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1.
Daniel P. Schwartz 《Microchemical Journal》1977,22(4):457-462
In a convenient, rapid procedure, a very small column of potassium methylate — Hyflo Super-Cel is used to convert microgram amounts of glycerides to methyl esters. Transesterification is complete in hydrocarbon but not in chlorinated solvents or in CS2. The methyl esters can be recovered in 92–95% yield if desired. Regardless of the solvent used, the recovered methyl esters are representative of the original fatty acid composition of the glycerides. 相似文献
2.
FDU-15-SO3H, a solid acid material prepared from the sulfonation of FDU-15 mesoporous polymer, has been demonstrated to serve as an efficient catalyst in the esterification of palmitic acid with methanol as well as in the transesterification of fatty acid-edible oil mixture. FDU-15-SO3H achieved an acid conversion of 99.0% when the esterification was carried out at 343 K with a methanol/palmitic acid molar ratio of 6:1 and 5 wt% catalyst loading. It was capable of giving 99.0% yield of fatty acid methyl esters (FAME) when the transesterification of soybean oil was performed at 413 K and the methanol/oil weight ratio of 1:1. FDU-15-SO3H was further applied to the transesterification/esterification of the oil mixtures with a varying ratio of soybean oil to palmitic acid, which simulated the feedstock with a high content of free fatty acids. The yield of FAME reached 95% for the oil mixtures containing 30 wt% palmitic acid. This indicated the sulfonated mesopolymer was a potential catalyst for clean synthesis of fuel alternative of biodiesel from the waste oil without further purification. 相似文献
3.
Biodiesel comprises of fatty acid alkyl esters prepared from vegetable oils or animal fat by esterification/transesterification
with short-chain alcohols (methanol or ethanol, for example). It is a biodegradable renewable fuel. Its production is growing
exponentially due to greater concerns about environmental protection and depletion of fossil fuel resources. Further, its
production from non-edible oils and animal fat is more desirable than from edible oils due to lower cost of non-edible feedstocks
and elimination of food verses fuel issues. Solid acid catalysts are ideal for conversion of such low-grade oils to biodiesel. Biodiesel from non-edible
oils can be produced by two methods: (1) simultaneous esterification of fatty acids and transesterification of fatty acid
glycerides and (2) hydrolysis of glycerides followed by esterification. This account reports the catalytic performance of
solid, Fe–Zn double-metal cyanide (DMC) complexes and other acid catalysts in these transformations for biodiesel production.
The factors influencing the catalytic performance of the solid acid catalysts in biodiesel production are discussed. 相似文献
4.
《Journal of separation science》2017,40(10):2214-2227
Algae can synthesize, accumulate and store large amounts of lipids in its cells, which holds immense potential as a renewable source of biodiesel. In this work, we have developed and validated a GC–MS method for quantitation of fatty acids and glycerolipids in forms of fatty acid methyl esters derived from algae biomass. Algae Scenedesmus dimorphus dry mass was pulverized by mortar and pestle, then extracted by the modified Folch method and fractionated into free fatty acids and glycerolipids on aminopropyl solid‐phase extraction cartridges. Fatty acid methyl esters were produced by an optimized one‐step esterification of fatty acids and transesterification of glycerolipids with boron trichloride/methanol. The matrix effect, recoveries and stability of fatty acids and glycerolipids in algal matrix were first evaluated by spiking stable isotopes of pentadecanoic‐2,2‐d2 acid and glyceryl tri(hexadecanoate‐2,2‐d2) as surrogate analytes and tridecanoic‐2,2‐d2 acid as internal standard into algal matrix prior to sample extraction. Later, the method was validated in terms of lower limits of quantitation, linear calibration ranges, intra‐ and inter‐assay precision and accuracy using tridecanoic‐2,2‐d2 acid as internal standard. The method developed has been applied to the quantitation of fatty acid methyl esters from free fatty acid and glycerolipid fractions of algae Scenedesmus dimorphus . 相似文献
5.
Natasha Coral Elizabeth Rodrigues Victor Rumjanek José Roberto Zamian Geraldo Narciso da Rocha Filho Carlos Emmerson Ferreira da Costa 《Magnetic resonance in chemistry : MRC》2013,51(2):69-71
Production of alternative fuels, such as biodiesel, from transesterification of vegetable oil driven by heterogeneous catalysts is a promising alternative to fossil diesel. However, achieving a successful substitution for a new renewable fuel depends on several quality parameters. 1H NMR spectroscopy was used to determine the amount of methyl esters, free glycerin and acid number in the transesterification of soybean oil with methanol in the presence of hydrotalcite‐type catalyst to produce biodiesel. Reaction parameters, such as temperature and time, were used to evaluate soybean oil methyl esters rate conversion. Temperatures of 100 to 180 °C and times of 20 to 240 min were tested on a 1 : 12 molar ratio soybean oil/methanol reaction. At 180 °C/240 min conditions, a rate of 94.5 wt% of methyl esters was obtained, where free glycerin and free fatty acids were not detected. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
6.
Justina Gaidukevi? Jurgis Barkauskas Anna Malaika Paulina Rechnia-Gor?cy Aleksandra Mo?d?yńska Vitalija Jasulaitien? Mieczys?aw Koz?owski 《催化学报》2018,39(10):1633-1645
本文研究了不同石墨烯基材料用作转酯化反应制备生物柴油催化剂的性能.将磺酸基或磷酸盐基嫁接到热还原的氧化石墨烯表面,制备了固体酸石墨烯基样品.并采用扫描电镜、X射线衍射、热重分析、X射线光电子能谱、N_2吸附-脱附法、电位滴定法、元素分析以及红外光谱法对所制样品进行了全面表征.将所制样品用于130℃带压力的条件下菜籽油与甲醇转酯化反应中,并将其催化活性与商用的多相酸催化剂Amberlyst-15的进行了比较.结果表明,所有改进的样品在转酯化反应中均表现出催化活性,但各样品上生物柴油产率差别较大.其中以苯二氮磺酸基功能化的热还原氧化石墨烯样品上脂肪酸甲酯产率最高,反应6 h后达70%,也明显高于商用催化剂Amberlyst-15.该样品也表现出良好的重复使用性能. 相似文献
7.
超临界甲醇中的酯化和酯交换反应是利用植物油、动物油或废油脂制备生物柴油的新工艺.它的最大特点是不需要添加催化剂,超临界甲醇既是反应媒介,又是反应物. 相似文献
8.
Pauls RE 《Journal of chromatographic science》2011,49(5):384-396
This review surveys chromatographic technology that has been applied to the characterization of biodiesel and its blends. Typically, biodiesel consists of fatty acid methyl esters produced by transesterification of plant or animal derived triacylglycerols. Primary attention is given to the determination of trace impurities in biodiesel, such as methanol, glycerol, mono-, di-, and triacylglycerols, and sterol glucosides. The determination of the fatty acid methyl esters, trace impurities in biodiesel, and the determination of the biodiesel content of commercial blends of biodiesel in conventional diesel are also addressed. 相似文献
9.
Sodium methylate splits the ester linkage of glycerides, glycerophosphatides, cholesterin esters, waxes, and estercerebrosides under formation of fatty acid methylesters. Sodium methylate neither attacks the acid-amide linkage nor esterifies free fatty acids. Patty acid methylesters can be easily prepared for gas-liquid chromatography by the described alkali-catalyzed transesterification methods. The advantages of these methods are: 1. the simplicity of the technique, 2. the rapidity of the trans-esterification reaction, 3. the various combinations with thin-layer chromatography, 4. the application for the analysis of μg-quantities, and 5. the rapid parallel preparation of many samples on silicagel plates. 相似文献
10.
Noorzalila Muhammad Niza Kok Tat Tan Zainal Ahmad Keat Teong Lee 《Chemical Papers》2011,65(5):721-729
In this study, biodiesel has been successfully produced by transesterification using non-catalytic supercritical methanol
and methyl acetate. The variables studied, such as reaction time, reaction temperature and molar ratio of methanol or methyl
acetate to oil, were optimised to obtain the optimum yield of fatty acid methyl ester (FAME). Subsequently, the results for
both reactions were analysed and compared via Response Surface Methodology (RSM) analysis. The mathematical models for both
reactions were found to be adequate to predict the optimum yield of biodiesel. The results from the optimisation studies showed
that a yield of 89.4 % was achieved for the reaction with supercritical methanol within the reaction time of 27 min, reaction
temperature of 358°C, and methanol-to-oil molar ratio of 44. For the reaction in the presence of supercritical methyl acetate,
the optimum conditions were found to be: reaction time of 32 min, reaction temperature of 400°C, and methyl acetate-to-oil
molar ratio of 50 to achieve 71.9 % biodiesel yield. The differences in the behaviour of methanol and methyl acetate in the
transesterification reaction are largely due to the difference in reactivity and mutual solubility of Jatropha curcas oil and methanol/methyl acetate. 相似文献
11.
A new heterogeneous K2CO3 supported by a layered double hydroxide (LDH), Mg–Al hydrotalcite, was prepared and used as a catalyst for the biodiesel preparation by a tri-component coupling transesterification of methanol, vegetable oil, and methyl acetate. K2CO3/Mg-Al exhibits high catalytic activities, and biodiesel yield can reach 99.48% within 20 min under 60°C, with 6 wt.% of K2CO3/Mg-Al, 1:1:12 molar ratio of rapeseed oil, methyl acetate, and methanol. Fourier-transform infrared spectroscopy, X-ray diffraction (XRD), scanning electron microscopy, nitrogen physical adsorption, thermogravimetry analysis, and CO2-chemical adsorption were used to assess the physical properties of the prepared K2CO3/Mg-Al. Using the tri-component coupling transesterification, 12.2% cost reduce can be get by reducing the cost from 8458 to 7424 ¥/t compared with di-component transesterification containing oil and methanol as resource. 相似文献
12.
《Radiation Physics and Chemistry》2006,75(1):48-52
C-11 labelled methyl esters have been synthesized via the transesterification of enol esters in the presence of C-11 methanol and 1,3 dichlorodibutylstannoxane as catalyst. This method leaves functional groups intact and allows access to a wider variety of C-11 labelled methyl esters compared to the BF3 catalysed ester formation, which uses carboxylic acids and C-11 methanol as starting materials. 相似文献
13.
Chanatip Samart Surachai Karnjanakom Chaiyan Chaiya Prasert Reubroycharoen Ruengwit Sawangkeaw Metta Charoenpanich 《Arabian Journal of Chemistry》2019,12(8):2028-2036
The experimental parameters for biodiesel production from para rubber seed oil and methanol using a SO3H-MCM-41 catalyst were optimized statistically. The SO3H-MCM-41 catalyst was synthesized by co-condensation in the presence of tetraethyl orthosilicate, 3-mercaptopropyl (methyl) dimethoxysilane (MPMDS) and cetyl-trimethylammonium bromide. In the last step, the solid catalyst (SH-MCM41) was oxidized by H2O2 to SO3H-MCM-41. The acid capacity of the obtained SO3H-MCM-41 catalyst was quantified by back titration with 0.1 M sodium hydroxide. The physical and chemical properties of the SO3H-MCM-41 were characterized by nitrogen adsorption/desorption, X-ray diffractometry, Fourier transform infrared spectroscopy and thermogravimetric analysis. The effect of varying the catalyst loading (wt.%), reaction time (h) and temperature (°C) and molar composition of MPMDS on the biodiesel yield were investigated using a 2k factorial design. The optimal conditions to maximize the biodiesel yield, obtained from the response surface analysis using a Box–Behnken design, was a 14.5 wt.% catalyst loading, and a reaction time and temperature of 48 h and 129.6 °C. Under these conditions a fatty acid methyl ester (biodiesel) yield of 84% was predicted, and an 83.10 ± 0.39% yield experimentally obtained. 相似文献
14.
Mirit Kolet Melad Atrash Karen Molina Daniel Zerbib Yael Albo Faina Nakonechny Marina Nisnevitch 《Molecules (Basel, Switzerland)》2020,25(24)
Replacing fossil fuels with biodiesel enables the emission of greenhouse gases to be decreased and reduces dependence on fossil fuels in countries with poor natural resources. Biodiesel can be produced by an esterification reaction between free fatty acids (FFAs) and methanol or by transesterification of triglycerides from oils. Both reactions require homogeneous or heterogeneous catalysis. Production of biodiesel catalyzed by heterogeneous catalysts seems to be the preferred route, enabling easy product separation. As we have previously shown, the Lewis acids AlCl3 and BF3 can serve as highly efficient catalysts under ultrasonic activation. The present study focused on the development of oleic acid (OA) esterification with methanol by the same catalysts immobilized in silica matrices using the sol–gel synthesis route. During the course of immobilization, AlCl3 converts to AlCl3 × 6H2O (aluminite) and BF3 is hydrolyzed with the production of B2O3. The immobilized catalysts can be reused or involved in a continuous process. The possibility of biodiesel production using immobilized catalysts under ultrasonic activation is shown for the conversion of FFAs into biodiesel in batch and continuous mode. 相似文献
15.
Summary The direct esterification and gas chromatographic analysis of aromatic carboxylic acids as n-propyl esters is described.Derivatization is performed in aqueous solution with n-propanol in the presence of sulfuric acid. The n-propyl esters of benzoic, phthalic, trimellitic and pyromellitic acids permit their gas chromatographic separation from each other and from fatty acids and aliphatic dicarboxylic acids. At mode ratios of [H2O]/[n-PrOH]0.03 the water present does not interfere with the esterification reaction. At mole ratios above 0.03 anhydrous sodium sulfate is used for binding the water, at mole ratios of [Na2SO4anh.]/[H2O]=0.51–1.52 and of [H2SO4]/[Na2SO4anh.]=0.43–1.28, respectively. 相似文献
16.
Orthorhombic perovskite Na0.1Ca0.9TiO3 nanorods were synthesized at low calcination temperature via alkali hydrothermal synthesis. The synthesized nanorods exhibits a square based prism morphology, with a width and length of 200–500 nm and 2–3 μm respectively. The structural, textural and basic characteristics of the catalyst were examined by SEM, TEM, XRD and BET. The growth direction of the nanorods was confirmed to be along the long symmetry [110] zone axis and the exterior surfaces are found to be polar (110) and (002) with either Ti or Ca exposed in those facets. The catalytic activity of the nanorods was investigated for the transesterification of the low-input Camelina Sativa oil and methanol to give the fatty acid methyl ester (FAME). Effects of important reaction parameters such as methanol to oil molar ratio, catalyst dosage, reaction temperature and reaction time on oil conversion were examined. Optimized biodiesel yield of 93 % was achieved with catalyst dosage of 6 % w/w, methanol to oil molar ratio of 36:1 at reaction temperature of 60 °C for 8 h. 相似文献
17.
Summary The direct esterification and gas chromatographic analysis of aromatic carboxylic acids as n-butyl esters is described.Derivatization is performed in aqueous solution with n-butanol in the presence of sulfuric acid. The butyl esters of benzoic, phthalic, hemimellitic, trimellitic, trimesic and pyromellitic acids permit their gas chromatographic separation from each other and from fatty acids and alipatic dicarboxylic acids. At mole ratios of [H2O]/ [n-BuOH]0.04 the water present does not interfere with the esterification reaction. At mole ratios above 0.04 anhydrous sodium sulfate is used for binding the water, at mole ratios of [Na2SO4 anh.]/[H2O]=0.25–0.75. 相似文献
18.
19.
《中国化学会会志》2018,65(6):681-686
Fe3O4@Gly nanoparticles were synthetized by coprecipitation and studied in the transesterification of soybean oil and methanol to determine its performance for biodiesel synthesis. The magnetism and catalytic performance of Fe3O4@Gly alkaline catalyst were investigated in detail. With a catalyst dosage 1.5 wt %, methanol/soybean oil ratio of 15:1, reaction temperature of 65 °C, and a reaction time of 3 h, the highest yield of biodiesel was 95.8%. The strong base catalyst CaO was used as comparison, from which it was seen that Fe3O4@Gly was more hydrophobic than the former. Moreover, because of the complete dissolution of oleic acid in methanol, Fe3O4@Gly could make better contact with oleic acid, which made it perform far better than pure CaO in oleic acid. In addition, after four times recycling, the yield of biodiesel was still 86.6%. The results show that Fe3O4@Gly possesses excellent properties of acid resistance and recyclability. The catalyst can be a high‐efficiency alkaline heterogeneous catalyst for biodiesel production. 相似文献
20.
Faezeh Farzaneh Zahra Mohammadi Zahra Azarkamanzad 《Journal of the Iranian Chemical Society》2018,15(7):1625-1632
Fe3O4 nanoparticles were modified with tetraethylorthosilicate (TEOS) and (3-chloropropyl)trimethoxysilane (CPTMS) followed by immobilization with different amines such as guanine, piperazine, methylamine, morpholine, aniline, ethylenediamine, 3-aminopropyltriethoxysilane, and melamine, designated as Fe3O4@SiO2@CPTMS@amine (nanocatalyst). The prepared nanocatalysts were characterized by means of FTIR, XRD, VSM, SEM, and TEM. Trans-esterification reactions of soybean oil with methanol were then carried out in the presence of the Fe3O4@SiO2@CPTMS@amine as a nanocatalyst. Optimization of the reaction parameters revealed that the fatty acid methyl esters (FAMEs or biodiesel) is obtained in 6–96% yields by using methanol to oil molar ratio of 36 in the presence of 6% of nanocatalysts containing melamine and guanine, respectively, at 160 °C within 3 h. The stability and reusability of the catalyst as well as the effect of reaction parameters on the FAME yield are described in this paper. 相似文献