Lubricant production is energy-intensive. A lot of energy is required to go from the refined crude oil to the finished lubricant. Accordingly, the CO2 balance of motor and hydraulic oil, concrete release agent, cutting and grinding oil does not look exactly rosy. For years, the lubricant specialist Zeller+Gmelin has therefore been making intensive efforts to improve the CO2 footprint: A current example is the production of CO2-optimized industrial lubricants by recycling.

The topics of environment and sustainability have long been important to Zeller+Gmelin. Even if it doesn't always seem so easy for a chemical company, constant dripping wears away the stone. The lubricant experts in Eislingen look at all areas to see whether anything can be changed and improved in the long term for the benefit of the environment. The renunciation of the production of products containing boric acid is such an example in the direction of sustainability, environmental protection and health protection. For many years now, new lubricant products such as concrete release agents, chainsaw and lawn mower oils have been developed as environmentally friendly bio-lubricants. The sustainable product portfolio of the lubricant manufacturer also includes environmentally friendly bio-hydraulic oils in the automotive and motor vehicle sectors, especially for outdoor use. A large-scale project to conserve resources was also the reconditioning of used barrels and containers in a kind of recycling cycle. Reconditioned kegs not only conserve material resources, but also have a significantly lower carbon footprint than newly manufactured kegs.
Probably the most important step on this sustainability path so far was the determination of our own CO2 footprint using the CO2 balance sheet and the associated achievement of climate neutrality on the basis of the value-adding and recognized KEFF check.

Recycling with tradition

The idea of recycling is by no means new to the traditional Swabian company and has its roots as early as 1935: the subsidiary Südöl has been collecting and recycling lubricants and industrial cleaning agents for almost 90 years. Among other things, Südöl recycles used machine and motor oils and processes them into new base oils and fuels. Reprocessing base oils and bringing them back into the recycling cycle as fresh oils not only conserves resources, but also uses less energy: the CO2 footprint of a recycled oil is significantly lower compared to the production of fresh oil.
"Conscientious use of resources and responsibility towards our environment are central components of our corporate philosophy," emphasizes Jürgen Wranik, Head of R&D Lubricants at Zeller+Gmelin. "We are noticing an increasing need for sustainable solutions and are therefore consistently pursuing a series of developments and measures to reduce emissions or avoid them completely."

>From gentle splitting to the use of biogenic raw materials

One of these measures is the production of CO2-optimized lubricants. It is well known that there are always three ways to get there, including an improved CO2 footprint in the manufacture of lubricants. "We rely on three processes when recycling industrial lubricants: first the so-called "gentle splitting", then recycling with refining and finally the new development from biogenic raw materials. We have been using the latter for many years in the development of lubricants in the agricultural and forestry sectors," says Jürgen Wranik. So what applies to the environmentally friendly, water-based Divinol chainsaw and lawn mower oils is now also being implemented for lubricants for metalworking: the use of biogenic raw materials in new developments of cooling lubricants, grinding oils or wire drawing agents.
The "gentle splitting" of used oils separates oil-water phases from one another, removes deposits through filtration and cleans them. With the help of refining, a used oil is refined into a second refinery product, so that, according to Zeller+Gmelin, an extraordinarily sustainable base oil is produced, which is almost waste-free. Biogenic, CO2-optimized lubricants are developed when recycling is not possible, for example in the case of consumption lubrication, stamping oils or corrosion protection.

CO2 savers

Industrial companies are obliged to dispose of their old or used oil properly and that costs money. Even if the trend in metal cutting is towards minimum quantity lubrication (MMS), there are still huge amounts of used lubricants. By returning it to the recycling loop, not only immense costs can be saved, but resources and the environment can be protected at the same time.
Large quantities of high-quality, water-immiscible oil are usually dragged out during machining, grinding or forming. During machining, the lubricant ends up in the waste container together with the chips, e.g. via a chip conveyor. Which in turn goes to a disposal company that separates metal chips and lubricant. The metal is recycled as raw material, the lubricant usually is not. Similar to other processing methods such as deep drawing of sheet metal. There, the drawing agents used, for example during cleaning, are dragged out via the parts washing system. The industrial companies had to dispose of the mixture of drawing agent, parts cleaner, water, surfactants and solid particles at great expense. R&D Manager Lubricants Jürgen Wranik: "This is exactly where our concept comes into play. For us, the used oil from metalworking is a valuable raw material that we are happy to take back and recycle." This improves the waste balance and the CO2 footprint of the metalworking companies. When using fresh oil in the production of lubricants, the rising base oil prices have a significant impact, which is not the case when reusing your own recyclate. According to Zeller+Gmelin, cost savings of between 30-50 percent can be achieved by using a recyclate compared to fresh oil in the lubricant. The testing laboratory of the lubricant manufacturer in Eislingen ensures that the process oil in circulation is of consistently high quality.
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