Lithium-based greases hold about 70% of the grease market share due to their versatility, historic affordability, and superior performance. However, the recent increase in electric vehicle production has drastically reduced the availability of lithium, forcing people to seek lithium grease alternatives. I recently sat down with Dr Anoop Kumar, Senior Staff Scientist at Chevron Products Company, a division of Chevron U.S.A. Inc., to discuss the future of the grease market and what to do if lithium grease is no longer an option for your machinery.
Q: What led to the popularity of lithium grease and why has it retained such a large market share?
A: Calcium greases were the first to be widely used in machinery, but ultimately declined because they were unable to withstand high temperatures. Then, sodium-based greases became popular. Though they could handle high temperatures, they had extremely poor water resistance. Lack of success with calcium and sodium greases led to the rise of lithium greases—though they were more expensive at the time, these greases were multipurpose, exhibited stability in high temps, and excellent water resistance. As they eventually became more affordable, lithium greases have successfully maintained their popularity throughout the years.
Q: Why are so many organizations reconsidering the use of lithium grease?
A: There are a couple reasons for this. The first is the exponential and unprecedented increase in price in the last few years. The price of lithium greases used to be relatively less compared to other high-performance greases like Calcium Sulfonate, Polyurea, and Aluminum Complex. Now, due to the huge drift of lithium batteries in electric vehicles, there is reduced availability of lithium for greases, and the price gap has pretty much diminished.
Another reason is that there is a proposal in Europe to classify lithium as a category 1A substance. 1A stands for chemical substances for which there is scientific evidence that the substance is carcinogenic, mutagenic or reprotoxic for humans. If this is approved, it may only be a matter of time before other parts of the world follow, leading to decreased market share of lithium grease.
Q: Calcium sulfonate greases are growing in popularity due to their excellent EP performance and oxidation stability. Are they an acceptable alternative to lithium greases?
A: In-heavy duty industrial applications, Ca-Sulfonate greases have shown superior performance in terms of extreme pressure, anti-wear, water resistance, rust protection, and more. Yes, they are potentially an acceptable alternative, especially now that their price is level with lithium greases. In the past, there were concerns about low pumpability, but thanks to advancements in technology, this is less of a concern today.
Source: “Choosing a Multi-Purpose Grease: Lithium Complex or Calcium Sulfonate?”, Machinery Lubrication Magazine, 2014
Q: Which applications are calcium sulfonate greases best suited for?
A: Ca-Sulfonate greases thrive in heavy-duty, off-highway, and other industrial applications. One advantage of Ca-Sulfonate chemistry is that it can be tailored as food grade greases. Though Ca-Sulfonate by itself is not food grade, it can be developed to be food grade by using permitted ingredients, making it an acceptable choice for food & beverage and pharmaceutical manufacturing.