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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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基于对醋酸甲酯与甲醇二元共沸特性的分析,提出热集成变压精馏分离醋酸甲酯和甲醇的工艺. 利用Aspen Plus软件对该分离过程进行模拟,以NRTL活度系数方程为物性计算方法,其二元相互作用参数由气液相平衡数据回归,分析了加压塔和常压塔的理论板数、进料位置及回流比对分离效果的影响,并进行了能耗比较. 结果表明,该工艺能很好地分离醋酸甲酯和甲醇,较佳的工艺条件为:加压塔操作压力909 kPa,理论板数32,第21块板进料,回流比4.2,塔釜醋酸甲酯纯度99.8%;常压塔操作压力101 kPa,理论板数30,第20块板进料,回流比4.6,塔釜甲醇纯度99.0%. 与常规变压精馏相比,热集成变压精馏可节能达45.8%;与以水为萃取剂的萃取精馏分离工艺相比,热集成变压精馏分离工艺更适合醋酸甲酯与甲醇体系的分离. 相似文献
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A process composed of a fixed-bed and a distillation column with a side withdraw, mainly methanol, is developed to hydrolyze methyl acetate (MA) as a typical byproduct in polyvinyl alcohol (PVA) and pure terephthalic acid (PTA) factory. The process is simulated by employing the equilibrium stage model RadFrac and plug flow model Rplug in Aspen Plus. Experiments are also carried out in a lab-scale to evaluate the process. The results show that at the molar ratio of water to methyl acetate about 4.0-5.0 in the feed stream and the volume ratio of distillate to feed MA above a critical value, the side product contains more than 80% (by mass) (MeOH) and less than 2% (by mass) MA, while the bottom contains more than 46% (by mass) acetic acid (HAc) and less than 0.5% (by mass) methanol with almost complete conversion of MA. Compared with the old catalytic distillation process we proposed before, this process can cut down 47.6% energy consumption and a distillation column. 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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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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Bernd Bessling Jan-Martin Lning Andr Ohligschlger Gerhard Schembecker Kai Sundmacher 《化学工程与技术》1998,21(5):393-400
The production of methyl acetate in a reactive distillation process – prior art for 15 years – is often used as an example to study the basic phenomena of reactive distillation. The present paper deals with a theoretical and experimental analysis of methyl acetate synthesis in a reactive distillation column. A design method based on the interpretation of reactive distillation line diagrams is used to identify the main process parameters and to provide a foundation for experimental investigation. The significant influence of the reflux ratio on the conversion in the column is shown by mini plant experiments using supported ion exchanger in the form of Raschig rings as a heterogeneous catalyst. These experiments demonstrate the catalytic quality of this packing material. To simulate the reactive distillation column with a simple stage-to-stage method, the separation efficiency of the catalytic rings is investigated. Comparison of experimental and simulation results reveals that a simple model based on the assumption of simultaneous chemical and phase equilibrium describes the experimental data quite well over a wide range of reflux ratios. Furthermore, simulation results show that the conversion depends less on the number of reactive stages than on the use of two feed stages. 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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王成习 《中国化学工程学报》2001,(4)
A nonequilibrium stage model was used to simulate countercurrent multicomponent catalytic distillation processes for methyl acetate hydrolysis. Computations of stage efficiencies or height equivalent to a theoretical plate (HETP) were entirely avoided by this model. The consistency of simulated results and experimental data in conversions and concentration of each component along a column indicates that the model predicts the actual process well. The influences of operating parameters on hydrolytic conversions, such as feed molar ratios, feed locations, feed and reflux rates, heights of reactive and stripping sections, were analyzed adequately by simulating calculations. A good operating mode was then obtained, which is helpful to the development of a new 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
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乙酸甲酯水解工艺设计 总被引:1,自引:0,他引:1
在分析目前国内乙酸甲酯水解工艺的基础上,提出采用福州大学催化精馏水解技术代替传统的固定床水解反应器进行水解的新工艺。着重从工程设计方面对其工艺过程进行探讨。 相似文献
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