Fatty alcohols commercial production

The first commercial production of fatty alcohol ia the 1930s employed the sodium reduction process usiug a methyl ester feedstock. The process was used ia plants constmcted up to about 1950, but it was expensive, hazardous, and complex. By about 1960 most of the sodium reduction plants had been replaced by those employing the catalytic hydrogenolysis process. Catalytic hydrogenation processes were investigated as early as the 1930s by a number of workers one of these is described ia reference 26. 

Linear a-olefins were produced by wax cracking from about 1962 to about 1985, and were first commercially produced from ethylene in 1965. More recent developments have been the recovery of pentene and hexene from gasoline fractions (1994) and a revival of an older technology, the production of higher carbon-number olefins from fatty alcohols. 

The principal iadustrial production route used to prepare fatty amines is the hydrogenation of nitriles, a route which has been used since the 1940s. Commercial preparation of fatty amines from fatty alcohols is a fairly new process, created around 1970, which utilizes petrochemical technology, Ziegler or Oxo processes, and feedstock. 

At room temperature, ca 60 wt % ethylene oxide is needed to solubilize the fatty acids. Surface activity of the ethoxylates is moderate and less than that of alcohol or alkylphenol ethoxylates (84). The ethoxylates are low foamers, a useful property in certain appHcations. Emulsification is the most important function. Its importance is reflected in the wide range of lipophilic solubiHties available in the commercial products. Like all organic esters, fatty acid ethoxylates are susceptible to acid and alkaline hydrolysis. 

Anhydrosorbitol Esters. Eatty acid esters of anhydrosorbitol (see Alcohols,polyhydric) are the second largest class of carboxyHc ester surfactants. The important commercial products are the mono-, di-, and triesters of sorbitan and fatty acids (Table 18). Sorbitan is a mixture of anhydrosorbitols, principally 1,4-sorbitan (1) and isosorbide (2) ... 

Provitamin D. Provitamin is made from cholesterol, and its commercial production begias with the isolation of cholesterol from one of its natural sources. Cholesterol occurs ia many animals, and is generally extracted from wool grease obtained by washing wool after it is sheared from sheep. This grease is a mixture of fatty-acid esters, which contain ca 15 wt % cholesterol. The alcohol fraction is obtained after saponification, and the cholesterol is separated, usually by complexation with 2iac chloride, followed by decomplexation and crystallisation. Cholesterol can also be extracted from the spiaal cords and brains of animals, especially catde, and from fish oils. 

Fatty Acid Esters of Methyl Alcohol.—The following esters of methyl alcohol are commercial products, and all have fruity odours, and are very suitable for blending with flower oils to impart distinctive secondary odours to them. They are, generally speaking, very expensive, some of them costing as much as 12 per lb., but, as only minute quantities... 

Monoester salts of phosphoric acid derived from fatty alcohol ethylene oxide adduct or alkylphenol ethylene oxide adduct useful as surfactants are prepared by addition of R(OCH2CH2) OH, alkali fluoride and (C12P0)20 in a molar ratio of 0.9-1.5 0.05-1 1.0 at -50 to + 10°C and hydrolysis of the Cl-containing intermediates with a base. The monoester phosphates showed comparable or better washing and foaming efficiency than commercial products [12]. 

The first commercial production of fatty alcohols in the 1930 s employed a sodium reduction process (Bouveault-Blanc) (2). However, the high usage (4 mol/mol alcohol) of expensive sodium soon led to replacement of this method of reduction by catalytic hydrogenation. 

In both cases, commercial products have alkyl chain lengths from 8 to 18 carbons but the ether amine derived products usually have branched alkyl chains as they are produced from fatty alcohols such as 2-ethylhexanol, isodecyl and tridecyl alcohol. Those produced from alkyl amines usually have linear hydrocarbon chains because they are produced from naturally derived fatty acids except when made from 2-ethylhexylamine. 

Fatty alcohols are one of the most useful intermediates for the production of nonionic surfactants, some of which are listed in Fig. 36.34. A detailed discussion on all the commercially available nonionic surfactants is beyond the scope of this work and only the major surfactant types are covered. A more complete discussion of different surfactant classes and their properties is available elsewhere.38... 

Provitamin D2. Ergosterol is isolated exclusively from plant sources. The commercial product is ca 90—100% pure and often contains up to 5 wt % of 5,6-dihydroergosterol. Usually, the isolation of provitamin D2 from natural sources iavolves the isolation of the total sterol content, followed by the separation of the provitamin from the other sterols. The isolation of the sterol fraction iavolves extraction of the total fat component, its saponification, and then reextraction of the unsaponifiable portion with an ether. The sterols are ia the unsaponiftable portion. Another method is the saponification of the total material, followed by isolation of the nonsap onifiable fraction. Separation of the sterols from the unsap onifiable fraction is done by crystallization from a suitable solvent, eg, acetone or alcohol. Ethylene dichloride, alone or mixed with methanol, has been used commercially for recrystallization. In the case of yeasts, it is particularly difficult to remove the ergosterol by simple extraction, thereby obtainiag only ca 25% recovery. Industrially, therefore, the ergosterol is obtaiaed by preliminary digestion with hot alkaUes or with amiaes (28—33). Variations of the isolation procedure have been developed. Eor example, after saponification, the fatty acids may be precipitated as calcium salts, which tend to absorb the sterols. The latter are then recovered from the dried precipitate by solvent extraction. 

Sensitivity is thought to be associated with the content of free fatty alcohols present in lanolin products rather than the total alcohol content. The safety of pesticide residues in lanolin products has also been of concem. However, highly refined hypoallergenic grades of lanolin and grades with low pesticide residues are commercially available. See also Section 18. 

In commercial products quaternary ammonium surfactants are almost never used alone. They are often used in combination with long-chain fatty conditioners, especially cetyl and stearyl alcohols [25], which serve to boost the conditioning effects of the quats [39], The addition of cetyl alcohol to cetrimonium bromide was found to reduce combing forces by nearly 50% [25], In another study, Fukuchi et al. [40] found a significant decrease in surface friction with the combination of cetyl alcohol and behentrimonium chloride. 

Higher alcohols in the range of C6 to C18 have many industrial applications. Commercial interest includes the whole group of primary and secondary, branched and unbranched, and even- and odd-numbered alcohols. Higher tertiary alcohols are not industrially significant [109]. The C6 to Cn alcohols are called plasticizer alcohols and the C,2 to Cj8 are called surface-active or detergent alcohols because of their respective major end use [109]. Alcohols > C8 are often called fatty alcohols because that was their first original primary source. The world production capacity is currently 3 million ton/yr, of which 88% are synthetic [108,109],... 

Solid, mp 142-143, Practically inso] in water, alcohol. Note The commercial product, a waxy solid, also con-iiins other alkyltrimethylammonium stearates, since the taadecyl chain is derived from soybean fatty adds. 

In nature one also finds chiral fatty acid or fatty alcohol derivatives with a hydroxyl or amino substituent at the alkyl chain. Common examples are given in Table 2.2.2 of the fatty acids in cheap commercial castor oil (a fat mixture) consist of ricinoleic acid (12-/ -hydroxy-9-Z-octadecene-carboxylic acid). The hydrogenation product (R)-12-hydroxy-stearic acid is the cheapest chiral fatty acid (about 100/g). Sphingosin (2-S-amino-4-E-octadecene-l,3-R-diol) is a chiral a--arnino-diol, which is found in large amounts in nerve tissue ( 5,000/g). Chirality is expensive, if it is localized within the hydrophobic chain. 

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