络合萃取法在2-萘酚废水处理中的应用研究

采用络合萃取法,以三烷基胺和磷酸三丁酯为萃取剂、煤油为稀释剂处理2-萘酚β-盐母液废水。试验结果表明：采用20％三烷基胺-20％磷酸三丁酯-60％煤油的混合型络合萃取剂对2．萘酚废水进行萃取具有较高的COD脱除率。     

没食子酸萜醇酯的合成与结构鉴定研究

提出一种没食子酸萜醇酯的舍成路线:先将没食子酸进行乙酰化保护得到3,4,-三乙酰没食子酸,3,4,-三乙酰没食子酸分别与金合欢醇、香叶醇、芳樟醇、橙花叔醇、薄荷醇和氢化松香醇等6种萜醇类化合物进行室温超声波辅助的N,N,-二环己基碳二亚胺脱水酯化,得到3,4,-三乙酰没食子酸萜醇酯;3,4,-三乙酰没食子酸萜醇酯再经水合肼脱乙酰化,得到对应的没食子酸萜醇酯.没食子酸金合欢酯、没食子酸香叶酯、没食子酸芳樟酯、没食子酸橙花叔醇酯、没食子酸薄荷酯和没食子酸氢化松香酯的总得率分别为86.17%、8.26%、76.32%、87.0%、79.22%和82.4%.该方法反应温度低,反应时间短,转化率较高.并对上述6种没食子酸萜醇酯的结构进行了鉴定.     

Reactive Extraction of Levulinic Acid Using TPA in Toluene Solution: LSER Modeling,Kinetic and Equilibrium Studies

Abstract

Levulinic acid, a carboxylic acid containing ketone structure, is a clear to brownish semi‐solid melting at 37°C; soluble in alcohol, ether, and chloroform, levulinic acid can be used as an acidulant in foods and beverages. Organic solutions of amines are being used increasingly to separate organic acids from aqueous mixture solutions by reactive extraction. The design of an amine extraction process requires kinetic data for the acid–amine+solvent system used. Kinetic studies for the extraction of levulinic acid from aqueous solution with tripropylamine (TPA) diluted in toluene were carried out using a stirred cell for kinetic studies. Equilibria for levulinic acid extraction by TPA in toluene as a diluent have been determined. All measurements were carried out at 298.15 K. The equilibrium data were also interpreted by a proposed mechanism of complexation by which (1∶1) and (2∶1) acid‐amine complexes are formed. Kinetics of extraction of levulinic acid by TPA in toluene has also been determined. The results of the liquid‐liquid equilibrium measurements were correlated by a linear solvation energy relationship (LSER).     

A study on reactive extraction equilibrium between acetic acid and bis-succinimide of C9232

C9232 is a typical emulsifier of emulsion liquid membrane and its main component, bis-succinimide, has amine functional groups which react with carboxylic acids. The average numbers of secondary amine groups and isobutylene units in the bis-succinimide were determined through elemental analysis. Acetic acid was extracted by emulsion liquid membrane with use of C9232, and we verified that C9232 was suitable for its extractant in the emulsion liquid membrane systems. Equilibrium experiments for reactive extraction of acetic acid by C9232 were carried out by varying the overall acetic acid concentration and overall C9232 concentration in liquid-liquid extraction systems. Also, an equilibrium model for the reactive extraction of acetic acid was investigated for the purpose of analyzing the emulsion liquid membrane systems for separation of acetic acid from other carboxylic acids or sugars in the future. The calculated results from the equilibrium model were in good agreement with the experimental data.     

Intensification of enzymatic conversion of glucose to lactic acid by reactive extraction

Lactic acid is an important commercial product and extracting this out of aqueous solution is a growing requirement in fermentation-based industries and recovery from waste streams. The design of an amine extraction process requires (i) equilibrium and (ii) kinetic data for the acid-amine (solvent) system used. Equilibria and kinetics for lactic acid extraction by Alamine 336 in octanol as a diluent have been determined and compared with other diluents studied earlier. An approach for extracting the lactic acid by a long-chain tertiary amine, which is in the dispersed phase as a liquid ion exchanger (LIX), is presented. A mathematical model for slurry phase reactor with glucose in the continuous aqueous phase, the amine with a diluent in the dispersed phase and the immobilized enzyme as the solid catalyst, has been developed using equilibrium and kinetic data for reactive extraction. Effects of various parameters affecting the conversion of glucose have been discussed. The model has been solved for batch and semi-batch modes. It has been shown that the semi-batch mode yields approximately five times higher productivity than batch mode.     

Purification of phosphoric acid in a gravity wash column

A gravity wash column is a common type of continuous solid–liquid separator, which can be applied in the final step in the suspension crystallisation process of purifying phosphoric acid. In this work, a mathematical model based on material balance was presented for the purification process in a gravity wash column, and the experimental data of suspension crystallisation of phosphoric acid hemi‐hydrate were correlated. The developed purification model can be used to calculate concentration profiles of impurities along the column axis and to predict the effect of operating conditions on the purity of the product stream of phosphoric acid. The model parameters were also estimated by fitting the model with experimental data. © 2012 Canadian Society for Chemical Engineering     

Chemically modified polysulfones for molecular imprinting. Synthesis and complexation with a fluorescent model template

Polysulfone (PSU) was chemically modified to prepare new molecular imprinted membranes (MIMs). Several amounts of amine and sulfonyl groups were introduced into the PSU chemical structure in order to create interactions with acid or base templates, such as biomolecules or biomacromolecules. A fluorescent dye, Acridine Orange base (AO), was used as a model template and its complexation with the prepared PSUs was monitored by spectroscopic techniques. This study showed an absence of complexation with the native PSU and a strong complexation with the aminated and the sulfonated PSUs. Partially allylated PSU bearing amine or sulfonyl groups were also synthesized. These compounds are expected to be used as precursors for designing new crosslinked molecular imprinting membranes (MIMs), exhibiting high stability of the template memory.     

Recovery of pyruvic acid with weakly basic polymeric sorbents

BACKGROUND: Carboxylic acids are among the most important substances that can be manufactured from biomass. However, the recovery of carboxylic acids from fermentation broths presents a challenging separation problem. To avoid the production of waste salts and net consumption of chemicals in the calcium carboxylate salt process, the use of reversible chemical complexation with polymeric sorbents and extractants is attractive for carboxylic acid recovery. Pyruvic acid is widely used in the manufacture of medicines, pesticides and foodstuffs and can be produced by fermentation. Since the acidity of pyruvic acid (pK_a = 2.49) is stronger than that of normal carboxylic acids, and as few reports on the recovery of pyruvic acid are available, the sorption of pyruvic acid from aqueous solution on two types of weakly basic polymeric sorbent, tertiary amine D301R and primary amine D392, was investigated over a wide pH range and at various salt (MgSO₄) concentrations. RESULTS: Overloading adsorption of pyruvic acid on both weakly basic polymeric sorbents occurred, with the overloading of D392 being greater than that of D301R. The adsorption of pyruvic acid on both sorbents was greatly affected by the solution pH and the salt concentration in the aqueous phase. An overloading model was able to predict the experimental uptake data very well. CONCLUSION: Solution pH is one of the most important operating conditions, and both polymeric sorbents D392 and D301R can be used to recover pyruvic acid from dilute aqueous solution with high efficiency at a solution pH around 2. The uptake by D392 is greater than that by D301R owing to steric hindrance of the tertiary amine. Copyright © 2008 Society of Chemical Industry     

Aspen HYSYS对胺法脱碳再生工艺模拟的适用性

为分析Aspen HYSYS软件模拟的可靠度,进一步确定HYSYS软件在胺法脱碳再生工艺中的适用性,基于自主设计搭建的胺法脱碳中试试验装置,建立相应的HYSYS软件稳态仿真模型,对不同原料气气质、胺液流量、胺液配方、再生压力、再生温度下的胺液解吸率及再生能耗进行模拟、误差计算,分析HYSYS软件在胺法脱碳再生工艺中的适用性。研究结果表明,利用HYSYS软件模拟胺法脱碳过程中的再生工艺时,模拟结果随工艺参数的变化规律与试验结果总体保持一致,除个别不利于再生的工艺参数外,HYSYS软件的模拟适用性均较好;HYSYS软件中影响再生效果的5个工艺参数对模拟适用性影响较大的是再生压力,MDEA+MEA和TEA+MEA两种不同配方影响较小。另外,对再生能耗模拟误差影响较大的是再生温度,在一定塔底压力下,再生温度存在一个转折点,高于该温度时,再生能耗大幅度增加。本次验证过程中,再生温度115℃左右为一个转折点,但HYSYS软件的总体模拟能耗适应性均较差。     

On the Direct Addition of Amine N–H to Ch≡C Triple Bonds with Late Transition Metal Catalysts

The kinetics of the transition metal-catalysed direct addition of amine NH bonds to carbon--carbon multiple bonds (hydroamination) has been explored by in situ spectroscopic techniques. From an open mass balance it was concluded that an intermediate species was formed during the cyclisation of 6-aminohex-1-yne. This species was identified as the enamine 2-methylene-piperidine, which is the primary hydroamination product.     

Synthesis of α‐Tertiary Amine Derivatives by Intermolecular Hydroamination of Unfunctionalized Alkenes with Sulfamates under Trifluoromethanesulfonic Acid Catalysis

An efficient and mild trifluoromethanesulfonic acid‐catalyzed hydroamination of unfunctionalized alkenes to afford α‐tertiary amine derivatives at temperatures as low as room temperature is reported. 2,2,2‐Trifluoroethyl sulfamate was found to be the optimal nitrogen source because its good solubility in both organic solvents and water facilitated both conversion and purification. The reaction conditions were compatible with a variety of substrate functional groups and afforded moderate to good yields. The desired amine compounds could be obtained easily by means of a mild, one‐pot, redox‐neutral deprotection procedure. Caryolane amine was synthesized with excellent chemo‐ and regioselectivities by means of a cascade hydroamination reaction of β‐caryophyllene.

     

超临界一步法合成聚醚胺的工艺

采用超临界流体技术,一步反应合成了聚醚胺,旨在解决羟基胺化的技术瓶颈。主要研究了催化剂用量、物料配比、反应时间、反应温度、临氢压力对转化率的影响。确立了较佳反应条件为：催化剂用量7.5%,液氨对聚醚质量比1.5∶1,反应时间7.5 h,反应温度160 ℃,临氢压力1.0 MPa。最后,利用了核磁共振波谱技术对产品结构进行了表征。此工艺路线的成功开发,将为替代聚醚胺传统釜式间歇生产工艺,实现连续生产提供强有力的依据。     

Simulation of continuous packed bed reactive distillation column for the esterification process using activity based kinetic model

A mathematical model for the continuous packed bed reactive distillation process of esterification of acetic acid with methanol is developed. The kinetic rate equation, which plays a major role for the performance of reactive distillation and it is the part of model, is required for the liquid phase reversible esterification reaction. The mineral sulphuric acid is used as the catalyst. The kinetic experiments are carried out under different temperatures in the range of 305.15 to 333.15 K and catalyst concentrations in the range of 0.1267 mole H⁺/lit to 0.6537 mole H⁺/lit. From that experimental data the kinetic model is developed and the same is used for the simulation of reactive distillation process. Equilibrium stage model, in which the vapour and the liquid leaving a stage are assumed to be in equilibrium with each other, has been used for the simulation of reactive distillation process by incorporating our kinetic model. Conversion of acetic acid as function of reflux ratio and reboiler ratio has been predicted. The liquid composition and temperature profiles versus stage number have been also predicted. Finally, the optimum operating conditions obtained from the simulation results for high pure methyl acetate by reactive distillation process.     

三辛胺萃取马来酸(Ⅰ) 平衡特性

以三辛胺 (TOA)为萃取剂 ,正辛醇、甲基异丁基酮 (MIBK)、正己烷和氯仿为稀释剂开展了萃取平衡特性及负载溶剂红外光谱结构分析的实验研究 .结果表明 ,稀释剂对萃取的影响与马来酸和萃取剂的浓度有关 .对于 4种稀释剂体系 ,当平衡水相酸浓度较低时 ,萃取马来酸的次序为质子化稀释剂大于一般极性的稀释剂 ;反之 ,萃取马来酸的次序为 :MIBK >正辛醇 >正己烷 >氯仿 .TOA在平衡水相酸浓度较低时能提供较大的萃取分配系数 ,萃取剂化学计量饱和后存在“过载”现象 ,大小次序为MIBK >正辛醇 >正己烷 >氯仿 .负载溶剂的红外光谱分析表明 ,马来酸作为二元有机酸 ,与TOA只存在一盐的萃合物形式 ,有机相中不存在马来酸的聚集体 ,可以认为只有 1∶1型酸胺萃合物     

转鼓反应器中油酸氧化裂解制备壬二酸的研究

在转鼓反应器中实现了油酸臭氧氧化裂解制备壬二酸的连续化操作。考察了转鼓转速、液体流量、气体流量对转鼓反应器内气液传质反应速率的影响。在双膜理论的基础上,利用恩田公式来计算气相传质系数、液相传质系数,建立了转鼓反应器中两步反应速率模型,并将模型预测值与实验值进行了比较。实验结果表明:在转鼓反应器中,油酸氧化裂解反应速率分别随转鼓转速和液体流量的增大,先增大后趋于平缓;随着气体通量的增加,转鼓反应器内油酸氧化裂解反应速率先增大然后减小;在转鼓转速为1 699 r/min、液体流量为45 mL/min、气体流量为3 L/min时,在转鼓内油酸氧化裂解可获得最大的气液传质反应速率。模型预测值与实验值比较,两者吻合得较好,验证了模型的可靠性。     

醋酸稀溶液的络合萃取

络合萃取法对于极性有机物稀溶液的分离具有高效性和高选择性。本文以醋酸稀溶液为分离对象,通过系统的相平衡实验筛选出30 wt％三辛胺(或7301)+20 wt％正辛醇+50 wt％煤油混合溶剂。同时,探讨了叔胺类萃取剂对醋酸萃取的过程机理,研究了混合溶剂萃取稀醋酸工艺的可行性。     

Estimation of Binding Constants of Cd(II), Ni(II) and Zn(II) with Polyethyleneimine (PEI) by Polymer Enhanced Ultrafiltration (PEUF) Technique

Abstract

Continuous and batch processes of polymer enhanced ultrafiltration for the estimation of binding constants of divalent cadmium, nickel, and zinc ions have been elaborated. Polyethyleneimine was used as a complexation agent. Effect of pH and ionic strength on the binding ability of target metal ions to polyethyleneimine were estimated by continuous mode PEUF system. A mathematical model was developed to estimate apparent complexation constants of metal ions with PEI. The development of this model, which is in good agreement with experimental data, enables to compare the data obtained in both continuous and batch system and correlate the effect of pH and ionic strength with apparent binding constants.     

Factors Influencing Phase Disengagement Rates in Solvent Extraction Systems Employing Tertiary Amine Extractants

Abstract

Phase disengagement rate is a critical property in determining the usefulness of a particular solvent extraction system in hydro-metallurgy. A survey of a number of commercial tertiary amine extractants of the type used in uranium extraction hydrometallurgy has been carried out to suggest whether structural factors influence phase disengagement behavior and to provide a useful comparison of different amines with regard to phase disengagement and uranium extraction. The amines ((C_nH_2n+1)₃N) were chosen to cover a range of alkyl chain lengths including straight-chain and branched-chain compositions, and the chemical makeup of the liquid-liquid systems closely paralleled that of the systems used in the Amex uranium extraction process. Batch phase disengagement tests showed significant trends with respect to amine structure and composition using acid sulfate solutions with or without added colloidal silica and actual ore leach solutions as the aqueous phase. In general, organic continuous (OC) phase disengagement became slower with increasing n (number of carbons per chain) whether branched or linear chain, but for any given n, the branched chain amines had much faster OC phase disengagement than the linear chain amines. A key structural factor affecting OC phase disengagement was found to be the backbone chain length (longest chain in each alkyl group) since the OC phase disengagement measurements could be correlated vs backbone chain length on a single curve regardless of whether the amine was branched or linear. Aqueous continuous (AC) phase disengagement rate was rapid for the acid sulfate solution but decreased greatly with decreasing for the acid sulfate solution but decreased greatly with decreasing n when colloidal silica was added or when leach solution was used. With both leach and colloidal silica solutions, AC phase disengagement was correlated with wetting behavior or the amine systems on a glass (silicate) surface. A model based on silica attachment to the liquid/liquid interface was suggested to explain the stabilization of AC dispersions by silica and the related problem of interfacial crud formation. In addition to faster AC phase disengagement and less emulsion (crud) stabilization, the larger molecular weight amines (n ≥ 10) were found to have higher uranium extraction coefficients and lower tendencies to form third phases. Presumably, solubility losses to the aqueous phase are also lower. The results suggest that the performance of some Amex systems may be improved by using branched chain tertiary amine extractants of higher molecular weight than are now normally used.     

Equilibria and kinetics for reactive extraction of lactic acid using Alamine 336 in decanol

Lactic acid is an important commercial product and extracting this from aqueous solution is a growing requirement in fermentation‐based industries. The design of an amine extraction process requires (i) equilibrium and (ii) kinetic data for the acid–amine (solvent) system used. The equilibrium complexation constants for ratios of (1:1) and (2:1) have been estimated. The kinetics of extraction of lactic acid by Alamine 336 in decanol has also been determined. The reaction between lactic acid and Alamine 336 in decanol in a stirred cell falls in Regime 3, ie extraction accompanied by a fast chemical reaction occurring in the diffusion film. The reaction has been found to be zero order in Alamine 336 and first order in lactic acid with a rate constant of 0.21 s^?1. These data will be useful in the design of extraction processes. © 2002 Society of Chemical Industry     

REACTIVE EXTRACTION OF BETA-LACTAM ANTIBIOTICS: IR SPECTROSCOPIC STUDIES

Infrared spectroscope study on reactive extraction of Cephalosporin-C (CPC) and 6-Aminopenicillanic acid (6-APA) with secondary and tertiary amines and a quaternary amine salt as the extractants in butyl acetate as the diluent has been reported. The study aims at analysing the chemical interaction involved in the complexation of the molecules with the extract-ant and the reaction stoichiometry. Amberlite LA-2, Trioctylamine and Aliquat-336 (Tricaprylyl methyl ammonium chloride) were used as the extractants. The results of experimental extraction equilibrium study and spectroscopic analysis indicate the formation of (1:1) complex vie ion-exchange reaction of CPC and 6-APA with Aliquat-336. The ion-pair extraction with Amberlite LA-2 and Trioctylamine exhibited non-stoichiometric complexation in accordance with experimental observation on equilibrium relationship