Despite all the efforts to the contrary, it's an uncomfortable truth that our world mostly still runs on oil, made from dead little creatures and pumped from under the ocean. So a machine that could generate oil, without the need for drills or rigs or pipelines, just by combining hydrogen and CO2, sounds quite attractive.
Manufactured by Germany company Sunfire, the key element is the Fischer-Tropsch process, which turns carbon monoxide and hydrogen into liquid hydrocarbons. To get from having water and CO2 to having hydrogen and carbon monoxide, there are a few steps: firstly, the water is turned into steam, and the oxygen and hydrogen separated in solid oxide electrolyser cells. The hydrogen is then used to reduce CO2 down to carbon monoxide, which is combined with hydrogen to give some sweet, sweet hydrocarbons.
The process isn't quite as magical as it sounds, as it requires quite a lot of electricity in the first place, in order to turn water into steam. But at the moment, Sunfire is claiming that the whole process is about 70 per cent energy efficient -- much better than conventional diesel or petrol engines.
In terms of scale, one of the machines pictured above, which costs "seven figures", can produce about a barrel of fuel per day, while recycling 3.2 tonnes of CO2. On that basis, it's going to take a hell of a lot of machines (and cash!) to meet our demand for fossil fuels -- the US alone averages 18 million barrels per day. [CNET]