Researchers from Lund University in Sweden have developed an innovative automotive fuel system that operates in cycle mode and minimizes greenhouse gas emissions. This system uses a unique liquid that, when combined with a solid catalyst, turns into hydrogen fuel for the car. After use, the spent liquid is taken from the car’s tank, filled with hydrogen and made ready for reuse. This process creates a closed system that significantly reduces the impact on the environment.

Lund researchers have shown in two research papers that the method works and has the potential to become an efficient energy storage system in the future, although it is still basic research.

“Our catalyst is one of the most effective catalysts, at least when you look at publicly available research,” says Ola Wendt, professor at Lund University’s Department of Chemistry and one of the authors.

Addressing climate impacts and hydrogen research

To reduce the impact on the climate, it is necessary to find alternative ways to produce, store and convert energy to reduce carbon dioxide emissions from fossil fuels. One way involves the much-talked-about hydrogen, which many see as the solution of the future in energy storage. Nature stores energy in chemical bonds, and hydrogen contains the highest energy density per weight.

“But gas can be difficult to work with, so we are looking at a hydrogen-charged liquid fuel that can be fed through a pump, often similar to what is available at gas stations today,” says Ola Wendt.

The concept is known as LOHC (Liquid Organic Hydrogen Carriers) and is not new in that sense. The challenge is to find the most efficient catalyst that can extract hydrogen from the liquid.

The system is designed to operate with a liquid “charged” with hydrogen. The liquid is pumped through a solid catalyst that extracts hydrogen. This could be used in a fuel cell, which converts chemical fuel into electricity while the “spent” liquid is transferred to another tank. The only emission is water.

Filling and large-scale production

The used fluid can then be drained at the gas station before refilling with newly loaded fluid. This would likely mean large-scale production of the substance comparable to modern oil refineries.

“We converted more than 99 percent of the hydrogen gas present in the liquid,” says Ola Wendt.

The researchers also calculated whether the fuel could be used in larger vehicles such as buses, trucks and airplanes.

“With the big tanks they have, you can cover almost the same distance as a tank of diesel. You will also convert approximately 50 percent more energy compared to compressed hydrogen,” says Ola Wendt.

Components and Challenges

Liquids used: isopropanol (a common screen cleaning ingredient) and 4-methylpiperidine. Sounds too good to be true? Yes, some problems remain, at least for now. First of all, the service life of the catalyst is quite limited. The other is iridium, where the catalyst is a precious metal.

“But we estimate you need about two grams of iridium per car. This is comparable to today’s catalytic converters for exhaust gas cleaning, which contain around three grams of platinum, palladium and rhodium, which are also precious metals,” says Ola Wendt.

This is a technical solution based on fundamental research. Ola Wendt believes that if the decision is made to pursue a finished product, the concept could be ready within a decade, provided it is economically viable and of public interest.

Another problem is how hydrogen is produced; Most of the production today is not environmentally friendly. Then hydrogen needs to be stored and transported efficiently, which is not that easy today. Refueling with compressed hydrogen also has risks. Researchers from Lund hope to solve this in their own way.

“Today, 98 percent of hydrogen is fossil and is produced from natural gas. A byproduct is carbon dioxide. From an environmental perspective, the idea of ​​producing hydrogen for steel, batteries and fuel makes no sense if it is done with natural gas,” says Ola Wendt, but there is currently no information on how to do this. Numerous studies explain that “green” hydrogen can be produced by splitting water into hydrogen and oxygen using renewable energy.

At the same time, Ola Wendt believes that political solutions are needed to ensure that renewable energy sources and ecologically clean alternatives can gain a suitable foothold.

“It has to be cheaper, and for that political decisions are needed. “Renewable energy has no chance of competing with the resources you extract from the ground, where transport is almost the only cost, as is the case with fossil fuels,” he concludes.