Hydrogen and natural gas are among the alternative fuels that are starting to get more attention, as automakers work on ways to reduce emissions. But Audi is working on yet another option that you may not have heard much about yet.
The German automaker has completed a series of tests that prove its synthetically engineered “e-fuels” burn more efficiently in internal combustion engines than traditional fossil fuels and produce fewer emissions. The next step is to refine the production process and develop synthetic “e-ethanol” and “e-diesel” for use in automobiles.
Audi says e-fuel is superior because of its purity. Unlike fossil fuels, which vary in composition depending on their place of origin, synthetic fuels are engineered to be absolutely pure. That’s why they burn more efficiently with fewer emissions.
Audi has been producing e-fuels at a research facility in Hobbs, New Mexico, in conjunction with Joule, a firm that specializes in developing synthetic fuels with solar energy. At the facility, genetically engineered photosynthetic microorganisms in brackish or waste water metabolize carbon dioxide after being exposed to sunlight and produce pure fuel as a byproduct.
The tests Audi conducted at its research and development facility in Ingolstadt, Germany, focused on how the synthetic fuel behaves throughout the combustion process.
One test simulated conditions inside an engine using a pressure chamber. A camera recorded how the fuel behaved as if being injected into an engine. Another test used an engine with a small quartz glass window so engineers could see how the synthetic fuel interacted with the airflow in the combustion chamber.
“Our test shows that as well as electric driving on renewable electricity, there are other concepts that permit long-distance, low-emission driving,” said Reiner Mangold, head of sustainable product development at Audi, in a press release.
Audi did not say when synthetic fuel might be ready for sale to consumers.
Joule says on its website that the company’s method of creating synthetic fuels is better than other methods that use agricultural or algal biomass, such as corn or fibers from plants, because it does not require arable land, fresh water or crops to produce it.
Once its technology is fully commercialized, Joule aims to produce 25,000 gallons of synthetic ethanol and 15,000 gallons of synthetic diesel per acre annually, for as little as $1.28 per gallon and $50 barrel, excluding subsidies.