Natural alcohol sulfates

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 reaction of olefin sulfation and its possibilities has been extensively studied [3-10] and it was used to produce alcohol sulfates. Dry distillation of spermaceti gives palmitic acid and cetene-1, which can be sulfated with sulfuric acid to give cetyl-2 sulfate [11]. Other surfactants were obtained from olefins produced from natural substances, such as alcohol sulfates by sulfation of olefins from decarboxylation of oleic acid [12], by sulfation of olefins made by dehydrating hydroabietyl alcohol, by direct sulfation of abietyl alcohol [13,14], or by sulfation of natural terpenes [15]. 

A published account of laboratory batch sulfations of Alfol 1214 SP, Alfol 1216 SP, and natural coconut alcohol using chlorosulfonic acid at atmospheric pressure and 16 L/min dry air sparged through the reaction mixture to remove HC1 is available [42], The optimal conditions and the characteristics of the triethanolamine alcohol sulfates obtained are shown in Table 1. 

Tosylate derivatives are not usually found in nature, but sulfate derivatives of alcohols are common (52). They are formed by the reaction of an alcohol with sulfate, catalyzed by a sulfotransferase enzyme. 

Since FAS can be produced either from vegetable oil based or petrochemical-based fatty alcohol (Fig. 4.9), both types have been evaluated in a life-cycle analysis with a positive overall result for the natural based product. With vegetable-based fatty alcohol sulfate, the analysis starts with the harvesting of the oil fruits (palm kernels or coconuts) and their processing to isolate the desired plant oil. Subsequent transesterification and hydrogenation of the methyl ester intermediates lead to the fatty alcohols, which are finally sulfated to produce the desired product. Based on this analysis the environmental impact of vegetable oil based fatty alcohol sulfate compared with the petrochemical based product is as follows ... 

The shift to oleochemicals has been supported by increasing environmental concerns and a preference by some consumers, especially in Europe, for materials based on natural or renewable resources. Although linear alkylbenzenesulfonates (LASs) are petrochemically based, alcohol ethoxylates, alcohol ethoxysulfates, and primary alcohol sulfates are derived from long-chain alcohols that can be either petrochemically or oleochemically sourced. There has been debate over the relative advantages of natural (oleochemical) vs synthetic (petrochemical) based surfactants. However, detailed analyses have shown there is litde objective benefit for one over the other. 

Sulfates and sulfated products include alcohol sulfates, ethoxyiated and sulfated alcohols ethoxyiated and sulfated alkylphcnols and sulfated natural oils and fats. 

Assuming a typical oil reservoir containing medium heavy crude oil and employing a reservoir flow rate of 0.26 m/day. The solution viscosity could be increased to 30 mPa s by adding about 1000 pg/rril (0.1%) partially hydrolyzed polyacrylamide polymer (at pH 8.5). The interfacial tension could be reduced to 0.1 mN/m by adding 1% sodium carbonate, which reacts with the crude oil to produce natural surfactant. The interfacial tension could be further reduced to 0.03 mN/m by adding 0.1% ethoxylated alcohol sulfate cosurfactant. 

Only a few natural sources of fatty alcohols were known at this time. Production on a technical scale could be first realized by the reduction of methyl or butyl esters of fatty acids with metallic sodium after the Bouveault-Blanc process. Nearly simultaneously, the high-pressure hydrogenation of fatty acids to the resulting alcohols was developed by Schrauth. Hence, fatty alcohols were soon available on the market in a price range that made it possible to produce fatty alcohol sulfates for use in detergents. 

Alkyl sulfates are produced commercially from either linear synthetic or natural alcohols. As mentioned before, the oleochemical fatty alcohols have even-numbered carbon chains, whereas the petrochemical-based fatty alcohols have both odd- and even-numbered carbon chain distribntions. There are, however, no differences noted in the performance or physical properties of formnlations made from oleochemical versus petrochemical sources. ... 

Overview of New Technology in Petroleum AND Naturally Derived Alcohol Sulfates... 

Alkyl sulfates or primary alcohol sulfates (PAS), which were the first synthetic surfactants used in personal care in the United States, are mainly used in toothpaste formulations. As for the AES, the alkyl moiety is typically a mixture of Ci2-Cjg chains. According to the application, one can find sodium, ammonium, magnesium, or triethanolamine salts of fatty alcohol sulfuric acid. They are obtained by the sulfation of a fatty (natural or synthetic) primary alcohol with a mixture of air/SOj according to the following reaction ... 

The neutralization step can be carried out in much the same way as in the neutralization step in the production of fatty alcohol sulfate. As a result of the nature of the reaction and conditions during sulfonation, a dark-colored product is produced, which requires bleaching. Postreaction treatment with H2O2 and NaOCl yields a product with an acceptable color (26). 

Chem. Descrip. Linear alcohol sulfates Ionic Nature Anionic... 

Chem. Descrip. sodium lauryl sulfate, natural alcohol cut Chem. Analysis Sodium sulfate 0.5% max. sodium chlrodie 0.1% max. free oil 0.5% max. 

---