|Components of the e-gas plant. Click to enlarge.|
Audi is celebrating progress on its e-gas plant under construction in Werlte, Germany with a topping-out ceremony. End products from the plant will be hydrogen and synthetic methane (Audi e-gas), to be used as fuel for vehicles such as the new Audi A3 Sportback TCNG. (Earlier post.)
The Audi e-gas plant, which can convert six megawatts of input power, will utilize renewable electricity for electrolysis, producing oxygen and hydrogen, the latter which could one day power fuel-cell vehicles. Because there is not yet a widespread hydrogen infrastructure, however, the hydrogen is reacted with CO2 in a methanation unit to generate renewable synthetic methane, or Audi e-gas. Chemically speaking, this e-gas is nearly identical to fossil-based natural gas. As such, it can be distributed to CNG stations via the natural gas network and will power vehicles starting in 2013.
This power-to-gas technology opens up new possibilities for sustainable mobility and tomorrow’s energy industry. The e-gas project marks a transition toward alternative forms of energy for automobiles.—Reiner Mangold, Head of Sustainable Product Development at Audi AG
The CO2 used in Audi’s e-gas plant is a waste product from a nearby biogas plant, operated by energy provider EWE. The e-gas plant will annually produce about 1,000 metric tons (1,102 US tons) of e-gas and will chemically bind some 2,800 metric tons (3,086 US tons) of CO2. (This corresponds to the amount of CO₂ that 224,000 beech trees absorb in a year, according to Audi.)
The Werlte facility will generate enough CO2-neutral synthetic methane to power 1,500 new Audi A3 Sportback TCNG vehicles 15,000 km (9,320 miles) every year. This compact five-door car will arrive at dealerships in late 2013. Audi plans to launch a second TCNG model, based on the A4, in 2015.
A special certification procedure will verify that the same amount of e-gas that owners purchase for their Audi TCNG vehicles is fed into the network by the e-gas plant. A similar balanced-cycle method is used to verify procurement of green power.
The ability to store large quantities of wind or solar energy via the dual electricity/gas principle could significantly foster the expansion of renewable energies, Audi suggests. The Audi e-gas project can be easily replicated in any country with a natural-gas network.
The Audi e-gas plant in Werlte is being built on a site owned by energy provider EWE AG measuring 4,100 m2 (44,132 sq ft) overall. Ground was broken in September 2012. As owner, Audi is constructing the plant in cooperation with equipment manufacturer SolarFuel GmbH. They have prioritized the optimization of energy flows. Waste heat generated during electrolysis and methanation, for example, is used in the adjacent facility.
Once the electrolysis units have been installed, the methanation reactor will be supplied and connected. This specialized unit some 16 meters (52 ft) in height will be provided by MAN, a sister company in the VW Group. e-gas production will begin in early 2013 and feeding into the public natural-gas network in summer 2013.