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Jie He Baoyun Xu Weijiang Zhang Cuifang Zhou Xuejia Chen 《Chemical Engineering and Processing: Process Intensification》2010
The production of n-butyl acetate by transesterification of methyl acetate with n-butanol, catalyzed by acidic ion-exchange resin NKC-9, was experimentally investigated in a homemade catalytic distillation column with a diameter of 80 mm. A non-equilibrium stage model for describing the catalytic distillation process was established and solved with Newton-Homotopy method. The effect of feeding mode, reflux ratio, material molar ratio and number of reactive sections on the conversion of methyl acetate was investigated. The experimental results agree well with those obtained by the theoretical simulation calculations, indicating the accuracy and reliability of the non-equilibrium model. It can be concluded that the non-equilibrium model established in this paper can provide theoretical guidance for the further process design and optimization. 相似文献
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Xin Gao Xingang Li Hong Li 《Chemical Engineering and Processing: Process Intensification》2010,49(12):1267-1276
An equilibrium stage model was developed for the simulation of the catalytic distillation process of methyl acetate (MeOAc) hydrolysis. In the model, the influences of the reactive kinetics, residence-time, liquid holdup, and separation efficiency of the catalytic packing were considered. The model predicted the conversion of MeOAc and the mass ratio of acetic acid to water in the hydrolysis mixture. The predictions were in good agreement with experimental data. A novel process was designed based on the results of theoretic analysis and the simulation research. This new process had a higher conversion of MeOAc compared with the results in previous research and was found to be energy efficient. Optimal effect parameters and design factors of new technology on energy consumption and conversion were also determined and summarized as the following: the position of side draw is 18th to 19th stages, the catalytic distillation (CD) column pressure is at 350 kPa, the volume ratio of reflux to feed is 6–8, mole ratio of feed water to MeOAc is 3.5–4.5, and the mass ratio of side withdrawal to feed is 0.32–0.34. 相似文献
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离子液体催化反应精馏是提高酯交换平衡反应转化率的一种绿色有效方法。以离子液体1-丙基磺酸-3-甲基咪唑三氟甲烷磺酸盐([PSO3HMIm][OTf])和离子液体1-辛基-2,3-二甲基咪唑双(三氟甲烷磺酰)亚胺盐([OMMIm][Tf2N])的混合物作为乙酸甲酯和正己醇进行酯交换反应合成乙酸正己酯的催化剂,测定了酯交换反应动力学。探讨了混合比、反应温度、反应物初始摩尔比、催化剂浓度对反应速率和乙酸甲酯转化率的影响,考察了催化剂的回收性能。利用实验数据回归得出混合离子液体催化酯交换反应动力学方程。在反应动力学的基础上进行了乙酸甲酯和正己醇的酯交换反应精馏流程模拟,分析了理论板数、回流比、进料位置及反应段塔板数、催化剂用量、持液量等参数对反应精馏塔的影响。在优化的操作条件下,获得纯度为0.9993的乙酸正己酯产品。 相似文献
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采用“背包式”反应精馏深度水解乙酸甲酯,考察了工艺条件对水解率和酸水比的影响,并与传统的单塔催化精馏工艺进行了对比。结果表明:提高水酯比可以显著提高乙酸甲酯的水解率;回流进料比的增加有利于提高水解率但会增加能耗,较佳回流比为3.0左右;乙酸甲酯水解率随空速的增加而降低的速度较慢,可以适当提高空速以增加处理能力;增加固定床体积有利于酯的预水解,但是不一定有利于酯的总转化率。采用“背包式”催化精馏工艺可以实现乙酸甲酯的深度水解,且优于传统的单塔催化精馏工艺。 相似文献
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乙酸甲酯催化精馏水解工艺研究 总被引:10,自引:0,他引:10
采用阳离子交换树脂为催化剂 ,研究了乙酸甲酯催化精馏水解工艺。反应区充填离子交换树脂催化剂捆束包 ,提馏段充填Mo Ti金属板波纹丝网填料。在小试、中试 (塔径为 2 0 0mm)和工业化 (塔径为1 0 0 0mm)实验中 ,系统地研究了水酯摩尔比、回流进料比和空速对酯分解率和分解液中酸水质量比的影响 ,获得不改变现有聚乙烯醇生产中乙酸甲酯分解回收工艺流程的最佳分解率为 50 %— 60 % ,由此导致比原工艺节能约 30 %和原有设备利用率成倍提高 相似文献
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乙酸甲酯的催化精馏水解实验研究 总被引:1,自引:1,他引:0
童阜广 《化学工业与工程技术》2010,31(4):15-17
在自行设计的催化精馏塔中,以Amberlyst 35wet阳离子交换树脂为催化剂,全回流操作下,对乙酸甲酯催化精馏水解进行了研究。考察了空速、塔高度、回流进料比(体积比)以及进料中水酯物质的量比等操作条件对水解反应的影响。实验结果表明,在空速0.09 min-1,催化剂装填高度80 cm,提馏段7块塔板,回流进料比5∶1,进料中水酯物质的量比6.5∶1时,乙酸甲酯水解率达到83.5%。 相似文献
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Process alternatives for methyl acetate conversion using reactive distillation. 1. Hydrolysis 总被引:1,自引:0,他引:1
Yu-Der Lin 《Chemical engineering science》2008,63(6):1668-1682
In a polyvinyl alcohol (PVA) plant, reaction stoichiometry indicates that equal molar of methyl acetate is generated for every mole of PVA produced. This work explores an alternative to convert methyl acetate back to acetic acid (raw materials of PVA plant), methyl acetate (MeAc) hydrolysis. The design and control of methyl acetate hydrolysis using reactive distillation is studied. Because of the small chemical equilibrium constant (∼0.013) and unfavorable boiling point ranking (MeAc being the lightest boiler), the reactive distillation exhibits the following characteristics: (1) total reflux operation and (2) excess reactant (water) design. The proposed flowsheet consists of one reactive distillation column with a reactive reflux drum, two separation columns, and one water-rich recycle stream. A systematic design procedure is used to generate the flowsheet based on the total annual cost (TAC). Two dominate design variables are: recycle flow rate (for the degree of excess in water) and the overhead impurity level of acetic acid in the product column (to avoid tangent pinch). Finally, the operability of the hydrolysis plant is evaluated. A plantwide control structure is developed followed by process identification and controller tuning. The results show that reasonable control performance can be achieved using simple temperature control for feed flow and feed composition disturbances. 相似文献
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V. V. Dil'man V. A. Lotkhov A. A. Lipatova S. Ya. Kvashnin N. N. Kulov 《Theoretical Foundations of Chemical Engineering》2005,39(5):455-462
Experiments are carried out to determine, under comparable conditions, the mass-transfer efficiency of a packed column in catalytic distillation of a chemically reactive mixture and in multicomponent distillation of the same mixture that is uncomplicated by chemical transformations. The reactive distillation process involves the reversible equimolar reaction of transesterification between butyl acetate and ethanol to form butanol and ethyl acetate. It is shown that the experimental data on the packed zone of the column are satisfactorily fitted by an equilibrium cascade model. The number of stages in the cascade is found from the Fenske-Underwood equation. In the experiments performed, both in the catalytic distillation and in the multicomponent distillation uncomplicated by chemical transformations, the height equivalent to a cascade stage is the same (20 cm). 相似文献
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Multiple Analysis in a Reactive Distillation Column for the Synthesis of tert‐Amyl Methyl Ether
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tert‐Amyl methyl ether (TAME) is produced via reactive distillation. A simulation is set up and controlled on Aspen HYSYS v 8.0 for generating the highest purity of TAME. This simulation includes a plug‐flow reactor and a reactive distillation column. Emphasis was put on finding the optimal operating conditions of the reactive distillation column in order to get the maximum purity of TAME. The operational parameters were reflux ratio, number of reactive stages in the distillation column, and condenser pressure. The results indicated the optimal reflux ratio and condenser pressure which could be adapted to industrial scale. 相似文献
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用人工神经网络模型模拟催化精馏塔 总被引:12,自引:0,他引:12
尝试用人工神经网络模型模拟醋酸甲酯水解催化精馏塔的操作过程,并寻求最佳工艺条件。以进料水酯比、回流进料比和醋酸甲酯的体积流率与催化剂体积比作为输入层的三个节点,醋酸甲酯的转化率和塔釜中的酸水比为输出层的两个节点,采用BP算法结合模拟退火算法,利用小试实验数据训练网络并检验训练结果;内插或外推一系列假想的工艺条件,让网络预测操作结果,最后确定最佳操作目标,通过网络模型寻找一组最佳工艺条件。结果表明:以充足可靠的实验数据为基础,神经网络模型能精确预测实验结果;利用人工神经网络模型对工艺条件进行优化,可取得令人满意的结果。 相似文献
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In this paper, a reactive distillation (RD) column was applied for synthesis n-butyl acetate from n-butanol and acetic acid. The Langmuir-Hinshelwood-Hougen-Watson (LHHW) kinetic model and an equilibrium stage model for separation were employed to study the RD process. The results obtained from the equilibrium stage model agreed well with the experiments. The effects of operating variables on the n-butanol conversion and n-butyl acetate purity were further investigated. The optimal column configuration for the production of n-butyl acetate was designed with 5 rectifying stages, 8 reaction stages and 13 stripping stages by the simulation study. According to the simulation results, n-butanol conversion and n-butyl acetate purity all reached greater than 96%. 相似文献
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A new reactive and extractive distillation process with ionic liquids as entrainer and catalyst (RED-IL) was proposed to produce methanol and n-butyl acetate by transesterification reaction of methyl acetate with n-butanol. The RED-IL process was simulated via a rigorous model, and high purity products of methanol and n-butyl acetate can be obtained in such a process. The effects of reflux ratio, feed mode, holdup, feed location, entrainer ratio and catalyst concentration on RED-IL process were investigated. The conversion of methyl acetate and purities of products increase with the holdup in column, entrainer ratio and catalyst content. An optimal reflux ratio exists in RED-IL process. Comparing to the mixed-feed mode, the segregated-feed mode is more effective, in which the optimal feed locations of reactants exist. 相似文献
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In this paper, the feasibility of applying catalytic distillation for the hydrolysis of methyl acetate is studied experimentally. An optimum technological process for the hydrolysis is determined, based on experimental results and mathematical simulations. The methyl acetate conversion can be greatly increased, and the energy consumption reduced, for certain operation conditions via the catalytic distillation process. 相似文献
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采用离子液体1-磺酸丁基-3-甲基咪唑硫酸氢盐([HSO3bmim][HSO4])和1-丁基-3-甲基咪唑双三氟甲磺酰亚胺盐([BMIM][Tf2N])分别作为催化剂和萃取剂,对乙酸甲酯与乙醇合成乙酸乙酯和甲醇的反应萃取精馏(RED)过程进行了模拟计算。在反应动力学和汽液相平衡分析基础上建立了反应萃取精馏流程,研究了理论板数、回流比、持液量、进料位置、溶剂比(萃取剂进料与原料进料摩尔流量的比值)、催化剂进料流量等参数对反应萃取精馏过程的影响。在优化的操作条件下,甲醇纯度为0.9922,乙酸乙酯纯度为0.9905,乙酸甲酯转化率为0.9922。 相似文献