US-based fuels specialist Joule and Audi have developed an extraordinary process to produce e-ethanol and e-diesel where microorganisms suspended in brackish, or waste water can use sunlight and waste CO2 to create fuels without the need for biomass.

Measuring around three thousandths of a millimeter in diameter, these photosynthetic microorganisms have been genetically modified to prevent them from multiplying by using the sunlight-aided photosynthesis process that they would normally use. On the contrary, they are simulated to use this process to convert the waste CO2 and waste water into liquid fuels. The organisms then secrete and can then easily be separated from water and concentrated without further efforts.

This is an exceptionally simple and relatively inexpensive process that does not need crop-based biomass that has traditionally been a key component of synthetic fuels. The resource-sparing process means that facilities can be located in remote areas, even a desert.

Audi and Joule have already commissioned such a demonstration facility in New Mexico that is producing sustainable e-ethanol, which has the same chemical properties of bio-ethanol. The Audi e-ethanol that contains 85% of this wasted materials, along with 15% fossil fuel petrol can power petrol vehicles capable of running on E85 fuel, by only making minor modifications to the vehicle.

On the other hand, the e-diesel will work highly effectively with existing Audi TDI clean diesel systems without the need for any modifications. Large scale commercial application may indeed by some time away, but the concept sounds very promising.