Fatty alcohol production

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]. 

Polyoxyethylene alkyl ethers are nonionic surfactants produced by the polyethoxylation of linear fatty alcohols. Products tend to be mixtures of polymers of slightly varying molecular weights and the numbers used to describe polymer lengths are average values. 

Fatty alcohols make up one of the major basic oleochemicals having an increasing growth rate. As a primary raw material for surfactants, growth in fatty alcohol production parallels increasing economic prosperity and improved standards of living. Fatty alcohols are the raw materials of choice for surfactant manufacture because of their biodegradability and availability from renewable resources. 

Crude alcohol passes to the refining section (3) where low levels of residual methyl esters are converted to wax esters and recycled to the hydrogenation section (2). A refining column removes light and heavy impurities, and the refined fatty alcohol product is polished to convert any residual carbonyls to alcohols. 

The majority of the world s oleochemical-derived alcohol sulfates comes from four main sources today—coconut, pahn, palm kernel, and tallow. The majority of surfactant alcohol volume comes from coconut and palm kernel oil due to the high content of C 2- a ft " fatty-alcohol production as discussed earlier. However, several new initiatives are now underway to broaden the available existing sources of plant oils. 

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 By about 1960 most of the sodium reduction plants had been replaced by those employing the catalytic hydrogenolysis process.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. 

The primary products used are fatty acids with 12—18 carboa atoms and fatty alcohols, or esters of fatty acids such as the glycerides of rapeseed and lard oil (18). Eatty acid amines and amides are used ia metal working, particularly ia emulsions (18). 

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 conversion of fatty alcohols is approximately 99%. The reaction product is then condensed and sent to a distillation column to remove water and high boilers. Typically, a-olefin carbon-number distribution is controlled by the alcohol composition of the reactor feed. The process is currentiy used to produce a-olefins from fatty alcohols. A typical product composition is at <5%, at 50—70%, C g at 30—50%, C2Q at <2%,... 

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. 

Fig. 4. Quaternaries from a-ole ins of fatty alcohols where R is a fatty alkyl group. The product is alkylhen yl dimethyl quaternary.

Dispersants (qv) have been added to the pulper to maintain stickies in a colloidal state. The small particle size reduces the problems stickies cause on the paper machine and in paper products. Among the chemicals that have been used are fatty alcohol ethoxylates, alkylphenol ethoxylates, lignosulfonates, and naphthalene sulfonates (18). 

Anionic surfactants are the most commonly used class of surfactant. Anionic surfactants include sulfates such as sodium alkylsulfate and the homologous ethoxylated versions and sulfonates, eg, sodium alkylglycerol ether sulfonate and sodium cocoyl isethionate. Nonionic surfactants are commonly used at low levels ( 1 2%) to reduce soap scum formation of the product, especially in hard water. These nonionic surfactants are usually ethoxylated fatty materials, such as H0CH2CH20(CH2CH20) R. These are commonly based on triglycerides or fatty alcohols. Amphoteric surfactants, such as cocamidopropyl betaine and cocoamphoacetate, are more recent surfactants in the bar soap area and are typically used at low levels (<2%) as secondary surfactants. These materials can have a dramatic impact on both the lathering and mildness of products (26). 

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