Audi’s E-Fuel Future: Bringing Carbon-Neutral Mobility to the Marketplace

By Jeremy Del Nero on 13 June 2013
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Audi, an automaker at the forefront of the renewable transportation fuel movement, DSC_0665has long concerned itself with powering personal transportation with sustainable alternatives to conventional fuels.  In recent years, Audi has invested in wind power and experimented with using stored renewable energy to power its e-tron fleet.

But Audi’s interest has not only been on the experimental front.  In terms of mass produced cleaner, more fuel-efficient vehicles, Audi has offered buyers a variety of clean diesel automobiles, along with other German manufacturers.  The success of the clean diesel in many regions including Audi’s home market, Germany, is unparalleled.  In the past few years, more new cars sold are diesel-powered versus petrol.  In part, this is because taxes on diesel fuel are lower but cars such as the Audi A3 TDI are able to achieve excellent fuel economy and low greenhouse gas emissions without sacrificing performance.

In 2011, Audi developed e-gas, a renewable methane gas for use in powering its environmentally friendly A3 Sportback TCNG, which fuels its turbocharged engine with compressed natural gas.  E-gas is produced with wind-powered electrolysis, which breaks down water into hydrogen and oxygen.  Then, in a methanation process, using waste CO2, the hydrogen atoms are bonded to carbon to form CH4 (methane gas).  E-gas is a drop-in fuel and can be used as a direct replacement for natural gas.  This means the fuel could be used in other applications, such as heating homes.

But Audi wanted to find a solution not just for its cars running on natural gas, but also those powered by conventional gasoline and diesel.  Enter Joule Fuels.

Joule Fuels, a subsidiary of Joule Unlimited and founded in 2009, has focused on addressing the environmental and economic concerns resulting from declining fuel resources. Joule has centered its efforts on creating what it calls “liquid fuel from the sun” through a sustainable process involving widely available resources.  In September of last year, Audi and Joule joined forces, combining their technologies and goals to advance the production of sustainable fuel.

Audi enlisted Joule’s strategies and technologies to create new sustainable transportation fuels called e-ethanol and e-diesel.  These are biofuel alternatives based on Joule’s Sunflow-E and Sunflow-D fuels for use in ethanol and diesel powered vehicles.

The requirement for biomass was the Achilles heel for Joule in searching for a new environmentally friendly fuel.  The energy company’s ability to forego biomass in its process is indeed a significant achievement.

The partners announced the construction of an industrial plant in Werlte, Germany, which will use Joule’s engineered microorganisms, solar energy, salt water, and waste CO2 to produce the e-ethanol and e-diesel.  The plant is slated to be operational as early as next year.

Joule’s use of photosynthetic microorganisms, engineered to act as catalysts rather than inputs for the reaction, means that the resulting fuels produced are not biofuels but rather a more renewable and sustainable alternative.

In the reaction, Joule’s proprietary microorganism takes in CO2, non-potable water, sunlight and other inexpensive and readily availably nutrients.  Then it directly and continuously expels renewable e-ethanol and e-diesel fuel.  Unlike organisms that are literally used up in biofuel production, Joule’s will continue to exude fuel for several weeks before dying out.

The fuel production plant models environmentally friendly behavior throughout the fuel creation and consumption process.  Climate change is addressed by making use of renewable energy and waste CO2.  The reaction also uses abundant seawater rather than precious and limited fresh water. Most alternative fuels rely on some form of biomass, but Joule’s has no food or agriculture involvement, and uses far less acreage than fuel crops.

The principle of Audi’s e-fuel cycle is closing the loop of CO2 emissions.  It’s well known that car exhaust contributes to CO2 emissions, which is why the use of CO2 as a raw ingredient makes the process ideally CO2 neutral.

The potential exists for the production and consumption of e-fuels to be carbon-neutral in the future. While some conventionally generated electricity and gas is still used in the production and transportation of e-gas, Audi and Joule hope that one day CO2 may be captured directly from the air, rather than importing it from other sources, which would be the first step towards achieving a carbon-neutral status.

Drivers who participate by purchasing e-ethanol or e-diesel will be engaging in a credit system.  That is to say they may not be pumping the new fuel directly unto their vehicles, but they will be supporting the system nonetheless, and Audi will supply receipts proving that the amount purchased will be fed directly back into the system.  Renewable electricity operates using a similar infrastructure; consumers who sign up to get their energy from renewable sources are contributing directly to the cause, but the actual energy powering their homes may be coming from conventional sources.

The e-fuels will comprise a percentage of the blendstock used in the fuel at the pump.  The percentage will vary, but approximately 25-60% of the blendstock will be comprised of e-ethanol or e-diesel.

Joule provided estimates for production amount and pricing.   The plant will produce up to 25,000 gallons per acre per year of e-ethanol and 15,000 gallons per acre per year of e-diesel.  The e-fuels will be competitively priced and shouldn’t fluctuate in cost to any significant degree. The companies aim to ultimately price e-diesel at about $50 a barrel and e-ethanol at approximately $1.28 a gallon.  These prices could eventually be even lower, however, as they do not reflect any potential subsidies.  The companies are working hard to achieve these goals by 2020.

Audi and Joule’s plan is very important to the future of transportation fuel. The attempts have been successful on a small scale, and as the two bring a more mainstream solution into the marketplace, e-fuel technology could be introduced on a global scale and transform the way we power transportation.

(Photo: Accura Media Group)