Linolenic methyl ester

Reaction temperature and time were significant operating parameters, which are closely related to the energy costs, of the biodiesel production process. Figure 7 shows the effect of reaction time on the transesterification of rapeseed oil at a catalyst concentration of 1%, molar ratio of 1 6, and 60°C. Within 5 min, the reaction was rapid. Rapeseed oil was converted to above 85% within 5 min and reached equilibrium state after about 10 min. Several researchers reported that the conversion of vegetable oils to FAME was achieved above 80% within 5 min with a sufficient molar ratio (8,11). For a reaction time of 60 min, linoleic acid methyl ester was produced at a low conversion rate, whereas oleic and linolenic methyl ester were rapidly produced. 

Fell et al. presented a micellar two-phase system in which fatty acid esters can be hydroformylated [30]. Short fatty acids react in a mixture of water and the substrate without adding any surfactants. The rhodium/NaTPPTS catalyst system was able to conduct the reaction of methyl 10-undecenoate at 100°C with 30-bar synthesis gas pressure with a conversion of 99% without any surfactant. The reaction of linolenic acid ester was hindered by phase transfer problems which could be overcome by employing surfactants. The addition decreased the reaction time, so the same rhodium catalyst could achieve a conversion for linolenic methyl ester of 100%. The authors... 

C12 to C20, primarily Ci6 to ( is), used as surface lubricants in the manufacture of food-contact articles. The method, which uses ethyl palmitate (Eastman Chemicals No. 1575 Red Label) as an internal standard, has been validated at 200 ppm total FAME [185]. Other FAME standards (methyl palmitate, methyl stearate, methyl oleate, methyl linoleate and methyl linolenate) are available (Applied Science Laboratories) [116], Worked out examples of additive determinations are given in the Food Additives Analytical Manual [116], which also describes a great many of indirect food additives, such as BHA, BHT, TBHQ, l-chloro-2-propanol, DLTDP, fatty acid methyl esters, w-heptyl-p-hydroxybenzoate, propyl-gallate, sodium benzoate, sodium stearoyl-2-lactylate, sorbitol and phenolic antioxidants. EPA methods 606 and 8060 describe the CGC separation of phthalate esters (direct injection) (cf. Figure 4.2). 

Acetic acid, butyl ester Acetic acid, pentyl ester Acetic acid, decyl ester Acetic acid, benzyl ester Acetic acid, benzyl ester Acetic acid, 1-cyclohexenyl ester Acetic acid, 3-cyclohexenyl ester Butyric acid, benzyl ester Phenylacetic acid, propyl ester Oleic acid, methyl ester Linoleic acid, methyl ester Linolenic acid, methyl ester Adipic acid, methyl ester Adipic acid, ethyl ester Adipic acid, diethyl ester Adipic acid, dipropyl ester Adipic acid, (methylethyl)ester Adipic acid,... 

Linalool, cis, oxide 0 , 1 S172 Linalool, trans, oxide 1 3172 Linalool Pi , Resin , Lf 0 ° Linoleic acid methyl ester 1 73172 Linoleic acid 1 73172 gjCSl34 Linolenic acid methyl ester 0 Linolenic acid 1 3172 gjCSl34 Longifolene, (+) 1 3068 Longifolene 1 3172 qCS156 Inflorescence... 

The flavour of distillates from apple and pear is characterised by typical aroma compounds from these fruits formed by enzymatic degradation of fatty acids to C6-fragments like hexanol, trans-2-hexenol, as well as ethyl esters and acetates of hexanoic acid. In distillates of pears, especially of the variety Bartlett pear, the characteristic pear flavour is mainly dominated by the ethyl and methyl esters of frans-2-czs-4-decadienoic acid and trans-2-trans-A-decadienoic acid [27-29], The biogenesis of these monounsaturated, diunsaturated, and triunsaturated esters may be explained by -oxidation of unsaturated linoleic and linolenic acid in the fruits. The sesquiterpene compound a-farnesene, which is formed during postharvest ripening and storage of Bartlett pears [28], shows that quality and intensity of distilled pear spirits is mainly influenced by the quality and degree of ripeness of the fruits. 

A mixture of palladium chloride and triphenylphosphine effectively catalyzes carboxylation of linoleic and linolenic acids and their methyl esters with water at 110°-140°C and carbon monoxide at 4000 psig. The main products are 1,3-and 1,4-dicarboxy acids from dienes and tricarboxy acids from trienes. Other products include unsaturated monocar-boxy and dicarboxy acids, carbomethoxy esters, and substituted a,J3-unsaturated cyclic ketones. The mechanism postulated for dicarboxylation involves cyclic unsaturated acylr-PdCl-PhsP complexes. These intermediates control double bond isomerization and the position of the second carboxyl group. This mechanism is consistent with our finding of double bond isomerization in polyenes and not in monoenes. A 1,3-hydrogen shift process for double bond isomerization in polyenes is also consistent with the data. 

Lipid standards (2°/o solutions in chloroform) a triacylglycerol (triolein), cholesterol ester (cholesterol linoleate), fatty acid (palmitoleic, oleic, etc.), fatty acid methyl ester (linolenic acid, methyl ester), a glycerophosphatide (phosphatidylcholine, phosphatidylethano-lamine, etc.), a diacylglycerol (diolein), and a monoacylglycerol (monoolein). 

For example, the LIFDI mass spectrum of biodiesel from oilseed rape revealed methyl esters of long-chain fatty acids as typical plant lipid constituents (Figure 14.3). The most prominent signal originated from the methyl ester of oleic acid (Ci i, m/z 296.4), accounting to 42.6% of the TII, followed by the methyl esters of linoleic acid (Ciga,m/z 294.4,23.8%), linolenic acid (Cm-,m/z 292.4,4.4%), stearic acid (Ci8 o, m/z 298.5, 2.8%), palmitic acid (Ci6 0, m/z 270.4, 1.4%), and gondoic acid (C2o i,... 

Refined and bleached rapeseed oil were obtained from Onbio Co. Ltd. (Pucheon-Si, Korea). Table 1 presents the fatty acid composition and characteristics of rapeseed oil. Reference standards of FAMES such as palmitic, stearic, linolenic, linoleic, and oleic methyl ester of >99% purity were purchased from Sigma (St. Louis, MO). Methanol and catalysts such as KOH, NaOH, and sodium methoxide were analytical-grade chemicals. 

I Average conversion yield Linolenic acid methyl ester Linoleic acid methyl ester Oleic acid methyl ester... 

The vegetable oil used was rapeseed oil (Nacalai Tesque Kyoto, Japan) without further treatment. The fatty acid content of the rapeseed oil mainly consisted of unsaturated fatty acids (93 wt%), with the saturated fatty acids of palmitic and stearic acids accounting for only a small amount (7 wt%). Various fatty acids of oleic (C181), linoleic (C18 2), linolenic (C18 3), and palmitic (C16 0) acids as well as their methyl esters were purchased from Nacalai Tesque. Anhydrous methanol and distilled water were also supplied by the same company. 

Unsaturated fatty acids or methyl esters are obtained via hydrolysis with water or by transesterification with methanol, while glycerol is produced as a by-product. The structures of some common unsaturated Cig-fatty acids, such as oleic, linoleic, and linolenic are shown in Scheme 1. 

Rapeseed methyl ester (RME) is another alternative biofuel that can be used in diesel engines. RME has the advantages that it is renewable compared to diesel, non-toxic and less flammable compared with many other fuels, like ethanol. RME has the same cetane number, viscosity and density as diesel, contains no aromatic compounds and is biologically degradable with minor contamination in soil. RME can be produced from vegetable oils, but is mostly produced from rapeseed oil by pressing of the seeds or by extraction. Up to 3 tons of rapeseed can be produced from one hectare. The fatty acids in rapeseed oil are mostly oleic acid, linoleic acid and linolenic acid. The oil is pressed from the plant and after some purification allowed to react with methanol in the presence of potassium hydroxide as a catalyst, to produce a methyl ester, see Figure 6.6. 

Write the formulas of the reaction, converting linolenic acid to its methyl ester. 

Esterification—Continued by azeotropic distillation with benzene, 22, 38 by nitric acid, 22, 65 of desoxycholic acid, 24, 41 of lactic acid, 26, 4 of linoleic acid, 22, 77 of linolenic acid, 22, 83 of pyruvic acid with use of methyl ester column, 24, 72 Ester interchange, 26, 5, 19 between polylactic acid and allyl alcohol, 26, 5... 

Fig. 1.13. Separation of a product of partial transesterificaiion of rapeseed oil with methanol using combined RPC and NARPC gradient elution. Column Separon SGX Cm, 7 pm, 150 x 3 mm i.d. Ternary gradient from 30% A + 70% B to 100% B in lO min and to 50% B -t- 507r C in 20 min. followed by isocratic elution with the final mobile phase composition for 5 min, at I ml/min. Injection volume 10 pi. UV detection at 205 nm. Notation of sample compounds Ln. L, O and G are used for linolenic acid, linoleic acid, oleic acid, gadoleic acid, respectively, and for their acid parts in mono-, di- aixl tri-acylglycerols and methyl esters Me means methyl in methyl esters.

Again, it is important to note that methyl esters of lard and tallow are the sum of the methyl esters of fatty acids found in the original fat. Methyl lard for example, will contain methyl myristate, methyl palmitate, methyl stearate, methyl oleate, methyl linoleate, and methyl linolenate in the same percentages as the lard used as the raw material, unless the manufacturer fractionates the material, thereby selecting methyl esters of certain fatty acids over others. 

B. Studies on Soybean Oil Methyl Ester and Methyl Linolenate Using Mixtures of PtCl2(PPhs)a and SnCla-2H20... 

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