Image: Michal Jarmoluk – Pixabay.
A team of researchers from the University of Illinois at Chicago (USA) has discovered a way to convert almost 100% of industrial exhaust gases into ethylene, which is the basis for the manufacture of plastic.
The possibility of converting carbon dioxide into ethylene has been studied for a long time, but this is the first time that scientists have achieved such an optimal result. The discovery was published in the “Cell Reports Physical Science » September 9, 2022.
In practice, the transformation of carbon dioxide into ethylene (C2H4) is done by electrolysis. An electric current passes through a cell charged with equal parts of carbon dioxide (CO2) and a water-based solution (H2O). An electrical catalyst pulls the hydrogen atoms of the water molecules into the other half separated by a membrane, where they combine with the carbon atoms in the carbon dioxide. Ethylene, a hydrocarbon, is thus created.
A process with negative CO2 emissions
This process would allow generate 1 ton of ethylene from 6 tons of carbon dioxide. It is therefore as much CO2 that is not released into the atmosphere, or at least not immediately. Almost all of carbon dioxidewould be recovered by this process, whereas the tests carried out so far have only enabled the use of around 10% of the CO2.
Since the operation uses electricity, renewable energies can be integrated to make the whole process carbon negative. The innovation is not insignificant when we know that the production of ethylene is among the highest carbon emitters, after ammonia and cement. Ethylene is used to make plastics for industry, but also chemical products. It is produced from fossil gas or naphtha (from the refining of crude oil) in a process very heat hungry and therefore energy.