含麝香体系多元溶液固液平衡研究

测定了酮麝香、二甲苯麝香在单一溶剂和混合溶剂中的溶解度以及酮麝香的中间体 2 ,6 二甲基 4 叔丁基苯乙酮在不同溶剂中的溶解度 ,并且测定了多溶质多溶剂体系的固液平衡 ,采用UNIFAC活度系数法进行以上体系的固液平衡计算 ,计算结果与实验测定结果吻合良好。采用文中提出的方法不仅可以预测多溶质体系在溶液中共同达到饱和时的溶解度 ,而且可以预测部分溶质达到饱和时的溶解度 ,这对于溶液结晶具有重要的指导意义     

Simple multipurpose apparatus for solubility measurement of solid solutes in liquids

Solubility is one of the most basic chemical phenomena. It has a key role in understanding of major unit operations such as crystallization, solid–liquid extraction, and dissolution. In addition, solubility data is crucial for design, development, and operation of these processes. Therefore, solubility measurement of solid solutes in different solvents or solvent mixtures as a function of temperature can be of great significance to the university students and researchers. In this article, comparatively inexpensive apparatus for solubility measurement of solid solutes in pure or mixture of solvents, which can be easily assembled by using readily available equipment in the laboratory, is demonstrated. The proposed apparatus uses classical isothermal technique for measurement of solubility. Solubility of the naturally occurring antimalarial drug artemisinin was measured in n-hexane-ethyl acetate mixtures of varying composition at different temperatures to demonstrate the suitability and reliability of the proposed solubility measurement apparatus.The proposed apparatus has been used to conduct laboratory exercises in the course “Industrial Separation Technology” offered to undergraduate students of chemical engineering program at University of Southern Denmark. The exercises included solubility measurement and cooling crystallization of salicylic acid from five different organic solvents and extraction of artemisinin from the leaves of the plant Artemisia annua by using different solvents. Performance of the apparatus during laboratory exercises was evaluated through the survey among students. The results showed the general positive feedback from students and revealed enhanced interest among students to understand the exercises through the simple design of the apparatus.     

超临界流体色谱法测定固体在二氧化碳中的溶解度

开发了一种测定超临界二氧化碳中大分子溶质的溶解度的方法。这一方法将微型超微界流体萃取直接与超临界色谱相耦合，超临界流体色谱采用ＦＩＤ作为检测器。实验中两者具有同一压力、温度及同样的ＣＯ２流速度。     

Estimation of solubility parameter components of solutes and polymers using heat of vaporization and heat of sorption of solutes

In a recent study, a two‐dimensional solubility parameter model was used to correlate the heat of solution for solutes ranging from n‐alkanes to alcohols, dissolved in isotatic polypropylene (PP), poly(ethyl ethylene) (PEE), and poly(dimethylsiloxane) (PDMS). When literature data of solubility parameter components of solutes were used, the correlation had some scattering for solutes with low values of cohesive energy density. In this study, the components of solubility parameters of solutes and polymers were estimated from cohesive energy and heat of sorption of solutes. Good correlation was obtained for the specific heat of sorption (ΔU_sorp/V) for solutes ranging from n‐alkanes to alcohols, and PDMS had a polar component as previously estimated. Free volume effect in solution process may be the source of a small systematic deviation from the model. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

不同pH值下酚类的络合萃取

络合萃取法分离极性有机物稀溶液具有高效性和高选择性。在已有工作基础上,利用三正辛胺(TDA)、磷酸三丁酯(TBP)为络合剂,正辛醇、甲墓异丁基酮(MIBK)或煤油为稀释剂,在较宽的pH值条件下实验测定了酚类稀溶液的萃取相平衡分配系数;讨论了络合剂种类、络合剂浓度、稀释剂种类以及被萃取溶质种类对络合萃取相平衡分配系数的影响;提出了同时考虑络合萃取作用和物理萃取作用的平衡分配系数的表达式。     

Ionic liquids: Solubility parameters and selectivities for organic solutes

Ionic liquids (ILs) are innovative solvents for chemical processing. In this work, a database on activity coefficients of organic solutes at infinite dilution in ILs was collected from literature sources. The activity coefficients have been correlated by activity coefficient model for the regular solution and have been used to estimate the solubility parameter of ILs. The solubility parameters of ILs have been further correlated based on a concept of the group contribution method. Through the analysis of the database and the prediction results of selectivities, it was shown here that as compared with conventional organic solvents, higher selectivity can be achieved by using ILs as working solvents for separation of alkane/aromatic, aromatic/aromatic hydrocarbon mixtures via extraction or supported liquid membrane. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3034–3041, 2013     

Selection of Biphasic Liquid Systems in Liquid‐Liquid Chromatography Using Predictive Thermodynamic Models

The possibility of using thermodynamic models for screening biphasic liquid systems, including systems for which liquid‐liquid equilibrium data are not available, is demonstrated. The liquid‐liquid equilibrium in different biphasic systems and the partition coefficients of solutes in these systems are predicted with UNIFAC and COSMO‐RS. The predictions are based only on the molecular structure of the solutes and solvents. The advantages and limitations of the two models are explored using fourteen solutes and five biphasic solvent systems. The overall results show that the theoretically selected systems closely match the systems chosen by experimental screening. The experimental work needed for selecting a suitable biphasic system for a given separation problem can be drastically reduced with the help of predictive thermodynamic models.     

Development of artificial neural network models for supercritical fluid solvency in presence of co-solvents

This paper presents the application of artificial neural networks (ANN) to develop new models of liquid solvent dissolution of supercritical fluids with solutes in the presence of cosolvents. The neural network model of the liquid solvent dissolution of CO₂ was built as a function of pressure, temperature, and concentrations of the solutes and cosolvents. Different experimental measurements of liquid solvent dissolution of supercritical fluids (CO₂) with solutes in the presence of cosolvents were collected. The collected data are divided into two parts. The first part was used in building the models, and the second part was used to test and validate the developed models against the Peng-Robinson equation of state. The developed ANN models showed high accuracy, within the studied variables range, in predicting the solubility of the 2-naphthol, anthracene, and aspirin in the supercritical fluid in the presence and absence of co-solvents compared to (EoS). Therefore, the developed ANN models could be considered as a good tool in predicting the solubility of tested solutes in supercritical fluid.     

Stabilization of asphaltenes by phenolic compounds extracted from cashew‐nut shell liquid

The liquid extracted from cashew‐nut shell is composed almost completely of phenolic compounds containing 15‐carbon chains with variable unsaturation degrees, meta‐substituted in the aromatic ring. The similarity of these compounds with the structures described as efficient peptizing agents for asphaltenes, the crude oil polar fraction, induced us to evaluate cashew‐nut shell liquid (CNSL) and its derivatives, cardanol and polycardanol, as asphaltene stabilizing agents. The results confirm that CNSL and cardanol have a performance comparable to nonylphenol. Polycardanol was not only less efficient than its monomer, but, instead, enhanced the precipitation of asphaltenes. This effect may be ascribed to the large number of phenol groups present in the polymer that may flocculate the asphaltene particles or increase its polarity, reducing its solubility in aliphatic solvents. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 29–34, 1999     

Generalizing solubility parameter theory to apply to one‐ and two‐dimensional solutes and to incorporate dipolar interactions

Hildebrand and Hansen solubility parameters are commonly used to identify suitable solvents for the dispersion or dissolution of a range of solutes, from small molecules to graphene. This practice is based on a number of equations, which predict the enthalpy of mixing to be minimized when the solubility parameters of solvent and solute match. However, such equations have only been rigorously derived for mixtures of small molecules, which interact only via dispersive forces. Herein, we derive a general expression for the enthalpy of mixing in terms of the dimensionality of the solute, where small molecules are considered zero‐dimensional, materials such as polymers or nanotubes are one‐dimensional (1D) and platelets such as graphene are two‐dimensional (2D). We explicitly include contributions due to dispersive, dipole–dipole, and dipole‐induced dipole interactions. We find equations very similar to those of Hildebrand and Hansen so long as the solubility parameters of the solute are defined in a manner which reflects their dimensionality. In addition, the equations for 1D and 2D systems are equivalent to known expressions for the enthalpy of mixing of rods and platelets, respectively, as a function of surface energy. This agreement between our expressions and those commonly used shows that the concept of solubility parameters can be rigorously applied to extended solutes such as polymers, nanotubes, and graphene. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Three‐dimensional solubility parameters of poly(ε‐caprolactone)

The three‐dimensional solubility parameter model was applied to analyze solution thermodynamic data of 27 solutes in poly(ε‐caprolactone) (PCL) between 70 and 110 °C. A linear regression method was compared with a nonlinear least square regression method, which searches solubility parameter components by minimization of the sum of error squares. The parameters of polymers were the same by both methods. When compared with the error in predicting χRT/V, the data showed a different slope from the simple three‐dimensional model. These deviations were reduced by a different model using a smaller weight on the polar and hydrogen bonding components. In the new model, the solubility parameter components were closer to the value of a structure analogue of PCL. The confidence intervals for the parameters were estimated from a linearized equation based on the sum of error squares. The solubility parameter components obtained were different from the average values of the five solutes with the smallest χ. The inclusion of solutes with high hydrogen bonding components contributed to the increase of the component in the nonlinear regression method. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2002–2009, 2006     

Hydrotrope-Induced Enhancement of Room Temperature Surface Activity for High Krafft Point Fluorinated Surfactants

Potassium perfluorooctane sulfonate (KPFOS) and sodium perfluorooctane sulfonate (NaPFOS) exhibit poor surface activities in aqueous solution at room temperature because of their high Krafft points. In this work, we attempted to increase the solubility of KPFOS and NaPFOS and consequently improve their surface activities at room temperature with sodium p‐methylbenzene sulfonate (BS) and urea, which are typical hydrotropes in industrial applications. The effects of BS and urea on the surface tension of the aqueous solutions of KPFOS and NaPFOS were investigated at 25 °C. When the hydrotropes were added, the effectiveness of KPFOS and NaPFOS in surface tension reduction was greatly enhanced and KPFOS showed higher efficiency in surface tension reduction than NaPFOS. On the other hand, BS had much stronger ability than urea to reduce the surface tension of KPFOS and NaPFOS in water. In particular, with the assistance of BS the minimum surface tension of KPFOS approached 19 mN/m at 25 °C. It was worth noting that in the presence of BS, the surface tension of an apparently “saturated” solution (i.e., with coexisting surfactant solid) continuously decreased with increasing surfactant concentration. This behavior was ascribed to enrichment of branched PFOS isomers in aqueous phase with the assistance of BS, as evidenced by high‐resolution ¹⁹F NMR. Hydrotropes were able to recover the inherent character of KPFOS and NaPFOS as highly surface‐active fluorinated surfactants by increasing the solubility of branched isomers. This is an easy way to enhance the effectiveness in surface tension reduction at room temperature for fluorinated surfactants with high Krafft points.     

COMPARISON OF EXACT AND APPROXIMATE SOLUTIONS OF TRANSIENT RESPONSE FOR LEACHING BY SCF IN CSTR

Leaching or extraction by supercritical fluids (SCF) is a relatively new technology which offers several key advantages over traditional methods, especially enhanced solubility and rapid diffusion. Because the molecular properties are somewhere in between those of either liquid or gas, the design of SCF systems does not fit the classical mold based on intuitive or well-known rules of thumb. In the present work, transient transport for dissolution of solutes filling granulated porous media is studied for SCF leaching in spinning basket or slurry reactors. We present an approximate model based on taking the intraparticle composition profile to be always parabolic. This leads to a simple one-term expression (transportable on the back of a postage stamp) which is shown to compare very favorably with the more tedious exact solution. The approximate solution thus allows designers to quickly delineate those conditions, such as sampling times, which are realizable in the experimental sense. Moreover, it is shown that parameters such as diffusivity can be estimated directly, using only time-to-peak information. The specific results presented are directly applicable to SCF systems, but the analysis can be used for any extraction system     

Interaction Parameter Method for Investigating BTEX Extraction Using the Hollow‐Fiber Microporous Membrane Liquid/Liquid Extraction Technique

This work focused on the extraction of BTEX from aqueous solution by a hollow‐fiber microporous membrane liquid/liquid extraction (HF‐MMLLE) technique. A simple and rapid method based on the Hansen solubility parameters (HSP) theory was adopted to theoretically determine the interaction parameter (χ₁₂) between the extractants and BTEX. Experiments were carried out to establish the relationship between the interaction parameter and the extraction performance. Furthermore, the distribution coefficient and permeability coefficient related to the extraction performance were also discussed, which verified the relationship from a quantitative idea. It was observed that the liquid/liquid extraction was based on the strong affinities between the extractants and the target pollutants. This method should be paid more attention for its potential application in other solvent‐sensitive processes.     

Mechanism of simultaneous solutes separation and concentration by size exclusion cyclic separation

The semicontinuous separation/concentration of two solutes with different molecular size by the size exclusion cyclic separation method is based on the opposite swelling responses of two gels to a temperature change. Experimental results of separation and concentration of solutes are verified qualitatively by the theoretical models based on the local equilibrium assumption. Separation of two solutes is shown by the breakthrough curves in coupled gel columns. In closed coupled columns, the volumetric space for the large molecules which are totally excluded from the gels becomes smaller, creating a concentrating effect as the gels swell when temperature changes. A mechanistic model is suggested to predict the large molecule concentration to increase to its solubility limit as cycle repeats.     

缔合模型用于超临界萃取溶解度计算

基于在超临界萃取过程中,同时存在超临界流体相－固相相平衡和超临界相缔合反应平衡的假设,提出一一个用于超临界萃取溶解度计算的缔合模型。该模型式用于２７个固体溶质和５个液体溶质在超临界溶剂中溶解度的计算,其平均相对偏差绝大多数体系均小于１０％。     

Correlation and Prediction of Carbon Dioxide Solubility in n‐Paraffin Systems

This work discusses high‐pressure gas solubility. Reference state is the Henry's law and a two‐parameter corresponding states model is used for the liquid phase. Pure gas is used as the vapor phase for the high‐molecular paraffin's gas‐liquid equilibrium. The systems under study are mixtures of carbon dioxide and normal paraffin up to a chain length of 44 carbon atoms. Correlated liquid compositions are in the 1 % to 3 % average absolute relative deviation range, with a maximum error of about 7 %. Using a known system as reference, the model could be used to predict solubility. In this case average absolute relative deviations are below 6 % in most cases.     

THE SOLUBILITY OF PARAFFINIC HYDROCARBONS AND THEIR DERIVATIVES IN SUPERCRITICAL CARBON DIOXIDE

The solubilities of twenty-five paraffinic model compounds, octadecane (C₁₈H₃₈) through tetracosane (C₂₄H₅₀) and related monofunctional derivatives, were measured in supercritical carbon dioxide at 310 and 320 K. The derivatives included sulfides, amines, phosphines, ketones and other functional groups. Several of the solutes were liquids at the extraction temperatures and pressures, and both liquid and fluid phase binary composition data are reported in some cases. A systematic attempt was made to explore how the presence of a particular functional group on the solute molecule affected the solubility of the compound relative to the parent hydrocarbon of equivalent chain length.     

预分散溶剂萃取分离苯酚溶液的研究

Predispersed solvent extraction (PDSE) is a new method for separating solutes from aqueous solution by solvent extraction and one which has shown promise for extraction from extremely dilute solution very efficient and very quick. The use of colloidal liquid aphrons in predispersed solvent extraction may ameliorate the problems such as emulsion formation, reduction of interracial mass transfer and low interfacial mass transfer areas in solvent extraction process. In present paper, colloidal liquid aphrons are successfully generated using kerosene as a solvent,tributyl phosphate(TBP) as an extractant, sodium dodecyl benzene sulphate(SDBS) as surfactant in aqueous phase and Tween-80 in oil phase. Extraction of phenol from dilute solution was studied by using colloidal liquid aphrons and colloidal gas aphrons in a semi-batch extraction column. It has been found that the PDSE process is more suitable for extraction of dilute solutions. It has also been discovered that the PDSE process has a great advantage over traditional single-stage extraction process.     

Modeling the phase behavior in binary mixtures involving blowing agents and thermoplastic resins

The thermophysical properties of mixtures of thermoplastic resins and blowing agents, together with the knowledge of the solubilities of these components, are the basis for the manufacturing of plastic foams. In this work, the solubilities of blowing agents trichlorofluoromethane, dichlorodifluoromethane, chlorodifluoromehane, and 1,2‐dichloro‐1,1,2,2‐tetrafluoroethane in thermoplastic resins poly(styrene), high density poly(ethylene), low density poly(ethylene), poly(propylene), poly(vinyl chloride), poly(carbonate) and poly(propylene oxide) were modeled by using the Perturbed Chain‐Statistical Associating Fluid Theory (PC‐SAFT) and the Sánchez‐Lacombe equations of state (EoS), fitting a single temperature‐dependent binary interaction parameter. PC‐SAFT is a theoretically based equation of state with three pure component parameters that describe efficiently the thermodynamics of complex systems. Earlier works with this EoS have already predicted the phase coexistence properties of various refrigerants and higher order alkane series compounds, along with their mixtures. The pure component parameters for the blowing agents were obtained by regression of vapor pressure and liquid density data, while the pure component parameters for the thermoplastic resins were obtained by regression of pure liquid PVT data. The parameter estimation was performed by using a modified maximum likelihood method. The solubility results obtained with both EoS have been compared; the results from PC‐SAFT showed a higher accuracy in terms of solubility pressure deviations. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers