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1.
During direct ethoxylation of fatty methyl ester over Al-Mg composite oxide catalyst, the activity was nearly proportional to the total number of active Al acidic sites on the catalyst surface per unit weight of catalyst. Lower active Al acidic site densities resulted in a narrower ethylene oxide (EO) adduct distribution of obtained ethoxylate. We developed a new catalyst with a large surface area on which many acidic sites are distributed uniformly by partially poisoning the Al acid sites of high-Al content Al-Mg composite oxide with alkali. This catalyst was used for direct ethoxylation of fatty methyl esters to obtain ethoxylated fatty methyl esters with narrow EO adduct distribution efficiently.  相似文献   

2.
乙氧基化催化剂进展及发展方向   总被引:3,自引:0,他引:3  
非离子表面活性剂的研究在精细化工领域及表面活性剂体系中占有重要地位。而乙氧基化催化剂的研究是这一领域较为活跃的一个研究方向。结合近年来国内外相关的研究工作,从乙氧基化催化剂的发展过程、催化机理、反应动力学等几个方面综述了乙氧基化催化剂研究的最新进展,分析了影响催化活性及催化性能的各种因素,探讨了未来的发展趋势。  相似文献   

3.
For the purpose of estimating the reaction mechanism of the direct ethoxylation of a fatty ester in the presence of an Al-Mg composite oxide catalyst, a labeled fatty methyl ester C11H23CO18OCH3 containing 18O isotope was synthesized and directly ethoxylated. The product was evaluated by gas chromatography-mass spectrometry (GC-MS). The GC-MS spectra showed that the 18O isotope label was present only in the methoxy group at the molecular end of the ethoxylated fatty methyl ester. This supports the reaction mechanism of coordination anionic polymerization where the bond between the acyl and methoxy groups of the fatty methyl ester molecule was broken, caused by the bifunctional effect of the acid-base active sites; an intermediate chemisorption species was formed; and then ethylene oxide was addition-polymerized sequentially, in parallel.  相似文献   

4.
Supercritical fluid chromatographic determinations of ethylene oxide distributions in ethoxylated alcohols with subsequent computer calculations of relative propagation to initiation ethoxylation rate constants for each ethoxylated oligomer have been carried out for normal octanol under varying reaction conditions. A number of other alcohols were also ethoxylated under essentially constant conditions. In the normal octanol studies, within an approximately fifteen-fold change in absolute ethoxylation rates due to variations in temperature, pressure, and potassium hydroxide catalyst concentration, the data indicate that such changes do not affect ethylene oxide distributions. Suggestions by earlier workers of changes in relative ethoxylation rate constants with the average degree of ethoxylation were verified. Chain length for normal alcohol feeds does not affect distributions in the C-8 to C-13 range, but branching at the carbon α to the hydroxyl carbon increases the relative propagation to initiation rate constants, and a secondary alcohol exhibits an even higher ratio. Presented in part at the 80th and 81st National Meetings of the American Oil Chemists’ Society, May 1989, Cincinnati, Ohio; and April 1990; Baltimore, MD.  相似文献   

5.
半间歇搅拌釜式乙氧基化反应器的数学模拟   总被引:1,自引:0,他引:1  
以KOH催化条件下乙二醇乙氧基化为例,建立了工业规模的、同时考虑动力学、气液平衡、气液传质、反应体积变化和惰性气体氮气影响等的半间歇搅拌釜式乙氧基化反应器的数学模型。通过数学模拟考察了环氧乙烷进料速率对反应器操作的影响,得到安全限制下适宜的环氧乙烷进料速率。在此基础上,模拟得到反应器中压力、环氧乙烷在气液相中的组成及乙氧基化产物随时间的分布,并同工业试验数据进行了比较。结果表明了模型的可靠性。  相似文献   

6.
乙氧基化生产过程中,通过正交试验,找出最优工艺条件,在固定投料量的基础上,调整催化剂用量,增加熟化工艺,延长气提时间,降低产品中游离环氧乙烷(EO)含量,使得下游磺化生产中二恶烷的含量处于较低水平。  相似文献   

7.
天然脂肪醇的合成研究进展   总被引:1,自引:0,他引:1  
综述了脂肪酸甲酯中压加氢制天然脂肪醇工艺的国内外研究进展;讨论了开发新型催化剂、缓和操作工艺条件(气相加氢、添加溶剂、超临界流体)等方面的研究,指出了各种方法的优缺点;并指出虽然新型催化剂的研究取得了一定的进展,但大规模工业化应用少见报道,中压加氢工艺将是工业生产天然脂肪醇的发展方向,以超临界流体为介质的加氢工艺具备了反应压力低、氢酯比低、生产能力高和环境友好等诸多优点,具有良好的工业应用前景。  相似文献   

8.
针对近几年由于石油价格上涨给表面活性剂行业带来的压力,阐述了在洗涤剂市场中天然脂肪醇的巨大增长,重点介绍了Lurgi公司的蜡酯改进工艺、美国Davy公司的脂肪酸甲酯的特殊氢化工艺以及对全球Davy工艺技术的脂肪醇牛产装置概况。  相似文献   

9.
Lauric acid has been esterified with some C1–C18 aliphatic alcohols by a commercial lipase, Lipolase 100 L, using isooctane as a solvent. When lauric acid and fatty alcohols were taken in the mole ratio 1:1, first order kinetics were observed for all the alcohols studied. The highest reaction rate was observed for n‐butyl alcohol. Lauric acid was esterified with stearyl alcohol, in varying acid to alcohol mole ratios to explain the first order kinetics of the reaction. A kinetic model for the lipase‐catalysed esterification in a biphasic organic–aqueous system has been proposed. Based on the interfacial substrate concentration, an analytical rate equation for initial rate of the reaction was derived and confirmed with the experimental data. © 2002 Society of Chemical Industry  相似文献   

10.
我国表面活性剂“十一五”发展规划   总被引:3,自引:0,他引:3  
介绍我国表面活性剂工业的生产和发展现状、以及发展特点。我国表面活性剂产量已居世界第二位,全行业装备水平有了较大提高,且能生产50大系列所有常规表面活性剂,目前正在向绿色化、多功能、专用化方向发展。最后对我国表面活性剂工业存在的问题和差距进行了分析,并提出了相应的对策和措施。  相似文献   

11.
合成了负载型杂多酸催化剂-磷钼酸/5A分子筛,并用红外光谱对其进行了分析。探讨了杂多酸浸渍浓度,浸渍时间,焙烧温度及焙烧时间对乙醇脱水制乙烯收率的影响,实验表明:杂多酸浸渍浓度0.002moL.L-1,浸渍回流时间24h,焙烧温度400℃,焙烧时间4h,催化剂活性最高,乙烯收率可达98.9%以上。  相似文献   

12.
研究了亚临界条件下不同醇与油酸的催化酯化反应,考察了在醇油摩尔比为4∶1,反应温度在醇的临界点附近时,亚临界醇与油酸酯化反应转化率随时间变化的规律。结果表明,亚临界条件下醇与油酸催化酯化转化率与醇的种类、临界点和结构有关;直链醇的碳链越短,反应温度越接近其临界点,反应速率越快;直链醇的酯化反应速率高于支链醇,支链醇中伯醇反应速率高于仲醇。  相似文献   

13.
椰油甲酯中压加氢制脂肪醇动力学研究   总被引:1,自引:0,他引:1  
使用装有20mL催化剂的固定床反应器,在反应温度515K~533K、反应压力4 5MPa~9 0MPa、椰子油甲酯流量8 4mL·h-1~21 6mL·h-1及氢气标准流量100L·h-1~190L·h-1的反应条件下,采用均匀设计方法,安排了实验全过程。通过对实验取得的一系列椰子油甲酯加氢制脂肪醇转化率试验数据,根据化学反应方程式和滴流床反应器模型进行了逐步回归数理统计分析处理,确定了反应动力学参数,建立了反应动力学模型,得出由转化率表示的动力学方程。得到的结论是在实验条件下甲酯中压催化加氢制脂肪醇反应为滴流床型式,滴流床指数0 426,反应级数2级。  相似文献   

14.
脂肪醇聚氧乙烯醚磷酸酯三乙醇胺盐的研制及其应用   总被引:1,自引:0,他引:1  
以脂肪醇和环氧乙烷为原料,五氧化二磷为酯化剂,三乙醇胺为中和剂,合成了脂肪醇聚氧乙烯醚磷酸酯三乙醇胺盐,对其合成工艺及其复配油剂在腈纶上的应用进行了研究。结果表明,最佳合成工艺条件为:环氧乙烷与脂肪醇的摩尔比为2.0,脂肪醇聚氧乙烯醚与五氧化二磷的摩尔比为3.8,五氧化二磷投料时间1.5 h,酯化温度70℃,酯化反应时间3.0 h,三乙醇胺的加入量是脂肪醇聚氧乙烯醚磷酸酯的0.73-0.76 倍。用酯肪醇聚氧乙烯醚磷酸酯三乙醇胺盐为单体复配的油剂,其在腈纶中的应用情况与进口日本油剂相当。  相似文献   

15.
通过浸渍法结合液相还原法将金属Pt,Ni和Sn负载在活性炭上制备了多组分Pt/C催化剂,并应用于催化氧化直接制备醇醚羧酸的反应中,考察了催化剂组分不同对脂肪醇聚氧乙烯醚(AEO9)氧化法制备醇醚羧酸(AE9C)过程中催化性能的影响;采用TEM,XRD和XPS对催化剂进行了表征。结果表明,在Pt/C催化剂中加入Ni和Sn后,Pt的颗粒粒径变小,分散性更好,Pt0的含量增加,从而提高了催化剂的活性。多组分Pt/C催化剂与单一组分Pt/C催化剂相比,AE9C产率提高了27.54百分点。  相似文献   

16.
安维中  孟霞  李宏熙  周立明  朱建民 《化工学报》2012,63(11):3602-3608
以正丁醇和环氧乙烷为原料合成乙二醇正丁醚(EGMBE)为例,利用数学模型和模拟分析方法,研究了包含大量反应热效应的乙氧基化反应精馏(ERD)塔中反应热的利用及系统能量优化问题。研究表明,当采用常规的、将反应段直接叠加于提馏段之上的塔设计时,反应热并没有贡献于分离操作或减小再沸器的热负荷,而只是被冷凝器中的冷却介质移走。分析了反应热的可利用途径,提出一种将反应段和提馏段分割、从反应段移出反应热供提馏段加热的内部热集成乙氧基化反应精馏结构--IHIERD。模拟结果表明,IHIERD 将使再沸器的温度从462.5 K降低到420.0 K,冷凝器负荷降低11%,外部能量输入降低14%,节能效果显著。  相似文献   

17.
脂肪醇聚氧乙烯醚的厌氧与好氧生物降解性   总被引:9,自引:0,他引:9  
以脂肪醇聚氧乙烯醚(AEO)为目标污染物,在等同条件下做厌氧消化污泥和好氧活性污泥对其生物降解性能的对比实验,得出了同一系列AEO分子中聚氧乙烯基与整个分子的降解难易程度的关系。表明:①污泥会对AEO分子产生吸附一脱附作用而出现假降解率,克服假降解率的干扰是准确测定AEO生物降解性的关键因素;②厌氧和好氧条件下,AEO均可降解,但厌氧降解要稍优于好氧降解;③AEO中聚氧乙烯基的单元数(n)是影响其生物降解的重要因素,相同碳链的直链烷基,生物降解率随n的增加而明显降低。  相似文献   

18.
This study was designed to determine digestibilities of fatty acid monomers, dimers and polymers as components of diets containing thermally oxidized oils. Male Wistar rats were fed semipurified diets supplemented with unheated, heated and a 1:1 mixture of unheated/heated olive oils at 6, 12 and 20% w/w of diet. In a 14-d experimental period, fecal lipids were extracted and analyzed by a combination of adsorption and high-performance size-exclusion chromatographies. Thus, it was possible to separate and quantitate five groups of fatty acids—nonpolar monomers, oxidized monomers, nonpolar dimers, oxidized dimers and polymers. Nonpolar fatty acid monomers showed high digestibilities, although significantly influenced by the alteration level of the dietary oil. The apparent absorption of oxidized fatty acid monomers averaged 76.6%. Among polymeric fatty acids, the lowest digestibilities were found for nonpolar dimers (10.9% on average), whereas oxidized dimers and polymers possessed higher apparent absorbability than expected, ranging from 22.7% to 49.6%. Chemical modifications prior to absorption, leading to less complex products, may have contributed to enhanced digestibility of polymers.  相似文献   

19.
国内脂肪醇市场现状与发展趋势(续前)   总被引:2,自引:0,他引:2  
上述4家国内资本投入的脂肪醇项目,将在2007年脂肪醇生产能力开始增加至11.9万t。加上外资投入的16万t,至2008年我国的脂肪醇生产能力将比现在增加27.9万t。在短短的3年时间内,中国脂肪醇产能迅速增加,供过于求的局面已成定局。2006年国内脂肪醇生产能力最新统计见表4。  相似文献   

20.
Boron esters B(OR)3, readily derived from boric acid and alcohols, combine with iodide or bromide to catalyze the ethoxylation of alcohols and phenols, giving good rates and narrow product distributions. The combined action of a weak electrophile [B(OR)3] and a weak nucleophile (halide) allows for the ethoxylation of base‐sensitive alcohols. Experiment suggests a new mechanism for this commercially important reaction proceeding through key β‐haloalkoxy intermediates.  相似文献   

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