An update from the rerefining industry was therefore of great interest to delegates to the recent annual congress of the Union of European Independent Lubricant Manufacturers (UEIL). Alternative sources of base oil are being looked at more closely than ever, and attendees were primed to hear from senior executives at two significant European rerefiners, Fabio Dalla Giovanna of Italys Viscolube, and Christian Hartmann of Puralube, in Germany.

As in North America, one of the reasons for Europes current base oil supply difficulties is the relatively high prices achievable for fuel products. For many refiners, the extra costs associated with base oil production are not seen as a sensible investment, stated Dalla Giovanna, so feedstocks are used elsewhere. However, he pointed out, the energy costs associated with rerefining a used oil are indeed significantly lower than the costs associated with virgin base oil production. He explained that this is because modern rerefining, such as Viscolubes Revivoil technology, only needs two processing steps – purification and final hydrogenation. By comparison, virgin base oil production involves distillation, deasphalting, solvent extraction, dewaxing, hydrofinishing and final fractionation steps.

Today, the main market for rerefined oils is Germany, where 10 percent of the lubricants sold are produced from rerefined oils. However it cannot be long before the rest of Europe recognizes the real value of waste oil, Dalla Giovanna predicted.

There have been concerns in the past about the quality and potential toxicity of rerefined products, he acknowledged, but these should all have been removed by now.

Likewise, Dalla Giovanna confirmed, there have been major steps forward in the quality area over the past few years, thanks to a high level of investment in projects in Italy, Germany and Poland. Nowadays, he said, the major European rerefiners are producing base oils meeting all the current technical toxicity and environmental concerns.

Only a few years ago production of API Group II quality level base oils from waste oil would have been considered unthinkable, Hartmann noted. However the severe hydroprocessing achieved in the new rerefining plants now coming onstream in Europe mean that Group II quality base oils are now easily achievable. Indeed, about 70,000 metric tons of this quality are produced annually. Group II+ may ultimately really be a better description of the quality achievable, Dalla Giovanna agreed.

The quality of the rerefiners feedstock is improving, too, with a high percentage of European engine oils now incorporating polyalphaolefins and API Group III base oils. These do enable higher quality rerefined base oils to be produced. An interesting side issue is that the increased viscosity modifier content of the waste oil feedstock means this contaminant actually improves the quality of the rerefinerys heavy asphalt/bitumen byproduct.

A key point, Hartmann added, is that neither the Viscolube or Puralube process (Puralube uses the UOP HyLube technology) produces any waste. All the feedstock is either converted into fresh base oil or becomes a component in asphalt or fuel oil.

The European lubricants market is demanding more base oils of a higher quality level. Unlike the United States, there is not a technical demand for API Group II oils, but they are recognized as a defining standard. Europes automotive manufacturers, faced with increasing pressure on vehicle emission levels, are demanding very low sulfur content in engine oils. The latest generation of high-pressure, hydrotreated rerefined base oils meets these low-sulfur requirements and in addition is water-white in color. Such high-quality regenerated base oils are now achievable by 70 percent of Europes rerefining capacity, Hartmann estimated.

ATIEL, the Technical Association of the European Lubricant Industry, has long considered that mineral base stocks can be made from crude oil or used oil. The group does stipulate that rerefined base stocks should be free from the pollutants caused by manufacturing, contamination or previous use.

So if quality and oil performance are not a problem, what about toxicity and the environment? CONCAWE (the oil companies European Organisation for Environment, Health & Safety) has confirmed that the latest generation of severely hydrotreated rerefining plants produces rerefined base oils free of contaminants with favourable impact on the environment and/or human health, Hartmann said. He went on to present a recent life cycle analysis from IFEU, an environmental research establishment in Germany. Its 2005 study compares the environmental impact of rerefining versus primary production, and confirmed that on a life-cycle basis, Europes five top rerefiners score better than virgin base oil processes in a number of key areas, including fossil fuel consumption, global warming contribution, acidification, particulates emissions and others.

Over the past 30 or 40 years, base oil production techniques have moved from a mild solvent technology to the current hydrocracking and isomerisation processes. At present these latest processes produce relatively small quantities of very high quality base oils. It has been suggested that gas-to-liquid (GTL) base oil plants under construction in various parts of the world may be part of the answer; the base oil output from such plants is expected to be of very high quality, and so will the used lubricants made from them.

However, cautioned Hartmann, these plants are essentially fuel units, and if the economics are not right the predicted volumes of high quality base oil may not be generated. This makes it essential that rerefining be given serious consideration by both the lubricants industry and legislators.

Hartmann expressed hope that the European Union will confirm its support for rerefining via new and modified Directives, as the EUs legislation is known. The existing Waste Oil Directive – which obliges member states to make recycling of used oil into base oil the preferred option versus other disposal methods like burning – may be repealed, he mused. This is because in reality few member states have implemented it. Any revised legislation should be slimmed down and made less complicated – but a preference for rerefining over other disposal methods must be maintained within the reissued Directive, he said.

Both speakers insisted that a firm Europe-wide policy needs to be established. At present about 400,000 metric tons of rerefined base oil is produced annually, so significant investment is needed to increase this volume.

Some countries, such as United Kingdom, have no rerefining capacity at all but do have very good collection services; unfortunately, this collected waste oil is simply burnt. This use of waste oil in Europe as a fuel is in difficulties because of the potential pollution caused if the oil is not burned under tightly controlled conditions. The time is right for rerefining to become endorsed as a sensible route forward, the two presenters urged – and one that will increase the availability of an important raw material. What is really needed, they concluded, is some pressure from lubricant blenders in their own countries to ensure that a uniform message is presented to EU representatives.