Organic Liquid Mixtures Research Articles

Mineralogical characterization and washability of Indian coal from Jamadoba

ABSTRACTCoal characterization becomes a prelude for designing of washing circuits and also utilization of washed products. In the present paper, an attempt has been made to characterize coal obtained from an operating washery (Jamadoba, Jharia) as a case study. Two approaches, viz., physical and chemical characterization approaches, have been attempted after crushing the coal to finer size (−3.0 mm) for improved liberation. In the first approach, physical characterization of feed coal was done by density fractionation (float and sink test) using mixtures of organic liquids, besides determination of Hardgrove Grindability Index to estimate the friability nature of the coal. In the second approach, mineralogical characterization of coal has been done by modern analytical methods such as X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), Fourier-Transform Infrared Spectroscopy (FTIR), thermogravimetric, and differential thermal analyses.The results of the float–sink test indicated coal to possess difficult washing characteristics having its near-gravity material content of 31.5 at 1.52 g/cc washing density and is of ‘formidable type’ as per Bird's Scale of Classification. The results of Hardgrove Grindability Index (HGI) indicated that the coal to be medium hard. Further, the difficulty washing has been established by estimating the values of Washability Number and Washability Index. The results of mineralogical analysis on the inorganic mineral matter composition indicated that the coal to contain quartz as the major gangue mineral and kaolinite, illite, montmorillonite, rutile, calcite, siderite, and pyrite as minor gangue components. The present paper enumerates that for development of a beneficiation strategy, physical characterization studies (such as Washability Index and Washability Number), etc., are important. However, mineralogical and chemical characterizations place a vital role from the end utilization point of view.

Tetramethylammonium chloride + glycerol deep eutectic solvent as separation agent for organic liquid mixtures: Assessment from experimental limiting activity coefficients

Solute retention data acquired by gas-liquid chromatography were used to determine the activity coefficients at infinite dilution for 24 organic solutes in the deep eutectic solvent (DES) consisting of tetramethylammonium chloride and glycerol in a molar ratio of 1.001:2. The organic solutes included alk-1-anes, alk-1-enes, alk-1-ynes, cycloalkanes, alkanols, alkylbenzenes, ketones, esters and heterocyclics. The measurements were undertaken at four different temperatures, viz T = (313.15, 323.15, 333.15 and 343.15) K with an estimated uncertainty of ±3.8%. From the experimental infinite dilution activity coefficient data, the values of partial molar excess enthalpy at infinite dilution were calculated using Gibbs Helmholtz relationship. Limiting selectivity and capacity values were also calculated from experimental limiting activity coefficients and compared to those of other separation agents, including other deep eutectic solvents, ionic liquids and industrial molecular agents. Results obtained in this study indicate that tetramethylammonium chloride + glycerol DES can potentially be used as an alternative solvent for nitrogen and sulphur removal from transportation fuels as well as the separation of cycloalkanes, aromatics and esters from light alkanols.

Multifunctional oil-water and immiscible organic liquid separation by micropore arrayed Ti foil

In this work a multifunctional micropore array (size from 5 to 42 μm) was produced by using one-step femtosecond laser microdrilling for oil-water and oil-oil separation. This novel method has many advantages, such as high precision (size error is less than 1 μm), simple operation (one step), extensible function (even complex microstructures) just to name a few. The prepared foil exhibited superhydrophilic and underwater superoleophobic properties, which can be used to separate the light oil (C8H18) and water mixtures. After heating in dark environment 0.5 h, the prepared foil showed superhydrophobic and underwater superoleophilic properties, and can be used to separate the heavy oil (C2H4Cl2) and water mixtures. In addition, the heated sample also showed robust ability to separate the immiscible organic liquid mixtures (formamide and C2H4Cl2), exhibiting multifunctional applications. Interestingly, the heated samples would recover its original superhydrophilicity after UV irradiation in ethanol for 1 h. The samples don’t contain any fluorinated compounds and display environmental stability even after sonic cleaning and scratch. This work will provide a new insight into the design of intelligent devices for oil/water mixtures separation, organic liquid mixtures separation, and water droplet manipulation.

Liquid-Liquid Equilibrium Data for the System N-Octane + Toluene + DES at 293.15 and 313.15 K and Atmospheric Pressure

Deep eutectic solvents (DESs) are promising alternative for ionic liquids due to their low cost and sustainability. Considerable attention is paid on the ability of DES to replace ionic liquids in the separation of organic liquid mixtures via extraction. In this sense, it is important to determine the physicochemical parameters of liquid-liquid equilibrium for the industrially significant mixtures and deep eutectic solvents. In the present work a mixture of n-octane, toluene and DES based on choline chloride and malonic acid was studied at 293.15, 313.15 K and atmospheric pressure. Tie-lines were obtained and ability of deep eutectic solvents to separate aliphatic-aromatic mixture was analyzed. Experimental liquid-liquid equilibrium data were fit with the NRTL model, and interaction parameters of components were obtained and discussed.

Estimation of Interfacial Tension in Mixtures of Linear Hydrocarbons and Immiscible Organic Liquids with Water by Dissipative Particle Dynamics (DPD)

Petroleum systems have a high level of complexity due to the presence of a huge variety of organic compounds, mainly hydrocarbons. These characteristics, not only make difficult its recovery but also its study. In this sense, the study of parameters, such as the local variation of interfacial tension (IFT) is essential to understanding the behavior of different interfaces that arise through the extraction, transport and oil refining processes. Accordingly, in the present study, theoretical estimations of IFTs of linear-hydrocarbon-water, linear-hydrocarbon-glycerol, and mixtures of 11 types of organic-liquid with water were performed. The system elements were built by using coarse-graining technique and the dynamics were carried out by the Dissipative Particle Dynamics (DPD). With this technique was possible to reproduce, in a systematic way, an important set of IFT values for systems of oil industrial interest, which reproduced trends obtained from experimental analogous conditions.

Determination of the soret coefficient based on the separation of mixtures of organic liquids in a thermogravitational column

The technique of the direct determination of the Soret coefficient based on the results of separating binary mixtures of organic liquids in a thermogravitational column has been developed. The criterial equations that describe the separation of mixtures in an unsteady state have been obtained. A comparison of the calculated values of the Soret coefficient with the experimental data obtained by the results of separation in horizontal cells has been presented. The satisfactory agreement of the results has been noted.

Sustainable products from bio-oils

Abstract

Solubility of 2-isopropylimidazole in nine pure organic solvents and liquid mixture of (methanol + ethyl acetate) from T = (278.15 to 313.15) K: Experimental measurement and thermodynamic modelling

Solubility of 2-isopropylimidazole in nine organic solvents including methanol, ethanol, n-propanol, isopropanol, acetone, acetonitrile, ethyl acetate, toluene, 2-butanone and liquid mixture of (methanol+ethyl acetate) were determined experimentally by using the isothermal saturation method over the temperature range from (278.15 to 313.15)K under atmosphere pressure (101.2kPa). The solubility of 2-isopropylimidazole in the pure solvents increased with a rise of temperature. In general, the mole fraction solubility obeyed the following order from high to low in different pure solvents: methanol>ethanol>2-butanone>n-propanol>acetone>isopropanol>ethyl acetate>acetonitrile>toluene. For the (methanol+ethyl acetate) mixture with given initial composition, the mole fraction solubility of 2-isopropylimidazole increase with increasing temperature and mass fraction of methanol. The obtained solubility of 2-isopropylimidazole in the pure solvents was correlated with the modified Apelblat equation and λh equation; and in the binary solvent mixture, the Jouyban–Acree model, van’t Hoff–Jouyban–Acree model and modified Apelblat–Jouyban–Acree model. The maximum values of root-mean-square deviation (RMSD) and relative average deviation (RAD) were 19.29×10−3 and 1.07%, respectively. In addition, the standard dissolution enthalpy was calculated.

Separation of organic liquid mixture by flexible nanofibrous membranes with precisely tunable wettability

Separation of liquid mixtures, especially organic liquid mixtures, is widely used in industrial processes but still faces challenges with respect to separation in a high-efficiency, low-energy mode. In this work, we report a flexible wettability-tunable nanofibrous membrane composed of a high-performance fluoro-polymer as the matrix and fluorosilane as a surface energy regulator that can be successfully applied in immiscible organic liquid mixture separation. The separation is achieved by tuning the surface energy of a membrane to a value between the surface tensions of two organic liquids. Moreover, for use in different mixed liquid systems, we programmatically designed nanofibrous membranes with the proper surface energy that could intercept the relatively high surface tension liquid and allow the low surface tension liquid to pass through. These membranes are expected to become a competitive candidate for complex organic chemical product separation, resource recycling, and environmental protection. Polymer nanofibre membranes with tunable wetting properties can match the surface tension of complex liquids and separate them. Purifying organic liquids with similar physical properties often requires energy-intensive methods. However, a membrane developed by Yong Zhao from Beihang University in China and colleagues offers high-throughput separation, thanks to incorporate of ‘dopants’ made from long silicon fluorocarbon chains, which repel both water and oil, into electrospun nanofibres made from poly(vinylidene fluoride-co-hexafluoropropylene enabled the team to selectively adjust membrane wetting to match organic liquid targets. With organic liquids having slightly different surface tensions, such as propylene glycol and benzene solutions, the membranes intercepted the high-surface tension liquid while the other passed through spontaneously. The flexible membrane offers improved mechanical properties over conventional ceramic membranes and is promising for cleaning oil spills and treating other environmental problems. Organic liquid separation is currently an important but troublesome issue, which closely related to resource recycling and environmental protection. Here we reported a wettability-tunable nanofibrous membrane that can be used for efficient separation of wide ranges of immiscible organic liquid mixtures.

A Robust Cu(OH)2 Nanoneedles Mesh with Tunable Wettability for Nonaqueous Multiphase Liquid Separation.

The separation of organic liquid mixtures is achieved by Cu(OH)2 nanoneedle-covered copper mesh based on the difference of the liquid surface tension. The as-prepared membrane allows the penetration of organic liquid with smaller surface tension and blocks the higher. Thus, the effective separation of these two organic liquids can be achieved.

A semi-empirical equation for describing the surface tension of aqueous organic liquid mixtures

A thermodynamic analysis is made for the dependence on composition of the surface tension showing that the latter is a mechanical thermodynamic property which is linearly related to the reciprocal of each component standard molar surface area; and that there is no simple mixing formula linking the ideal surface tension to pure-component surface tensions.The ability of five current empirical equations to correlate the surface tension of the ideal and real binary systems water–ethanol or propan-2-ol or ethanenitrile or 1,4-dioxane at T = 298 K is examined. Polynomial equations are not able to describe the general, overall trend of surface tension variation across the entire composition range, where equations containing a hyperbolic term perform much better. This is the case of the proposed new equation in which two of its parameters can be estimated theoretically.

Grafting of cellulose acetate with ionic liquids for biofuel purification by a membrane process: Influence of the cation

A new strategy was developed for grafting ionic liquids (ILs) onto cellulose acetate in order to avoid IL extraction and improve its performance for ethyl tert-butyl ether (ETBE) biofuel purification by the pervaporation membrane process. This work extended the scope of IL-containing membranes to the challenging separation of organic liquid mixtures, in which these ILs were soluble. The ILs contained the same bromide anion and different cations with increasing polar feature. The membrane properties were strongly improved by IL grafting. Their analysis in terms of structure-property relationships revealed the influence of the IL content, chemical structure and chemical physical parameters α, β, π* in the Kamlet–Taft polarity scale. The ammonium IL led to the best normalized flux of 0.182kg/m2h for a reference thickness of 5μm, a permeate ethanol content of 100% and an outstanding infinite separation factor for the azeotropic mixture EtOH/ETBE at 50°C.

Evaluating the Molecular Interaction of Organic Liquid Mixtures Using Near-Infrared Spectroscopy.

The near-infrared transmission spectra of two organic liquid three-component systems of variable compositions were investigated in detail. To evaluate the interaction of the different components in the two systems the experimental spectra of the pure components were compared to mathematically constructed "pure component" spectra. Though usually the correlation coefficient (CC) and Manhattan distance (MD) are used to measure the similarity of spectra, in the present investigations principal component analysis (PCA) was found to be a more effective tool to investigate the difference between these spectra and derive parameters characterizing the interaction between the different components. Thus, PC scores for the two types of spectra established some distinct patterns which clearly expressed their differences. For a three-dimensional coordinate system of selected principal components, the Euclidean distances between the mathematically constructed and the experimental spectra of the pure components were calculated. Finally, the mean values of the distances for each component provided indices to rank the interaction of the components in the mixtures. Thus, the results offer a convenient approach that can quantitatively evaluate the molecular interactions of the individual components in organic liquid mixtures by various spectroscopies.

Influence of liquid organic fertilizer on growth and yield of maize (Zea mays L.)

Since identification of sustainable and cost effective organic input is vital, an experiment was carried out at Crop Farm, Eastern University Sri Lanka, Vantharumoolai from May to August 2010 to investigate the effect of liquid organic mixture (Jeetvamirta) on growth and yield of maize (cv. Pacific 984). The experimental design was randomized complete block design (RCBD) with four replicates. Different application frequencies of Jeewamirta were considered as treatments and treatments were defined as follows; T1- once a week application, T2- once in two weeks application, T3- once in three weeks application and T4- as control plot. Measurements viz. leaf area and plant biomass were taken at two weeks interval and data were analyzed statistically. The results revealed that there were significant (p AGRIEAST 2010 (9) p.11-16

Dip-in Indicators for Visual Differentiation of Fuel Mixtures Based on Wettability of Fluoroalkylchlorosilane-Coated Inverse Opal Films

We have developed the dip-in indicator based on the inverse opal film (IOF) for visual differentiation of organic liquid mixtures, such as oil/gasoline or ethanol/gasoline fuel mixtures. The IOF consists of a three-dimensional porous structure with a highly ordered periodic arrangement of nanopores. The specularly reflected light at the interface of the nanopores and silica walls contributes to the structural color of the IOF film. This color disappears when the nanopores are infiltrated by a liquid with a similar refractive index to silica. The disappearance of the structural color provides a means to differentiate various liquid fuel mixtures based on their wettability of the nanopores in the IOF-based indicators. For differentiation of various liquid mixtures, we tune the wettability threshold of the indicator in such a way that it is wetted (color disappears) by one liquid but is not wetted by the other (color remains). Although colorimetric differentiation of liquids based on IOF wettability has been reported, differentiation of highly similar liquid mixtures require complicated readout approaches. It is known that the IOF wettability is controlled by multiple surface properties (e.g., oleophobicity) and structural properties (e.g., neck angle and film thickness) of the nanostructure. Therefore, we aim to exploit the combined tuning of these properties for differentiation of fuel mixtures with close compositions. In this study, we have demonstrated that, for the first time, the IOF-based dip-in indicator is able to detect a slight difference in the fuel mixture composition (i.e., 0.4% of oil content). Moreover, the color/no-color differentiation platform is simple, powerful, and easy-to-read. This platform makes the dip-in indicator a promising tool for authentication and determination of fuel composition at the point-of-purchase or point-of-use.

Effect of Anion on Behaviour of Li-S Battery Electrolyte Solutions Based on N-Methyl-N-Butyl-Pyrrolidinium Ionic Liquids

The electrochemical behaviour and electrical performance are investigated for a series of lithium-sulfur (Li-S) cells in which the electrolyte solutions are organic solvent-ionic liquid mixtures that are based on the 1-butyl-1-methylpyrrolidinium (C4mpyr) cation with a range of anions. In each case, performance is compared with cells that are based on a standard mixed-ether organic electrolyte.The capacity of cells assembled with electrolytes containing 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl) trifluorophosphate (C4mpyr-FAP), 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate (C4mpyr-OTf), or 1-butyl-1-methylpyrrolidinium tricyanomethanide (C4mpyr-TCM) decline rapidly due to low conductivity, high polysulfide solubility and side reaction of electrolyte with electrodes, respectively. Our results confirm that polysulfide solubility is strongly controlled by the anion of the ionic liquid and verify that not all ionic liquids decrease polysulfide solubility. In agreement with previous reports, 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (C4mpyr-TFSI) shows the best compatibility in Li-S batteries and has a higher coulombic efficiency of greater than 99% over 100 cycles. Furthermore, impedance spectroscopy confirms that electrolyte composition influences the SEI layer formed on the lithium anode and its subsequent impedance.

Combining mixing rules with QSPR models for pure chemicals to predict the flash points of binary organic liquid mixtures

Flash point is a key property of liquids to evaluate the safety of industrial processes. Mixing rules are commonly used to calculate the flash point of liquid mixtures, but they need knowledge of the ones of pure compounds. Theoretical methods notably based on quantitative structure property relationships (QSPR) already exist to predict flash points of pure compounds. So, in this paper, direct combination of these two types of approaches was investigated to achieve predictions even when the flash points of pure compounds were unknown. Three relevant mixing rules and four QSPR models, based on simple constitutional descriptors, were considered. Based on a data set of 284 experimental data of binary mixtures extracted from literature, two reliable combinations were highlighted. The most accurate one reached an error in prediction of only 2.9°C but needed knowledge of the boiling point and Antoine's coefficients of each component of the mixture. A new full-predictive method was in particular proposed with also a low error in prediction (4.4°C), requiring only knowledge of the molecular structure of each pure compound and molar fraction of the mixture. Errors in each predictive method keep quite reasonable against expected accuracies of direct measurements of flash point of binary mixtures.

Surface Tension Prediction of Organic Binary Liquid Mixtures

Equations have been reported in the literature to predict the surface tension of binary liquid mixtures. However, the equations involve large number of variables and are very complex. In the present article an attempt is made to propose an empirical equation to predict the surface tension of binary organic liquid mixtures. A simple equation, ‘Hadkar Equation’, has been proposed and was used to calculate the surface tension of binary liquid mixtures that have already been reported in the literature and was found to give the results close to the reported values. To verify the utility of the equation for the prediction of surface tension of liquid mixture, the surface tension of a few organic binary liquid mixtures was determined using drop weight method. The ‘Hadkar Equation’, was found to be useful in the prediction of surface tension of organic binary liquids having weak force of attraction.

Estimation of Some Important Thermodynamic Properties of Organic Liquid Mixtures from Ultrasonic Velocity and Density Data

Using the recently proposed equations for calculating thermal expansion coefficient (α) and isothermal compressibility (βT) from density (ρ) and ultrasonic velocity (u) values, six binary organic liquid mixtures have been considered. These are: n-heptane+toluene (I); n-heptane+n-hexane (II); toluene+n-hexane (III); cyclohexane+nheptane (IV); cyclohexane+n-hexane (V), and n-decane+n-hexane (VI) at 298.15 K. Literature data for ρ and u of these mixtures are employed to compute α, βT, as well as γ, Pint and Γ. Calculated values of βT are compared with the earlier ones, and the agreement is found to be good.

Molecular Interactions in Binary Organic Liquid Mixtures Containing Ethyl Oleate and Ethanol at 2MHz Frequency

Molecular interactions of binary mixtures of Ethanol with a new organic compound Ethyl Oleate are investigated at a constant ultrasonic frequency of 2MHz under the temperature range of 303.15K-318.15K. The effect of mole fraction of Ethyl Oleate on velocity of sound wave and the density and viscosity of binary mixtures at various temperatures were studied. The effects on density (ρ), viscosity (η), adiabatic compressibility (βad), inter molecular free length (Lf) and internal pressure (Пi) also was studied.