Reductive ozonolysis of soybean oil: Laboratory optimization of process variables

Statistically designed experiments were carried out to determine the effect of reaction variables in the reductive ozonolysis of soybean oil to azelaaldehydic glyceride methyl acetal. Yields of this acetal were essentially quantitiative under optimum conditions, which include a 1:1 mixture of acetic acid and butanol as solvent, a solvent-oil ratio of 1.5:1, and hydrogenation at 150 psig and 50 C with palladiumon-charcoal catalyst. ARS, USDA.     

The peroxidic species generated by ozonolysis of oleic acid or methyl oleate in a carboxylic acid medium

The ozonolysis of oleic acid or methyl oleate in a carboxylic acid medium produces three major peroxidic species as well as aldehyde. These peroxidic compounds have been identified as 1-acyloxyalkyl-1-hydroperoxides, 1,2,4-trioxolanes, and bis(1-acyloxy-1-alkyl) peroxides. The bis(1-acyloxy-1-alkyl) peroxides have not been reported previously as oleic acid or methyl oleate ozonolysis products. A¹H nuclear magnetic resonance examination of the ozonization products of oleic acid or methyl oleate in carboxylic acids, as well as methanol and iso-octane, led to the identification of the peroxidic compounds and aldehyde.     

Ozonolysis of cyclododecene

Ozonolysis of cyclododecene was carried out to produce an w-formyl carboxylic acid (12-oxododecanoic acid) which is derived from zwitterion and aldehyde moiety that are formed during the reaction. The ozonolysis was performed to examine the product distribution under such reaction variables as temperature, kinds of solvent, and presence of catalyst. The yield of polymeric ozonide, which is undesirable product, was measured to be dominantly 86% without pyridine catalyst, whereas, only 10.25% with the catalyst. The optimum reaction condition was to be in MC (methylene chloride) solvent, and in the presence of equimolar olefin and pyridine catalyst at O°C, at which the yields of polymeric ozonide, 1,12-dodecanedialdehyde, 1,12-dodecanedicarboxylic acid, and 12-oxo-dodecanoic acid were 10.25%, 26.72%, 26.31%, and 36.72%, respectively.     

Amines from aldehydes derived from the ozonization of soybean esters

Investigations were carried out on reductive amination of caproaldehyde, pelargonaldehyde and azelaaldehydate esters, obtainable from ozonolysis of soybean oil products, with ammonia and hydrogen in the presence of nickel catalyst. A solvent system giving good yields of primary amine while suppressing amide formation was devised. Excess ammonia and homogeneous solutions suppressed secondary amine formation. Nonpolar solvents suppressed ammonolysis. Optimum conditions for reaction varied with the aldehyde. Excellent yields of hexylamine (91%), nonylamine (90%), methyl 9-aminononanoate (92%) and butyl 9-aminononanoate (93%) were obtained from caproaldehyde, pelargonaldehyde, methyl azelaaldehydate and butyl azelaaldehydate, respectively, when aminated in anhydrous ammonia and either cyclohexane or methyl cyclohexane. Presented at the AOCS meeting, Chicago, 1964. A laboratory of the No. Utiliz. Res. and Dev. Div., ARS, USDA.     

密闭电石炉气脱氧催化剂的制备和表征

为脱除密闭电石炉气中体积分数为2%的O₂,制备了以铜为主催化剂,锰和钴为助催化剂,以活性炭为载体的低温高活性脱氧催化剂。在120 ℃,该催化剂可将体积分数为98%的CO、2%的O₂且流量为1.5 L·min^-1的原料气中的O₂脱除至0.2%以下,满足将密闭电石炉气作为化工原料气的要求。正交实验结果表明,催化剂活性组分质量分数为铜6.5%、锰4%和钴0.5%时,能将O₂体积分数脱至0.054 1%。BET比表面积和XRD表征表明,制备的催化剂是一种组分负载量接近其在载体上的单层分散阈值的氧化态Cu-Co-Mn负载型催化剂,其中,Co对活性组分均匀分布于活性炭表面起重要作用。     

Process optimization for methyl ester production from waste cooking oil using activated carbon supported potassium fluoride

This paper presents the transesterification of waste cooking palm oil (WCO) using activated carbon supported potassium fluoride catalyst. A central composite rotatable design was used to optimize the effect of molar ratio of methanol to oil, reaction period, catalyst loading and reaction temperature on the transesterification process. The reactor was pressurized up to 10 bar using nitrogen gas. All the variables were found to affect significantly the methyl ester yield where the most effective factors being the amount of catalyst and reaction temperature, followed by methanol to oil ratio. A quadratic polynomial equation was obtained for methyl ester yield by multiple regression analysis using response surface methodology (RSM). The optimum condition for transesterification of WCO to methyl ester was obtained at 3 wt.% amount of catalyst, 175 °C temperature, 8.85 methanol to oil molar ratio and 1 h reaction time. At the optimum condition, the predicted methyl ester yield was 83.00 wt.%. The experimental value was well within the estimated value of the model. The catalyst showed good performance with a high yield of methyl ester and the separation of the catalyst from the liquid mixture is easy.     

Quantitative gas chromatographic analysis of lipids: Comparison of gas density balance and flame ionization detector

Accuracy of available detectors for gas chromatography is a subject of continuing research in analytical chemistry. The quantitative deficiency of the flame ionization detector, as well as of other detectors, has been widely recognized, and empirical correction factors have been required. By contrast, the gas density balance, the forgotten ideal detector, should not require calibration. A gas density balance, now available in a commercial chromatograph, and a flame ionization detector were compared for quantitative analyses of lipids. Wt percents of known methyl ester mixtures were determined, as well as mole percents of aldehyde fragments from certain ozonized octadecenoate isomers. Percentages were calculated from area response without correction factors for the gas density balance and with correction factors, based upon the number of ionizable carbon-atoms, for the flame ionization detector. Accuracy, as measured by percentage deviation from either known or theoretical values, was better for gas density balance data than for flame ionization detector data. Aldehyde and aldehydic ester fragments formed by reductive ozonolysis of octadecenoate isomers from partially hydrogenated methyl linolenate also were determined with each detector. Theoretically, ozonolysis of these monoenes should yield an aldehyde and an aldehydic ester in equal mole percents. Experimentally, the average of the ratios of aldehyde to aldehydic ester from each of the Δ5-Δ13 monoenes was 1.29 for the FID data (corrected) and 1.01 for GDB data (uncorrected). This difference in averages approaches significance at the 95% confidence level. For the Δ14 and Δ15 monoenes from which C₄ and C₃ aldehydes are formed, ionizable carbon-atom corrections proved even less adequate. Presented at the AOCS Fall Meeting, Chicago, September 1973. ARS, USDA.     

A simple,rapid micromethod for the determination of the structure of unsaturated fatty acids via ozonolysis

A micromethod for the localization of double bonds in unsaturated fatty acids via ozonolysis employing pyrolytic cleavage of ozonides in the presence of a hydrogenation catalyst is described. Cleavage of the ozonides is carried out in a gasliquid chromatographie instrument in a small glass tube, containing the catalyst, inserted in the top of the column opposite the in input heaters at 225C. Ozonides of methyl esters of straight chain unsaturated fatty acids are cleaved through the action of the catalyst to aldehyde fragments which are swept simultaneously into the column for analysis. The double bond positions are deduced from the chain length of the fragments. The method is demonstrated on methyl oleate, linoleate, linolenate and arachidonate. Presented at the AOCS Meeting, Cincinnati, October, 1965.     

油酸臭氧氧化法制取壬二酸的研究

以工业级油酸为原料,醋酸为溶剂,MoO3为催化剂,研究了臭氧氧化法制取壬二酸的过程。系统地考察了溶剂配比、反应温度、气体流量、臭氧浓度、催化剂配比等因素对各步反应的收率,以及壬二酸总收率的影响,并据此优选工艺条件。结果表明,适宜的工艺条件为:原料与醋酸质量比为1∶3,催化剂质量浓度为0.5%,臭氧化温度为20~25℃,臭氧浓度为48.63 mg/m3,氧化裂解温度为90℃,氧气流量为0.5 L/min。在此条件下,壬二酸产品的总收率可达72.42%。     

Reduction of methyl oleate ozonolysis products to aldehydes with activated zinc

Reduction of methyl oleate ozonolysis products with active zinc in the absence of acid or water gave an 88% yield of methyl azelaaldehydate. Under these neutral conditions, side reactions such as acetalization and aldehyde condensations could be more conveniently avoided than when zinc-acetic acid reduction is used. The activated zinc was prepared by treatment with acetic acid followed by washing to remove the acid. No. Utiliz. Res. and Dev. Div., ARS, USDA.     

质子交换膜燃料电池阴极催化剂的位置效应

考虑局部几何效应,通过二维稳态数学模型研究了质子交换膜燃料电池阴极催化剂的位置与其表面传质和反应能力的关系。模型方程涉及氧气在催化层气孔的传输,氧气在气相和电解质相界面的分配以及氧气和质子在电解质中的传递和电化学反应过程。计算结果表明,催化剂表面的氧气扩散能力对催化剂的位置变化非常敏感,随催化剂深入电解质内部,其表面的氧气扩散能力经短暂上升后迅速下降。催化剂位置对质子传递阻力的影响与氧气扩散类似,但位置效应要弱些。性能比较确定最优的催化剂位置是恰好处于刚被电解质膜完全覆盖的位置。     

Quantification of Nonanal and Oleic Acid Formed During the Ozonolysis of Vegetable Oil Free Fatty Acids or Fatty Acid Methyl Esters

The ozonolysis of unsaturated lipids is a process that has been used to generate aldehydes, acids, alcohols, and other biobased chemical intermediates. Reported here is a method that can be used to measure the formation of nonanal and oleic acid during the ozonolysis of unsaturated vegetable oil fatty acids or their methyl esters to indicate the extent of the ozonolysis reaction. Derivatization was performed using boron trifluoride in methanol solution to transform nonanal and oleic acid into nonanal dimethyl acetal and oleic acid methyl ester, respectively. Undecanal and 10‐heptadecenoic acid were used as internal standards and separation was performed using gas chromatography coupled with a flame ionization detector. The method was validated by performing a standard addition procedure in which nonanal or oleic acid standards were spiked into samples collected during the ozonolysis of oleic acid or canola oil fatty acid methyl ester (FAME). Linear regression results indicated that the measured nonanal and oleic acid are in good agreement with the actual amounts of nonanal and oleic acid added to the sample with at least 98 % recovery. The application of the method was demonstrated by the successful measurement of nonanal and oleic acid formed throughout the ozonolysis process for high oleic canola oil FAME.     

Feasibility of a Co Oxygen Carrier for Chemical Looping Air Separation: Thermodynamics and Kinetics

Chemical looping air separation (CLAS) is based on the chemical looping principle: oxygen carriers release oxygen to carrier gas in a reduction reactor and absorb oxygen from air in an oxidation reactor. High oxygen transport capacity, high reactivity in reduction and oxidation reactions, and resistance to attrition and agglomeration are some of the criteria that feasible oxygen carrier materials should fulfill. Thermodynamic analysis was applied to prove the potential of Co₃O₄ as oxygen carrier. ZrO₂ served as binder to improve the anti‐sintering property and reactivity. Kinetic experiments were performed to determine the reaction rate and conversion of the oxygen carrier. Stability and durability of the oxygen carrier were characterized before and after cyclic experiments. The Co/Zr oxygen carrier proved to be a suitable candidate for the CLAS process.     

Synthesis and characterization of poppy seed oil methyl esters

Response surface methodology(RSM) was used to determine the optimum conditions of the methanolysis of crude poppy seed oil using Na OCH3 as catalyst. The experiments were run according to five levels, four variable central composite rotatable design(CCRD) using RSM. The reaction variables, i.e., molar ratio of methanol/oil(3:1–9:1), catalyst concentration(0.5 wt%–1.25 wt% Na OCH3), reaction temperature(25–65 °C), and reaction time(20–90 min) were studied. We demonstrated that the molar ratio of methanol/oil, catalyst concentration,and reaction temperature were the significant parameters affecting the yield of poppy seed oil methyl esters(PSOMEs). The optimum transesterification reaction conditions, established using the RSM, which offered a89.35% PSOME yield, were found to be 7.5:1 molar ratio of methanol/oil, 0.75% catalyst concentration, 45 °C reaction temperature, and 90 min reaction time. The proposed process provided an average biodiesel yield of more than 85%. A linear correlation was constructed between the observed and predicted values of the yield.The gas chromatography(GC) analyses have shown that PSOMEs contain linoleic-, oleic-, palmitic-, and stearic-acids as main fatty acids. The FTIR spectrum of the PSOMEs was also analyzed to confirm the completion of the transesterification reaction. The fuel properties of the PSOMEs were discussed in light of biodiesel standards(ASTM D 6751 and EN 14214).     

Catalytic deoxygenation of unsaturated renewable feedstocks for production of diesel fuel hydrocarbons

The liquid-phase deoxygenation reaction of unsaturated renewables has been investigated in a semi-batch reactor. The reactants examined were the monounsaturated fatty acid, oleic acid, the diunsaturated fatty acid, linoleic acid and the monounsaturated fatty acid ester, methyl oleate. The reactions were carried out over a Pd/C catalyst under constant pressure and temperature in the following domain, 15-27 bar and 300-360 °C, respectively. The influence of carrier gas was additionally investigated. The impact as solvent (mesitylene) was studied as well and reaction pathways were proposed. Furthermore, continuous deoxygenation experiments were conducted, facilitating understanding of the catalyst stability and catalyst deactivation. The deoxygenation catalyst was characterized by physisorption, temperature programmed desorption (TPD), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM).     

Preparation of deuterated methyl 6,9,12-octadecatrienoates and methyl 6,9,12,15-octadecatetraenoates

Methyl 6,9,12-octadecatrienoate-15,15,16,16-d ₄ was obtained by Wittig coupling between 6,6,7,7-tetradeutero-3-nonenyltriphenylphosphonium iodide, 8, and the aldehyde ester, methyl 9-oxo-6-nonenoate. Methyl 6-oxohexanoate, obtained by ozonolysis of cyclohexene, was coupled in a Wittig reaction with [2-(1,3-dioxan-2-yl)ethyl]triphenylphosphonium bromide to give methyl 8-dioxanyl-6-octenoate. This compound was transacetalized to methyl 9,9-dimethoxy-6-nonenoate, which was then hydrolyzed to the aldehyde ester. For the preparation of compound 8, the tetrahydropyranyl ether of 2-pentynol was deuterated with deuterium gas and tris-(triphenylphosphine)chlororhodium. The tetradeuterated tetrahydropyranyl ether was converted to the bromide with triphenylphosphine dibromide, and the bromide was coupled with 3-butynol by means of lithium amide in liquid ammonia to give 3-nonynol-6,6,7,7-d ₄. Hydrogenation over Lindlar's catalyst converted the deuterated alkynol to 3-nonenol-6,6,7,7-d ₄. This deuterated alkenol was converted to the bromide with triphenylphosphine dibromide, then to the iodide with sodium iodide in acetone, and finally to 8 with triphenylphosphine in acetonitrile. Methyl 6,9,12,15-octadecatetraenoate-12,13,15,16-d ₄ was obtained by Wittig coupling between methyl 9-oxo-6-nonenoate and 3,4,6,7-tetradeutero-3,6-nonadienyltriphenylphosphonium iodide, 15. For the preparation of compound 15, the bromide obtained from the reaction of 2-pentynol with triphenylphosphine dibromide was coupled with 3-butynol with lithium amide in liquid ammonia. The resulting 3,6-nonadiynol was deuterated with deuterium gas in the presence of P-2 nickel, and the resultant deuterated nonadienol was converted to 15 through the bromide and iodide. The final products were separated from isomers formed during the synthetic sequences by silver resin chromatography.     

Optimization of polyol ester production by transesterification of Jatropha-based methyl ester with trimethylolpropane using Taguchi design of experiment

Polyol ester production from transesterification of Jatropha oil methyl ester (JOME) and trimethylolpropane (TMP) was investigated. The effects of temperature, pressure, ratio of JOME:TMP and catalyst amount were studied in optimization experiment, using Taguchi L9 experimental layout. The parameters explored were found to have a significant impact on the reaction. The order of importance of the variables was found to be pressure, temperature, JOME:TMP molar ratio and catalyst. The optimum reaction conditions were identified to be 483 K, 25 kPa; 1.0% w/w catalyst and JOME:TMP molar ratio of 4:1. At this optimum condition the JOME conversion obtained was 91.5%. Confirmation experiments were performed to demonstrate the effectiveness of this approach after the optimum levels of process parameters were determined.     

液液相转移催化法合成过氧化甲乙酮

在相转移催化剂的作用下 ,2 -丁酮由 3 0 %的双氧水氧化制取过氧化甲乙酮。通过正交试验和考察原料配比、反应温度、相转移催化剂用量、反应时间对产品质量的影响 ,确定了最佳工艺条件为 n双氧水 ∶n丁酮 =1 .5∶ 1 ,相转移催化剂采用三乙基苄基氯化铵 ,用量占总质量的 0 .4% ,在氨基磺酸的催化下 ,反应温度 5℃左右 ,反应时间 3 0 min,稀释剂用邻苯二甲酸二丁酯 ,产品经测定 ,对不饱和聚酯的凝胶时间适宜并稳定 ,产品活性氧含量高。     

松香酯化多相催化剂的研究

以浸渍法制备了ＺｎＣｌ２／Ｋａｏｌｉｎ多相催化剂，采用二元旋转回归试验设计方法，对催化剂制备过程中浸渍浓度［Ｚ１］、活化温度［Ｚ２］、及活化时间［Ｚ３］对催化剂活性的影响进行了研究，导出优化回归方程Ｙ＝－０．５５２１１７９－０．０２６６１７０Ｚ３－０．０００１５０３Ｚ１Ｚ２－０．００２９１６２Ｚ２１－０．０００００３０Ｚ２２。ＺｎＣｌ２／Ｋａｏｌｉｎ多相催化剂与ＺｎＯ均相催化剂相比，在相同的反应温度下，松香十二醇酯酯化转化率提高５．５７％，反应时间缩短９．１％；在相同反应时间内达到相同转化率时，松香乙二醇酯酯化反应温度可降低２０℃。     

Estimation equations for practical use on lightness-reflectance (L/Y) ratios in the whole chromaticity gamut

A multiple regression analysis is reported to predict L/Y ratios as a function of chromaticity coordinates x, y. the specified variables were selected statistically from the 20 terms of Ψ^mψⁿ. the quantities Ψ, ψ are the transformed values of x, y, respectively, and 1 ≦ m + n ≦ 5. the contour lines of equal L/Y ratios are estimated in the whole chromaticity gamut including spectral colors by using each of the regression equations with 6, 9, and 20 specified variables. the regression equations with 20 specified variables can satisfactorily predict the corresponding experimental results. In case of regression equations with 6 specified variables, the predicted contour lines are significantly different in shape from those of the corresponding experiments. the same defects are found in the Ware-Cowan equation only using 4 specified variables recommended by CIE Division 1 for further tests.