Detergents from fatty alcohols

In 1932 the first household detergent based on synthetic surfactants was brought into the market under the name FEWA (Feinwaschmittel). The product was produced from fatty alcohol sulfate by Bohme Fettchemie in Chemnitz. The shortage of the necessary natural raw materials caused by World War II led to the development of products based on more readily available raw materials [2],... 

The C12-C18 fatty acid fractions, approximately 85% of the coconut oil fatty acid composition, are the primary raw materials for detergent-grade fatty alcohols. Coconut oil is a primary source of basic oleochemicals and a host of other oleochemical derivatives. Figure. 12.1 indicates some of the major processes by which various oleochemicals and their derivatives can be obtained from fats and oils. These processes are applicable to coconut oil with the exception of epoxidation and direct sulfation because coconut... 

In 2004 it was estimated that about 80000 metric tonnes of natural fatty acids were consumed for manufacture of quaternary ammonium salts, in North America, Europe and Japan, using the nitrile process. Another 85 000 tonnes were converted to amines and other derivatives (Table 2.1). In 2006, North America consumed 35000 tonnes of quats made via the nitrile process and another 44 000 produced from fatty alcohols or olefins [39]. There has been growing competition between oleochemical- and petrochemical-based detergent alcohols for surfactant use, driven by the high price of crude oil and the increased supply of natural oils, particularly palm. 

The most widely used alkyl sulfate in shampoo preparation is lauryl sulfate. The alkyl component of this sulfate ranges from C-10 to C-18 with a predominance of the C-12 (lauryl) component. By distillation of the fatty alcohol, certain cuts can be obtained which offer the best effects in foaming, cleansing, and rinsing properties for the alkyl sulfate preparation. The range which appears to be most desirable is between C-12 and C-16. Lauryl sulfate detergents are available in various salt forms with the sodium, ammonium, and triethanolamine types being used most frequently in shampoos. 

Nowadays these compounds are usually blended with other surfactants, including nonionic types (section 9.6). In 1990 a typical low- or non-phosphate domestic detergent contained 7% linear alkylbenzenesulphonate and 6% nonionic fatty alcohol ethoxylate [16]. There is increasing use of the long-chain fatty alcohol poly(oxyethylene) sulphates previously described (e.g. 9.12) as a partial or complete replacement for linear alkylbenzenesulphonates [15] since they are made from renewable feedstocks such as tallow and palm oil [16]. 

Nonionic surfactants contain (Fig. 23) no ionic functionalities, as their name implies, and include ethylene oxide adducts (EOA) of alkylphenols and fatty alcohols. Production of detergent chain-length fatty alcohols from both natural and petrochemical precursors has now increased with the usage of alkylphenol ethoxylates (APEO) for some applications. This is environmentally less acceptable because of the slower rate of biodegradation and concern regarding the toxicity of phenolic residues [342]. 

Fats and oils are triesters of the trivalent alcohol glycerol and three (different) even-numbered aliphatic carboxylic acids, the fatty acids. Fats and oils differ in the length and the number of unsaturated bonds in the carbon chain. The shorter Cio-Ci4-fatty acids are obtained from coconut oil and palm kernel oil. These fatty acids are mostly saturated, and they are used in the manufacture of detergents. Cig-fatty acids are more widely used. Oleic acid, a Cig-fatty acid with an unsaturated bond on the ninth carbon atom, can be produced from many crops. Specific varieties or genetically modified plants, such as rape, have a content of over 90% oleic acid [4]. 

Oily soils containing amphiphilic species, such as fatty acids or fatty alcohols, can also be removed from substrates as a result of the formation of liquid crystal or mesomorphic phases between the amphiphile and a detergent. The liquid crystals are then broken up by subsequent osmotic penetration by water [140-142], Removal of solid soils by mesophase formation can be accelerated by increasing the temperature. This has been reported for stearyl alcohol [143] and for lauric, palmitic, and stearic acids [128, 129] and is likely due at least in part to the increased penetration of the soils at higher temperatures [128,129,143],... 

Application To produce natural detergent alcohols from fatty acids using esterification, hydrogenolysis and refining. 

Davy Process Technology, UK Natural detergent alcohols Fatty acids Natural detergent alcohols are produced from fatty acids using esterification, hydrogenolysis and refining 6 NA... 

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