用共沸反应精馏制取叔丁醇钾的工艺设备及放大

采用将反应和共沸精馏结合为一体的工艺和具有大比表面积的填料塔,由氢氧化钾制取叔丁醇钾。小试及放大研究表明氢氧化钾的转化率达到９３％以上。     

叔丁醇催化精馏脱水制异丁烯模拟研究

以质量分数85%叔丁醇(TBA)为原料,对TBA催化精馏脱水制异丁烯工艺进行模拟计算。回归了自制的磺酸阳离子树脂催化剂的动力学数据,并使用Fortran编写了动力学子程序接口。应用Aspen Plus模型系统地讨论了反应段塔板数、操作压力、回流比、精馏段和提馏段塔板数、进料位置对TBA脱水效果的影响。在TBA进料量100 kg/h,反应段每块塔板填装45 kg催化剂,塔顶液相采出异丁烯的条件下进行模拟,结果表明:精馏段4块塔板,反应段5块塔板,提馏段4块塔板,操作压力0.35 MPa,回流比1.5,进料位置在第4块塔板时,TBA转化率达99.5%。     

叔丁醇脱水制异丁烯研究进展

综述了叔丁醇脱水催化剂的研究现状,比较了液体酸催化剂、阳离子交换树脂、活性氧化铝等催化剂的活性、选择性、稳定性等特点;讨论了脱水反应器工艺、固定床工艺和催化精馏工艺的优缺点;指出叔丁醇脱水制异丁烯的发展方向是采用大孔树脂催化剂和催化精馏工艺。树脂催化剂的改性和催化剂的装填方式是研究的重点。     

叔丁醇脱水制异丁烯研究

采用D005-Ⅱ型强酸阳离子树脂为催化剂,以叔丁醇为原料,在连续催化精馏实验装置上,进行了脱水制异丁烯的研究,考察了操作压力、回流比、叔丁醇进料空速对叔丁醇转化率的影响。结果表明,进料空速0.5~0.75 h~(-1),操作压力0.40~0.45 MPa,回流比1.6~1.8的操作条件下,叔丁醇转化率98.8%,异丁烯含量≥97%。     

共沸精馏在丙烯醇脱水工艺中的应用

南京树脂厂生产中,产生一定数量的含水丙烯醇,为了回收利用,采用共沸精馏脱水工艺,可得到合格丙烯醇。本文就共沸剂的选择、工艺、装置与操作作了介绍.     

叔丁醇催化精馏脱水制高纯度异丁烯中试研究

采用大颗粒阳离子树脂催化剂,在Φ100 mm×4 100 mm的催化精馏中试装置上对叔丁醇脱水制异丁烯进行研究,考察操作压力、回流比、叔丁醇进料量和催化剂填装量对叔丁醇转化率的影响。结果表明,在操作压力0.39 MPa、回流比1.5、叔丁醇进料量4.32 L/h、催化剂填装量6 kg的条件下,叔丁醇转化率达98.12%,经分离后可以得到纯度为99.83%的异丁烯。     

基于化学热泵系统的叔丁醇脱水反应精馏过程

采用柱状阳离子交换树脂S-54作催化剂研究了叔丁醇脱水的反应精馏过程.在实验基础上建立了该过程的数学模型,采用超松弛法,并以动态方程逼近计算稳态过程对模型进行了求解,计算结果与实验结果吻合良好.在以上研究基础上考察了不同进料流量、进料组成、进料位置以及不同回流比等对反应转化率的影响,进行了上述工艺操作参数的模拟寻优,得到以下结论：反应精馏操作实现了水从反应体系中的有效移除,减小了水对反应的阻害作用,使叔丁醇接近完全分解;同时改变操作压力可以适用不同温度热源的热量回收要求.     

共沸精馏中共沸剂的选择

1前言在化工生产中，生产原料、中间产品和最终产品都需要采用适当的分离方法而达到一定的纯度，而最常用和最有效的分离方法是“精馏”。然而当被分离物系组分间的相对挥发度接近于1或等于1时，采用普通精馏方法分离这样的物系，在经济上是不合理的，在技术上也是不可能的。因此需采用某些特殊精馏方法，如共沸精馏方法来实现分离的目的。所谓共沸精馆分离方法是向待分离系统中加入一个新组分，而加入的新组分和被分离物系中一个或几．八分形成最低共沸物，并从塔顶蒸出，所加入的新组分Ji‘1共沸刑或挟带剂．在共沸精馏过程中，共沸剂选…     

用填料塔将异丙醇连续共沸精馏脱水

用填料塔(柱)进行了用环己烷作夹带剂的连续共沸精馏法异丙醇(IPA)脱水生产无水异丙醇的实验,系统地研究了连续共沸精馏脱水的各影响因素。结果表明,连续共沸精馏最佳条件是进料位置在提馏段填料高度占全塔填料高的4/5处,进料流速为2mL·min~-1,回流比为17和塔釜温度为83℃。在最佳条件下可得到高纯无水异丙醇。实验比较了工业化的两个流程方案:(1)由预浓缩精馏塔、共沸精馏塔、异丙醇精制塔和夹带剂回收塔各1个构成的4塔流程;(2)3塔流程(比方案(1)少1个异丙醇精制塔)。结果表明,方案(1)的共沸精馏塔易产出无水异丙醇-环己烷混合物,再在精制塔中得到含水和环己烷分别小于0.2 wt%和0.1 wt%的高纯度无水异丙醇产品,此方案共沸塔操作弹性大(釜温75℃~82℃)、易于连续生产。方案(2)同样可产出高纯度无水IPA,且比方案(1)节能139kWh/t IPA,但对共沸精馏塔的操作自控严格(釜温82℃~83℃),一旦塔釜进入较多水分(如1wt%)则要中断进料、蒸馏约2h排水。     

共沸精馏技术研究及应用进展

本文综述了共沸精馏的特点、分类、共沸剂的选择及相关国内外研究进展。根据所形成的共沸物是否能分离为不互溶的两个液相,共沸精馏可分为均相共沸精馏和非均相共沸精馏。综述了近年国内外共沸精馏技术的应用研究和进展。特别指出在含有少量难分离共沸/近沸杂质的分离方法,具有可行性强,可靠性高等优势,是共沸精馏技术发展的一个重要方向。     

叔丁醇脱水制备异丁烯研究

采用搅拌釜反应器,由叔丁醇脱水制备异丁烯,产物异丁烯存放时间及取样方式、反应温度和压力对异丁烯质量具有影响。优化结果表明,存放时间≯2 h,取样方式为钢瓶取样,70~80℃,0.2~0.5 MPa(表压)和塔顶采出速率3~5 kg/h为最佳实验条件。     

Tert-butanol dehydration to isobutylene via reactive distillation

Selective tertiary-butanol (tBA) dehydration to isobutylene has been demonstrated using a pressurized reactive distillation unit under mild conditions, wherein the reactive distillation section includes a bed of solid acid catalyst. Feeding tBA to the middle of the distillation section, anhydrous isobutylene product is recovered as an overhead fraction and co-product water as a bottoms fraction. Suitable solid acid catalysts include zeolite Beta, hydrogen-fluoride-treated -zeolites, and HF-treated montmorillonite clays. Quantitative tert-butanol conversions have been realized.     

Optimization study on the azeotropic distillation process for isopropyl alcohol dehydration

Modeling and optimization work was performed using benzene as an entrainer to obtain a nearly pure anhydrous isopropyl alcohol product from dilute aqueous IPA mixture through an azeotropic distillation process. NRTL liquid activity coefficient model and PRO/II with PROVISION 6.01, a commercial process simulator, were used to simulate the overall azeotropic distillation process. We determined the total reboiler heat duties as an objective function and the concentration of IPA at concentrator top as a manipulated variable. As a result, 38.7 mole percent of IPA at concentrator top gave the optimum value that minimized the total reboiler heat duties of the three distillation columns.     

酸烯酯化合成甲基丙烯酸叔丁酯工艺研究

以甲基丙烯酸、异丁烯为原料,叔丁醇为烯烃阻聚剂,采用固定床反应器进行酸烯酯化合成甲基丙烯酸叔丁酯。探讨了酸烯投料比、反应温度、反应压力及进料空速对酸烯酯化反应的影响。结果表明,最佳反应条件为:酸烯摩尔比为3,反应温度40℃,反应压力0.5 MPa,进料空速为4 h-1。在此条件下,甲基丙烯酸转化率53.4%,异丁烯转化率80.6%,甲基丙烯酸叔丁酯选择性达96.5%。     

隔离壁精馏塔萃取精馏制无水叔丁醇研究

用隔离壁精馏塔萃取精馏制无水叔丁醇,在溶剂比为1.5,回流比为2∶1,叔丁醇原料进料速度为1.7 mL/min时,塔顶叔丁醇的质量分数达到99.6%;塔釜乙二醇的质量分数达到97.7%,可直接作萃取剂循环利用。用AspenPlus对该工艺和二塔萃取精馏工艺对比,结果与实验相一致,塔顶叔丁醇质量分数的相对误差为0.4%,塔釜乙二醇质量分数的相对误差1.3%。结果显示,该工艺比现有工艺省了1个塔、1个再沸器和1个冷凝器,节能27%,降低了能耗和设备投资。     

Simulation and analysis of dehydration distillation column based on distillation mechanism integrated with neural network

In an industrial solvent dehydration distillation column (SDDC) model, the Murphree efficiency represents the separation ability of a distillation tray and the SDDC model’s performance depends on the value accuracy of the Murphree efficiency. Because there are many operation conditions having nonlinear effect on Murphree efficiency, it is difficult to determine its value. To develop a precise and robust SDDC model, a novel hybrid model combining distillation mechanism with neural network is proposed. In the SDDC hybrid model, the neural network is employed to model the nonlinear relationship between the operation conditions and Murphree efficiency, which is embedded into the SDDC mechanistic model. The results showed a good predicting and robust performance of the hybrid model under different operation conditions. Based on the hybrid model, the effect of the operation conditions on SDDC was analyzed to obtain some useful guiding rules for the SDDC operation.     

13C CP/MAS and2H NMR study of tert-butyl alcohol dehydration on H-ZSM-5 zeolite. Evidence for the formation of tert-butyl cation and tert-butyl silyl ether intermediates

The dehydration reaction of tert-butyl alcohol, selectively labelled with¹³C in CH₃ or C-O groups (t-BuOH[2–¹³C₂] andt–BuOH[1-¹³C]), as well as selectively deuterated in methyl groups (t-BuOH[2-²H₉]), was studied on H-ZSM-5 zeolite simultaneously with¹³ C CP/MAS and²H solid state NMR. When adsorbed and dehydrated on zeolite at 296 K,t-BuOH[2–¹³C₁] andt-BuOH[1–¹³C] give rise to identical₁₃C CP/MAS NMR spectra of oligomeric aliphatic products. This is explained in terms of the fast isomerization of the tert-butyl hydrocarbon skeleton via the formation of tert-butyl cation as the key reaction intermediate. An alkoxide species, most probably tert-butyl silyl ether (t-BuSE), was also detected as the side reaction intermediate. This intermediate was stable within the temperature range 296–373 K and decomposed at 448 K to produce additional amounts of final reaction products, i.e. butene oligomers. NMR data point to the existence of equilibria between the initial tert-butyl alcohol, tert-butyl cation and butene that is formed from the intermediate carbocation.     

用共沸精馏隔壁塔生产无水乙醇的研究

提出1种单塔共沸精馏生产无水乙醇的新工艺流程,即采用隔壁塔替代常规共沸精馏流程中的脱水塔及提浓塔.应用ASPEN PLUS模拟软件,对新工艺流程及常规共沸精馏流程进行了模拟,并对2种工艺流程作了对比,结果显示新工艺流程可以节省能耗28.2%,并能降低设备投资费用和操作费用.