Dr. Mohammad Asadi is leading a project at the Illinois Institute of Technology that combines CO2 with wind- and solar-generated electricity to produce renewable propane.

CHICAGO—Researchers at the Illinois Institute of Technology (IIT) have demonstrated breakthrough technology that is capable of producing propane from carbon dioxide and electricity from intermittent renewables, such as wind and solar, with unprecedented efficiency. The project has been selected by the U.S. Department of Energy's Advanced Research Projects Agency-Energy program to receive more than $3.8 million in funding through the Grid-free Renewable Energy Enabling New Ways to Economical Liquids and Long-Term Storage initiative.

Leading the project is Dr. Mohammad Asadi, who along with his team at IIT, are combining CO2 with wind- and solar-generated electricity to produce renewable propane. "This is a negative-carbon process, using only captured CO2, water and renewable electricity as inputs," said Dr. Asadi. "We believe that when this technology is scaled up, it will produce renewable propane at a lower carbon intensity than any other current pathway while remaining cost-competitive with conventional propane."

Most renewable propane commercially available today is recovered as a byproduct during the production of renewable diesel and sustainable aviation fuel (SAF), which commonly uses waste fats, oils and greases as feedstocks. 

"We have been pursuing renewable propane pathways that can produce fuel with a potential carbon intensity significantly below zero, and this project will show it can be done at scale," said Tucker Perkins, president and CEO of the Propane Education & Research Council (PERC), which is providing an active advisory role on the project. "We're seeing huge demand for renewable propane to lower carbon emissions, particularly in hard-to-abate industries like transportation and port operations. This technology could be a key to turbo-charging supply to meet that demand." 

PERC views "on-purpose" renewable propane production as a beneficial step forward for the propane industry.

The IIT project team aims to showcase the process on a kilowatt scale, equivalent to processing up to 4 kilograms per day of propane utilizing a system of multiple carbon dioxide electrolyzer stacks. By employing multiple stacks, the configuration permits operation within 1 to 100 percent of its capacity, accommodating intermittent and variable power supplies. The full process will result in an unprecedented 97 percent propane selectivity, according to researchers.

"Of all the pathways we have identified for producing renewable propane, none have approached the 97 percent propane selectivity Dr. Asadi and his colleagues have demonstrated," said Dr. Sai Satish Guda, research and development manager at PERC. "It is an extraordinarily efficient process, converting almost all the raw materials into the final product. Ultimately, that will mean less costs associated with separating byproducts from the resulting propane."