For reduce the amount of CO2 in the atmospherescientists have already imagined many systems to capture it. Engineers from UIC or University of Illinois Chicago have, for their part, developed a device that can transform the collected CO2 into ethylene, a basic material of plastic.
Currently, plastic is one of the most widely used materials in the world. However, its production is linked to a high level of CO2 emissions. Over the years, scientists have tried to find ways to capture carbon dioxide and turn it into something useful. This latest study could be a solution to the problem.
According to UIC scientists, using renewable energy sources to power their system could produce plastic with a “negative emission” of CO2.
Operation of the device
The UIC team designed a electrochemical cell that can make the conversion of carbon dioxide to ethylene more efficient. Half of the cell chamber is filled with an aqueous solution while the other half contains carbon dioxide gas. These two parts are separated by a 3D copper mesh through which an electric current passes.
The process causes movement of charged hydrogen atoms from the part containing the aqueous solution to the other part. These atoms will then combine with charged carbon atoms to form ethylene C2H4 molecules.
According to the researchers, almost 100% of the carbon dioxide is transformed into ethylene during the process, which is superior what other systems can do. The by-products of the reaction are oxygen and other carbon-based fuels.
A negative issue
In normal times, the production of ethylene consumes a lot of energy and releases up to 1.5 tonnes of CO2 for each tonne of ethylene produced. With regard to this new method, the scientists indicate that if energy from renewable sources is used, would produce plastic by consuming more CO2 than we produce.
According to Meenesh Singh, first author, carbon emission is negative. For one ton of ethylene produced, the system consumes 6 tons of CO2.
In terms of energy, the process converts about 10% of solar energy into carbon-based products, and about 4% into ethylene. According to the explanations, the 10% referred to here is 5 times what the current best method can achieve, and the 4% is roughly the yield of natural photosynthesis.