Fatty acid methyl esters melting points

Operation of the Biodiesel Cost Optimizer is fast and easy, making it possible to make large sets of simulations in a short time. This helps better understanding the different value of the different fatty acid methyl esters. It will quickly become clear, when using the Biodiesel Cost Optimizer, that oleic acid methyl esters are the preferential FAME in every biodiesel formula. Oleic acid methyl esters bring a relatively high oxidation stability (50h or more), combined with a more than acceptable CN of around 56, and excellent melting point at -19 °C. Unfortunately, pure oleic acid methyl esters are not available in the market. 

Solubilities of some fatty acid methyl esters in acetone are given in Table 8.13. The solubilities are rather close to those of the corresponding acids and the differences (the greater solubility of the esters) can be related to their lower melting points compared to the fatty acids. 

Kahlke and Richterich 1965) and plasma lipids of Refsum s (1946) case T. E. (Kahlke 1964 a). Methods and results were identical in both instances although a nuclear resonance spectrum was obtained only in the first case and a complete mass spectrometric analysis only in the second case. Phytanic acid was isolated by preparative gas-liquid chromatography from a mixture of fatty acid methyl esters. Traces of stearic acid were removed as the urea inclusion compound by treatment with a saturated methanolic solution of urea (Cason et al. 1953). After repeated crystallization from acetone at minus 70—80 C and drying under vacuum at minus 10 C, phytanic acid was obtained as a white crystalline powder with a melting point of minus 7—6 C. At room temperature phytanic acid is a colorless, odorless oil. The lack of hydrogen uptake with exhaustive... 

Until 1939, she continued her research on the specific heats and heats of crystallisation of a number of homologous series, including hydrocarbons, fatty acids, methyl and ethyl esters, and amides. The work was of importance in relation to the cause of the alternation in melting points of the homologous series. Her experimental work ceased at the beginning of the Second World War, when her duties as Librarian and Secretary took up all of her time. In addition, she was an ambulance driver during the air raids. She died on 17 December 1952. 

Esterification of at least 45% of the hydroxyl groups with long chain fatty acids, e.g., stearic or behenic acid, results in a semi crystalline material (side chain crystallization). The obtained materials are characterized by melting point ranges which are approximately 10 °C lower than the comparable methyl esters. 

TABLE 3. Melting Points of Some Fatty Acids and Methyl Esters Illustrating the Effect of Chain Length and Unsaturation. 

Vegetable oil-based poly(ester amide)s are prepared by a three-step reaction procedure in which a base such as sodium methoxide is used as the catalyst for the first two steps and metal oxide/hydroxide is used for the last step of the reaction (Fig. 5.2). In the first step, methyl esters of the fatty acids are produced by transesterifiction of oil with methanol, followed by transformation to dihydroxy fatty amide by amidation reaction with dihydroxyalkylamine and, finally, esterification reaction by treatment with dibasic acid or anhydride at a relatively high temperature to obtain the desired poly (ester amide). This may be done either by azeotropic distillation or by direct polycondensation under an inert atmosphere. Poly(ester amide) can also be synthesised at a low temperature through a condensation polymerisation reaction in the absence of an organic solvent. In this reaction, V,V-bis(2-hydroxyalkyl) fatty amide and dibasic anhydride are heated at a temperature lower than the onset of the melting points of the component. By-products, such as water, are removed by a vacuum technique. 

The palm oil methyl ester (MEl) and its blends with DF have shown poor cold flow behavior especially for B30 and this can be explained by the fact that this ester naturally contains more saturated fatty acids (38 %) than, for example, ME2 (7 %). These saturated compounds have higher melting and crystallization points. 

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