The shift towards better quality lubricants has resulted in slower growth in demand for esters that are used in lubricants, such as polyol esters and phosphoric acid esters, according to consultancy Kline & Co.
Within the lubricant industry, esters are commonly used in a variety of applications, ranging from industrial lubricants, hydraulics, marine and automotive, to refrigeration, metalworking and wind turbines.
“So the frequency of change of lubricants is going down, and therefore the demand for lubricants is growing slowly, even probably slower than global [gross domestic product] growth we are seeing,” Kunal Mahajan, a project manager in Kline & Co.’s chemicals practice, said during an online webinar on Oct. 11 based on insights from its “Industrial Esters: Market Analysis and Opportunities” report. “Therefore, we are seeing lower growth for polyol esters as well as phosphoric acid esters.”
Mahajan noted that polyol esters, which are among the slowest growing categories, are mainly used in lubricants. Phosphoric acids are also used in lubricants, he added.
Polyol esters, which are based on monobasic acid and polyhydric alcohol, are suited for use at high temperatures but some suffer from poor hydrolytic stability. Complex polyol esters are a combination of diacids and polyol esters, which provide both thermal stability and good viscosity.
Phosphate esters – made from phosphoric acid and alcohol – are fire resistant and hard-wearing but are not miscible with mineral oils. The lubricants industry uses phosphate esters as antiwear additives and as fire-resistant fluids in a variety of applications, from hydraulic and transmission fluids to compressor oils and aircraft lubricants. Phosphate esters are ashless and serve as an alternative to metal-containing additives.
Kline estimated the global industrial esters market value at about $22.3 billion in 2022. Lubricants were about eighth in terms of industrial esters application demand, trailing paints and coatings, food and beverage, adhesives and sealants, personal care, lithium-ion battery and textile.
Among ester categories, acrylic esters led in 2022 with more than one quarter of the global demand, Kline found, followed by carboxylic acid esters, fatty acid esters, carbonic acid esters, polyol esters and sulfonic and sulfuric acid esters. Fatty acid esters are made from animal or vegetable fats and oils and offer good oxidative stability in lubricant applications. Among other applications, some carboxylic acids are used for manufacturing energy-efficient lubricant esters for refrigeration units, such as air conditioners and refrigerators.
China dominated in demand for industrial esters last year, according to Kline, accounting for more than half of demand, followed by Europe, the United States, India and Southeast Asia.