A Breakthrough Discovery In Carbon Capture Conversion For Ethylene Production
A group of scientists led by Meenesh Singh at the College of Illinois Chicago has discovered a way to convert 100% carbon dioxide from the industrial exhaust into ethylene, a fundamental building block for plastic products.
Their findings are released in Cell Reports Physical Science.
While scientists have been exploring the possibility of transforming carbon dioxide to ethylene for more than a decade, the UIC group’s technique is the first to achieve nearly 100% utilization of carbon dioxide to produce hydrocarbons. Their system uses electrolysis to change captured carbon dioxide gas into high purity ethylene, with other carbon-based fuels and oxygen as byproducts.
The procedure can convert up to 6 metric tons of carbon dioxide into one metric ton of ethylene, recycling almost all Carbon captured. Because the system runs on electricity, using renewable energy could make the process carbon negative.
According to Singh, his group’s approach surpasses the net-zero carbon objective of other carbon capture and also conversion technologies by actually reducing the total carbon dioxide result from the industry.
“It is a net negative,” he said. “For every 1 ton of ethylene generated, you are taking six tons of carbon dioxide from point sources that otherwise would be released to the atmosphere.”
Previous efforts at transforming carbon dioxide into ethylene have relied on reactors that create ethylene within the source CO2 emission stream. In these cases, as little as ten percent of carbon dioxide emissions typically convert to ethylene. The ethylene must later be divided from the CO2 in an energy-intensive process often involving fossil fuels.
In UIC’s method, an electric current is passed through a cell, half of which is filled with captured CO2, the other half with a water-based solution. An electrified catalyst draws charged hydrogen atoms from the water particles into the other half of the unit divided by a membrane, where they combine with charged carbon atoms from the carbon dioxide molecules to form ethylene.
Among made chemicals worldwide, ethylene ranks 3rd for carbon emissions after ammonia and cement. Ethylene is utilized not only to create plastic products for the packaging, agricultural, and also automotive industries but also to generate chemicals used in antifreeze, medical sterilizers, and vinyl siding for houses.
Ethylene is generally made in a process called steam cracking that needs enormous amounts of warm. Cracking generates around 1.5 metric tons of carbon emissions per ton of ethylene produced. On average, manufacturers create around 160 million tons of ethylene yearly, resulting in more than 260 million tons of carbon dioxide emissions worldwide.
In addition to ethylene, the UIC scientists could produce other carbon-rich products applicable to the sector with their electrolysis approach. They likewise achieved a very high solar energy conversion efficiency, directly transforming 10% of power from the solar panels to carbon product outcome.
This is well above the state-of-the-art standard of two percent. For all the ethylene they generated, the solar power conversion efficiency was around 4%, approximately the same rate as photosynthesis.
More information:
Aditya Prajapati et al, CO2-free high-purity ethylene from electroreduction of CO2 with 4% solar-to-ethylene and 10% solar-to-carbon efficiencies, Cell Reports Physical Science (2022). DOI: 10.1016/j.xcrp.2022.101053
Read the original article on PHYS.
