磷钼杂多酸催化合成乙酸乙酯的研究

以磷钼杂多酸为催化剂，以乙醇和乙酸为原料合成乙酸乙酯。经实验确定了最佳反应条件：酸醇比为2．5：1—3．0：1磷钼酸用量为酸质量的2．5％一3．0％，反应时间为4．5h，酯化率达94％以上。     

硫酸铁催化合成乙酸乙酯工艺研究

以硫酸铁为催化剂，合成乙酸乙酯，探讨影响酯化反应的各种因素，在最佳反应条件催化剂占物料总量6．5％，酸醇比为1：1．5，反应时间为30min时，乙酸的转化率可达98．1％，精酯收率达93．5％。     

纳米稀土复合超强酸SO42-/ZrO2-La2O3催化合成乙酸冰片酯及其动力学初探

采用纳米稀土复合固体超强酸SO4^2-／ZrO2-La2O3催化合成乙酸冰片酯，并对反应条件和该反应的动力学进行了探究。结果表明，在反应温度为120℃，催化剂用量为天然冰片质量的6％．天然冰片与乙酸的摩尔比为1：6，反应时间为8h时，反应的酯化率和选择性可达到93．14％和99．8％．研究发现，该催化剂可重复使用，并能活化再生。给出了反应速率方程，测出了反应的活化能。     

微波催化酯化合成乙酸乙酯

在铌酸的催化下，采用微波辐射技术，快速合成了乙酸乙酯。最佳反应条件为：乙酸和乙醇的摩尔比为4：1（mol/mol)，催化剂0.8g，微波功率336W，微波辐射时间8min，转化率91．5％。     

微波辐射硫酸铁铵催化合成乙酸正丁酯的研究

以硫酸铁铵为催化剂,采用微波辐射的方法催化合成乙酸正丁酯。讨论了微波辐射的功率、反应时间、酸醇摩尔比、催化剂的用量以及分水因素对酯化反应的影响。通过单因素实验确定合成乙酸正丁酯的最佳反应条件为：微波辐射功率为240W,辐射时间为15min,催化剂用量为1．3g,酸醇比为1．2：1．0,酯化率为98．2％。本方法具有反应时间短、反应条件温和、后处理简单且环保无污染等特点。     

微波辐射硅钨酸催化合成乙酸异戊酯

以硅钨酸作催化剂，4A分子筛为脱水剂，采用微波辐射技术，乙酸和异戊醇直接合成乙酸异戊酯，考察了催化剂用量，微波辐射功率，时间，乙酸与异戊醇物质的量比对反应转化率的影响，最佳反应条件为：乙酸与硅钨酸物质的量的比为1：0．001384，微波辐射功率及时间为340W，20min，乙酸，异戊醇物质的量比为1：1．5，此条件下乙酸转化率为97％。     

Fe^3＋／HZSM-5分子筛催化合成乙酸乙酯

以固体超强酸Fe^3 ／HZSM-5为催化剂，以乙醇和乙酸为原料合成乙酸乙酯。考察了催化剂用量、酸醇比、反应温度及反应时间对酯化率的影响。结果表明，催化剂用量为(重量)反应液重的5％，酸醇比为2．5：1，反应温度为110-130℃，反应时间为3h．酯收率为93％．     

磷钼钒杂多酸催化合成乙酸正丁酯的研究

研究了以乙酸和正丁醇为原料,磷钼钒杂多酸为催化剂合成乙酸正丁酯的反应,考察了原料醇酸物质的量比、反应时间、反应温度、催化剂用量等因素对酯化反应的影响,经过试验确定了合成乙酸正丁酯的较佳工艺条件,醇酸物质的量比为1．2：1,磷钼钒杂多酸催化剂用量为反应液总量的0．6％,反应时间为85min,反应温度为115℃,在此条件下,乙酸正丁酯的收率为93％-95％。     

离子液体催化反应精馏合成乙酸乙酯工艺模拟

为研究离子液体在反应精馏中的作用,采用离子液体1-丁基-3-甲基咪唑硫酸氢盐（[BMIM]HSO₄）作为催化剂,对乙酸和乙醇合成乙酸乙酯的反应精馏流程进行了计算模拟。在确定了参数的酯化反应动力学的基础上,用Aspen Plus软件建立了反应精馏流程,研究了催化剂用量、精馏段理论板数、反应段理论板数、乙醇进料位置、进料摩尔比、持液量及回流比等参数对反应精馏过程的影响。研究结果表明,塔顶乙酸乙酯的质量分数随催化剂用量、精馏段理论板数、反应段理论板数和持液量增大而增大,工艺流程存在最佳回流比以及最佳进料酸醇摩尔比。得到的优化条件如下：离子液体与乙酸摩尔比为1：2.5,进料酸醇摩尔比为4：1,理论塔板数为21块,乙酸和催化剂在第7块理论塔板进料,乙醇在第19块理论塔板进料,塔板持液量0.1L,回流比为4,塔顶乙酸乙酯的质量分数可以达到98.73%。     

固体酸S2O28-/Fe2O3-SiO2催化合成乙酸丁酯的研究

本文研究了以S2O^28^-／Fe2O3-SiO2固体酸为催化剂，以乙酸、丁醇为原料合成乙酸丁酯，考察了影响反应的因素，结果表明最佳工艺条件是：固体酸催化剂前驱体经微波陈化处理，醇酸摩尔比为1．2：1，催化剂用量为0．8g(乙酸用量为0．2mol的情况下)，带水剂为10mL，反应时间为3．0h，酯化可达到97．7％，可重复利用6次以上。     

固体酸SG/p-TSA催化合成乙酸乙酯

采用浸渍法制备硅胶(SG)/对甲苯磺酸(p-TSA)催化剂,并用XRD对其进行了表征。利用冰醋酸和无水乙醇为原料,以SG/p-TSA为催化剂合成乙酸乙酯。考察了反应时间,催化剂的用量,原料配比等对该反应的影响。最佳合成条件为:反应温度为100℃,反应时间为100 min,酸醇摩尔比为1.0∶1.9,催化剂用量为5%,产率为95.40%。催化剂不经处理可重复使用,使用3次以后的产率为81.11%。     

硅胶固定化咪唑酸性离子液体的合成及在酯化反应中的应用

为了减少离子液体用量,缩短反应时间,提高酯化反应的催化效率,该文以硅胶为原料与-γ(2,3-环氧丙氧基)丙基三甲氧基硅烷(KH-560)反应,合成了环氧基硅烷化硅胶,再与1-甲基咪唑硫酸氢盐发生开环反应,制备了一种硅胶固定化1-甲基咪唑硫酸氢盐离子液体。探讨了该离子液体在无机酸促进下对合成乙酸乙酯反应中原料摩尔比、酸的用量及离子液体用量等因素对反应的影响。实验表明,当n(乙醇)∶n(乙酸)=1.5∶1,该固定化离子液体用量为1.00 g,盐酸用量为2.0 mL时,乙酸乙酯的最高产率可达90.0%。固定化离子液体重复使用5次,酯的产率由90.0%降至85.1%。将该固定化离子液体应用于催化乙酸异戊酯、苯甲酸乙酯、草酸二乙酯、乙酸正丁酯和马来酸二乙酯的合成,酯的产率比仅用盐酸单组分催化分别提高了20.4%、25.6%、28.2%、22.3%和16.1%。通过简单滤除就可实现离子液体与产物的分离。     

Coproduction of Ethyl Acetate and n‐Butyl Acetate by Using a Reactive Dividing‐Wall Column

The performance of the reactive distillation dividing‐wall column for coproduction of ethyl acetate and butyl acetate was experimentally studied. n‐Butanol and ethanol are raw reaction materials that react with acetic acid in the reaction zone to produce n‐butyl acetate and ethyl acetate, respectively. n‐Butyl acetate is not only a product, but also acts to remove water generated by the esterification reactions. The effects of various parameters, such as catalyst loading per stage, reflux ratio, liquid split and molar feed ratios, ethyl acetate/n‐butyl acetate purity, pressure drop, and total energy consumption, are investigated. Results show that ethanol could be completely converted and the products could be easily separated, which shows great industrial application potential in the coproduction of ethyl acetate and n‐butyl acetate.     

Transesterification of supercritical ethyl acetate by higher alcohol

The transesterification of supercritical ethyl acetate by a higher alcohol occurred at 573 K without the further addition of catalysts. The transesterification by a primary alcohol apparently obeyed zero-order kinetics with respect to ethyl acetate and the primary alcohol during most of the reaction. The transesterification was assumed to be a two-step reaction. The initial step is the hydrolysis of the supercritical ethyl acetate to acetic acid by the small amount of water in the reaction system. The later step is the esterification of the generated acetic acid with the higher alcohol. When a primary alcohol was used as the reaction partner for the supercritical ethyl acetate, a high yield of the transesterified product was obtained. On the other hand, when a secondary alcohol was used, a moderate yield was obtained. The moderate yield with a secondary alcohol would be due to the transformation of the transesterified product into unknown products.     

磷钨酸催化反应精馏合成乙酸乙酯的研究

以乙酸和乙醇为原料、以杂多酸磷钨酸为催化剂,采用间歇式进料、反应精馏技术合成乙酸乙酯,对合成工艺条件进行了研究,时产物组成进行了气相色谱分析.确定反应精馏法合成乙酸乙酯的最佳工艺条件为:反应温度84～90℃、酸醇体积比1.4:1、回流比4:1、反应时间1.5 h、催化剂用量0.9 g,在此条件下,乙酸转化率达到83%、...     

Hydrolysis and oxidative decomposition of ethyl acetate in sub- and super-critical water

Hydrolysis of ethyl acetate in sub-critical (633 K, 200 bar) and super-critical water (673 K, 240 bar) has been investigated in a tubular flow reactor as a model reaction for the depolymerisation of polyesters. Super-critical reaction conditions enable approximately a 10-fold hydrolysis rate in comparison to sub-critical process. The reaction products ethanol and acetic acid are stable under these conditions. Additionally, oxidative decomposition experiments were carried out using ethyl acetate, ethanol and acetic acid as feed in the presence of air, non-catalysed as well as in the presence of a heterogeneous MnO₂–CuO/Al₂O₃ catalyst (Carulite 150^®). The catalyst caused only slight increase of ethyl acetate conversion in oxidation compared to hydrolysis, but a noticeable increase in CO₂ formation due to destruction of ethanol and acetic acid. In absence of catalyst, the degrees of conversion and selectivities were not affected by addition of oxygen. Fresh and spent catalysts were characterised with standard methods (BET, ICP), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The catalyst material was identified as chemically and mechanically stable under the applied reaction conditions, however, a significant sintering accompanied by a deep structural alteration and a slight reduction were observed. Additionally, the stability of reactor material regarding to corrosion was also tested.     

SO4^2-ZrO2固体超强酸催化合成乙酸乙酯的研究

利用中心组合设计试验考察醇酸比、反应温度、催化剂用量和反应时间4个因素对SO4^2-ZrO2固体超强酸催化合成乙酸乙酯的影响,运用响应面法对其工艺参数进行优化。研究结果表明,根据试验数据建立的二次回归数学模型具有高度显著性（P〈0．0001）,相关系数R^2=0．9854．说明预测值和试验值之间具有很好的拟合度,可用此模型来分析和预测SO4^2-ZrO2固体超强酸催化合成乙酸乙酯的转化率。通过对二次回归数学模型解逆矩阵得到SO4^2-ZrO2固体超强酸催化合成乙酸乙酯的最优化条件为：醇酸比3：1、反应温度84．98℃、催化剂用最3．02％和反应时间3h,在此条件下,乙酸转化率的预测值为96．45％。试验值为85．87％,二者相对偏差为0．60％。因此,利用响应面分析法进行SO4^2-ZrO2固体超强酸催化合成乙酸乙酯的工艺参数的优化是可行可靠的,可以较好地预测乙酸的转化率。     

Ozonolysis of Canola Oil: A Study of Product Yields and Ozonolysis Kinetics in Different Solvent Systems

The use of ozonolysis has been proposed as a step in the production of vegetable-oil-based polyols as replacements for the equivalent petrochemicals. As part of an evaluation of the commercial viability of ozonolysis, the intermediates and products formed from the ozonolysis of canola oil using different protic and aprotic solvents and solvent mixtures were systematically studied by GC-FID and size-exclusion chromatography with refractive index detection (SEC-RI). It was found that the use of an aprotic solvent (ethyl acetate) leads to the formation of oligomeric ozonolysis products whereas alcohols and/or mixtures of ethyl acetate with alcohols for the ozonolysis of canola oil do not form high molecular weight compounds. In addition, when ethyl acetate is used as the solvent, the formation of carboxylic acids is observed in the early stages of ozonolysis whereas the use of alcohols significantly reduces acid formation. As expected, extending the ozonolysis time led to extensive carboxylic acid formation, especially using ethyl acetate as a solvent. It was found that the optimum time for the complete ozonolysis of canola oil was largely independent of the solvent used for ozonolysis. However, the yield of ozonolysis products differs considerably depending on the solvents employed. Overall, a clear correlation between the ozonolysis time, product yields and the reaction exothermicity was observed.     

Brnsted酸型离子液体[Emim]HSO_4催化酯化反应的研究

以吡啶为探针分子,采用红外光谱对合成的离子液体[Emim]HSO4的酸性进行了表征。以[Emim]HSO4离子液体为催化剂研究了乙酸和乙醇的酯化反应。考察了反应温度、反应时间和离子液体／反应物量比对酯化反应的影响．实验得到的优化反应条件为：反应温度40℃,反应时间1h,离子液体：反应物：1：5时,乙酸的转化率为76．73％,乙酸乙酯的选择性为100％。反应后离子液体易于与反应产物分离。     

单塔连续制备乙酸乙酯工艺研究

采用反应精馏技术,连续合成乙酸乙酯,通过加入带水剂,使反应生成的水完全带出。在选择的实验条件下,塔顶粗酯产品中乙酸乙酯含量达到91％以上,基本不含酸。塔顶粗酯直接用盐液萃取,可获得符合GB3728—91合格品要求的乙酸乙酯产品。