Recycling Grease Presents Challenges


Recycling Grease Presents Challenges
A heavy-duty machinery technician pumps grease into industrial machine, using a hand pump gun. © Virrage Images

Virtually no grease is recycled, it was disclosed at the European Lubricating Greases Institute’s 33rd annual general meeting and conference in Amsterdam last week. Delegates gathered to discuss a slate of topics including sustainability, a major challenge facing the whole lubrication industry.

To tackle these challenges, ELGI set up five sustainability task forces in August 2022 to look at various aspects of grease sustainability. They look at regulation and communication, carbon footprints, life cycle analysis, end users and end of life.

Several characteristics of grease and grease production have unique sustainability issues, compared to blending lubricating oils. The manufacturing process can be energy intensive and disposal of waste at the end of life problematic.

Less than 1% of grease is recycled, Manfred Jungk, founder of MJ Tribology and head of the ELGI sustainability technical consortium, told the conference.

“Where lubricant grease is ending up is a difficult question to answer,” Jungk said. “When you open a starter motor that is run for 20 years in the vehicle, and you open the bearing, there isn’t much grease left. Maybe some black flakes. So, how do we recover, recycle this?”

The sustainability of grease raw materials is also a challenge. Like most finished lubricants, grease is largely made from mineral base oil, which is derived from crude oil, but switching to more sustainable alternatives is more difficult with grease than with fluid lubes.

“Crude will have a place moving forward,” said Marika Rangstedt, sustainable development manager at Nynas, a naphthenic crude oil refiner. “When you make asphalt when you make chemical products, that you can recycle basically endlessly …. Then I think there will be crude-based solutions available as well.”

Greases also play a more central role in lubricating electric vehicles, which, unlike their internal combustion engine counterparts, do not require several liters of engine oil. But EVs are putting pressure on the raw materials that the grease industry uses. Lithium is a key component in EV batteries and in the most common types of soap thickeners used in grease. About 69% of greases produced in 2021 used lithium, according to the National Lubricating Grease Institute’s 2021 Annual Production Survey, yet this may be declining, as EVs gobble up more supplies of this strategic mineral.

While annual global grease demand has been a steady 1.2 million metric tons per year for a decade, population and industrial activity has grown. From this, Jungk inferred improvements in grease performance and energy efficiency of end-use applications.

“If you look at current energy consumption – over the last decades and projected – and at the increase of population, at the same time, lubricants demand is flat,” Jungk said. “So, we definitely do something good in the lubricants industry. We keep the world moving without increasing the total volume of lubricants.”