Solar power could be used to chemically "re-energise" the greenhouse gas carbon dioxide into carbon monoxide for use in syngas, the feedstock for the Fisher-Trospch process to produce synthetic fuels, say researchers at the US government's Sandia national laboratory.
Sandia scientists are developing the Counter Rotating Ring Receiver Reactor Recuperator (CR5) to use sunlight to re-energise CO2 and turn it into carbon monoxide. Potential sources of CO2 are powerplants, smokestacks and breweries, but researchers also think CO2 in the air will be a viable source in the future.
The carbon monoxide and water is combined to produce hydrogen and CO2. This CO2 is used to create more carbon monoxide, which is then combined with the previously generated hydrogen to create syngas. The syngas is processed in an F-T reactor to produce heavy paraffinic waxes from which fuels are produced using conventional refinery methods.
"This invention, though probably a good 15 to 20 years away from being on the market, holds a real promise of being able to reduce carbon dioxide emissions while preserving options to keep using fuels we know. Recycling carbon dioxide into fuels provides an attractive alternative to [CO2 sequestration]," says Ellen Stechel, project champion in Sandia's fuels and energy transitions department.
The research has also attracted interest and some funding from the US Defense Advanced Research Projects Agency.
Over the past year the concept has been shown to work through multiple cycles of the chemical process. A prototype CR5 device is being built using a solar furnace to concentrate the solar energy to re-energise CO2. Initial tests will break down water into hydrogen and oxygen and that will be followed by the breaking down of CO2 to carbon monoxide and oxygen.
Source: FlightGlobal.com
