Audi and project partners Climeworks and sunfire have opened a pilot plant in Dresden that produces diesel fuel from water, carbon dioxide and green electricity. The project allows Audi, Climeworks and sunfire to show that industrialization of e fuels is possible.
The opening of the pilot plant was graced by Johanna Wanka, German Federal Minister for Education and Research; and Hagen Seifert, Head of Environmental Assessments, Renewable Energies and New Materials at Audi.
The sunfire plant operates according to the power-to-liquid principle and needs carbon dioxide, water and electricity as raw materials. Using the direct air capturing technology developed by Climeworks, the plant extracts carbon dioxide directly from the ambient air.
In another process, an electrolysis unit -- powered by green electricity -- splits water into hydrogen and oxygen. The hydrogen is then reacted with the carbon dioxide in two chemical processes conducted at 220 degrees Celsius and a pressure of 25 bar to produce an energetic liquid called Blue Crude.
The pilot plant in Dresden-Reick can produce around 160 liters of Blue Crude daily, almost 80 percent of which can be converted into synthetic diesel called Audi e-diesel that is free of sulfur and aromatics.
Since Audi e-diesel has high cetane content, it ignites very easily. Likewise, the e-diesel’s chemical properties enable blending in any ratio with fossil diesel. The project is funded partly by the German Federal Ministry for Education and Research with Audi being the exclusive partner in the auto industry. [source: Audi]