Oleochemical

Oleochemicals (from Latin: oleum “olive oil”) 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]

Processes

Important processeses in oleochemical manufacturing include hydrolosis and transesterification, among others.

Hydrolysis

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

RCO₂CH₂–CHO₂CR–CH₂O₂CR + 3 H₂O → 3 RCOOH + HOCH₂–CHOH–CH₂OH

The addition of base helps the reaction proceed more quickly, the process being saponification.

Transesterification

Fats react with alcohols (R'OH) instead of with water in hydrolysis) in a process called transesterification. Glycerol is produced together with the fatty acid esters. Most typically, the reaction entails the use of methanol (MeOH) to give fatty acid methyl esters:

RCO₂CH₂–CHO₂CR–CH₂O₂CR + 3 MeOH → 3 RCO₂Me + HOCH₂–CHOH–CH₂OH

FAMEs are less viscous than the precursor fats and can be purified to give the individual fatty acid esters, e.g. methyl oleate vs methyl palmitate.

Hydrogenation

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 the fatty alcohols. For some applications, fatty acids are converted to fatty nitriles. Hydrogenated of these nitriles gives fatty amines, which have a variety of applications.^[4]

Applications

The largest application for oleochemicals, about 30% of market share for fatty acids and 55% for fatty alcohols, is for making soaps and detergents.^[5]:21 Lauric acid, used to produce sodium lauryl sulfate and related compounds, which are used to make soaps and other personal care products.

Other applications of oleochemicals include the production of lubricants, solvents, biodiesel and bioplastics. Due to the use of methyl esters in biodiesel production, they represent the fastest growing sub-sector of oleochemical production in recent years.^[5]:15

Oleochemicals are important raw material for polymeric resins specially alkyd based because of possible functional group modifications. These modifications are based on reaction of vegetable oil with excess glycerol to obtain monoglyceride, which is then converted into polymeric resins i.e. alkyd by reacting with dicarboxylic acids or anhydrides. Recently polyesteramide resins are also prepared using vegetable oil as an oleochemical.^[6][7]

Oleochemical industry development

Europe

Through the 1996 creation of Novance and the 2008 acquisition of Oleon, Avril Group has dominated the European market of oleochemistry^[8]

Southeast 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.^[9] 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.^[10] 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.^[5]:24

References