The Audi e-gas plant, which can convert six megawatts of input power, will utilize renewable electricity for electrolysis. This process splits water molecules into oxygen and hydrogen, or Audi e-hydrogen, which could one day power fuel-cell vehicles. Because there is not yet a widespread hydrogen infrastructure, however, the hydrogen is then 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.
The CO2 used in Audi’s e-gas plant is a waste product from a nearby biogas plant, operated by energy provider EWE. The CO2, which would otherwise pollute the atmosphere, is chemically bonded into the fuel at the Audi e-gas plant – making Audi e-gas climate-neutral. 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.
Audi e-gas is an energy-rich fuel ideal for internal combustion engines. The Werlte facility will generate enough CO2-neutral e-gas 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.
The e-gas production will begin in early 2013 and feeding into the public natural-gas network in summer 2013.
Source: Audi AG.