Nynas AB announced last week that it has started to rerefine used electrical transformer oils at its base oil plant in Nynashamn, Sweden, using the recycled fluids to make new transformer oils marketed as having a small greenhouse gas footprint.
It is at least rare for virgin base oil plants to be used for rerefining. Two industry sources told Lube Report they were not aware of the practice having been done previously.
The Nynashamn plant has capacity to make 400,000 metric tons per year of naphthenic base oils, and Nynas has long used some of that output to make transformer oils production capacity.
The company is now collecting used material from customers and returning it to the plant where it is hydroprocessed to be turned back into transformer oil. The company markets the new product under the name Nytro RR 900X. It’s highest grade of virgin transformer oils is marketed under the name Nytro.
Officials said the sustainability movement has created demand for a recycled product.
“Nytro RR 900X contributes to sustainable development and raw material efficiency by reusing end-of-life transformer fluid,” Gaia Franzolin, marketing director at Nynas, said in an Aug. 31 news release.
She added that Nynas’ re-refining process “recovers valuable molecules that are no longer fit for service in their present form, making the best use of the fluid’s original production impact.”
Nynas claims that making the recycled fluids generates at least 70% less greenhouse gas emissions compared to a virgin transformer oil.
The company said the product is suitable for use in a wide range of electrical applications, including high voltage and high-power transformers. The new grade complies with the IEC 60296 standard, which requires the feedstock of re-refined fluids to be sourced 100% from power equipment such as high voltage switches or transformers.
High-voltage switches contacts are opened and closed in oil.
The reason for placing high-voltage switches in oil is that the oil will break the circuit when the switch is opened ensuring a safe break of the current flow. Usually, electric arcs form between the contacts when they are opened in oil and the oil will quench the arc. The dielectric property of oil reduces flashes, bounds the contacts, and absorbs heat in the high-voltage electric transformers.
“Our product retains the well-known dielectric behavior of traditional naphthenic dielectric fluids,” Nynas said.
Hydrodec also produces recycled transformer oils at its plant in Canton, Ohio, United States, which uses a proprietary catalyst to remove impurities and then hydrogenates the fluid. Hydrodec and its Ohio facility were acquired by United Kingdom-based used oil collector and rerefiner Slicker Recycling Ltd. in November 2021.