Audi will soon be launching the A3 Sportback g-tron developed to enable long-distance mobility that is also environment friendly. The A3 Sportback g-tron is powered by a 110 PS 1.4-litre TFSI engine that can be operated in two ways: through ultra-clean Audi e-gas produced using green electricity; or through compressed natural gas. Both are readily available in Germany.
In Audi e-gas mode, the g-tron entirely does not emit carbon dioxide, which means mobility can be achieved without harming the environment. Audi e-gas is a synthetic methane produced at the Audi e-gas facility in Werlte, Germany. Green electricity is used in the production of Audi e-gas, and the generation process binds as much carbon dioxide as is released when the g-tron is driven using gas.
On average, the Audi A3 g-tron consumes just between 3.2 and 3.3 kilograms of gas per 100 kilometers, with fuel costing at around EUR3.50 per 100 kilometers.
The buying principle for Audi e-gas is straightforward: the carmaker records the amount of gas customer pays for using their Audi e-gas fuel card. Audi then ensures that exactly this amount of Audi e-gas is fed into the German natural gas network. Customers selecting this option can get an Audi e-gas fuel card for a flat price of EUR14.95 euros.
Likewise, the costs for the amount of gas refueled by each customer are taken via the Audi e-gas fuel card, which can be used to purchase Audi e-gas at over 650 fuel stations in Germany. The A3 Sportback g-tron will have a starting price of EUR25,900 in Germany. Audi has no plans to roll out the A3 Sportback g-tron in the United Kingdom due to the lack of infrastructure required to fully implement natural gas filling stations.
Audi has set an e-gas plant in Werlte (Emsland), which involves the major process stages of electrolysis and methanation. In electrolysis, the plant makes use of renewable power in order to break water down into its two main elements – hydrogen and oxygen – in three electrolyzers. Once the hydrogen is obtained from the process, it can be stored separately, to be used in the future for powering fuel-cell vehicles.
However, in the current absence of a hydrogen infrastructure, there is a need for a second process to be carried out, wherein the hydrogen is reacted with carbon dioxide to produce synthetic methane (Audi e-gas). This is almost exactly the same as fossil fuel natural gas, in chemical terms, and therefore can be distributed using natural gas grid for refueling vehicles to CNG filling stations throughout Germany.
The CO2 used in the e-gas plant is already waste gas from a biomethane plant nearby that is operated by EWE (power utility) and runs on organic waste. That plant separates the CO2 from the crude biogas in order to create highly pure biomethane. The annual output expected from the Audi e-gas plant is about 1,000 metric tons, capturing an estimated 2,800 metric tons of carbon dioxide that would pollute the atmosphere otherwise. This results to a climate-neutral fuel.
Audi built the e-gas plant together with plant engineer ETOGAS. Throughout the production process at the plant, efficiently using the flow of energy is a high priority. During the methanation, water heat is given off, and this is put to great use in the sanitization of the waste and the preparation of biogas. This increases overall efficiency. The e-gas plant is presently being commissioned and will be supplying synthetic gas to the grid.