There are currently around 15 operators rerefining in Europe, including Italian refiner Viscolube and Spains Sertego. Almost 90 percent of used oil generated in the European Union – roughly 1.7 million metric tons per year – is collected, with around a third of that being processed back into base stocks.

One of the largest rerefiners is a German company, Avista Oil Group. The company employs around 700 people in three locations in Europe and the United States: Dollbergen in Germany, Kalundborg in Denmark and Peachtree City, Georgia, in the U.S. Combined, they can handle around 500,000 metric tons of used oil per year.

Avista was founded in 1951 in Germany, at a time when interrupted supplies of crude and other feedstocks across Europe after the Second World War encouraged the establishment of a rerefinery at the Dollbergen site. At first, the technology was basic and inefficient, but this has radically changed since. From API Group I++ oils, rerefiners such as Safety-Kleen and the soon-to-open Green Oil and Lubesplant in Romania can now offer Group II, while both Avista and Puraglobe have Group III capacity.

Avistas patented Expanded Selective Refining process yields rerefined base oils that go under the trade name of Kernsolvat. The company claims this technology produces very little waste products and even the solvents involved are reused. The technology guarantees full preservation of synthetic oils and produces highly refined Group I and Group II+ base stocks, which are produced and sold in varying viscosity ranges – KS100, KS150 and KS200.

The company also produces finished lubricants in Dollbergen that are sold in around 50 markets in small packages and bulk capacities.

Avista has built a network for the provision of high-quality feedstock for its various plants and has become one of the largest used oil collectors in the world, with collection companies in Germany, the Netherlands, Belgium, Denmark, the Czech Republic, Poland, the United Kingdom and the U.S.

Avista Oil is also looking to expand into untapped markets, such as sub-Saharan Africa, where collection rates are low and where it can offer a range of base oils and finished lubricants to complement the slate of virgin base oils currently used by blenders.

Avista was also the first producer of base oils to be confirmed by vehicle inspection company Dekra that its process saves almost 30 percent CO₂ compared with primary refining.

The story has not always been one of success. In July 2017, a fire ripped through the Kalundborg rerefinery, and while no one was hurt, the plant was a write-off. The company and its U.K. joint venture partner, Slicker Recycling Ltd, a subsidiary of U.K.-based packaging company Greenbottle Ltd, decided to rebuild it from scratch to produce the largest and most modern rerefinery in Europe.

The new unit will increase feedstock capacity over that of the destroyed plant by 45,000 t/y of waste oils to 100,000 t/y. The rerefinery is due to start production by the end of 2019. In the meantime, waste oil collected in Denmark is processed at Dollbergen, meaning no loss to collection quantities and output has been maintained.

There have been less destructive setbacks, too. Consumers and industry insiders perception of rerefined base oil quality has been askance. The U.S. Federal Trade Commission and the American Petroleum Institute rejected Avistas request to change the wording of rules to specify rerefined base oil is of equal or better quality compared to virgin base oil. The company still has a way to go to win both the technological and marketing battles.

The trajectory of rerefining has yet to rise consistently upward and the sector has struggled to encroach upon the virgin oil space, despite government-mandated collection targets in many developed markets.

But with the price of crude feedstock for conventional base stock refining nudging ever upwards, potentially accelerated by the Iran sanctions, could rerefining at last take off?

Adding a higher quality product such as a Group l+ 150 at competitive prices to existing materials may open more doors and minds to the practicalities of using rerefined base stocks in a responsible and environmentally friendly manner.