Scientists Convert CO2 into Oxalic Acid to Process Rare Earths

The discovery could see the US produce its own rare earth elements while decreasing carbon dioxide pollution.
Loukia Papadopoulos

Scientists at Michigan Tech have found a new way to capture and convert carbon dioxide into something useful. In this case, the CO2 is being turned into oxalic acid that can process rare earth elements from ore bodies.


These rare earths are very much in demand as they are used in our everyday electronics such as cell phones. However, currently, they are not produced in the United States (US). Most of the world's rare earths (90 percent or more) come from China.

A crucial carbon dioxide scrubber

As such, the researchers' new development may one day make it possible for the US to generate its own rare earths. This would not only be economically wise, and perhaps even profitable, it would also increase the country's security.

The team's novel carbon dioxide scrubber has already been tested at Michigan Tech's steam plant. The plant's flue gas, the gas exiting to the atmosphere via a flue channel, contained eight percent carbon dioxide.

The newly developed scrubber brought those emissions down to four percent. Now, the team is hoping to further reduce it to below two percent.

"Below two percent, we are happy," said S. Komar Kawatra, a professor of chemical engineering at Michigan Technological University who is leading the project. "Below one percent, we will be very happy."

If this seems ambitious, rest assured it is not. The team has already called it a "real possibility" as they have succeeded at bringing it down to zero in the laboratory.

Next challenges

"Our next challenges are, how much can we scale the scrubber up and what can we use the carbon dioxide for," said Sriram Valluri, one of Kawatra's Ph.D. students working on the project. 


This part is crucial as industry has hesitated to use carbon dioxide scrubbers due to cost. Current methods of removing carbon dioxide from emissions use amines, nitrogen-based chemical compounds.

These compounds cost an exorbitant $20,000 a ton and have lead to industry dumping carbon dioxide in our oceans or burying it underground.

Luckily, Kawatra's solution is based on carbonates such as soda ash that only cost $200 a ton. As such, the new scrubbers would provide a cost-efficient solution to removing CO2 from the atmosphere.

The next step is finding something useful to do with the captured carbon dioxide. So far, in the laboratory, the researchers have been successful in turning it into oxalic acid. 

This development has been met with much enthusiasm from the researchers in terms of hopeful commercial future applications. "We have to find a way to utilize it commercially," added John Simmons, a Michigan Tech alumnus in the Chemical Engineering Academy at Tech and chairman of Carbontec Energy in Bismarck, North Dakota.

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