Liquid-liquid equilibrium for the ternary systems of solvents+water+propionic acid at 25 ‡C and atmospheric pressure

Liquid-liquid equilibrium data for the ternary systems of toluene+water+propionic acid, o-xylene+water +propionic acid, methyl isobutyl ketone+water+propionic acid, ethyl acetate+water+propionic acid, and 1-butanol +water+propionic acid were measured at 25 ‡C and atmospheric pressure. The reliability of the experimental tie-line data was ascertained by means of the Othmer-Tobias, Bachman-Brown, and Hand correlations. For the extraction effectiveness of solvents, the distribution and selectivity curves were plotted. In addition, these experimental tie-line data were also correlated with NRTL and UNIQUAC models.     

Water Content of Organic Solvents and their Relationship to Extraction of Nitric and Acetic Acid from UREX+ Streams

This study investigates the equilibrium absorption of water in various solvents and solvent-mixtures being considered for the counter-current solvent extraction of acetic acid from improved Uranium Extraction (UREX+) process solutions. It then seeks to determine if there is any correlation between the equilibrium water content of these solvents and their equilibrium extraction of 0.25 M nitric and 0.025 M acetic acid. The UREX+ process is a proliferation resistant version of the Plutonium Uranium Extraction (PUREX) process. The solvents studied were n-Dodecane (nDD), 1,2 Dichloroethane (DCE), and Phenyltrifluoromethyl Sulfone (FS-13), and mixtures of these solvents with Tributyl Phosphate (TBP). After studying both pure water and acidified aqueous systems, it seems the water absorption mechanism is independent of the diluent used and remains constant with the addition of the 0.25 M nitric and 0.025 M acetic acid.     

水＋醋酸＋甲基叔丁醚三元体系汽液平衡数据的实验测定及数学模拟

用改进的Rose釜测定了常压下H2O＋HAc＋甲基叔丁醚三元体系部分汽液平衡数据,借助实验数据,利用AspenPlus软件对该三元体系NRTL和UNIQUAC方程的模型参数进行了回归。回归结果反过来用于汽液平衡的数学模拟,结果表明实验数据与模拟结果很吻合,该结果可以为相关研究及工业设计提供帮助。     

Determination and Correlation of Solubility for D-Xylose in Volatile Fatty Acid Solvents

The solubility of D-xylose in formic acid and binary solvents of formic acid with formic acid and acetic acid, propionic acid, n-butyric acid or isobutyric acid was measured in the temperature range from 300.35 to 325.05 K using the synthetic method by a laser monitoring technique at atmospheric pressure. The solid-liquid equilibrium data will provide essential support for industrial design and further theoretical study. The experimental data show that the solubility of D-xylose in formic acid and in the mixtures of formic acid＋acetic acid （1︰1）, formic acid＋propionic acid （1︰1）, formic acid＋n-butyric acid （1︰1）, and formic acid＋isobutyric acid （1︰1） increases with temperature. The Apelblat equation, theλh model, and the ideal solution equation correlate the solubility data well.     

乙酸乙酯-间苯二酚-酸性盐水液液相平衡测定及关联

乙酸乙酯作为萃取剂在酸性盐水环境下萃取间苯二酚。平衡法测定了40℃、101.33 kPa时乙酸乙酯-间苯二酚-酸性盐水准三元体系的液液相平衡数据,实验结果表明间苯二酚的存在增加了乙酸乙酯和水的相互溶解度,降低了萃取效率;盐的存在则降低了乙酸乙酯在水中的溶解度,有利于间苯二酚的萃取。用NRTL模型对实验数据进行了关联,得到了乙酸乙酯-间苯二酚-酸性盐水体系的液液相平衡模型参数,关联结果与实验数据基本吻合。测定的液液相平衡数据可为间苯二酚萃取过程以及间苯二胺水解联产间苯二酚和间氨基苯酚的生产装置的工艺设计提供依据。     

Modification of bed-coking batch with tar derived from Mongolian and Russian lignite

Quantitative characteristics are presented for the bitumen extracted from Podmoskovnyi, Kansko-Achinsk, Irkutsk, Baganursk, and Tugrugnursk lignite and the humic acids from the Tugrugnursk deposit by polar solvents (hexane, diethyl ether, acetone, chloroform, benzene, toluene, 1 : 1 alcohol-benzene mixture, pyridine, and acetic acid).     

Bitumen from Mongolian and Russian lignite

Quantitative characteristics are presented for the bitumen extracted from Podmoskovnyi, Kansko-Achinsk, Irkutsk, Baganursk, and Tugrugnursk lignite and the humic acids from the Tugrugnursk deposit by polar solvents (hexane, diethyl ether, acetone, chloroform, benzene, toluene, 1 : 1 alcohol-benzene mixture, pyridine, and acetic acid).     

Recovery of carboxylic acids C1?C3 with organophosphine oxide solvating extractants

This study was aimed at examining the use of the organophosphine oxides Cyanex^®921 and Cyanex^®923 for the extraction of formic, acetic and propionic acids from aqueous solutions. The stripping of monocarboxylic acids with water from the loaded extractants was also examined. The studies were aimed at determining the equilibrium conditions for extraction and stripping. Overall, the effect of the kind of extractant was not significant although Cyanex^®921 extracted carboxylic acids slightly better than Cyanex^®923 with 1:1 complexes being formed by both extractants with the acids during extraction. The efficiency of extraction depended on temperature, acid concentration and solvent, with toluene a better diluent for the extractants than octane or Exxsol^®D 220/230. Extraction efficiency increased as the concentration of acid in the feed decreased and, also, as the temperature increased, the amount of acid extracted decreased. The extraction and stripping isotherms were determined. The apparent enthalpy and entropy of the extraction reaction were determined. Distribution data for the transfer of carboxylic acids from aqueous (NaCl) solutions to organic solvents in the presence of trialkylphosphine oxide were determined at 293 K with the distribution ratios increasing as the concentration of NaCl increased. Copyright © 2005 Society of Chemical Industry     

Solvent effects on esterification equilibria

Solvents are known to have strong impacts on the yields of equilibrium reactions. This work focuses on the thermodynamic investigation of these solvent effects on esterification reactions of acetic acid and propionic acid with ethanol. Esterification of acetic acid was performed in the solvents acetone, acetonitrile (ACN), dimethylformamide (DMF), and tetrahydrofurane as well as in mixtures thereof. ACN promotes the esterification of acetic acid, whereas it is strongly suppressed by DMF. The esterification of propionic acid was investigated with various reactant concentrations in acetone. The experimental equilibrium data in pure solvents and solvent mixtures were modeled using the thermodynamic equilibrium constant K_a and the reactant/product activity coefficients predicted by the perturbed chain‐statistical associating fluid theory (PC‐SAFT). For a given K_a, PC‐SAFT is able to predict the influence of the solvent and even solvent mixtures on the equilibrium concentrations of esterification in almost quantitative agreement with the experimental data. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3000–3011, 2015     

Experimental,equilibrium modelling,and column design for the reactive separation of biomass-derived 2-furoic acid

Electrochemical conversion of biomass to value-added chemicals has gained impetus in recent years. Herein, we present a methodology for recovering biomass-derived 2-furoic acid from the dilute aqueous stream by reactive extraction. The reactive extraction was performed using a chemical extractant, trioctylamine (TOA), with diluents (octanol, chloroform, and diethyl ether). Equilibrium parameters influencing the recovery of 2-furoic acid were evaluated. Using TOA in various diluents, the 2-furoic acid was recovered with 85%–99% efficiency. A 1:1 complex of the 2-furoic acid—TOA was formed in the organic phase, and the experimental equilibrium complexation constant was compared with that obtained from the relative basicity and Langmuir models. The equilibrium parameters were used for column design to estimate the solvent to feed ratio (S/F) and the number of theoretical stages (NTS). The NTS required is 12 to attain 99% recovery of 2-furoic acid in counter-current extraction. The present study sheds light on the reactive extraction process adopted for process intensification with electrochemical conversion, paving the way for the commercialization of valuable products obtained from biomass.     

Experimental Measurements and Correlations Isobaric Vapor-Liquid Equilibria for Water + Acetic Acid + Sec-butyl Acetate at 101.3 kPa

Isobaric vapor-liquid equilibrium(VLE) data for acetic acid+sec-butyl acetate and water+acetic acid+sec-butyl acetate systems were determined at 101.3 kPa using a modified Rose type. The nonideality of the vapor phase caused by the association of the acetic acid was corrected by the chemical theory and Hayden-O’Connell method. Thermodynamic consistency was tested for the binary VLE data. The experimental data were correlated successfully with the Non-Random Two Liquids (NRTL) model. The Root Mean Square Deviation (RMSD) of the ternary system was 0.0038. The saturation vapor pressure of sec-butyl acetate at 329 to 385 K was measured by means of two connected equilibrium cells. The vapor pressures of water and sec-butyl acetate were correlated with the Antoine equation. The binary interaction parameters and the ternary VLE data were obtained from this work.     

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).     

三烷基氧膦络合萃取一元有机羧酸

络合萃取法对极性有机物稀溶液的分离具有高效性和高选择性。选择甲酸、乙酸、丙酸、丁酸为分离对象 ,三烷基氧膦 (TRPO)为络合剂 ,煤油为稀释剂 ,进行了系统的萃取相平衡实验 ,测定了络合剂浓度、稀释剂组成等因素对萃取平衡分配系数的影响。实验结果表明 ,溶质的亲油性对络合萃取平衡影响起主导作用 ;随TRPO浓度增大 ,萃取平衡分配系数呈增大趋势 ;随溶质初始浓度增大 ,有机相的溶质浓度向饱和萃取量接近 ;饱和萃取量随络合剂浓度的增大而增大。对相平衡分配系数进行拟合 ,精度令人满意。     

三辛胺萃取一元羧酸的平衡规律(Ⅱ)表观萃取平衡常数与规律表征

在本文（Ⅰ）报关于三辛胺（TOA）萃取甲酸、乙酸、丙酸、丁酸、戊酸、一氯乙酸、二氯乙酸、三氯乙酸、乙醇酸、乙醛酸、乳酸等11种羧酸萃取平衡特性的研究基础上,采用质量作用定律分析方法建立了TOA对一元羧酸的萃取平衡模型,拟合了模型参数——表观反应萃取平衡常数K₁₁,并获得了满意的拟合精度;提出了影响TOA萃取一元羧酸平衡的3个因素：溶质的亲油性lgP、溶质的酸性pK_a、TOA的表观碱度pK_a,B,并确定了K₁₁与这3参数的关系,经拟合实验测定的114个K₁₁,获得了一元羧酸K₁₁的关联式.为一元羧酸分离工艺中萃取剂的选择提供了指导.     

盐对水+丙酸+环乙醇三相体系在298.2，303.2和308.2 K下液液相平衡的影响

Effects of salt and temperature on the liquid phase equilibrium of the (water + propionic acid + cyclohexanol) system were investigated. The liquid-liquid equilibrium data in the presence of KCl for various salt ionic strength of 0.5, 1.0, 1.5, 2.0, and 2.5 mol•dm3 and in absence of the salt at T (298.2, 303.2, and 308.2) K were determined. The experimental results were correlated based on the Othmer-Tobias equation and Pitzer ion-interaction model. Thermodynamic properties such as distribution coefficients and activity coefficients of propionic acid in water + cyclohexanol were determined. In addition, the separation factor, S, of the chosen solvent was obtained for the investigated system.     

藻类水热液化产物生物油分离纯化及组分分析

杜氏盐藻通过水热液化制备得到的生物油,先采用溶剂分割分别得到正己烷相、二氯甲烷相和乙醚相,再对二氯甲烷相进行柱层析分离纯化。正己烷相和乙醚相直接通过GC-MS和FT-IR进行分析,二氯甲烷相先经柱层析分离后结合GC-MS、二次质谱和FT-IR等确认不同馏分的产物组成。研究结果表明:二氯甲烷相经柱层析分离可得到16个馏分,分别是石油醚馏分(A₁),主要是烯烃类;石油醚:乙酸乙酯馏分(A₂),主要是酸类化合物;石油醚:丙酮馏分(A₃),主要是酰胺类;石油醚:甲醇馏分(A₄),主要是烷烃类;甲醇馏分(A₅),主要是十八碳烯酰胺。经柱层析分离纯化后,生物油的回收率高达91.38%;获取较全的生物油组分信息,为藻类液化机理的分析和生物油的改质提供了依据。     

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.     

Isolation and purification of perfluorodecanoic and perfluorooctanoic acids from rat tissues

A procedure for the extraction, separation, and isolation of perfluorodecanoic and perfluorooctanoic acids from biological samples is described. The use of conventional lipid extraction procedures leads to substantial loss of the perfluorinated fatty acids added to tissue. The presence of sulfuric acid in aqueous saline during phase partitioning is essential for the recovery of perfluorodecanoic and perfluorooctanoic acids in the organic phase following their extraction from tissue. The perfluorinated fatty acids are co-eluted with simple lipids from silica gel columns using diethyl ether/trifluoroacetic acid (100∶1, v/v). Simple lipids are separated by thin layer chromatography. By substituting trifluoroacetic acid for acetic acid in the developing solvents, perfluorodecanoic and perfluorooctanoic acids migrate with other free fatty acids.     

Studies on transport properties of short chain aliphatic carboxylicacids in electrodialytic separation

An electrodialysis process was employed to investigate the concentration of formic, acetic and propionic acid solutions under different experimental conditions. In this process interpolymer-type ion-exchange membranes were used due their high chemical stability and durability. The effects of concentration, electric current and time on the electrodialysis process were studied. A mathematical equation representing the water transport behavior of the electrodialysis process for concentrating acids under the influence of different current densities was developed. This equation is valid for any electrodialysis process with ion-exchange membranes used under similar operating conditions. The reliability of the water transport equation was tested through comparison with the experimental data. Results indicate that electrodialysis is an effective method for concentrating shorter chain aliphatic carboxylic acid solutions. Ionic transportation, power consumption and current efficiency data reveal the following trend of the electrodialysis process's efficiency during concentration of carboxylic acid solutions: formic acid > acetic acid > propionic acid.     

水-醋酸-二异丙醚三元体系液液相平衡数据的测定

实验测定了水-醋酸-二异丙醚三元体系在293.15 K、303.15 K的液液相平衡数据.分别采用Othmer-Tobias和Bachman方程对实验数据进行了可靠性检验,相关性系数均大于0.983.绘制了三元液液平衡相图.