How CO2 can replace oil, natural gas and coal

Crude oil, natural gas or coal are not only used for heating or to produce fuel. They also form the basis of so-called Synthesis gas. The gas is a mixture of carbon monoxide and hydrogen and is widely used. It is required for the production of fertilizerin the alcohol manufacture and even synthetic fuels can be gained from it.

However, synthesis gas has one drawback: It consists of fossil energy, thus causing CO2 emissions and is therefore a burden on the climate. Dogukan Apaydin and his team from Dominik Eder’s research group at the Vienna University of Technology want to change that.

The starting material for Apaydin’s method is, of all things, the greenhouse gas CO2, which is split back into valuable carbon monoxide molecules. This is already possible, but under high pressure and high temperatures, the process is complex and consumes a lot of energy. The team at TU Wien therefore chose a different approach and uses it electricity as well as one Catalystwhich, so to speak, drives the chemical reaction.

Research on MOCHAs

The catalyst was only discovered a good 20 years ago, it is organometallic chalcogenolate compounds, as the researchers call them simply MOCHAs. In 2002, these MOCHAs were manufactured for the first time in the USA, but interest was low due to a lack of applications. Apaydin himself came into contact with the MOCHAs during a research stay in California and brought the research field with him to Vienna.

“Even in 2018, MOCHAs were not used, the synthesis methods only delivered one milligram of the material,” explains Apaydin of futurezone. It was only in Vienna that the scientists recognized that the inconspicuous material could serve as a catalyst that CO2 splitting makes possible.

MOCHA crafting significantly improved

So more catalyst material was needed. The team at the Vienna University of Technology was able to significantly improve the production of the MOCHAs and the yield hundredfold per synthesis. In addition, production is significantly faster. “It used to take 72 to 96 hours to make, we can do it in 5 hours or less,” says Apaydin.

The materials are also cheap, the MOCHAs used are made of Silberthe element Selenium and an organic carbon compound. The resulting powder is mixed with a solvent to form a kind of ink and applied to electrodes that are immersed in CO2-enriched water. If you now apply electricity, synthesis gas – i.e. carbon monoxide and hydrogen – and oxygen are produced.

CO2 from industry

“Currently, the CO2 used comes from the bottle, but in future it can come directly from it industrial plants filtered out,” Apaydin is convinced. The electrochemical cell for synthesis gas production is modular and can be set up directly at the plant, the reaction takes place at room temperature. If the electricity for this comes from renewable sources, the process is also completely CO2-neutral.

“I see great potential for reducing CO2 with this,” says the researcher, comparing the technology with the early days of solar systems, which 30 years ago were much more complex and expensive to produce than they are today. “With the right infrastructure and political will, MOCHAs can be widely used in the future to convert CO2 into synthesis gas and thus make their contribution to climate protection afford,” Apaydin is certain.

Crisis fuels research

CO2 conversion is currently a popular field of research, interest in it is due to the Climate crisis also increased in Austria. “But the investments in research still have room for optimization,” Apaydin put it diplomatically.

It is not the first time that the research field has experienced an upswing. During the oil crisis in the 1970s there was a feverish search for methods to save on expensive oil and to produce synthesis gas from CO2. With the crisis, research interest also flattened out, regrets Apaydin and expresses a wish to politicians: “It would be nice if research were not only supported in times of crisis.”