Synthetic oleochemicals

Oleochemicals, by their very name, may be defined as chemicals from oil. These could be natural fats and oils, or oils of petrochemical origin. To have a clear distinction, oleochemicals derived from natural oils are termed natural oleochemicals, whereas those derived from petrochemicals are termed synthetic oleochemicals (8). 

The natural oleochemicals are obtained from natural oils with the least change in the stmcture of the carbon chain fraction. In contrast, synthetic oleochemicals are built up from ethylene to the desired carbon chain fraction or from oxidation of petroleum waxes. 

The natural oleochemicals are obtained from natural oils with the least change in the structure of the carbon chain fraction. In contrast, synthetic oleochemicals are built up from ethylene to the desired carbon chain fraction or from oxidation of petroleum waxes. Fats and oils are renewable products of nature. One can aptly call them oil from the sun where the sun s energy is biochemically converted to valuable oleochemicals via oleo-chemistry. Natural oleochemicals derived from natural fats and oils by splitting or trans-esterification, such as fatty acids, methyl esters, and glycerine are termed basic oleochemicals. Fatty alcohols and fatty amines may also be counted as basic oleochemicals, because of their importance in the manufacture of derivatives (6). Further processing of the basic oleochemicals by different routes, such as esterification, ethoxylation, sulfation, and amidation (Fig. 12.1), produces other oleochemical products, which are termed oleochemical derivatives. 

Surfactant alcohols are linear, primary alcohols with carbon chain lengths in the C12-C14 and the C16-C18 range. Surfactant alcohols can be derived from either petrochemical or oleochemical feedstocks, and thus are referred to either as synthetic alcohols or as natural (oleochemical) alcohols. Petrochemical feedstocks used for surfactant alcohol production are ethylene and, to a lesser degree, paraffins. 

Most of the preceding sections in this chapter have emphasized the use of CM for the homologation of terminal olefins. The microscopic reverse of this reaction, however, is also of great synthetic interest, as it provides a mild method for the cleavage of olefins. When ethylene gas is used as the cross-partner, the resulting CM reaction is known as ethenolysis. Prior to 2000, ethenolysis was almost exclusively used within the oleochemical industry to process unsaturated fatty oils or triglycerides into compounds of lower molecular weight. With the advent... 

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. 

The oldest surfactant is soap, which may be traced back to the ancient Egyptians and beyond. Synthetic surfactants had been produced in the first half of the 20th century but it was only after World War II, with the development of the modern petrochemical industry, that alternative feedstocks to oleochemicals became readily available. Hence chloroparaf-fins and/or alphaolefins and benzene were used to produce alkylbenzene (or alkylate ), processes were developed to produce a range of synthetic fatty alcohols and alkylene oxide chemistry resulted in ethylene oxide and propylene oxide building blocks becoming readily available. 

Fatty alcohols, by which the author means those in the range C and above, are split into two classes, petrochemical and oleochemical, or, as they are more usually referred to, synthetic and natural. The discussion of the relative merits of synthetic vs natural products has been at the forefront of surfactant technology for many years and has produced a wealth of literature. It is beyond the scope of this work to discuss whether oleochemicals have an inherent environmental benefit over petrochemicals. A good deal of scientific study on life cycle analysis and macro environmental impact is available but social and ethical arguments, as well as the perceptions of the end consumer, also play a part. On a strictly scientific basis, the author sees no inherent advantage in either source. The performance of a surfactant based on synthetic materials may differ from a naturally derived one but neither is intrinsically better than the other. In terms of impact on humans and the environment, there is also no clear evidence to suggest a difference between the two sources of hydrophobe. 

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. ... 

The evolntion of the sophisticated prodncts and chemical-process technologies that are used today trace their origins back to the nineteenth centnry and the nascent chemical industry that relied on renewable oleochemical feedstocks. Synthetic snrfactants prepared by the reaction of olive oil with sulfnric acid, performed by Fremy in 1831, was among the first." ... 

The history of surfactant applications in personal care products can be traced back to the ancient Egyptians. Soap was the only available surfactant in those early centuries. It was not until the Second World War that synthetic surfactants were developed and formulated into daily personal care products. Diversification and expansion of synthetic surfactants based on the technological and economical advances of the oleochemical and petrochemical industries made surfactants indispensable for daily life in industrialized countries such as the United States, western Europe, and Japan, and the same trends are expanding throughout the world. We now face a controversial problem cleansing ability as the primary function of surfactants versus gentleness to humans and environmental impact. 

The demand for inexpensive and renewable energy and chemical products will further spur the oleochemical industry. The metathesis of oleates offers new synthetic routes to valuable raw materials and feed stocks with high chemoselectivity. The reaction is catalytic and could be performed at ambient conditions. Moreover, solvents could be substituted with "green" ionic liquids that will further enhance the growth of production. 

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