反应精馏—萃取联合过程合成乙酸乙酯的研究

将固体酸作为主催化剂与不锈钢填料以一定的规律置于反应精馏塔中，以一路易斯酸作为辅助催化剂置于塔釜中，采用反应精馏的形式连续合成乙酸乙酯。塔顶全部酯相经萃取脱去水后再引出部分回流到反应精馏塔塔顶，构成了反应精馏－萃取联合过程。该过程酯化转化率高，酯相带水能力强，减少了回流比，降低了能耗，提高了设各的生产能力。     

醋酸乙酯生产装置中精馏分离系统的模拟和优化

本文采用Aspen Plus模拟软件对现有的醋酸乙酯生产装置中精馏分离系统进行了模拟和优化,考察了回流比、回流温度和进料温度等因素对酯化塔塔顶粗酯和精制塔塔底醋酸乙酯产品质量的影响,进一步优化了醋酸乙酯工业生产条件。模拟优化结果表明,酯化塔最佳操作条件为塔顶回流温度为25℃、回流比为2.75;精制塔最佳操作条件为塔顶回流温度40℃、回流比为2.34和进料温度为50℃。与现有生产装置相比,两塔节省0.5 MPa蒸汽5 t/h,7℃冷冻水520.5 t/h。     

反应精馏——萃取联合过程合成乙酸乙酯的研究

将固体酸作为主催化剂与不锈钢填料以一定的规律置于反应精馏塔中，以一路易斯酸作为辅助催化剂置于塔釜中，采用反应精馏的形式连续合成乙酸乙酯。塔顶全部酯相经萃取脱去水后再引起部分回流到反应精馏塔塔顶，构成了反应精馏－萃取联合过程。该过程酯化转化率主，酯相带水能力强，减少了回流比，降低了能耗，提高了设备的生产能力。     

流化催化精馏制备醋酸异戊酯的研究

在φ３０填料塔中研究了催化剂随物料流动的催化精馏过程。对醋酸与异戊醇酯化反应体系．考查了催化剂用量、进料酸醇比、进料位置、回流比、水相回流位置等因素对过程的影响。在选定的实验条件下,塔顶产品的酯含量达 ９５．１１％。酯对醇的单程转化率超过 ９５％。     

盐析效应在酯提纯中的应用研究

一、前言 工业上在生产醋酸乙(或正丙)酯(以下简称酯)的过程中,由于酯化反应中有水生成,故需对产物进行脱水提纯。但由于酯与水形成恒沸物,在常温下,它们也部分互溶,给工业上酯的提纯带来了较大的困难。传统上对酯的提纯是利用酯—水的恒沸组成和部分互溶中含水量的差别进行脱水,即通过精馏出来的恒沸物冷却后分出水相,酯相回流以带出水。这样脱去1吨水大约需     

酯化工艺塔EG循环量对酯化工艺的影响

改变酯化工艺塔EG循环量，测试工艺塔回流水中的非水分（有机物）含量，酯化热井中EG水含量及切片中端羧基和DEG含量，探讨酯化EG循环量变化对酯化反应的影响，为更高负荷生产扩展空间。     

醋酸正丙酯酯化塔选材浅析

目前,国内醋酸正丙酯的生产大都采用酯化工艺,即在硫酸催化剂存在下,醋酸与正丙醇发生酯化脱水反应生成醋酸正丙酯的工艺。由于使用硫酸作为酯化反应的催化剂,存在硫酸腐蚀性强、副反应多等缺点,致使酯化工段设备耐腐蚀选择较为困难。基于此,就醋酸正丙酯酯化塔的选材进行了研究探讨。     

硫酸催化合成1,2-丁二醇二醋酸酯的研究

论文讨论了用1,2-丁二醇和醋酸反应合成1,2-丁二醇二醋酸酯的工艺,并讨论了不同带水溶剂(甲苯,环已烷,苯),反应温度和催化剂用量对产品收率的影响,实验发现最佳的合成方法为:用甲苯带水,90%硫酸为催化剂,用量为0.6%(重量百分比),产品收率为75%,1,2-丁二醇二醋酸酯含量为95%,1,2-丁二醇单醋酸酯含量5.0%,酯含量99%以上。     

醋酸酯系列生产技术

正项目简介:醋酸酯主要包括醋酸乙酯、醋酸丙酯、醋酸丁酯等,是一种用量越来越大的环保型溶剂。本技术以醋酸以及相应的醇如乙醇、丙醇、异丙醇、丁醇等为主要原料,采用连续酯化法工艺合成相应的醋酸酯。同现有工艺相比,本技术采用催化精馏工艺,可以实现醋酸乙酯、丙酯、丁酯等产品的高效转化,而且可以根据市场情况,在同一装置实现不同醋酸酯产品的     

一种丙二醇甲醚醋酸酯的生产方法

正一种丙二醇甲醚醋酸酯的生产方法,涉及化学合成工艺,采用负载型催化剂,以丙二醇甲醚和醋酸为原料进行酯化反应,反应生成的水经过共沸精馏脱除,反应生成的产物经过精馏后取得丙二醇甲醚醋酸酯。本发明催化剂具有均一的分子大小的孔道,离子交换性能,酸催化活性,有良好的热稳定性和水热稳定性。本发明可实现一段式连续化生产丙二醇甲醚醋酸酯,操作方式简单,显著提高了丙二醇甲醚醋酸酯     

Fast Esterification of Acetic Acid with Short Chain Alcohols in Microchannel Reactor

Microchannel reactor was used for the fast synthesis of acetic acid esters, including methyl acetate, ethyl acetate, n-propyl acetate and n-butyl acetate. Effects of the inner diameter of microchannel reactors, dosage of catalyst, residence time, reaction temperature and molar ratio of alcohol to acetic acid on yields of esters were studied in the p-toluene sulfonic acid-catalyzed homogeneous esterification of acetic acid with alcohols. Yields of acetic acid ester reached 74.0, 70.1, 97.2 and 92.2% when methanol, ethanol, n-propanol and n-butanol were used as the alcohols, respectively and the residence time was of 14.7 min.     

Purification of ethyl docosahexaenoate by selective alcoholysis of fatty acid ethyl esters with immobilized Rhizomucor miehei lipase

Ethyl docosahexaenoate (E-DHA) is efficiently enriched by the selective alcoholysis of ethyl esters originating from tuna oil with lauryl alcohol using immobilized lipase. Alcoholysis of ethyl esters by immobilized Rhizopus delemar lipase raised the E-DHA content in the unreacted ethyl ester fraction from 23 to 49 mol% in 90% yield. However, the content of ethyl eicosapentaenoate (E-EPA) was higher than the initial content. Hence we attempted to screen for a suitable lipase to decrease the E-EPA content, and chose Rhizomucor miehei lipase. Several factors affecting the alcoholysis of ethyl esters were investigated, and the reaction conditions were determined. When alcoholysis was performed at 30°C with shaking in a mixture containing ethyl esters/lauryl alcohol (1:3, mol/mol) and 4 wt% of the immobilized R. miehei lipase, the E-DHA content in the ethyl ester fraction was increased and the E-EPA content was decreased. By alcoholyzing ethyl esters in which the E-DHA content was 45 mol% (E-tuna-45) for 26 h, the E-DHA content was increased to 74 mol% in 71% yield and the E-EPA content was decreased from 12 to 6.2 mol%. To investigate the stability of the immobilized lipase, batch reactions were carried out continually by replacing the reaction mixture with fresh E-tuna-45/lauryl alcohol (1:3, mol/mol) every 24 h. The decrease in the alcoholysis extent was only 17% even after 100 cycles of reaction. It was found that increasing the proportion of lauryl alcohol increased the conversion of E-EPA to lauryl-EPA. When an ethyl ester mixture in which the E-DHA content was 60 mol% (E-tuna-60) was alcoholyzed for 24 h with 7 molar equivalents of lauryl alcohol, the E-DHA content was raised to 93 mol% with 74% yield and the E-EPA content was reduced from 8.6 to 2.9 mol%.     

芳基丙酮α-溴代物的合成研究

研究了各因素条件下对芳基苯丙酮的溴代,生成α-溴代芳基苯丙酮的影响。结果表明,4-羟基苯丙酮,在以冰乙酸为溶剂,15℃下滴加液溴可得高选择性的α-溴-4-羟基苯丙酮;4-氯苯丙酮、3-氯苯丙酮,在以乙酸乙酯和氯仿混合为溶剂,加热回流可选择性分别生成α-溴-4-氯苯丙酮和α-溴-3-氯苯丙酮。     

Synthesis and Evaluation of Soy Fatty Acid Ester Estolides as Bioplasticizers in Poly(Vinyl Chloride)

Plasticizers are nonvolatile organic liquids that impart flexibility to polymers. Due to environmental, health, and safety reasons, the industry is looking for bioplasticizers to replace petroleum-derived phthalates. To fulfill this need, soy fatty acid ester estolides were synthesized, characterized, and evaluated as phthalate replacements. Soybean oil was transesterified with methanol or glycerol to form lower molecular weight fatty acid esters that were epoxidized and ring opened with acetic acid and acetylated to give the final products. Ring opening and acetylation of the epoxidized oleic acid esters gave acyclic acetate fatty acid ester estolides, whereas the polyunsaturated fatty acid esters, linoleate, and linolenate gave cyclic tetrahydrofuran derivatives and cross-linked higher molecular weight materials. The cyclization mechanism to form the tetrahydrofuran derivatives was postulated. Soy fatty acid ester estolides were compounded with formulated poly(vinyl chloride), (PVC) and tested for their functional properties. The physical and functional properties of the new bioplasticizers were compared with commercial plasticizers. The elasticity of PVC compounded with experimental plasticizers and commercial phthalates was comparable. PVC compounded with fatty acid methyl ester estolide showed lower glass transition temperature and similar tensile properties compared to PVC compounded with the commercial phthalate. PVC compounded with the glyceryl fatty acid ester estolide showed a higher glass transition temperature, higher tensile properties compared to PVC compounded with the commercial phthalate.     

Continuous Lipase-Catalyzed Alcoholysis of Sunflower Oil: Effect of Phase-Equilibrium on Process Efficiency

Phase-equilibrium diagrams of biodiesel synthesis substrate (oil/alcohol/alkyl esters) and product (alkyl esters/glycerol/alcohol) mixtures containing methanol, ethanol and propanol, respectively, were used for the identification of those composition ratios leading to mixture homogeneity. Based on the diagrams, complete conversion of the substrate oil contained in a sunflower oil/ethanol/ethyl ester mixture at a weight ratio of 7.6:11.4:81.0 resulted in the generation of an amount of glycerol capable of remaining in solution in the product mixture. In contrast, complete conversion using a mixture of a lower alcohol and ethyl ester content (19.0:6.0:75.0) leads to the separation of phases. A continuous reactor charged with Lypozyme TL-IM and fed with the former mixture showed constant conversion and productivity with time, whereas process efficiency was found to decrease drastically when the latter mixture was fed. When a sunflower oil/isopropanol/isopropyl ester mixture at a weight ratio of 35:35:30 was fed in the reactor charged with Novozym 435, the output glycerol concentration was equivalent to that theoretically expected. In contrast, feeding a sunflower oil/ethanol/ethyl ester mixture of equal proportions as above, the glycerol concentration was lower than expected, suggesting the occurrence of glycerol adsorption on the enzyme support.     

Acetoxylation of methyl oleate with a resin catalyst

The reaction of methyl oleate with acetic acid in the presence of a reticulated cation exchange resin produces methyl acetoxystearate. Saponification of this compound and subsequent acidification yields hydroxystearic acid. Time, temperature, acetic acid:ester ratio, and resin:ester ratio were examined for their effect on yield of methyl acetoxystearate. A yield of approximately 45% of theory was reached under the best conditions. The cation exchange resin promoted ester inter-change with the formation of oleic acid, acetoxy-stearic acid, and methyl acetate. An estolide polymer was formed, probably by ester inter-change between acetoxylated methyl oleate and oleic acid. Acetoxy esters were separated from unreacted methyl oleate and ester polymers by fractional distillation. Molecular weight and GLC data substantiate the product structure. Several other short-chain carboxylic acids were reacted with methyl oleate but gave lower yields of acyloxylated product than acetic acid. Presented at the AOCS Meeting in Cincinnati, October 1965. No. Utiliz. Res. Der. Div., ARS, USDA.     

Enrichment of high-purity nervonic acid ethyl ester from Acer truncatum Bunge seed oil by combination method of urea inclusion and molecular distillation

Acer truncatum Bunge is a type of maple that is unique to China. Its fruit setting rate and seed oil content are both high. The oil is mainly composed of C16–C24 fatty acids and contains 5%–7% nervonic acid (NA). NA and its derivatives can delay ageing and prevent and treat disorders such as senile dementia and Alzheimer's disease. The content of NA ethyl ester prepared by the seed oil of A. truncatum Bunge is 5.84%. We report a new process for the enrichment of NA ethyl ester by urea inclusion (UI) and molecular distillation (MD), with the aim of obtaining highly pure NA ethyl ester. First, based on the difference in fatty acid ethyl ester saturation and carbon chain length, unwanted compounds such as oleic acid ethyl ester, linoleic acid ethyl ester, and sterol were removed by one-stage UI, the content of NA ethyl ester was increased to 18.69%. The oil in the UI compound was used as a feed, and differences in the mean molecular free paths between the components were exploited to separate the C16–C20 fatty acid ethyl esters (FAEEs) by two-stage MD. The total content of C16–C20 FAEEs decreased to 3.69% and the purity of NA ethyl ester increased to 47.47%. A new purification process of UI-MD-UI was established and NA ethyl ester could be purified to 91.8%. The combination of MD and UI has an important reference value for the industrialization of producing high-purity NA ethyl ester.     

Incorporation of bromo-octadecane into long-chain ester monolayers at the air/water interface

Surface compatibility of 2-methoxy ethyl stearate and oleate esters with 1-bromo-octadecane (RBr) has been investigated at the air/water interface with a Langmuir film balance. The methoxy ethyl head group in the esters promotes flat conformation at the air/water interface as observed from its higher surface area (stearate, 22.41 Ų/molecule; oleate, 57.20 Ų/molecule) in comparison to the corresponding acids. The stearate ester forms a homogeneous mixed monolayer with maximal incorporation of 0.5 mole fraction of RBr. This is indicated by the retention of liquid condensed and solid condensed phases of stearate ester, and the positive deviation of the mean molecular area of the mixed film from the calculated additive areas. When the mole fraction of RBr (x ₂) exceeds 0.5, the onset of formation of heterogeneous mixed film is indicated by the appearance of initial and final collapse pressures. On the contrary, oleate ester shows the least compatibility with RBr, which is indicated by the progressive decrease in mean molecular area with x ₂. The more liquid expanded-phase structure of oleate ester probably does not promote compatibility with RBr at the air/water interface.     

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.     

1,2-环己二醇在溶剂中的溶解度

1 INTRODUCTION The solubility of solid in liquids is an excellent tool to investigate solute-solvent intermolecular forces in the liquid state. In this work the solubility of trans-1,2-cyclohexanediol in some polar solvents (wa- ter, methyl acetate, acetic ester, propyl acetate, butyl acetate, methyl acrylate, and ethyl acrylate) was mea- sured at temperatures ranging from about 300 K to 330 K, using a modification of the experimental tech- nique of laser monitoring observation system. So…