Audi e-diesel
German Minister of Education and Research Johanna Wanka testing out the first five litres of Audi e-diesel

In Germany, a research facility in Dresden has started to produce a carbon-neutral fuel source for German automobile company Audi.

Dubbed Audi e-diesel, the research facility produced its first batch of fuel in April, after a commissioning phase of just four months, according to Audi.

German-based cleantech company Sunfire, project partner of Audi and plant operator, produced the synthetic diesel from using air, water and renewable generated power.

The cleantech firm has built a demonstration rig for power-to-liquids, which was inaugurated by the German Federal Minister of Education and Research, Johanna Wanka in November 2014.

Sunfire said: “On behalf of the project partner Audi, an independent laboratory confirmed that the outstanding characteristics of the fuel are superior to the properties of fossil fuel.”

Testing the product

Wanka tested the first five litres produced in her car, an Audi A8 3.0 TDI clean diesel Quattro.

The minister commented: “This synthetic diesel, made using CO2, is a huge success for our sustainability research. If we can make widespread use of CO2 as a raw material, we will make a crucial contribution to climate protection and the efficient use of resources, and put the fundamentals of the ‘green economy’ in place.”

Sunfire said that the ministry had supported the development of the manufacturing plant in Dresden. “The new fuel is a synthetic diesel-distillate based on ‘Blue Crude’ (hydrocarbons),” Sunfire said in a statement.

According to Sunfire CTO Christian von Olshausen, the synthetic Sunfire diesel does not contain any sulphur or fossil oil making it eco-friendly – “The engine runs quieter and fewer pollutants are being created,” he said.

Blue crude

Audi stated that the only raw input materials needed are water and carbon dioxide. “The CO2 used is currently supplied by a biogas facility. In addition, initially a portion of the CO2 needed is extracted from the ambient air by means of direct air capturing, a technology of Climeworks, Audi’s Zurich‑based partner,” Audi said in a statement.

Sunfire said in a statement that: “The main advantage of the power-to-liquids technology comes to the fore when electricity prices rise to a level that makes hydrogen production unprofitable. After a short turnaround interval, the system can be switched to fuel cell mode and used to convert hydrogen reserves or any another fuel back into power and heat.”

Sunfire claims that the power-to-liquids demonstration rig is able to produce up to 160 l (42.2 gallons) of ‘blue crude’ per day.

Reiner Mangold, head of Sustainable Product Development at Audi, said: “In developing Audi e-diesel we are promoting another fuel based on CO2 that will allow long‑distance mobility with virtually no impact on the climate.

“Using CO2 as a raw material represents an opportunity not just for the automotive industry in Germany, but also to transfer the principle to other sectors and countries.”

According to Sunfire, the cleantech company is receiving backing from several corporate venture capital companies and funds, including Bilfinger Venture Capital, Total Ventures, German development bank KfW and Electranova Capital, a venture capital funds financed by Allianz and EDF.

Homepage pic credits: auto evolution