A team from the Freiburg Materials Research Center (FMF), a research institute of Albert-Ludwig University of Freiburg, has developed a process whereby waste carbon dioxide can be recycled into methanol, a green alternative to petrol.
Led by Professor Dr Ingo Krossing, the researchers sought to find a method whereby the large volume of CO2
produced by industry especially could be harnessed to provide a useful source of energy. They have achieved the first step in an ambitious process with their original system of methanol production.
Research into the process, which combines CO2
and hydrogen by hydrogenolysis in a high pressure environment, has been going on for many years, and the suggestion that a ‘methanol economy’ could form a viable alternative to proposed hydrogen or ethanol economies is itself not new.
"Our goal is to develop new catalyst systems and methods for accelerating the chemical reaction even more," stated doctoral candidate Elias Frei. With the use of oxides of zinc, copper and zirconium as catalysts, the reaction can take place at much lower temperatures.
Along with his colleague Dr Marina Artamonova, Frei is also experimenting with techniques in which the catalysts are coated in a thin film of ionic liquids (ie salts in a liquid form). This accelerates the reaction by drawing carbon dioxide and hydrogen in and expelling the products, methanol and water.
If the process is adapted to be carried out on a large scale, as the researchers hope will be the case in around two years, CO2
will be filtered from the waste gas of combined heat and power plants before being used to produce methanol. Because methanol releases CO2
when burned, there is the potential to recycle it once more.
As well as being used as a fuel for internal combustion, in combination with petrol or undiluted, methanol offers a chemical means of storing hydrogen for use in fuel cells.
"There is enough energy out there, but it needs to be stored," explained Frei. "As a sustainable means of energy storage, methanol has potential in a wide range of areas. We want to use that potential, because the storage and conversion of energy are important topics for the future."