC systems use a catalyst to chemically combine hydrogen with a liquid organic molecule, forming a hydrogenated liquid that can be stored or transported like a conventional fuel. A second catalytic reaction is subsequently used to release the hydrogen and regenerate the initial carrier molecule.

Crucially, LOHCs can be handled using existing petrochemical infrastructure, such as pipelines, tankers, and large-scale storage facilities. “This significantly reduces the cost and complexity of building new hydrogen-specific infrastructure, which is one of the major barriers to widespread hydrogen deployment,” says Zeeshan Tariq, a member of the team.

Read more at KAUST Discovery.