Oleochemicals fatty acids

Weber, N., E. Fehling, K.D. Mukhergee, K. Vosmann, B. Dahlke, S. HeUbardt, and W.H. Zech. 1994. Hydroxylated fatty acids oleochemicals from plant oils. Inform 5 475. 

Compared with the fatty alcohol sulfates, which are also oleochemically produced anionic surfactants, the ester sulfonates have the advantage that their raw materials are on a low and therefore cost-effective level of fat refinement. The ester sulfonates are produced directly from the fatty acid esters by sulfona-tion, whereas the fatty alcohols, which are the source materials of the fatty alcohol sulfates, have to be formed by the catalytic high-pressure hydrogenation of fatty acids esters [9]. The fatty acid esters are obtained directly from the fats and oils by transesterification of the triglycerides with alcohols [10]. 

In polymer applications derivatives of oils and fats, such as epoxides, polyols and dimerizations products based on unsaturated fatty acids, are used as plastic additives or components for composites or polymers like polyamides and polyurethanes. In the lubricant sector oleochemically-based fatty acid esters have proved to be powerful alternatives to conventional mineral oil products. For home and personal care applications a wide range of products, such as surfactants, emulsifiers, emollients and waxes, based on vegetable oil derivatives has provided extraordinary performance benefits to the end-customer. Selected products, such as the anionic surfactant fatty alcohol sulfate have been investigated thoroughly with regard to their environmental impact compared with petrochemical based products by life-cycle analysis. Other product examples include carbohydrate-based surfactants as well as oleochemical based emulsifiers, waxes and emollients. 

For most of the further uses oils and fats must be split into the so-called oleochemical base materials fatty acid methyl esters, fatty acids, glycerol and, as hy-... 

Apart from being used as bio-diesel , fatty acid esters, which are obtained from fatty acids and alcohols, are becoming increasingly interesting as biodegradable replacements for mineral oils. In some application areas such as chain-saw oil, gearbox oils, hydraulic oils and lubricants for crude oil production these oleochemical products have already proved themselves. 

Oleochemicals, fatty acids, fatty amines and biodiesel... 

Justin Stege (Diversa Corporation) discussed the molecular evolution of enzymes for particular pathways, with a focus on the modification of oil composition. Oleochemical applications for such enzymes include applications as biocatalysts for fatty acid modifications. In a program to integrate production and processing, such enzymes can be used to modify the fatty acid content of vegetable oils in planta. Results show that expressing such new enzymes in oilseed crops has resulted in altered oil composition, and that the features may be used to better design plant-based oils for use as biofuels and as improved renewable feedstocks. 

Saponification, hydrolysis and esterification of vegetable oils to release fatty acids for the oleochemical uses detailed above, results in production of glycerol as a by-product. Glycerol is an important platform molecule in its own right, with numerous industrial uses (see Chapter 6 for more information). 

Oleochemical modification [e.g. Surfasam (Morard et al., 2007), WoodProtect (Magne et al., 2003)]. Wood is reacted with fatty compounds such as alkenyl succinic anhydrides or fatty-acetic anhydrides. The alkenyl or fatty base comes from vegetable oils (fatty acid or fatty acid esters) (Figure 5.9). 

Raw materials. It is possible to use any fatty acid as a feed material for sulphonation but economic considerations dictate that oleochemical material be preferred. Fatty acids are readily obtained from vegetable and animal oils and fats which are fatty acid triglycerides. These are transesterified to generate glycerol and three moles of a fatty acid ester, normally a methyl ester. The methyl ester can be distilled to give a specific cut and the fatty acid finally isolated by hydrolysis or hydrogenation of the ester. It is common to use animal fats (tallow) in which case the dominant C chains are 16 and 18. 

Sometimes the question asked is whether animal fat is absent from products such as cosmetics or from some other oleochemical product prepared from fats. This can include products such as emulsifiers. Where the product contains original triglyceride then this portion can be considered as described above, and the absence of cholesterol can be considered as good evidence that animal fats are absent. This, however, does not apply to triglycerides formed after saponification of fatty acids, followed by fractionation and recombination with glycerol. So-called fractionated coconut oil is manufactured by this process, and any similar product made from fatty acids from an animal source would not show the presence of any cholesterol. Similarly other oleochemicals formed from fatty acids derived from animal fats would also not contain cholesterol. In these cases it is often impossible to detect the presence of animal fat by testing for cholesterol. The only possibility in some cases might be to look at... 

The reaction is reversible and favored by the presence of moisture and catalysts including lipases, alkalis, and alkaline metals. In the oleochemicals industry, TAG are split by high-pressure steam. Unassociated fatty acids are called free fatty acids or FFA. 

Rendering produced an estimated 4.18 million metric tons of animal fats was produced in the United States in 2000 by rendering.87 Of this amount, approximately 18 percent and 6 percent were edible tallow and lard, respectively, and 41 percent and 35 percent were inedible tallow and grease. Approximately 15 percent and 34 percent of the edible tallow and lard, respectively, and 37 percent of the inedible tallow and grease were exported. Of the inedible tallow and grease used in the United States, an estimated 75 percent was used as animal feed, 16 percent was converted to fatty acids by the oleochemicals industry, 4 percent was used in soaps, and 3 percent in lubricants. Inedible animal fats are the lowest cost domestic fat sources. Their market price per pound sometimes is less than fuel oil, and rendering plants have chosen to bum them as fuels. In 2001, animal fats were included with vegetable oils for federally supported trials of biodiesel fuel. 

Fatty acids chemistry and processes have been summarized by Johnson and Fritz,190 and oleochemicals manufacture and use by Gunstone and Hamilton.191 Pathways for converting oils and fats into various oleochemicals are shown in Fig. 34.35.21,192... 

Fatty acids with trans or non-methylene-interrupted unsaturation occur naturally or are formed during processing for example, vaccenic acid (18 1 Hr) and the conjugated linoleic acid (CLA) rumenic acid (18 2 9tllc) are found in dairy fats. Hydroxy, epoxy, cyclopropane, cyclopropene acetylenic, and methyl branched fatty acids are known, but only ricinoleic acid (12(/f)-hydroxy-9Z-octadecenoic acid) (2) from castor oil is used for oleochemical production. OUs containing vernolic acid (12(5),13(/ )-epoxy-9Z-octadecenoic acid) (3) have potential for industrial use. 

Fatty acid salts and many polar derivatives of fatty acids are amphiphilic, possessing both hydrophobic and hydrophilic areas within the one molecule. These are surface-active compounds that form monolayers at water/air and water/surface interfaces and micelles in solution. Their surface-active properties are highly dependent on the nature of the polar head group and, to a lesser extent, on the length of the alkyl chain. Most oleochemical processes are modihcations of the carboxyl group to produce specihc surfactants. 

Reactions converting acids to esters or vice versa and the exchange of ester groups are among the most widely used in fatty acid and hpid chemistry (Figure 4). They find applications from microscale preparation of methyl esters for GC analysis to the industrial production of oleochemicals and biodiesel. The exchange of groups attached to the fatty acid carboxyl is usually an equihbrium process driven to one product by an excess of one reactant or the removal of one product, and it is usually... 

The fatty acid alkyl chain is susceptible to oxidation both at double bonds and adjacent allylic carbons. Eree-radical and photooxidation at aUylic carbons are responsible for deterioration of unsaturated oils and fats, resulting in rancid flavors and reduced nutritional quality, but they are also used deliberately to polymerize drying oils. Oxidation of double bonds is used in oleochemical production either to cleave the alkyl chain or to introduce additional functionality along the chain. Enzyme catalyzed oxidation is the initial step in the production of eicosanoids and jasmonates (biologically active metabolites in animals and plants respectively) but is not discussed further here. 

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