Novel way to convert CO2 and water into liquid hydrocarbon fuel

A team of chemists and engineers has discovered that concentrated light, heat and high pressures can drive the one-step conversion of carbon dioxide and water directly into useable liquid hydrocarbon fuels.

This simple and inexpensive new sustainable fuels technology can help limit global warming by removing carbon dioxide from the atmosphere to make fuel.

The process also reverts oxygen back into the system as a byproduct of the reaction, with a clear positive environmental impact, said the researchers from the University of Texas at Arlington.

"Our process has an important advantage as many of the hydrocarbon products from our reaction are exactly what we use in cars, trucks and planes, so there would be no need to change the current fuel distribution system," said Frederick MacDonnell, co-principal investigator of the project.

The researchers demonstrate that the one-step conversion of carbon dioxide and water into liquid hydrocarbons and oxygen can be achieved in a photothermochemical flow reactor operating at 180 to 200 degrees Celsius.

"We are the first to use both light and heat to synthesise liquid hydrocarbons in a single stage reactor from carbon dioxide and water," said Brian Dennis, professor of mechanical and aerospace engineering.

The next step is to develop a photo-catalyst better matched to the solar spectrum.

"Then we could more effectively use the entire spectrum of incident light to work towards the overall goal of a sustainable solar liquid fuel," added MacDonnell.

The authors envision using parabolic mirrors to concentrate sunlight on the catalyst bed, providing both heat and photo-excitation for the reaction.

Excess heat could even be used to drive related operations for a solar fuels facility, including product separations and water purification.

MacDonnell has also worked on developing new photocatalysts for hydrogen generation, with the goal of creating an artificial photosynthetic system which uses solar energy to split water molecules into hydrogen and oxygen.

The hydrogen could then be used as a clean fuel.