影响甲酯油与氯磺酸反应的因素研究

实验对不饱和甲酯油与氯磺酸进行磺酸化反应进行了研究,探讨了加料方式、原料配比、加料温度、保温反应温度对甲酯油与氯磺酸反应的影响。根据反应所得甲酯磺酸盐乳液的稳定性和磺化深度,确定了甲酯油与氯磺酸反应适宜条件:氯磺酸用量为40%、保温反应温度为60℃,最高磺化深度可以达到40.6%。

温度和乙醇对麻风树油甲酯蒸发特性的影响

为了探究温度和乙醇对麻风树油甲酯(JME)液滴蒸发特性的影响,采用挂滴式实验方法,在973和1073 K的温度下,研究不同乙醇添加量(0%,10%,50%)的JME液滴(JME,JME-E10和JME-E50)的蒸发过程,分析了温度与乙醇含量对燃油单液滴蒸发归一化直径平方的影响。结果显示:973 K时的燃油液滴的蒸发特性与1073 K时的燃油液滴的蒸发特性有明显差异,蒸发特性曲线不能简单地分为瞬态加热阶段、波动蒸发阶段和平衡蒸发阶段这3个阶段。环境温度和乙醇添加量都会在一定程度上影响麻风树油甲酯生物油的蒸发。在高温条件下,液滴中含有的易挥发成分形成气泡使得液滴膨胀发生微爆,并且单液滴的环境温度越高,蒸发时间越短,这是因为在骤变之前液滴的膨胀速率大于蒸发速率。液滴内存在气泡,且不断变大,这是因为气泡因内部压力大于环境压力而向液滴表面移动,气泡达到最大时,发生微爆。在973和1073 K时,JME有一段时间处于平衡蒸发,符合D^(2)定律,而JME-E10和JME-E50则不同,其在蒸发阶段液滴直径波动很大且蒸发过程中还发生了聚合反应。液滴随着温度增加平均蒸发速率变大,JME-E50在1073 K时,蒸发速率最大。3种燃油在不同温度下蒸发,最终都有少许残渣,这是因为不饱和组分发生聚合反应生成了高分子聚合物。

棉油甲酯异构化反应规律的研究

通过紫外光谱分析对棉油甲酯的异构化反应规律进行了研究 ,以碘为异构化催化剂催化活性高于二茂铁 ,通过实验确定了适宜的异构化反应条件为 :反应温度 180℃、反应时间 5h、催化剂用量为 0 .3% ,反应应在氮气保护的情况下进行 ,亚油酸的转化率为 5 6 .1%。

异构化棉油甲酯中共轭亚油酸的定量分析研究

研究了棉油甲酯在碘的催化下发生异构化反应的规律 ,运用气质联用仪和紫外光谱对异构化产物的成分进行了分析。在最佳的异构化条件下 ,异构化棉油甲酯中共轭亚油酸质量分数可达 31.2 % ,共轭转化率 5 6 % ;根据不同质量浓度样品的紫外吸收曲线找出样品质量浓度与吸光度之间的线性关系 ,并参照气质联用分析的共轭亚油酸质量分数结果 ,得出紫外光谱法分析计算异构化产物中共轭亚油酸质量分数的经验公式为 :ω(CLA) =0 .0 0 80 1A/C ,吸光系数为 0 .0 0 80 1,适宜的质量浓度为 0 .0 2～ 0 .0 4g/L ,误差小于 5 %。实验证实紫外光谱法是分析测定棉油甲酯异构化产物中共轭亚油酸的一种简便。

柴油机燃用麻疯树油甲酯的氮氧化物排放特性

研究了柴油机燃用麻疯树油甲酯的NOx排放特性。以1台轻型车用直喷式柴油机为试验样机,分别燃用6种不同生物柴油掺混比例的混合燃油,研究总的NOx排放以及NO,NO2,N2O等NOx主要组分的排放特性。结果表明,燃用各种混合燃油的NOx排放曲线形态较为接近,低负荷时差异较小,随负荷增加,排放差异增大。NOx排放以NO和NO2为主,NO排放随着负荷上升而增加,NO在总NOx排放中始终占有最高比例。NO2排放也占有相当比例,在低负荷时较高,随着负荷增大浓度降低,大负荷高温不利于NO2的生成。N2O排放量极低,在中低负荷时有一定生成量,高负荷N2O排放几乎为0,缸内稀燃低温有利于N2O排放的生成。在同一稳定工况下,随生物柴油混合比的提高,NOx,NO,NO2比排放量呈线性增加,N2O比排放量呈线性降低。发动机燃烧生物柴油后,NOx及其组分NO,NO2和N2O的排放量发生改变,而各自的排放变化规律并未发生变化。

棉油甲酯异构化反应规律的研究——共轭亚油酸含量的测定

研究了棉油甲酯在碘的催化下发生异构化反应的规律。运用气质联用仪和紫外光谱对异构产物的成分进行了分析,根据不同浓度样品的紫外吸收曲线找出样品浓度与吸光度之间的线性关系,并与气质联用分析结果相结合,得出计算异构产物中共轭亚油酸含量的经验公式。

麻风树油甲酯生物柴油着火与火焰发展特性研究

基于高压可视化定容燃烧弹试验台,利用高速相机和光学系统研究了在高压环境条件下麻风树油甲酯(JME)燃料着火与火焰发展特性。分析了燃烧在不同工况下,燃油的点火延迟和火焰浮起长度随喷射时间发展的变化规律。结果表明:在环境温度为773K,环境密度为21 kg/m^(3)工况下,随着氧浓度的增加,低氧浓度区域点火延迟先减少,在高氧浓度区域时基本保持不变,而在823 K的工况下则相反。而当氧气含量为15%,环境温度为823 K时,火焰浮起长度随环境密度增加而减小,相较于773K,高温的火焰浮起长度始终小于低温燃料的火焰浮起长度,是由于环境温度越高喷雾卷吸获得的内能越多,可燃混合气形成的速度加快,导致气相喷雾贯穿距增加,从而火焰浮起长度增加。

麻疯树油甲酯喷雾特性试验

基于高压可视化定容燃烧弹试验台,利用高速相机和光学系统在高压环境条件下对麻疯树油甲酯(JME)燃料的雾化特性进行研究,分析了不同试验条件下气相喷雾贯穿距和喷雾锥角的影响规律。结果表明:随着喷射时间的增加,JME燃料的喷雾贯穿距离呈现先增大后趋于稳定的趋势,且环境密度对其影响最大;喷雾锥角最大值出现在环境温度为823 K,环境密度为21 kg/m^(3),氧质量分数为15%的条件下。

低共熔溶剂中钯催化脂肪酸甲酯加氢反应的研究

为了在不影响生物柴油(脂肪酸甲酯)低温流动性的情况下提高其氧化稳定性,可对生物柴油进行选择性氢化,将多不饱和脂肪酸甲酯氢化为单不饱和脂肪酸甲酯。以低共熔溶剂(DES)为溶剂,使用PdCl2为催化剂,对脂肪酸甲酯的选择性氢化进行了研究。以亚油酸甲酯完全氢化为油酸甲酯时的碘值(76 g/100 g)作为反应的评价标准,得到的最佳反应条件为:以氯化胆碱和尿素合成的DES为溶剂、氯化钯与葵花籽油脂肪酸甲酯的物质的量的比为1∶20,反应温度60℃,转速600 r/min,此时氢化产品的碘值最低(87 g/100 g)。且氢化脂肪酸甲酯中,油酸甲酯的含量为74.19%,亚油酸甲酯的含量为13.44%,饱和脂肪酸甲酯含量几乎没有变化。

植物油制备生物柴油

报道了植物油在KOH为催化剂的作用下通过甲醇酯交换反应生成脂肪酸甲酯即生物柴油的试验研究。考察了反应条件如原料油、醇油比、催化剂用量、反应温度、反应时间等的变化对转化率和产品纯度的影响。采用气相色谱法测定反应体系中脂肪酸甲酯的含量。应用正交实验的方法找出精棉籽油酯交换反应的最佳反应条件为 :反应温度 45℃ ,醇油物质的量比 6∶1,催化剂用量 1 1% ,反应时间 60min。在此反应条件下原料油转化率可达 98 3 3 % ,粗产品得率可达 99 83 %。实验放大所得的生物柴油主要质量指标已达到ASTM生物柴油质量标准。

烃羧基硅油PHMS-g-AA的制备与表征

采用直接在聚硅氧烷链上引入含烃羧酸甲酯基基团,经水解制备烃羧基硅油的路线,与传统的制备方法相比,该合成路线简捷,反应产物得率较高。

直喷式柴油机燃用葵花籽油燃烧特性分析

在一台直喷式增压柴油机上进行了柴油、葵花籽油及其甲酯的性能试验,研究其燃烧放热规律。通过对实验结果的分析,发现葵花籽油及其甲酯的滞燃期比0#柴油长;葵花籽油甲酯的瞬时放热率峰值下降,燃烧持续期缩短。

稻米油酰基丝氨酸钠的合成及性能

以自制稻米油甲酯、丝氨酸为主要原料,通过酰胺化反应合成氨基酸型表面活性剂稻米油酰基丝氨酸钠。通过傅立叶红外光谱、核磁共振氢谱对产品进行结构表征,对合成产品的表面张力、增溶、乳化、泡沫、去污、润湿、抗硬水等性能进行研究。结果表明,稻米油酰基丝氨酸钠的收率可达91.73%,采用溴甲酚绿两相滴定法测得总活性物质量分数为78.5%。稻米油酰基丝氨酸钠具有较好的表面活性和增溶性,同时具有优良的乳化性、泡沫性、去污性、润湿性等性能。

Modification of methyl oleate for silicon-based biological lubricating base oil

A new kind of silicon-based biological lubricating base oil with good viscosity-temperature behavior,viscosity index,thermostability,oxidation stability and wear resistance performance was synthesized as a derivative of methyl oleate.Trimethylsilylation reaction was introduced to further improve methyl oleate oxidation stability and lubricity after epoxidation and open-ring reactions.The order of effectiveness of acid binding agent was N,N-diisopropylethylamine(DIEA) > pyridine > diethylamine > triethylamine,and the effects of various parameters on the trimethylsilylation reaction as well as on the silicon-oxygen bond stability and reaction yield were studied.A maximum yield of 34.54%was achieved at hydroxyl/trimethyl chlorosilane/DIEA molar ratio of1:1.25:1,reaction temperature 40℃,reaction time 1.5 h.

Green and efficient epoxidation of methyl oleate over hierarchical TS-1

The epoxidation of methyl oleate(MO)was conducted in the presence of aqueous H2O2 as the oxidant and hierarchical TS-1(HTS-1)as the catalyst;the catalyst was synthesized using polyquaternium-6 as the mesopore template.The effects of various parameters,i.e.,H2O2/C=C molar ratio,oxidant concentration,amount of the catalyst,reaction temperature,and time,were systematically studied.Furthermore,response surface methodology(RSM)was used to optimize the conditions to maximize the yield of epoxy MO and to evaluate the significance and interplay of the factors affecting the epoxy MO production.The H2O2/C=C molar ratio and catalyst amount were the determining factors for MO epoxidation,wherein the maximum yield of epoxy MO reached 94.9%over HTS-1 under the optimal conditions.

Pyrolysis Characteristics and Kinetics of Methyl Oleate Based on TG-FTIR Method

The thermal decomposition characteristics of methyl oleate were preliminarily investigated under nitrogen atmo-sphere by a thermogravimetric analyzer when the ester was heated at a heating rate of 10℃/min from room temperature to 600℃. Furthermore, the pyrolytic and kinetic characteristics of methyl oleate were intensively studied at different heating rates. The gaseous species obtained during thermal decomposition were also identiifed by the TG-FTIR coupling analysis. The results showed that the pyrolysis of methyl oleate proceeded in three stages, viz. the drying stage, the main pyrolysis stage and the residual pyrolysis stage. The initial decomposition temperature, the maximum weight loss temperature, the peak decomposition temperature and the rate of maximum weight loss of methyl oleate increased with the increasing heating rates. Gaseous CO, CO2 and H2O were the typical decomposition products from pyrolysis of methyl oleate. In addition, a kinetic model for thermal decomposition of methyl oleate was built up based on the experimental results using the Coats-Redfern integral method and the multiplelinear regression method. The activation energy, the preexponential factor, the reaction order and the kinetic equation for thermal decomposition of methyl oleate were obtained. Comparison of the experimental data with the calculated ones and analysis of statistical errors of pyrolysis ratios demonstrated that the kinetic model was reliable for studying the pyrolysis of methyl oleate. Finally, the kinetic compensation effect between the preexponential factors and the activation energy in the pyrolysis of methyl oleate was also conifrmed.

Relationship between Ethanol and 2-phenylethanol Stress Tolerance and Fatty Acid Compositions of Saccharomyces cerevisiae

In the present study, we investigated of the ethanol （Eth）, 2-phenylethanol （2-PE） and ethanol/2-phenylethanol （Eth/2-PE） stress tolerance and established relationship between stress tolerance and fatty acid compositions of wine yeast strain S. cerevisiae UCM Y-524 in relation to different cultivation factors. Changes in cell membrane fatty acid profiles studied under different temperature and media. The active oxygenation, semi-aerobic cultivation supplemented Tween 80 conditions were used in different combinations. The concentrations of 2-PE and Eth, the fatty acids methyl esters （FAMES） in the media were measured by GC-MS analyses. 2-PE, Eth, FAMES were identified by NIST02 MS database at the 2-PE and Eth standard solution （Merck, Germany）, bacterial FAMES standard （Supelco）. Palmitoleic and oleic acid were dominated for S. cerevisiae UCM Y-524. The unsaturated/saturated fatty acid （UFA/SFA） ratio was higher than five for S. cerevisiae UCM Y-524 at 14 ~C in simple medium and about more than three for other conditions. It has been found that yeast cells grown in the presence of the 2-PE, Eth and Eth/2-PE appear to increase the amount of unsaturated fatty acids, especially oleic acid, in cellular lipids especially under active oxygenation supplemented with Tween 80. S. cerevisiae UCM Y-524 has a higher tolerance under 2-PE, Eth and Eth/2-PE stress at 28 ~C in a simple medium under aerobic conditions. A higher concentration of unsaturated fatty acids in the membrane S. cerevisiae UCM Y-524 and a lower temperature under aerobic conditions, has been considered to have a positive influence on the excretion of 2-phenylethanol.

Solid Acid Used as Highly Efficient Catalyst for Esterification of Free Fatty Acids with Alcohols

Anovel solid acid catalyst, which was prepared from sodium alginate (SA) and metal chlorides and characterized with XRD and FT-IR spectrometry, was used for the preparation of biodiesel via esterification reaction. The study results showed that the aluminum-alginate complex prepared in a cheap and easy way exhibited high catalytic activity, and a 92.6% conversion of methyl oleate was obtained in the presence of 4m% of catalyst dosage upon refluxing for 3h of methanol and acid mixed in a molar ratio of 10:1. It should be noted that the catalyst can be applied to the esterification reaction of fatty acids with various carbon chain length on methanol or different short chain alcohols, indicating that the catalyst is suitable for the preparation of biodiesel from waste oils with a high acid value.

Enzymatic Synthesis of Fatty Acid Methyl Esters from Crude Rice Bran Oil with Immobilized Candida sp. 99-125

The non-edible crude rice bran oil was extracted from white rice bran, and then was catalyzed by immobilized lipase for biodiesel production in this study. The effects of water content, oil/methanol molar ratio, temperature, enzyme amount, solvent,number of methanol added times and two-step methanolysis by using Candida sp. 99-125 as catalyst were investigated. The optimal conditions for processing 1 g rice bran oil were: 0.2 g immobilized lipase, 2 ml n-hexane as solvent, 20% water based on the rice bran oil mass, temperature of 40 °C and two-step addition of methanol. As a result, the fatty acid methyl esters yield was 87.4%. The immobilized lipase was proved to be stable when it was used repeatedly for 7 cycles.

GC-MS Spectrums and Their Close Match Methyl Esters from Mushrooms of Papua New Guinea

The GC-MS spectrums of a sample from Amanitaceae family and Mycenaceae family were matched with their close match GC-MS spectrums from the spectrum library. The samples from Amanitaceae family （KMsp027） and Mycenaceae family （KMsp039） were found to contain fatty acid methyl esters （methyl palmitate and methyl linoleate）. It is proposed that the presence of methyl linoleate and methyl palmitate in the samples may show antibacterial activities if tested against different bacterial strains.