Audi has added to the information released in late September by Joule, the US second-generation biofuels developer in which it has invested.
Audi says its engineers have contributed to a breakthrough “of almost miraculous proportions” by helping to develop fuels for the TFSI and TDI engines of the very near future using nothing more than lengths of ordinary-looking pipe, waste CO2, sunlight and microscopic organisms suspended in waste water.
The ‘refineries’ responsible for the biofuels developed by Joule and Audi are the photosynthetic microorganisms injected into brackish water standing in the lengths of pipe. Measuring around three thousandths of a millimetre in diameter, these organisms have been genetically modified to prevent them from multiplying using the sunlight-aided photosynthesis process as they normally would. Instead, they are stimulated to use this process to convert the waste CO2 and the waste water into liquid fuels which they then secrete, and which can then be easily separated from the water and concentrated without the need for any further manufacturing steps.
Audi says the unparalleled global viability of these new fuels lies not only in the exceptionally simple and relatively inexpensive process which creates them, but also in the fact that the ‘feedstock’ used to produce them is entirely renewable, with no crop-based constituents, hence no indirect land use change effects.
In New Mexico, Audi and Joule have commissioned a demonstration facility which is already producing sustainable e-ethanol. This has the same chemical properties as bioethanol, which is normally produced using biomass. It will be possible to blend up to 85% ‘Audi e-ethanol’ with as little as 15% fossil-fuel gasoline for use by vehicles capable of running on E85 fuel.
Audi and Joule are currently in the process of ramping up the same facility to produce an ‘Audi e-diesel’ fuel. In contrast to petroleum-based diesel, which is a mixture of a wide variety of organic compounds, this fuel is not only free of sulphur and aromatics, but also has a high cetane value, giving it exceptional performance credentials for engine operating efficiency. Audi e-diesel will work in existing Audi TDI clean diesel systems without modification.
The partnership between Audi and Joule has been in place since 2011. Joule has protected its technology with patents for which Audi has acquired exclusive rights in the automotive field. Audi says its engineers involved in fuel and engine testing are helping to further develop Joule’s “remarkable” fuels so that they can genuinely be brought to market.
