E-diesel is the name of synthetic diesel created by Audi to be used in automobiles. Currently, an e-diesel variant is created by Audi research facility in partnership with a company named Sunfire. The fuel is created from carbon dioxide, water, and electricity with a process powered by renewable energy sources to create a liquid energy carrier called blue crude (in contrast to regular crude oil) which is then refined to generate e-diesel. E-diesel is considered to be a carbon-neutral fuel as it does not extract new carbon and the energy sources to drive the process are from carbon-neutral sources.
The process uses carbon dioxide, the most common greenhouse gas, which can be captured directly from air. Carbon dioxide is created largely by burning fossil fuels and contributes to global warming. Now Sunfire said it can recycle the gas to make a more efficient, carbon-neutral fuel.
Unlike conventional fossil fuels, the “e-diesel” doesn’t contain sulphur and other contaminants. “The engine runs quieter and fewer pollutants are being created,” Sunfire’s Christian von Olshausen said, in a report from CNN Money.
According to reports, the fuel is produced in three steps. First, the researchers heat up steam to very high temperatures to break it down into hydrogen and oxygen. This process requires temperatures of over 800 degrees Celsius (1,472 Fahrenheit) and is powered by green energy such as solar or wind power. Second, they mix the hydrogen with carbon dioxide under pressure and at high temperature to create what is called “blue crude.” Lastly, the blue crude is refined into fuels in a similar way fossil crude oil is refined into gasoline.
Audi has said that its lab tests have shown the “e-diesel” can be mixed with fossil fuels or used as a fuel on its own.
The efficiency of the method is pretty high – about 70%, and the synthetic fuel is free of contaminants that occur in regular diesel.