Carbon Dioxide and Water Successfully Converted Into Ethanol

Wouldn’t it be wonderful if we could do something useful with excess carbon dioxide other than capture it, compress it, and bury it deep in the bottom of the ocean? Scientists at Argonne National Laboratory may have discovered a way to do precisely that. According to a press release from ANL, researchers at the lab, working with partners at Northern Illinois University, have discovered a new electrocatalyst that converts carbon dioxide and water into ethanol with very high energy efficiency, high selectivity for the desired final product, and low cost. Ethanol is a particularly desirable commodity because it is an ingredient in nearly all US gasoline and is widely used as an intermediate product in the chemical, pharmaceutical, and cosmetics industries.

Photo-illustration: Unsplash (Kenrick Mills)

“The process resulting from our catalyst would contribute to the circular carbon economy, which entails the reuse of carbon dioxide,” says Di-Jia Liu, senior chemist in Argonne’s chemical sciences and engineering division and also a scientist at the Pritzker School of Molecular Engineering at the University of Chicago. “The process resulting from our catalyst would contribute to the circular carbon economy, which entails the reuse of carbon dioxide,” he says. The new electrochemical process converts carbon dioxide emitted from industrial processes, such as fossil fuel power plants or alcohol fermentation plants, into valuable commodities at reasonable cost.

The catalyst itself is made up of atomically dispersed copper on a carbon-powder support. It breaks down carbon dioxide and water molecules and selectively reassembles them into ethanol using an external electrical field. The electrocatalytic selectivity or ​Faradaic efficiency of the process is over 90%, which is significantly higher than it is when using any other reported process. The catalyst operates stably over extended operation at low voltage.

“With this research, we’ve discovered a new catalytic mechanism for converting carbon dioxide and water into ethanol,” said Tao Xu, a professor in physical chemistry and nanotechnology from Northern Illinois University. ​“The mechanism should also provide a foundation for development of highly efficient electrocatalysts for carbon dioxide conversion to a vast array of value-added chemicals.”

Because CO2 is a stable molecule, transforming it into a different molecule normally requires large amounts of energy, which makes the conversion process costly. Liu says, “We could couple the electrochemical process of CO2-to-ethanol conversion using our catalyst to the electric grid and take advantage of the low cost electricity available from renewable sources like solar and wind during off-peak hours.” Because the process runs at low temperature and pressure, it can start and stop rapidly in response to the intermittent supply of the renewable electricity.

The research took advantage of two facilities at ANL — the Advanced Photon Source and Center for Nanoscale Materials. It also had access to the lab’s Computing Resource Center. ​“Thanks to the high photon flux of the X-ray beams at the APS, we have captured the structural changes of the catalyst during the electrochemical reaction,’’ said Tao Li, an assistant professor in the Department of Chemistry and Biochemistry at Northern Illinois University and an assistant scientist in Argonne’s X-ray Science division.

This results of the research is opening new pathways that could lead to further improvements in catalyst design. “We have prepared several new catalysts using this approach and found that they are all highly efficient in converting CO2 to other hydrocarbons,” says Liu. ​“We plan to continue this research in collaboration with industry to advance this promising technology.” The research was published recently in the journal Nature Energy.

The Takeaway

The upshot of this new research is the creation of a process that could reuse and recycle carbon dioxide for fuels and chemicals that today are derived from either oil or natural gas. Notice the role that low cost renewable energy plays in this scenario. What we are witnessing is a convergence of technologies that may result in ways to substantially lower the amount of carbon dioxide that gets added to the atmosphere by industry and at far lower cost than previously thought possible.

Ethanol and the other chemicals that could result from this and similar processes are essential building blocks for the plastics industry. If this discovery could be combined with the creation of new recyclable and biodegradable plastics, that would be a major step forward in constructing a circular economy, one that does not destroy the environment in the pursuit of profits.

The Drawdown Project has just published an update of its road map to a sustainable world, which it says can happen today without waiting for new technologies to appear. This latest news from Argonne National Lab could be incorporated with the ideas promoted by this latest Drawdown Review to help create a business environment built on the notion that the Earth’s resources are finite and should be used as wisely as possible.

Author: Steve Hanley

Source: Clean Technica