Oleochemical

Oleochemicals are chemicals derived from plant and animal fats. They are analogous to petrochemicals derived from petroleum.

The formation of basic oleochemical substances like fatty acids, fatty acid methyl esters (FAME), fatty alcohols, fatty amines and glycerols are by various chemical and enzymatic reactions. Intermediate chemical substances produced from these basic oleochemical substances include alcohol ethoxylates, alcohol sulfates, alcohol ether sulfates, quaternary ammonium salts, monoacylglycerols (MAG), diacylglycerols (DAG), structured triacylglycerols (TAG), sugar esters, and other oleochemical products.

As the price of crude oil rose in the late 1970s,^[1] manufacturers switched from petrochemicals to oleochemicals^[2] because plant-based lauric oils processed from palm kernel oil were cheaper. Since then, palm kernel oil is predominantly used in the production of laundry detergent and personal care items like toothpaste, soap bars, shower cream and shampoo.^[3]

Industry in Asia

Southeast Asian countries' rapid production growth of palm oil and palm kernel oil in the 1980s spurred the oleochemical industry in Malaysia, Indonesia, and Thailand. Many oleochemical plants were built. Though a nascent and small industry when pitted against big detergent giants in the US and Europe, oleochemical companies in southeast Asia had competitive edge in cheap ingredients.^[4] The US fatty chemical industry found it difficult to consistently maintain acceptable levels of profits. Competition was intense with market shares divided among many companies there where neither imports nor exports played a significant role.^[5] By the late 1990s, giants like Henkel, Unilever, and Petrofina sold their oleochemical factories to focus on higher profit activities like retail of consumer goods. Since the Europe outbreak of 'mad cow disease' or (bovine spongiform encephalopathy) in 2000, tallow is replaced for many uses by vegetable oleic fatty acids, such as palm kernel and coconut oils.^[6]

Applications

The most common application of oleochemicals is biodiesel production. Fatty acids are esterified with an alcohol, commonly methanol to form methyl esters. Another common application is in the production of detergents. Lauric acid is used to produce sodium lauryl sulfate, the main ingredient in many personal care products. Other applications include the production of lubricants, green solvents, and bioplastics.

Hydrolysis

The fat splitting (or hydrolysis) of the triglycerides produces fatty acids and glycerol:

RCOOCH₂–CHOOCR–CH₂OCOR + 3 H₂O → 3 RCOOH + HOCH₂–CHOH–CH₂OH

The addition of base helps the reaction proceed more quickly.

Transesterification

If oils or fats are made to react with an alcohol (R'OH) instead of with water, the process is alcoholysis. It is also called transesterification, because the glycerol fragment of the fatty acid tri-ester is exchanged for that of another alcohol. Thus, the products are fatty acid esters and glycerol:

RCOOCH₂–CHOOCR–CH₂OCOR + 3 R'OH → 3 RCOOR' + HOCH₂–CHOH–CH₂OH

The fatty acid or fatty esters produced by these methods may be transformed. For example, hydrogenation converts unsaturated fatty acids into saturated fatty acids. The acids or esters can also be reduced to give fatty alcohols.

References

1. ^ Haupt, D. E.; Drinkard, G.; Pierce, H. F. (1984). "Future of petrochemical raw materials in oleochemical markets". Journal of the American Oil Chemists' Society 61 (2): 276. doi:10.1007/BF02678781. 
2. ^ Akaike, Yoshiteru (1985). "Other oleochemical uses: Palm oil products". Journal of the American Oil Chemists' Society 62 (2): 335. doi:10.1007/BF02541401. 
3. ^ Dewaet, F. (1985). "Quality requirements from a consumer’s point of view (oleochemical products)". Journal of the American Oil Chemists' Society 62 (2): 366. doi:10.1007/BF02541406. 
4. ^ The future of palm oil in oleochemicals Appalasami & de Vries, Palm Oil Developments 14-3, 1990
5. ^ Leonard, E. Charles; Kapald, S L (1984). "Challenges to a mature industry: Marketing and economics of oleochemicals in the United States". Journal of the American Oil Chemists' Society 61 (2): 176. doi:10.1007/BF02678763. 
6. ^ The Changing World of Oleochemicals Wolfgang Rupilius and Salmiah Ahmad, Palm Oil Developments 44, 2005