Researchers have made solar jet fuel from scratch for the first time by combining carbon dioxide and water in a reactor powered by concentrated sunlight.

So far, chemists at SOLAR-JET project - a four-year program funded by Europe's Seventh Framework Programme for Research and Technological Development - only made enough kerosene to fill a glass jar. In time, they believe a full-scale solar concentrator could produce 20,000 liters of jet fuel a day.

If the experimental technology is successful, it could recycle the harmful greenhouse gas carbon dioxide and repurpose it into petrol, diesel and the jet fuel kerosene.

"This technology means we might one day produce cleaner and plentiful fuel for planes, cars and other forms of transport," Máire Geoghegan-Quinn, European commissioner for research, innovation and science, said in a press release. "This could greatly increase energy security and turn one of the main greenhouse gases responsible for global warming into a useful resource."

To produce the fuel, researchers moved water and carbon dioxide through a solar reactor at 700 degrees Celsius (1292 degrees Fahrenheit). Shell, a global petroleum company, then separated and formed a synthetic gas, called syngas, composed of hydrogen and carbon monoxide.

It sounds easy enough, but problem is this well-established Fischer-Tropsch process - a series of chemical reactions developed in 1925 by researchers in Germany - can only happen at extremely high temperatures, usually above 2200 C (3992 F). But even more difficult, the syngas cannot be extracted until all the oxygen is removed as it is dangerously explosive, according to Chemistry World.

The Fischer-Tropsch process is already being used on a global scale by petroleum companies, including Royal Dutch Shell corporation. Once the solar reactor technology is perfected, the technique could be scaled-up.

In addition, Fischer-Tropsch derived fuels are already certified and can be used by existing vehicles and aircraft without modifications to their engines.

"With this first-ever proof-of-concept for "solar" kerosene, the SOLAR-JET project has made a major step towards truly sustainable fuels with virtually unlimited feedstocks in the future," Andreas Sizmann, the coordinator of the SOLAR-JET project, told Horizon Magazine.