The plant will use power-to-gas technology to make so-called e-gas for vehicles, such as the new Audi A3 Sportback TCNG. E-gas made at the plant can be distributed to compressed natural gas stations via Germany’s natural gas network and will power vehicles starting next year, Audi said.
The e-gas plant, which has the capacity to convert six MW of power, will use renewable electricity for electrolysis. The process splits water molecules into oxygen and hydrogen, which could one day power fuel-cell vehicles (see graphic).
However, since there is not yet a widespread hydrogen infrastructure, the plant takes the hydrogen and reacts it with CO2 in a methanation unit to generate renewable synthetic methane, or e-gas, Audi said.
The CO2 used in the plant is a waste byproduct from a nearby biogas plant operated by utility EWE. The CO2 is chemically bonded into the fuel at the plant, making e-gas climate neutral, Audi said. Waste heat generated during the electrolysis and methanation is used in an adjacent facility, which improves the facility’s efficiency, the automaker said.
The plant will produce about 1,000 metric tons of e-gas each year and will chemically bind some 2,800 mt of CO2, the equivalent amount of CO2 that 224,000 beech trees absorb annually.
The facility will generate enough e-gas to power 1,500 new Audi A3 Sportback TCNG vehicles for 9,320 miles every year, the automaker said. A special certification procedure will verify that the same amount of e-gas purchased by owners of the Audi TCNG is fed back into the network by the e-gas plant.
Earlier this month, Audi said it was developing a city car that will get 282 miles per gallon. The car, which is known internally as the 1.0 liter car, will be based on the existing Audi A1. The German automaker is also making an aggressive push into the diesel market.