Background The European Union uses 4.7 million tonnes of lubricants a year. Modern lubricants are complex chemical compounds and even after use remain highly toxic. Although it is clear that eventually corrective measures will need to be taken, prior to the project, however, only a small proportion had been recycled and a substantial amount was even discarded in an uncontrolled way. The potential for waste oil recycling is all the more remarkable considering that it takes only 1.3 tonnes of used oil to produce 1 tonne of recycled lubricant, while 10 tonnes of crude oil are required to produce the same amount of lubricants. In this regard, recycling of used lubricants could help to save natural resources and could be highly efficient in environmental and economic terms. Objectives With the planning, building and operation of the production-scale demonstration unit "MRD Selective Refining" for the regeneration of used lubricants the beneficiary aimed to produce new high-quality lubricants by a waste-free recycling process. A specific objective was to recover valuable synthetic oils without damaging their structure. The "MRD Selective Refining" technology was set up to separate undesired and desired substances from used lubricants by solvent extraction. The undesired fraction was to be used for industrial heating purposes, the solvent was to be recovered for permanent reuse in the extraction process and the desired fraction was expected to be high-grade base oil for the lubricant market. Therefore no waste was expected to remain following recycling, especially no oily clay, which normal recycling technologies generate (about 130 - 140 kg per tonne of reraffinate) and which has to be disposed under high costs. It was expected that recycled lubricants will meet the ever-growing demands for high-quality recycling products. The project further sought to achieve substantial environmental benefits by, for example, saving a significant quantity of raw oil. Results The production process consisted of the vacuum distillation of waste oils; the extraction of oil distillates through a selective solvent; the separation of undesired substances; the recovery of solvent substances; the production of base oils and the further processing into new lubricants. The project achieved all the goals for the plant: • 10 tonnes/hour throughput, • processing of waste oil input from low, medium and higher viscosity, • 8000 operating hours per year, • 92% of the input goes into the base oil output, only 8 % goes to incineration (e.g. the energy supply for the plant). The goals for the product / process were reached: • 100% recovery of synthetic oil components, • quantitative PAH (polycyclic aromatic hydrocarbons) decontamination, • solvent content in the product (base oil) below 1ppm (parts per million), • substantial improvement of base oil colour, • elimination of disturbing odours in the produced base oil, • low vapor losses (of base oil). One advantage for the recycling of waste oil compared to the production of lubricants from fresh oil can be seen in the different energy input. From 150-190 tonnes of crude oil only 1 tonne of poly-alpha-olefins (PAO, a main component of modern lubricants) can be gained, with an energy consumption of 11 GJ (equalling the energy of 250 kg of heating oil) and causing twice as much CO2 emissions than the production of "normal" base oil due to the extremely complex refining and chemical alteration. In contrast the new process enables a quantitative recycling with a fraction of the energy input. During the selective refining process developed by MRD the polycylic aromatic hydrocarbons (PAH) are effectively removed from the reraffinate. The innovation of the procedure consists in the extraction of solvent, which reduces the residue of toxic polycylic aromatic carbon hydroxides to a level below the threshold without damaging the remaining valuable hydrocarbons. As a result, the energy and raw material input for synthesis from crude oil can be saved. The new selective refining process therefore leads to a substantial reduction of greenhouse gases and sulphur dioxide. Furthermore, it no longer requires bleaching agents, which were difficult to dispose of (in the case of the beneficiary about 5,500 tonnes/year). There is another very clear environmental advantage for recycling of waste oil. According to the beneficiary, the waste reduction for the recycling process is already enormous. Previously, MRD had to buy and transport 4,000 tonnes/year of fullers earth (Bleicherde) from Spain to Dollbergen, which then adsorbed about 30% of the treated oil and thus 5,500 tonnes/year of hazardous waste had to be disposed of. Now there is zero waste in the recycling process, and as a result much better efficiency of the recycling compared to production from crude oil. According to the German ifeu Institute (in its 2005 revision of its ecobalance study of 2000) recycling of waste oil is highly preferable to incineration, if the recyclate contains the valuable synthetic components as available with with the new technology. ifeu further states that the material recycling has now – due to improved recycling technologies – clear ecological advantages compared to synthesis from crude oil and to combustion of waste oils. If the preference of waste oil recycling against incineration in legislation continues, then the selective refining technology will spread well. It is superior to conventional recycling (hydrogenation) and to incineration and a big step towards saving natural resources. This process can also be easily adapted to changes of waste oil quality, expected in the coming years. By adjustment of the processing parameters, the high quality of the reraffinate can be guaranteed. However, the strong cement industry favours incineration of waste oil as cheap fuel, especially after the enormous price increases of recent years. This project has been selected as one of the 22 "Best" LIFE Environment projects in 2006-2007