Carbon dioxide emissions are on the rise and refineries producing high-demand energy sources contribute to global warming.
To combat these issues, a team of chemists and engineers have invented an alternative process for producing liquid hydrocarbon fuels. They have proven that concentrated light, heat and high pressure can drive a one-step conversion of carbon dioxide and water directly into useable liquid hydrocarbon fuels.
Its simplicity and low cost make it an attractive solution. This technology can remove carbon dioxide from the atmosphere to make fuel while reverting oxygen as a byproduct of the reaction. The end results are a highly desirable energy source and a positive impact on the environment.
"Our process also has an important advantage over battery or gaseous-hydrogen powered vehicle technologies, 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.
How to Generate Liquid Fuel from CO2
The process runs in a photothermochemical flow reactor operating at 180-200 C and pressures up to 6 atmospheres. The hybrid photochemical and thermochemical catalyst used for the experiment was based on titanium dioxide, which is unable to absorb the entire light spectrum. Further developments are required to find a different catalyst capable of absorbing more of the spectrum for higher efficiency.
Excess heat generated by the reaction can then be applied to solar fuel facilities, used for product separations and water purification.
"We are the first to use both light and heat to synthesize liquid hydrocarbons in a single stage reactor from carbon dioxide and water," said Brian Dennis, professor of mechanical and aerospace engineering at the University of Texas at Arlington (UTA).
With more than $2.6 million in funding for sustainable energy projects, the researchers focused specifically on converting natural gas into high-grade diesel and jet fuel.
Developed in collaboration with an industrial partner in UTA's Centre for Renewable Energy and Science Technology, the research team is now working on commercializing their process.
MacDonnell is also developing new photocatalysts for hydrogen generation to create an artificial photosynthetic system using solar energy to split water molecules into hydrogen and oxygen; the hydrogen could then be used as a clean fuel.
The research is published under the title "Solar photothermochemical alkane reverse combustion” in the Proceedings of the National Academy of Sciences.