Esterification of fatty acids
Fatty Acid Esters

Fatty acids or derivatives of fatty acids are used in a wide variety of applications. The demand for fatty acids has been growing by about 4% per year over the past 10 years and has reached about 3,000,000 metric tons per year. Fatty acids are typically present in the raw materials used for the production of biodiesel. The natural fatty acids are obtained from the hydrolysis of hard animal fats (tallow), coconut, palm kernel and soybean oils and from the fractional distillation of crude tall oil (a byproduct of Kraft pulping of pine wood). These acids are almost entirely straight chain, even-numbered mono carboxylic acids containing from 8 to 22 carbons. Most new plants have been built in Southeast Asia which is the major source for coconut, palm and palm kernel oils. The market is dominated by two producers, the Uniquema group and the Henkel group representing about 50% world market share. Other fatty acids are derived from petroleum.

About 100,000 metric tons of the natural fatty acids are consumed in the preparation of various fatty acid esters. The simple esters with lower chain alcohols (methyl-, ethyl-, n-propyl-, isopropyl- and butyl esters) are used as emollients in cosmetics and other personal care products and as lubricants. Esters of fatty acids with more complex alcohols, such as sorbitol, ethylene glycol, diethylene glycol and polyethylene glycol are consumed in foods, personal care, paper, water treatment, metal working fluids, rolling oils and synthetic lubricants.

Direct esterification of fatty acids with alcohol catalyzed by an acid catalyst:

 

 

 

Examples of Fatty Acids

 

	Caprylic acid	(C8)	- Mp: 17°C, Bp : 240°C
	Capric acid	(C10)	- Mp: 32C, Bp : 270°C
	Lauric acid	(C12)	- Mp: 44°C, Bp : 299°C
	Myristic acid	(C14)	- Mp: 54°C, Bp : 3260°C
	Palmitic acid	(C16)	- Mp: 63°C, Bp : 352°C
	Stearic acid	(C18)	- Mp: 70°C, Bp : 376°C
	Arachic acid	(C20)	- Mp: 75°C
	Behenic acid	(C22)	- Mp: 80°C
	Lignoceric acid	(C24)	- Mp: 84°C
	Oleic acid	(cis unsaturated C18) - MP: 16°C
	Linoleic acid	(diene C18) - MP: -5°C
	Erucid acid	(cis unsaturated C22) - MP: 34°C
	Linolenic acid	(triene C18)