A team of researchers working for Audi in Germany has managed to make diesel fuel using just water and carbon dioxide.
The process, masterminded by cleantech firm Sunfire, is pretty simple. First, renewable energy is used to split water molecules into oxygen and pure hydrogen, while carbon dioxide is gathered from a biogas plant. Then, the two are mixed together under very hot and high-pressure conditions. The result is a liquid which the company has named 'blue crude'. That can then be refined into biodiesel.
The efficiency of the method is pretty high - about 70%, and the synthetic fuel is free of contaminants that occur in regular diesel. Audi says that it's suitable for either mixing with regular diesel or even to be used a fuel in its own right.
The production plant, which is located in Dresden, is set to produce about 160 litres of the synthetic diesel every day over the coming months, with the possibility of expansion. "If we get the first sales order, we will be ready to commercialize our technology", said Sunfire's CTO Christian von Olshausen.
Germany's Federal Minister of Education and Research, Johanna Wanka, added: "This synthetic diesel, made using CO2, is a huge success for our sustainability research. If we can make widespread use of CO2 as a raw material, we will make a crucial contribution to climate protection and the efficient use of resources, and put the fundamentals of the "green economy" in place."