Sunflower oil methyl esters

SFME = sunflower oil methyl esters PME = palm oil methyl esters RME = rapeseed oil methyl esters. See Tables 1.2 and 1.3 for other abbreviations. 

Although there are numerous publications on the effect of natural and synthetic antioxidants on the stability of oils and fats used as food and feed, until recently relatively little publicly available information was available on the effect of antioxidants on the oxidative stability of biodiesel. One of the earliest studies reporting of the effects of antioxidants on biodiesel was that of Du Plessis et aL (1985), which examined storage stability of sunflower oil methyl esters (SFME) at various temperatures for 90 d. Effects of air temperature, presence of light, addition of TBHQ (see Figure 1.1) and contact with steel were evaluated by analysis of free fatty acid content, PV, kinematic viscosity, anisidine value, and induction period. Addition of TBHQ delayed oxidation of samples stored at moderate temperatures (<30°C). In contrast, under unfavorable (50°C) conditions, TBHQ was ineffective. 

Rashid, U., Anwar, F., Bryan, R. M., Ashraf, S. (2008). Production of sunflower oil methyl esters by optimized alkali-catalyzed methanolysis. Biomass Bioenergy, 32, 1202-1205. 

Rajan, K., and K. R. Senthilknmar. 2009. Effect of Exhaust Gas Recirculation (EGR) on the Performance and Emission Characteristics of Diesel Engine with Sunflower Oil Methyl Ester. Jordan Journal of Mechanical and Industrial Engineering 3 (4) 306-311. 

Rashid, U., P. Anwar, B. R. Moser, and S. Ashraf 2008. Production of Sunflower Oil Methyl Esters by Optimized Alkali-Catalyzed Methanolysis. Biomass and Bioenergy 32... 

Figure 22.28 and Figure 22.29 show, respectively, the H and C-NMR spectra of the oligoesters prepared from epoxidized sunflower oil methyl esters (methyl biodiesel from sunflower oil) and di-l,2-cyclohexanedicarboxylic anhydride using triethylamine as initiator. These materials are soluble in common organic solvents such as acetone, ethanol, tetrahydrofurane, and chloroform, but insoluble in water. Oligoesters from epoxidized biodiesel can be used as intermediate materials for the synthesis of polyelectrolytes by saponification reactions with aqueous solution of sodium or potassium hydroxide at room temperature (Fig. 22.27). The products obtained after saponification present solubility in water. Amphiphilic materials, such as the polyelectrolytes prepared from epoxidized biodiesel, have hydrophobic and hydrophilic segments. They can spontaneously self-organize in a wide variety of structures in aqueous solution. Understanding the dynamics of the formation and transition between the various self-organized structures is important for technological applications.

FIGURE 22.28 H NMR spectrum of the oligoesters prepared from epoxidized sunflower oil methyl esters. 

Rapeseed oil methyl ester (RME) was the first biodiesel to be developed. Biodiesels based on other feedstocks such as used cooking oil and sunflower oil are now also commercially available. The first pilot plant with a capaeity of 500 tonnes/year was commissioned in 1988 in Austria. The first industrial scale biodiesel production plant went into operation in 1991. Its capacity was 10 000 tonnes/year. In the following years, biodiesel production plants of larger capaeities were established all over Europe, e.g. the plant at Livorno in Italy has a capacity of 80 000 toimes/year. Rouen in France has the world s largest biodiesel production plant with a capacity of 120 000 tonnes/year. Germany and Sweden also have biodiesel production plants of comparable capacities. 

In our first experiment we decided to test the conversion of sunflower oil into biodiesel (16). Treatment of sunflower oil (1) with NaOMe in MeOH results in formation of a mixtme of fatty acid methyl esters (FAME), also known as biodiesel, and glycerol (2) (Figme 4.3). The reaction was performed with a six-fold molar excess of methanol with respect to sunflower oil at elevated temperatures (60°C) using a basic catalyst (NaOMe, 1% w/w with respect to sunflower oil). The CCS was equipped with a heating jacket to ensure isothermal conditions. The sunflower oil was preheated to 60°C and was pumped at 12.6 ml/min into one entrance of the CCS. Subsequently, a solution of NaOMe in MeOH was introduced through the other entrance at a flow rate of 3.1 ml per minute. After about 40 minutes, the system reaches steady state and the FAME containing some residual sunflower oil is coming... 

Biodiesel (fatty acid methyl ester (FAME)) production is based on transesterification of vegetable oils and fats through the addition of methanol (or other alcohols) and a catalyst, giving glycerol as a by-product (which can be used for cosmetics, medicines and food). Oil-seed crops include rapeseeds, sunflower seeds, soy beans and palm oil seeds, from which the oil is extracted chemically or mechanically. Biodiesel can be used in 5%-20% blends with conventional diesel, or even in pure form, which requires slight modifications in the vehicle. 

In Europe, vegetable-oil-based fuels are mainly produced from rapeseed. In the USA, vegetable-oil-based fuels are mainly derived from soybeans. Another feedstock used in Europe and North America is sunflower seed. Most of the vegetable oil that is used as energy source for the generation of transportation fuel is converted to fatty acid methyl ester (FAME), often called biodiesel . 

The solubility of C60 and C70 in a series of vegetable oils, namely olive, sunflower, peanut, soybean, linseed and castor oil, has been determined quantitatively spectrophotometrically. Additionally, the solubility of C60 and C70 has been determined quantitatively in the methyl esters of brassica oilseed and only qualitatively in molten cow butter, molten stearic acid and molten behenamide. The experimental results show that the solubility of fullerenes appears to be dependent on the unsaturation level of the fatty acids composing the vegetable oils being lower in oils with higher unsaturation level. The solubility has been found dependent also on the polarizability parameter of the vegetable oils. 

Fullerenes were high purity grades (99 + %) from Southern Chemicals LLC. Vegetable oils were commercially available oils from olive, linseed, soybean, sunflower, peanut and castor. A methyl ester of brassica oilseed also was employed. 

Fig. 13.3 Electronic absorption spectra of C60 fullerene dissolved in (A) brassica oilseeds methyl ester (biodiesel) (B) olive oil (C) sunflower oil (D) soybean oil (E) linseed oil (F) linseed oil and C60 fullerene after heating at 150°C for 15 minutes...

Protons attached to the C atoms of the 1,2,4-trioxolane moiety of FOZs have chemical shifts at distinctly lower field than alcohols, ethers or esters. For example, the chemical shifts of the ozonide product in equation 100 (Section Vin.C.b.a) are S (CDCI3) 5.7 ppm for the H atoms of the trioxolane partial structure, and 4.1 ppm for the protons at the heads of the other ether bridge . Measurement of the rate of disappearance of these signals can be applied in kinetic studies of modifications in the ozonide structure. The course of ozonization of the methyl esters of the fatty acids of sunflower oil can be followed by observing in H and C NMR spectra the gradual disappearance of the olefinic peaks and the appearance of the 3,5-dialkyl-1,2,4-trioxolane peaks. Formation of a small amount of aldehyde, which at the end of the process turns into carboxylic acid, is also observed . 

Bambase, M.E., Jr. Nakamura, N., Tanaka, J. and Matsumura, M. (2007) Kinetics of hydroxide-catalyzed mefhanolysis of crude sunflower oil for the production of fuel-grade methyl esters./. Chem. Technol. Biotechnol., 82, 273. 

One paper from the group of Zhang reports [75] on the testing of various oils with MT0/H202 with CH3CN as solvent and imidazole as the nitrogen base. A base/MTO/H202/double bond ratio of 50 1 250 100 is used, and excellent results are obtained after 2 h at room temperature. Fatty acid methyl ester, sunflower oil, rapeseed oil, cottonseed oil, and palm oil can all be epoxidized with >99% selectivity and >98% yield with this system. 

Conversely, SFME exhibited relatively poor improvement in oxidative stability with the use of antioxidants, presumably due to the higher concentrations of linoleic acid methyl esters in sunflower oil in comparison to the other biodiesel samples evaluated by the authors. Therefore, a good correlation was found between the improvement in oxidative stability as measured by OSI when antioxidants are used and the fatty acid composition of the biodiesel sample (Mittelbach and Schober, 2003). 

Soumanou, M. M., and Bornscheuer, U. T. 2003. Improvement in lipase-catalyzed synthesis of fatty acid methyl esters from sunflower oil. Enzyme and Microb. Technol, 33, 97-103. 

These grafted strong bases were checked in their both soluble and immobilised form as catalysts for the transesterification of several vegetable oils such as linseed, rapeseed, sunflower and palm oil. When methanol is used, the reaction affords a mixture of the methyl esters, used as fuel for diesel engines21 22 (Figure 13). 

Southern Europe and France use relatively little canola oil. Instead, olive, sunflower, and peanut oils predominate. In the case of France, this is somewhat surprising, because this country is a large producer of canola seeds. But France uses large amounts of canola oil for biodiesel in the form of fatty acid methyl esters. 

The optimization of biodiesel production by transesterification of sunflower oil was studied (122). The best combination of process parameters was found to be three stoichiometric doses of methanol, 0.28% w/w of KOH, and 70°C temperamre. Several reports have been published on the properties of biodiesel manufactured with different fatty materials and on their performance in compression ignition engines, including information about sunflower oil and its esters (30, 31, 41, 123). Table 19 shows major properties of sunflower oil and its methyl esters. The physicochemical characteristics of these esters meet the norm specifications of different countries, even with improvements of some properties, such as the cetane number. 

Epoxides have received increased attention in view of their interest both as end-products and as chemical intermediates. Epoxidized oils—mainly high-oleic sunflower oil—and their ester derivatives have found important applications as plasticizers and additives for polyvinyl chloride (PVC). Epoxidized esters produced from high-oleic sunflower methyl esters have hydroxyl values of 0, oxirane values of 5.2/ 4.5, and iodine values of 1.7/1.5 (127)... 

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