乙醇法乙醛制醋酸乙酯的工业化可行性

简述了我国用乙醇法乙醛制醋酸乙酯工业化生产的可行性，介绍了国内外醋酯乙酯生产和市场概况以及国内对该技术的研究开发情况     

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%。     

带侧线反应精馏-渗透汽化生产乙酸乙酯集成过程模拟与分析

针对乙酸酯化法生产乙酸乙酯分离过程复杂、能耗大的缺点,提出了一种带侧线反应精馏-渗透汽化（RD-PV）集成过程。通过反应精馏塔侧线采出和渗透汽化膜组件及时移出水分,促进酯化反应向正反应方向进行,在达到乙酸高转化率的同时使乙酸乙酯产品达到高纯度。研究了反应精馏塔侧线采出位置、采出比、反应段塔板数、精馏段塔板数以及膜组件个数等对年度总成本（TAC）的影响,获得了TAC达到最小的过程参数。与传统双塔精馏分离过程对比,RD-PV集成过程节省能耗26.6%,但膜材料价格对RD-PV集成过程的TAC有较大影响,随着渗透汽化技术的成熟,当膜材料价格低于1913 CNY·m^-2时,RD-PV集成过程在经济上占据优势。     

间歇反应精馏合成乙酸异丙酯

以乙酸和异丙醇为原料通过间歇式反应精馏合成乙酸异丙酯,正交实验给出最佳合成条件为:回流比3、反应时间1.5h、乙酸与异丙醇的物质的量比1∶1.5、催化剂用量为乙酸体积2%,乙酸异丙酯的最大收率为92.8%。     

Reactive Chromatography for the Synthesis of 2-Ethylhexyl Acetate

Abstract

Reactive chromatography (RC) combines reaction and chromatography in a single unit. Due to simultaneous separation of products it can be advantageously used for reversible reactions to obtain the enhanced performance. It is a promising alternative to reactive distillation when the components are temperature sensitive and less volatile. In the present work, we study the application of RC for the synthesis of 2-ethylhexyl acetate through esterification of acetic acid with 2-ethylhexanol. Amberlyst-15 has been used as a catalyst/adsorbent. Several aspects such as reaction kinetics, multicomponent adsorption equilibria, and reaction-separation study using fixed bed chromatographic reactor are covered. The kinetics was studied in a stirred batch reactor. The effects of various parameters such as speed of agitation, particle size, temperature, mole ratio of reactants, and catalyst loading have been investigated. Kinetic modeling was performed using modified activity based Langmuir-Hinshelwood-Hougen-Watson (LHHW) model. Non-reactive binary adsorption experiments were performed to determine the parameters of Langmuir adsorption isotherm by minimizing the errors between the experimental and predicted breakthrough curves. Further, the reactive chromatography experiments were performed to obtain the reactive breakthrough curves which indicate a clear potential for the use of reactive chromatography for this reaction. The obtained data has been compared with the predictions of mathematical model of the chromatographic reactor.     

用于生产TAEE的反应精馏和全蒸发的混合过程

In this study, a reactive distillation column in which chemical reaction and separation occur simultaneously is applied for the synthesis of tert-amyl ethyl ether （TAEE） from ethanol （EtOH） and tert-amyl alcohol （TAA）. Pervaporation, an efficient membrane separation technique, is integrated with the reactive distillation for enhancing the efficiency of TAEE production. A user-defined Fortran subroutine of a pervaporation unit is developed, allowing the design and simulation of the hybrid process of reactive distillation and pervaporation in Aspen Plus simulator. The performance of such a hybrid process is analyzed and the results indicate that the integration of the reactive distillation with the pervaporation increases the conversion of TAA and the purity of TAEE product, compared with the conventional reactive distillation.     

乙酸戊酯酯化反应精馏过程系统控制模拟及分析

反应精馏技术是将反应和精馏两个单元操作耦合在一个设备中同时进行,其非线性给反应精馏过程的平稳操作和过程控制提出了更高的要求。目前,反应精馏过程控制研究都是针对特定反应体系进行的有针对性的研究,对于乙酸戊酯反应体系的控制研究少有报道。本文利用Aspen Plus和Aspen Dynamic 软件对乙酸戊酯的反应精馏过程进行动态模拟,针对塔釜产品组成要求提出温度控制和组成控制两种不同的控制方案,对两个控制系统分别进行±10%的进料流量扰动测试和酸醇比为1:1、1.2:1的进料组成扰动测试。研究了不同扰动对产品质量的影响并比较了两种方案在不同扰动干扰下的控制效果。结果表明:进料组成扰动会对两个控制方案造成较大影响;温度控制方案的控制稳定性要好于组成控制方案。     

Modeling of the Chromatographic Solvent Gradient Reversed Phase Purification of a Multicomponent Polypeptide Mixture

Abstract

A model for Calcitonin purification from an industrial peptide mixture using polymer‐based reversed phase columns was developed. Regressed competitive bi‐Langmuir isotherm parameters for pure calcitonin are strong functions of the eluent composition and were correlated to the overall Henry coefficient only. It is shown that, by keeping constant these correlations, the adsorption behavior of impurities can be predicted simply by estimating their Henry coefficient from the raw mixture. The same can be repeated with very good results when changing the stationary phase or the organic solvent in the eluent. In both cases, only the Henry coefficient must be re‐estimated from pulse injections.     

Inter-integration reactive distillation with vapor permeation for ethyl levulinate production: Equipment development and experimental validating

Ethyl levulinate, one of the main derivatives of levulinic acid (LA), is of significant potential as platform chemicals for bio-based materials. The esterification of LA was generally carried out in a conventional batch reactor or in a conventional reactive distillation column. However, traditional methods are hard to deal with equilibrium limited reactions and azeotropic issues. Therefore, the inter-integration reactive distillation with vapor permeation (R-VP-D) process, which integrated reaction, vapor permeation, and distillation into one single unit, is proposed in this paper and validated in the pilot-scale experiments. A comparative study is made between a pilot-scale RD column with and without VP module. Owing to the water-selective VP membrane and the ingenious design of related apparatuses, the R-VP-D process reveal a superiority in LA conversion of 21.9% maximum higher than RD without VP process and removing of product water about 53.6% from VP module, which indicates its promising industrial application in process intensification field.     

Synthesis of butyl acrylate in a fixed‐bed adsorptive reactor over Amberlyst 15

The butyl acrylate synthesis from the esterification reaction of acrylic acid with 1‐butanol in a fixed‐bed adsorptive reactor packed with Amberlyst 15 ion exchange resin was evaluated. Adsorption experiments were carried out with nonreactive pairs at two temperatures (323 and 363 K). The experimental results were used to obtain multicomponent adsorption equilibrium isotherms of Langmuir type. Reactive adsorption experiments using different feed molar ratios and flow rates were performed, at 363 K, and used to validate a mathematical model developed to describe the dynamic behavior of the fixed‐bed adsorptive reactor for the butyl acrylate synthesis. Due to the simultaneous reaction and separation steps, it was possible to obtain a butyl acrylate maximum concentration 38% higher than the equilibrium concentration (for an equimolar reactants ratio solution as feed at a flow rate of 0.9 mL min^?1 and 363 K) showing that sorption‐enhanced reaction technologies are very promising for butyl acrylate synthesis. © 2014 American Institute of Chemical Engineers AIChE J, 61: 1263–1274, 2015     

乙醛缩合合成乙酸乙酯产品的毛细管气相色谱分析

本文使用石英毛细管柱对乙醛缩合合成乙酸乙酯的产品进行了系统的分析，方法准确，灵敏度高，结果令人满意。     

Removal of reactive blue 19 and reactive blue 49 textile dyes by citrus waste biomass from aqueous solution: Equilibrium and kinetic study

The purpose of this study was to establish the potential of inexpensive and locally available biomaterial, that is, lignocellulosic waste of Citrus sinensis as biosorbent to remove reactive anthraquinone dyes from aqueous solution. The effects of immobilisation and chemical treatment of biosorbent were also explored for the enhanced sorption of dyes. Biosorbent was chemically treated with organic and inorganic reagents of which acetic acid augmented the sorption capacities for Reactive blue 19 and Reactive blue 49 attaining equilibrium in 60 min. While immobilisation of biosorbent into calcium alginate beads reduced the sorption capacity and the time to achieve equilibrium was prolonged up to 120 min. Sorption of both reactive dyes was found to be dependent on pH of media and maximum removal was observed at pH 2. The sorption process was fast and the data followed pseudo‐second‐order kinetic rate equation (R² = 0.99). The equilibrium data were also fitted to Freundlich, Langmuir and Temkin isotherms. The mechanism of sorption was found to be physiosorption. FTIR analysis and SEM imaging of biosorbent were also carried out to study functional groups involved and morphological changes at the surface of biomass. © 2011 Canadian Society for Chemical Engineering     

固体酸催化剂反应精馏法合成乙酸正丙酯的研究

研究了以阳离子交换树脂作为催化剂进行反应精馏合成乙酸正丙酯,分别考察了不同回流比、酸醇摩尔比以及不同固体酸催化剂类型对酯化反应的影响,并结合工艺条件进行催化剂的筛选,确定反应的较佳工艺条件。实验结果表明,回流比为1∶2,酸醇摩尔比为1∶2,乙酸正丙酯的收率为51.49%。     

Effect of adsorption of organic solvents on the band profiles in reversed-phase non-linear chromatography

The influence of the mobile phase composition on the adsorption equilibria in non-linear reversed-phase chromatography has been investigated. RP-18 and RP-18 endcapped columns have been selected with methanol-water and acetonitrile-water as a mobile phase and cyclopentanone as a solute. Due to its structure, cyclopentanone exhibited affinity to the active adsorption sites on alkyl chains as well as to the polar, uncovered surface of the adsorbent. The adsorption equilibria of solvents—methanol-water, acetonitrile-water on RP-18 and RP-18e columns—have been measured and the excess adsorption isotherms accounting for non-ideality of the mobile and adsorbed phase have been determined. The competitive heterogeneous adsorption model for the solute and organic solvent has been proposed and coupled with a model of column dynamics. The model predictions have been verified by comparison to experimental chromatograms.     

反应型表面活性剂的柱层析分离及TLC、IR分析方法的研究

论文采用加压柱层析法,对合成的烷基烯丙基琥珀酸酯磺酸钠混合物进行分离提纯,方法简便、快速,提纯质量高,分离效果好。采用薄层色谱法(TLC)确定柱层析的洗脱剂,并检测柱层析的分离效果,采用红外光谱法(IR)进行结构分析。     

离子液体反应萃取精馏合成乙酸乙酯

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。     

A continuous process for the recovery of lactic acid by reactive distillation

Separation and purification of lactic acid from the fermentation broth are difficult because of its non‐volatile nature and the presence of other organic acids. Esterification of lactic acid with methanol followed by hydrolysis of the separated methyl lactate is an effective technique for this purpose. A continuous process for recovery is proposed and various aspects are evaluated through simulation and experiments. In the proposed route, a vapor stream containing methyl lactate is removed from a two‐phase CSTR, used for esterification, operated under boiling conditions. The ester thus separated from the aqueous solution is further hydrolyzed in a reactive distillation column. Continuous removal of the volatile component (i.e. methanol) from the reaction zone increases conversion, thus pure lactic acid is obtained from the bottom of reactive distillation column. The results obtained in the experiments are compared with the simulation results. Further simulation studies were performed to obtain the suitable operating conditions for higher conversion and concentration of lactic acid. Copyright © 2006 Society of Chemical Industry     

Synthesis of graphene oxide decorated with strontium oxide (SrO/GO) as an efficient nanocomposite for removal of hazardous ammonia from wastewater

ABSTRACT

In this research, graphene oxide decorated with strontium oxide (SrO/GO) is introduced as a new adsorbent material for the efficient removal of ammonia from industrial wastewater. The new adsorbent was thoroughly studied in terms of morphology, crystallography and chemical composition using characterization techniques such as Fourier transform infrared (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and zeta potential analysis. Several parameters such as pH, adsorbent dosage, contact time, and ammonia initial concentration were investigated and optimized. Ammonia adsorption onto SrO/GO was validated with kinetics and adsorption isotherms by adopting different models. The results revealed that ammonia adsorption kinetic was of pseudo-second order (R² = 0.999) implying that chemisorption behavior and the equilibrium isotherm follows Langmuir model. This behavior shows a high maximum monolayer sorption capacity of 90.1 mg g^?1 at pH equal to 7 and contact time of 120 min pointing out the synergism advantageous effect. The abundant oxygen functional groups on the graphene oxide surface and the integrated Sr-O nanoparticles could efficiently interact with ammonia species creating a surface for more favorable and efficient removal of ammonia.