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1.
Robert O. Dunn Victor T. Wyatt Karen Wagner Helen Ngo Megan E. Hums 《Journal of the American Oil Chemists' Society》2019,96(7):805-823
Biodiesel (fatty acid methyl esters [FAME]) is produced from various fats, oils, and greases (FOG) using catalytic transesterification with methanol. These fuels have poor cold-flow properties depending on the fatty acid (FA) composition of the parent FOG. Improving the cold-flow properties of biodiesel will enhance its prospects for use during cooler months in moderate temperature climates. This work is a study on the use of skeletally branched-chain alkyl esters (BCAE) composed of the isopropyl, n-butyl, and 2-ethylhexyl esters of iso-oleic acid isomers (iPr-iOL, nBu-iOL, and 2EH-iOL). These BCAE additives were tested in blends with linear-FAME (L-FAME) derived from soybean oil (SME), lard (LME), tallow (TME), and sewage scum grease (SGME). Binary L-FAME/SME admixtures were also studied. Admixtures were tested for the effects of the additives on cloud point (CP), pour point (PP), and kinematic viscosities at standard (ν40 = 40 °C) and low temperatures (TL) = CP + 5 °C (νL). Although the BCAE additives were more effective than SME, relatively large additive concentrations (yAdd) were needed to depress CP and PP by more than 2 °C. Admixtures with high concentrations of BCAE additive had ν40 > 6.0 mm2 s−1, the maximum limit in ASTM fuel specification D 6751. While the iPr-iOL and nBu-iOL additives may be blended at concentrations up to yAdd = 0.50, 2EH-iOL should not exceed yAdd = 0.28 in LME, 0.31 in SGME, 0.35 in TME, or 0.41 in SME to avoid driving the admixture out of specification. Some anomalies observed in the results at low yAdd for SGME/BCAE admixtures were speculated to have been affected by the low-temperature rheology of SGME. 相似文献
2.
The viscosity of biodiesel, which is a mixture of fatty acid methyl esters (FAME), is an important physical property in the injection and efficient combustion. In this study, a simple correlation, with only one adjustable parameter, is proposed for predicting the viscosity of FAME and their mixtures (biodiesel) as a function of temperature. First, the adjustable parameter of the correlation is calculated for various FAME. The average absolute relative deviation (AARD) is obtained to be 0.97% for 226 data points. Second, the adjustable parameter of FAME is connected to the number of carbon atoms and the number of double bonds to build a predictive correlation for the calculation of viscosity. The AARD for 226 data points is obtained to be 2.28%. Third, the proposed model is employed to predict the viscosity of biodiesel without introducing any new adjustable parameter. To predict the viscosity of biodiesel, the average of the adjustable parameter is applied to the correlation. The AARD of 2.96% is obtained for 185 data points comprised of 23 different biodiesels. To better understand the ability of the correlation in the estimation of the viscosity of biodiesel and FAME, a comparison is made between the present correlation and a number of correlations available in the literature. 相似文献
3.
An Empirical Equation for Estimation of Kinematic Viscosity of Fatty Acid Methyl Esters and Biodiesel 下载免费PDF全文
Suriya Phankosol Kaokanya Sudaprasert Supathra Lilitchan Kornkanok Aryusuk Kanit Krisnangkura 《Journal of the American Oil Chemists' Society》2015,92(7):1051-1061
Kinematic viscosity (µ) is an important physical property of fatty acid methyl esters (FAME) and biodiesel. In this work, the Martin's rule of free energy additivity is extended to cover the kinematic viscosity of saturated and unsaturated FAME commonly found in nature. The proposed model can also be extended to estimate kinematic viscosity of biodiesel. The kinematic viscosity of a FAME or a biodiesel can be easily estimated from its carbon number (z), number of double bonds (nd) at different temperatures (T) without a prior knowledge of the viscosity of individual FAME. Both zave and nd(ave) can be derived from its fatty acid composition. Thus, kinematic viscosity of biodiesel at temperatures between 20 and 100 °C and at atmospheric pressure can be estimated. The average absolute deviation (AAD) estimated at 20–100 °C for saturated, unsaturated FAME, biodiesels and biodiesel blends are 4.15, 3.25, 6.95 and 2.79 %, respectively. The biodiesels collected in this study (191 data points) have the zave and nd(ave) between 14.10 and 17.96 and 0.21–1.54, respectively. The standard deviation was 0.249. The proposed model would be good for estimation of viscosity of biodiesel containing normal fatty acids, generally found in biodiesel feed stocks. 相似文献
4.
Hanh Ngoc Thi Le Kiyoshi Imamura Norie Watanabe Masakazu Furuta Norimichi Takenaka Luu Van Boi Yasuaki Maeda 《化学工程与技术》2018,41(5):1013-1018
Rubber seed oil (RSO) is a high‐potential feedstock for the production of biodiesel fuel (BDF) in Asia. Transesterification using fatty acid methyl esters (FAMEs) as co‐solvents was developed for BDF production from RSO with high content of free fatty acids (FFAs). The homogeneous system (FAMEs/triglyceride/methanol) was attained when the FAME content was more than 30 wt %. After esterification of RSO, the crude RSO obtained was transesterified with FAMEs as a co‐solvent. The quality of BDF with high FAME content satisfied the criteria of the EN 14214/JIS K2390 standards. These results suggest that FAMEs converted from FFAs can be applied as a co‐solvent and, thus, reused for BDF production. 相似文献
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Mohamad Firdaus Mohamad Yusoff Xuebing Xu Zheng Guo 《Journal of the American Oil Chemists' Society》2014,91(4):525-531
Fatty acid methyl esters (FAME) were the first fatty acid esters to be introduced for use as biodiesel. However, there is a growing interest in the use of fatty acid ethyl esters (FAEE) in biodiesel. Both FAME and FAEE have their own unique advantages and disadvantages. These differences are ultimately attributable to the structural differences imparted by the alcohols used in their production. Sources of reactants as well as their safety issues, are a focus of this review. Also reviewed are the comparative characteristics and properties of both biodiesel types in terms of physicochemical features and performance. Processing requirements, reaction times and molar ratios of alcohol to oil, together with problems and drawbacks, are discussed. Recent developments on improving the yield of biodiesel, include mixing methanol and ethanol in the same reaction with ethanol acting as a co-solvent, and enzymatic methanolysis and ethanolysis are also highlighted. 相似文献
7.
Our previous isolation of branched-chain fatty acid (BCFA) methyl esters from lanolin was improved and scaled up. Also, oleate
esters of isopropanol, oleyl alcohol and normal alcohols of 1–12 carbons chain lengths were prepared. Esters were made by
interesterification with sodium alcoholates and by esterification with Candida antarctica lipase. It proved easier to obtain pure esters by the enzymatic synthesis. Melting points and viscosities over the range
of 0–70 °C were determined in order to better identify potential lubricant targets that might be produced by genetically modified
oilseed crops. Isopropyl and butyl oleate have melting points of −33 and −32 °C, respectively and viscosities that range from
~17 cp (0 °C) to ~2.5 cp (70 °C). They should have suitable stability for lubricants. BCFA esters had viscosities similar
to their straight chain analogs. Viscosities increased with alcohol chain length and decreased with temperature. The dependence
of viscosity on temperature was fit with an equation based on Erying’s rate equation. Some esters with branched acid or branched
alcohol moieties, and some oleate esters might be utilized as biolubricants or biofuels on the basis of their melting points
and viscosities. 相似文献
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以混合脂肪酸甲酯为原料,采用尿素包合法(脲包法)分离不饱和脂肪酸甲酯。通过正交试验,得到了最佳工艺条件:混合脂肪酸甲酯(w):尿素(w):甲醇(v)为1:2.09:8.36,包合温度-10℃,包合时间18h。经过一次包合,不饱和脂肪酸甲酯的含量由原来的47.69%提高到86.74%,收率54.19%。 相似文献
10.
Ultrasonic Pretreatment Transesterification for Solid Basic-Catalyzed Synthesis of Fatty Acid Methyl Esters 下载免费PDF全文
Pingmei Guo Suhuan Ma Fenghong Huang 《Journal of the American Oil Chemists' Society》2017,94(5):733-740
Generally, ultrasound irradiation is required throughout the reaction for fatty acid methyl esters (FAME, namely, biodiesel) production, which is energy-consuming and difficult to scale-up. In order to improve the industrial application of ultrasonic technology, a systematic study of ultrasonic pretreatment solid basic (Na2SiO3)-catalyzed transesterification for FAME production from cottonseed oil was carried out, and the effect of ultrasonic waves on the properties of Na2SiO3 catalyst was assessed by X-ray diffraction (XRD), Fourier transform Infrared (FTIR) and scanning electron microscopy (SEM) characterization of fresh and collected catalysts. An ultrasonic frequency of 30 kHz, ultrasonic power of 200 W and ultrasonic pretreatment irradiation time of 30 min was determined to guarantee a satisfactory degree of transesterification. The optimum production was achieved in the reaction system at 45 °C with methanol/cottonseed oil molar ratio 5:1, catalyst dosage 3% and stirring speed 350 rpm resulting in a FAME yield of above 97% after 60 min of reaction under mechanical stirring with the ultrasonic pretreatment process. The new process has a shorter reaction time, a more moderate reaction temperature, a less amount of methanol and catalyst than only the mechanical stirring process without essential damage to activity and the structure of catalyst. These results are of great significance for applying the ultrasonic pretreatment method to produce FAME. 相似文献
11.
Energy Additivity Approaches to QSPR Modeling in Estimation of Dynamic Viscosity of Fatty Acid Methyl Ester and Biodiesel 下载免费PDF全文
Kanit Krisnangkura Kornkanok Aryusuk Suriya Phankosol Supathra Lilitchan 《Journal of the American Oil Chemists' Society》2016,93(10):1407-1414
Viscosity is an important physical property of fatty acid methyl esters (FAME) and biodiesel (mixture of FAMEs). In this work, quantitative structure–property relationship (QSPR) for estimation of dynamic viscosity of FAMEs and biodiesel is approached via the Gibbs energy additivity method. The Gibbs energy of dynamic viscous flow is simply derived from the sum of the Gibbs energy of kinematic viscous flow and Gibbs energy of volumetric expansion. The derived model can be used for estimation of dynamic viscosity of saturated and unsaturated FAMEs commonly found in nature. Also, the proposed model can be extended to a mixture of FAMEs or biodiesel as well as biodiesel blends. Thus, the dynamic viscosity of FAMEs as well as neat and blended biodiesels can be estimated by the same equation from the carbon number (z) and number of double bonds (nd) at different temperature (T). The average absolute deviation (AAD) values for saturated, unsaturated FAMEs, biodiesels, and biodiesel blends (at 20–100 °C) are approximately the same as the original model for estimation of kinematic viscosity. 相似文献
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Roberta Perroni Marouço da Costa Cristiane Gimenes de Souza Rafael Cavalcante dos Santos Débora França de Andrade Luiz Antonio d'Avila 《European Journal of Lipid Science and Technology》2021,123(12):2100069
The purpose of this study is to develop and validate a method based on size-exclusion chromatography (SEC) for the simultaneous determination of fatty acid methyl esters (FAME), monoacylglycerols (MAG), diacylglycerols (DAG), and triacylglycerols (TAG) in biodiesel. The proposed method presents good linearity. The limits of detection are 0.26% mass for FAME, 0.02% mass for MAG, 0.01% mass for DAG, and 0.02% mass for TAG. The limits of quantification are 0.78% mass for FAME, 0.06% mass for MAG, 0.01% mass for DAG, and 0.06% mass for TAG. Accuracy evaluated by recovery yielded values ranging from 98.93% to 117.67%. Precision is evaluated by repeatability (%), which is ranged from 0.03% to 13.67%. The proposed SEC method proves effective in determining the FAME, MAG, DAG, and TAG content of standard samples, and the paired t-test shows that the results obtained were statistically similar to the gas chromatography (GC) values. The method also has some advantages over the reference GC methods, since it obtains the content for each class analyzed, irrespective of its components. Also, it does not require derivatization, which makes it easier and also quicker (15 min) than the 60 min taken by the two reference methods, and it does not need an internal standard, which makes it cheaper. Practical Applications: Size exclusion chromatography (SEC) is an efficient method for simultaneous and quantitative determination of fatty acid methyl esters (FAME), monoacylglycerols (MAG), diacylglycerols and triacylglycerols (TAG). The method present itself as an alternative to reference methods (ASTM D 6584 and ABNT NBR 15764) based on gas chromatography (GC). The proposed method shows advantages compared to reference methods, once it makes possible to determine the content of each constituent class in samples, regardless of its components, what makes the peak integration easier. Beyond that, previous sample derivatization is unnecessary, what makes the method simpler, cheaper and faster (15 min) than both reference methods that demands together 60 min for analysis (ASTM D 6584 for MAG, DAGa and TAG and ABNT NBR 15764 for FAME analysis). 相似文献
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Shehu Isah Jainwei Zhang Girma Biresaw Gary D. Strahan Alberto Nunez Victor T. Wyatt Helen Ngo Gulnihal Ozbay 《Journal of the American Oil Chemists' Society》2021,98(6):683-695
Previously synthesized C36-dimer acids (DA) have been esterified (97 ± 0.2% conversion at 120 °C for 72 hours) with 2-ethylhexanol (2-EH) to produce a new class of C52-DA 2-EH esters that have potential application in biolubricant formulations such as base oils and additives. Investigation of physicochemical and lubricant properties showed the bio-based esters have good solubility in commercial base stocks such as polyalpha olefin (PAO-6) (>20 w/w) and high-oleic sunflower oil (HOSuO) (>20 w/w). The neat C52-DA 2-EH esters displayed a three- to eightfold higher kinematic viscosity and comparable viscosity index (VI = 134) as a commercial base stock, PAO-6 (VI =137). Both C52-DA 2-EH esters, whose parent C36-DA were synthesized with two different zeolite catalysts, were oxidatively stable above 176 °C. Blending C52-DA 2-EH esters in HOSuO improved the pour point (PP) of HOSuO from −18.8 to −21.0 °C at 1% w/w and the cloud point (CP) from −6.3 to −10.6 °C at 8% w/w of C52-DA 2-EH ester 1. A similar trend was observed for C52-DA 2-EH ester 2, indicating that the esters possess PP depressant (PPD) characteristics in HOSuO blends. Blending C52-DA 2-EH esters in PAO-6 increased the VI of PAO-6, which is an indication that the bio-based esters were acting as VI improvers (VII). It was concluded that C52-DA 2-EH esters can be employed commercially as bio-based base oils and as PPD and VII additives in lubricant formulations. 相似文献
16.
采用盐酸H2O2/HCOOH法,在微通道反应器内对不饱和脂肪酸甲酯进行环氧化反应。考察了双氧水用量、甲酸用量、反应温度及催化剂用量对反应的影响,得到最优的反应条件为:m(脂肪酸甲酯):m(甲酸):m(双氧水)=1:1.5:2,反应温度40℃,催化剂浓盐酸质量分数为3%(即浓盐酸质量占原料脂肪酸甲酯质量的百分数,下同),反应时间为110 s。在该条件下,产品环氧值为4.32%。 相似文献
17.
Three Brønsted acidic imidazole dicationic ionic liquids (ILs) with different length of alkyl chains, [Cn(Mim)2][HSO4]2 (n = 3, 6, 12), were prepared and used as catalyst for the esterification reaction of free fatty acids and methanol. Taking oleic acid as model acid, the catalytic performances of the synthesized ILs for the esterification were evaluated. The main physicochemical properties of the ILs, thermal stability, acidity, solubility in common solvents, and causticity on Austenitic stainless steel 316, were examined. [C3(Mim)2][HSO4]2 demonstrated the highest catalytic activity and enabled to assess the preliminary optimum esterification condition of oleic acid and methanol. Under optimized reaction conditions, the yield of oleic acid methyl ester was up to 95 %. The ILs have great potential as catalysts for producing fatty acid methyl esters from long‐chain free fatty acids. 相似文献
18.
Anna Cherepanova Evgeniy Savel'ev Leila Alieva Irina Kuznetsova Valentin Sapunov 《Journal of the American Oil Chemists' Society》2020,97(11):1265-1272
The current work has shown the potentials for the aerobic oxidation of fatty acid methyl ester (FAME) of vegetable oils in the production of polyvinylchloride (PVC) plasticizers with the exclusion of other reagents. The reaction mixtures contain epoxidized derivatives of FAME, and esters, with the quantity of the ester groups being higher than in the initial raw material. It was established that the increase in the additional ester groups resulting from the “aerobic” Baeyer-Villiger (BV) reaction has a significantly positive influence on the plasticizing ability of the oxidized FAME mixtures for PVC when compared to the formation of epoxide compounds. The development of the technology for the production of PVC plasticizers proposed in this investigation provides an opportunity for resolving some of the environmental issues normally associated with the use of phthalate-based plasticizers. 相似文献
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