Researchers at the University of Southern California's Loker Hydrocarbon Research Institute have developed a method for converting carbon dioxide (CO2) into methanol—a fuel for internal combustion engines and fuel cells and a raw material used to produce many petrochemical products. A team led by chemistry professors G.K. Surya Prakash and George Olah bubbled air through an aqueous solution of pentaethylenehexamine, adding a catalyst to encourage hydrogen to latch onto the CO2 under pressure. They then heated the solution, converting 79 percent of the CO2 into methanol. Although mixed with water, the resulting methanol can be easily distilled.

The carbon dioxide-to-methanol process. Image credit: Surya Prakash.Previous efforts have required a slower multistage process with the use of high temperatures and high concentrations of CO2, meaning that renewable energy sources would not be able to efficiently power the process. The process developed by the USC team operates at around 125-165 degrees Celsius, minimizing the decomposition of the catalyst, which occurs at 155 C. The process also uses a homogeneous catalyst, making it a quicker “one-pot” process. In the lab, the researchers demonstrated that they were able to run the process 5 times with minimal loss of the effectiveness of the catalyst.

“We need to learn to manage carbon," says Prakash, who says he hopes to refine the process to the point that it could be scaled for industrial use. “Of course it won’t compete with oil today, at around $30 per barrel,” he says.