System 1-butanol Research Articles

High-Pressure Vapor−Liquid Equilibria for CO2 + 2-Butanol, CO2 + Isobutanol, and CO2 + tert-Butanol Systems

In this study, the vapor−liquid equilibrium data of CO2 + isobutanol, CO2 + 2-butanol, and CO2 + tert-butanol systems were measured with an improved static-type phase equilibrium apparatus at temperatures of (331.9, 341.6, and 351.3) K and pressures from (50 to 120) bar. To ensure the accuracy and reliability of these measurements, the experimental data were compared with literature values, and these were found to be in quite good agreement. The mutual solubilities of CO2 + isomeric butanol systems decreased in the following order: CO2 + tert-butanol, CO2 + 2-butanol, and CO2 + isobutanol. The temperature and pressure effects on mutual solubilities between CO2 and isomeric butanols were also demonstrated and discussed.

Isobaric phase equilibria of the system 1-butanol + water containing penicillin G potassium salt at low pressures

The salt effect on the partially miscible system 1-butanol and water containing penicillin G potassium salt was investigated at low pressures using the ebulliometric method. The mean evaporation coefficient, f ̄ , of the small ebulliometer used was determined, and the reliability of the ebulliometric method was examined. Phase equilibrium data for the partially miscible system 1-butanol+water without salt and with different salt concentrations at 8.00, 5.33, and 2.67 kPa were measured with the ebulliometer. These data were used to calculate vapor–liquid equilibrium (VLE) compositions using the NRTL model and the modified NRTL model, respectively. vapor–liquid–liquid equilibrium (VLLE) compositions at certain pressure for the binary system without salt and with the salt were also calculated using the obtained NRTL parameters. Some of the results of the calculation were verified by experiments with a glass equilibrium still and gas chromatography analysis and showed good agreement. It was found that the salt effect of the penicillin G potassium salt on the 1-butanol+water binary system at low pressures causes the azeotropic temperature to rise slightly and increases the mutual solubility of the two components. When the penicillin G potassium salt concentration reached 10 wt.%, the 1-butanol+water system becomes completely miscible.

Chemical Equilibrium and Liquid−Liquid Equilibrium in Aqueous Solutions of Formaldehyde and 1-Butanol

A thermodynamic model for liquid−liquid phase equilibrium and chemical equilibrium in the formaldehyde + water + 1-butanol system is presented. The model is an extension of the vapor−liquid phase equilibrium model for the formaldehyde + water + methanol system. Formaldehyde reacts with water and alcohols to form oligomers. New experimental results (from NMR spectroscopic investigations) are reported for the chemical equilibrium in liquid formaldehyde + 1-butanol and formaldehyde + water + 1-butanol systems at temperatures from 278 to 348 K. New liquid−liquid phase equilibrium data are reported for temperatures of 298, 313, and 333 K. The model is able to reliably describe the liquid−liquid phase equilibrium, as well as the specification in the liquid phases.

Color bands polymer in methacrylic acid polymerization

White and pink alternative color band polymers were prepared by frontal polymerization technique in methacrylic acid-methanol, -ethanol, -butanol systems in presence of benzoyl peroxide, hydroquinone and N,N-dimethylaniline in a glass tube at 30°. The front velocity and frequency were found to be dependent on the initial concentration of methanol/ethanol/butanol, benzoyl peroxide and hydroquinone. A tentative mechanism of color band formation was proposed.

Relative permittivities of binary mixtures of 1-butanol + n-alkane AT 298.15 k

A previous study on the physical properties of 1-alkanol + n-alkane has establised a correlation between dielectric permittivity at 1 GHz and excess molar volumes for all binary systems that were studied. In order to determine whether this behaviour is similar at lower frequencies, relative permittivity was measured at 100 kHz. The refractive index was measured to explore the effects at higher frequencies. Mixtures under study are in particular the systems (1-butanol + n-hexane, or n-octane, or n-decane) at the temperature of 298.15 K and atmospheric pressure, over the entire composition range.

High-Pressure Phase Equilibria of Carbon Dioxide + 1-Butanol, and Carbon Dioxide + Water + 1-Butanol Systems

Phase equilibria data for CO2 + 1-butanol and CO2 + water + 1-butanol systems have been measured in the pressure range from 50 bar to 130 bar at 333.15, 343.15, and 353.15 K. A novel phase behavior apparatus was used for the measurements. For the CO2 + 1-butanol binary system, only vapor−liquid-phase equilibria were observed over the whole range. For the CO2 + water + 1-butanol ternary system, experimental observations were made of three single-phase regions, one vapor−liquid−liquid equilibrium region, two vapor−liquid equilibrium regions, and one liquid−liquid equilibrium region.

Volumetric and Acoustic Properties of the Ternary Mixture 1-Butanol+1-Chlorobutane+Tetrahydrofuran at 283.15, 298.15, and 313.15 K

Experimental densities (ρ) and speeds of sound (u) were obtained for the ternary system (1-butanol+1-chlorobutane+tetrahydrofuran) at three temperatures: 283.15, 298.15, and 313.15 K. Excess molar volumes (V E ) and isentropic compressibility deviations (Δκ S ) have been calculated from experimental data. A discussion of the thermodynamic behavior of the ternary system with temperature variation is presented.

Isobaric Vapor−Liquid Equilibria for the Binary System 2-Propanol + Methyl Ethyl Ketone and for the Ternary System 1-Butanol + 2-Propanol + Methyl Ethyl Ketone at 101.3 kPa

Isobaric vapor−liquid equilibrium data have been measured for the 2-propanol + methyl ethyl ketone binary system and for the 1-butanol + 2-propanol + methyl ethyl ketone ternary system at 101.3 kPa in a temperature range from 351 to 382 K. The data were found to be thermodynamically consistent according to the point to point L−W method of Wisniak. The equilibrium data were correlated using Wilson, NRTL, and UNIQUAC models for which the parameters are reported.

FT-IR spectroscopic investigations of hydrogen bonding in alcohol–hydrocarbon solutions

As part of a project on thermodynamic properties of H-bonding solutions, Fourier-transformed infrared (FT-IR) spectroscopic investigations of 14 binary systems of the type (alcohol or phenol)+hydrocarbon were carried out at temperatures of 283, 298 and 313 K. The alcohols were primary alcohols (1-alkanols from C1 to C6), secondary alcohols (2-propanol and cyclohexanol) and a tertiary alcohol (2-methyl-2-propanol), the solvents were n-hexane and cyclohexane. FT-IR spectroscopy provides quantitative information on the distribution of the alcohol molecules to the monomer and H-bonded species, respectively. Furthermore, direct evidence on the type of H-bonded species is obtained. For the data evaluation, H-bonding is described by a thermodynamically consistent chemical theory, which takes into account the monomer, dimer and one typical representative of the higher oligomers (UNIQUAC 1-2- n association model). In addition to the FT-IR data, NMR data have been taken for the system 1-butanol+cyclohexane, primarily to test the infrared (IR) spectroscopic results. Good agreement was observed. The large number of systems studied in the present work allows to obtain quantitative information on the influence of the shape and the size of both the alcohols and the solvents on H-bonding. The results provide a large data base for the development of thermodynamic models of H-bonding solutions.

Thermodynamics of the nitromethane + 1-butanol system near the upper critical point

A thermodynamic study for the nitromethane+1-butanol binary liquid system near its upper critical point UCP is presented. Densities, isentropic compressibilities, and isobaric molar heat capacities were measured throughout the composition range at atmospheric pressure and temperatures of 288.15, 293.15, 298.15 and 308.15 K. In addition, liquid–liquid equilibrium data are reported. Density data were used to obtain isobaric thermal expansivities and, via appropriate thermodynamic relations, isothermal compressibilities and isochoric molar heat capacities were derived. The excess quantities for these properties were calculated using the ideality criterion of Benson and Kiyohara. Results are discussed in terms of a high degree of non-randomness in the mixture expected near the UCP. In particular, excess heat capacities are good indicators of the above-mentioned effect.

Experimental Determination of the Vapor−Liquid Equilibrium at 101.32 kPa of the Ternary System 1-Butanol + Methanol + TAME

Experimental isobaric vapor−liquid equilibrium data are reported at 101.32 kPa for the ternary system 1-butanol + methanol + TAME (2-methoxy-2-methylbutane or tert-amyl methyl ether) and for one unmeasured constituent binary system (TAME + 1-butanol). These data were found to be thermodynamically consistent and were satisfactorily correlated with the Wilson, NRTL, and UNIQUAC equations. They have also been compared with predictions obtained from the application of ASOG and UNIFAC group contribution methods and from the correlation equations using interaction parameters of the constituent binary systems.

A new method for determining the phase in the X-ray diffraction structure analysis of phosphatidylcholine/alcohol

A new method based on a sampling theorem is proposed for determining the phase in the X-ray diffraction analysis of the structure of phospholipid systems. The thickness of a lipid layer is changed by changing the length of hydrocarbon chains in order to rebuild the continuous transform from the scattering amplitudes. By employing this method, the phases were accurately determined in a structure analysis of nine phospholipid/alcohol systems at the interdigitated gel phase. The nine systems are dimyristoylphosphatidylcholine(DMPC)/propanol, DPPC/methanol, DPPC/ethanol, DPPC/propanol, DPPC/butanol, distearoylphosphatidylcholine(DSPC)/methanol, DSPC/ethanol, DSPC/propanol and DSPC butanol systems.

Phase equilibria involved in extractive distillation of 2-methoxy-2-methylpropane+methanol using 1-butanol as entrainer

Consistent vapour–liquid equilibrium (VLE) data at 101.32 kPa have been determined for the ternary system 1-butanol+methanol+2-methoxy-2-methylpropane, correlated by means of the Wilson, NRTL, and UNIQUAC equations, and compared with the results predicted by using the same equations with interaction parameters obtained from data for the relevant binary systems. The predictions deviated only slightly from the experimental data. The Wilson equation provided the most satisfactory prediction. Moreover, deviations were smaller than those obtained when the equilibrium data were predicted using the ASOG-KT and the original and modified UNIFAC group-contribution methods. The results obtained with a commercial simulator (ChemCAD IV) indicate that extractive distillation with 1-butanol as entrainer is a feasible method for the separation of 2-methoxy-2-methylpropane (MTBE) and methanol.

Sol-gel derived macroporous titania films prepared from the system containing poly(ethylene glycol) together with long-chain alcohols

The effect of alcohol-type on macroscopic morphology has been examined for the macroporous titania (TIO2) films prepared by a sol-gel dip-coating method from the system containing poly(ethylene glycol) (PEG) and alcohols having larger alkyl groups than ethanol. The phase separation is enhanced by decreasing the compatibility between the solvent mixture and PEG as long as the polycondensation rate does not increase greatly. In the 1-butanol system, macroporous morphology appears clearly even at higher relative humidity as 70% RH due to the slower polycondensation. In contrast, the macroscopic domain formation is completely suppressed by the rapid polycondensation in the 2-propanol system.

Solubility effects on surfactant-induced unsaturated flow through porous media

It has been demonstrated that local surface tension depression due to the presence of an insoluble surfactant, myristyl alcohol, can result in capillary pressure gradients that cause significant flow in unsaturated porous media. We hypothesized that the effects of a soluble surfactant, butanol, would differ from those of myristyl alcohol despite the fact that both give a similar reduction in the surface tension of water. We investigated this hypothesis through a series of horizontal column experiments and unsaturated flow modeling. We found that both surfactants induced water flow from regions of high surfactant concentration to regions of low concentration but that the shapes of the resultant moisture content profiles were fundamentally different. Because surface tension depression from myristyl alcohol was confined to the original source zone, we were able to simulate the system using a standard unsaturated flow model by assigning separate sets of hydraulic functions to the initially clean and source zones. Modeling showed that the redistribution of water due to the initial surfactant-induced capillary pressure gradient created moisture content induced capillary pressure gradients which acted to balance the system over time. The moisture content profile within the butanol system indicated a propagation of the zone of reduced surface tension. Because the surface tension of water is a function of solute concentration, surfactant-induced capillary pressure gradients are expected to remain and influence the flow system as long as concentration gradients exist.

Physical Properties of the Ternary System 1-Butanol + Methanol + 2-Methoxy-2-methylpropane at 298.15 K: Measurement and Prediction

Densities, refractive indices, speeds of sound, excess molar volumes (VE), and deviations in molar refractions (ΔR) and isentropic compressibilities (Δκs) were determined for the system 1-butanol + methanol + 2-methoxy-2-methylpropane at 298.15 K and atmospheric pressure. The values of VE, ΔR, and Δκs were satisfactorily correlated by the Redlich−Kister polynomial. These values were also predicted using several empirical equations from the values of their constituent binary subsystems, and the best results were obtained with the Kohler and the Radojkovic equations.

Molar Volume, Refractive Index, and Isentropic Compressibility at 298.15 K for 1-Butanol + Ethanol + 2-Methoxy-2-methylpropane

Densities, refractive indices, and isentropic compressibility were measured for the system 1-butanol + ethanol + 2-methoxy-2-methylpropane at 298.15 K and atmospheric pressure. The derived excess molar volumes, deviations of molar refractions from the mole fraction average, and deviations of isentropic compressibility from the volume freaction average were correlated by the Redlich−Kister polynomial.

The influence of the temperature on the liquid–liquid equilibrium of the ternary system 1-butanol–1-propanol–water

Liquid–liquid equilibrium data for the ternary system 1-butanol–1-propanol–water have been determined experimentally at 25, 50, 85 and 95°C. The results obtained have been correlated simultaneously by the UNIQUAC method obtaining two sets of interaction parameters: one of them independent of the temperature and the other with a linear dependence. Both sets of parameters fit the experimental results well which is an improvement on using parameters depending of the temperature of 15%.

Solubilization of 1-butanol in a sodium dodecyl sulfate-poly(ethylene oxide) system by NMR and conductivity at 298.1 and 283.1 K

The effects of adding 0.1 molal 1-butanol to the aqueous SDS system at 298.1 K and the aqueous PEO–SDS system at 298.1 and 283.1 K have been studied. NMR NOESY experiments on the PEO– SDS–1-butanol system in D2O were obtained. NMR self-diffusion experiments and measurements of NMR chemical shifts and specific conductivity were carried out on the samples, i.e. on samples with PEO and without PEO. The addition of 1-butanol to an aqueous SDS–PEO system decreases the critical aggregation concentration (c.a.c). Determination of the second critical concentration (c2) depends on the method of measurements, i.e. the molecular species monitored. Conductivity measurements will give c2 as the SDS concentration where free micelles (micelles not bound to the polymer) are formed. PEO self-diffusion measurements, on the other hand, determine c2 as the SDS concentration where the polymer is saturated with SDS. Both the c.a.c and the c2 decrease upon 1-butanol addition. However, the c2 value exhibits a larger decrease than the c.a.c value. Thus, the amount of polymer bound surfactant molecules decreases upon addition of 1-butanol. Micellar solubilization of 1-butanol starts at c.a.c., but the solubilization capacity is low until the surfactant concentration reaches c2, where the increase in solubilization is significant. Thus, solubilization data can be used to detect c2, the concentration where free micelles form.

Isothermal vapor–liquid equilibria of octane with 1-butanol, 2-butanol, or 2-methyl-2-propanol

Isothermal vapor–liquid equilibria were measured for three binary systems of 1-butanol+octane at 373.15 K, 2-butanol+octane at 358.15 K, and 2-methyl-2-propanol+octane at 343.15 K. The measurements were made in a Rogalski–Malanowski type equilibrium still with circulation of both the vapor and liquid phases. Three binary isothermal systems form a maximum pressure azeotrope. The azeotropic data are x 1(AZ)=0.519 mole fraction and P(AZ)=75.71 kPa for 1-butanol (1)+octane (2), x 1(AZ)=0.750 mole fraction and P(AZ)=63.58 kPa for 2-butanol (1)+octane (2), and x 1(AZ)=0.968 mole fraction and P(AZ)=61.18 kPa for 2-methyl-2-propanol (1)+octane (2). The activity coefficients of three binary systems were correlated with the Wilson, modified Wilson, nonrandom two-liquid (NRTL), and UNIQUAC equations.