Natural Fatty Alcohols

Natural oils are hydrolyzed and the fatly adds separated by distillation. The acids are then hydrogenated to alcohols either as the methyl ester or as an ester with another fatty alcohol. 

Catalysts used for the hydrogenation step are usually copper chromite formulations, although copper oxide/zinc oxide catalysts have also been used. The process accounts for about half of the copper chromite catalysts used commer-dally. Both acid group and double bonds in the long carbon chain are hydrogenated during the reaction, which produces a saturated alcohol. When an unsaturated fatty alcohol is required, a more selective zinc chromite catalyst may be used. 

In commercial processes the copper chromite catalyst must be carefully promoted for use with different oils. Catalysts must resist the action of the acids being treated because colored metal soaps contaminate the products. To avoid dust formation the catalyst should also be strong enough to resist disintegration in the liquid reactants. Typical catalysts used are shown in Table 3.19. 

Type Copper chromite (wl%) Copper chromite (wt%) Copper oxide/zinc oxide (wt%) 

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Linear, even-numbered, primary alcohols—like the natural fatty alcohols—are produced by the aluminum organic alcohol synthesis after Ziegler, the so-called Alfol process. This alcohol synthesis proceeds in three steps ... 

R is mostly derived from natural fatty alcohols and is generally between C6H13 and C18H37. Sometimes R is partly unsaturated. On behalf of special applications R can also be derived from branched fatty alcohols, such as oxoalcohols or Guerbet alcohols. 

Fig. 36.19. Methyl ester process for production of natural fatty alcohols.

Fatty alcohols can be produced from natural oils, or synthesized from petrochemicals. The current world supply of fatty alcohols is equally divided between natural and synthetic. However, the use ratio of natural synthetics varies with each region. The overall world ratio is projected to go in favor of natural fatty alcohols. This can be attributed to the increasing supply and price stability of the lauric oils. The primary source of lauric oil is in the Southeast Asian region where most processing plants have been established. 

The glycosidation of the reducing sugars obtained from hemicelluloses leads to the alkyl polypentosides surfactants. Glycosylation needs fatty alcohols as raw materials. Natural fatty alcohols derived, for example, from coconut or palm kernel oil are used in the alkyl polyglycoside synthesis to buUd up the hydrophobic part of the surfactants. These alcohols are used as blends obtained after transesterification and fractionation of oils leading to corresponding fatty acid methyl esters, and... 

Natural fatty alcohols are primary linear alcohols whose... 

The commercial manufacture of fatty alcohols started in the late 1920s. The very first natural fatty alcohol was obtained by a simple ester cleavage of oil originating in the skull of the sperm whale. But a mere 4 years later, the first industrial-scale process had already been developed for producing a fatty alcohol from coconut fatty acid by high-pressure hydrogenation. In 1958, a route was developed from fatty acid methyl ester, which still remains the most economic method of producing... 

They are predominantly straight chained and monohydric, and can be saturated or have one or more double bonds. Alcohols with a carbon chain length above C22 are referred to as wax alcohols. Diols whose chain length exceeds are regarded as substituted fatty alcohols. The character of the fatty alcohols (primary or secondary, linear or branched chain, saturated or unsaturated) is determined by the manufacturing process and the raw materials used. Depending on the raw materials used, fatty alcohols are classified as natural or synthetic. Natural fatty alcohols are based on renewable resources such as fats, oils, and waxes of plant or animal origin, whereas synthetic fatty alcohols are produced from petrochemicals such as olefins and paraffins. 

Ziegler Alcohol Processes. Two processes for the production of synthetic fatty alcohols are based on the work of Ziegler on organic aluminum compounds the Alfol process, developed by Conoco and Ethyl Corporation s Epal process. Fatty alcohols synthesized by these processes are structurally similar to natural fatty alcohols and are thus ideal substitutes for natural products. 

By ethoxylation of natural fatty alcohols from vegetable oils with biobased ethylene oxide fiolly biobased nonionic fatty alcohol polyglycol ether surfactants can be manufaaured... 

In terms of quantities, the alkyl polyglycol ethers or fatty alcohol polyglycol ethers, which are readily obtainable by reaction of ethylene oxide with natural or synthetic alcohols, are of particular interest. For a long time, natural fatty alcohols, which can easily be prepared by hydrogenation of the corresponding fatty acids or methyl esters, were the main raw material base [21]. Neither the manufacture nor... 

Alkyl ether sulfates, also called alcohol ethoxysulfates, are prepared by addition of one to four oxyethylene groups to an alcohol which is then sulfated. Oxyethylation enhances water solubility and foaming over the analogous alcohol sulfate, giving a product useful in shampoos and in liquid and powdered detergents. The raw material for these products can be either natural fatty alcohols or primary or secondary synthetic alcohols, usually of C12-C18 chain length. The analogous alkylphenol ether sulfates are found in industrial applications. Ether sulfates are not as sensitive to water hardness as are other anionic surfactants. 

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