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Showing papers in "Journal of Chemical & Engineering Data in 2012"


Journal ArticleDOI
TL;DR: A new equation of state for the thermodynamic properties of natural gases, similar gases, and other mixtures, the GERG-2008, was presented in this paper, which is based on 21 natural gas components.
Abstract: A new equation of state for the thermodynamic properties of natural gases, similar gases, and other mixtures, the GERG-2008 equation of state, is presented in this work. This equation is an expanded version of the GERG-2004 equation. GERG-2008 is explicit in the Helmholtz free energy as a function of density, temperature, and composition. The equation is based on 21 natural gas components: methane, nitrogen, carbon dioxide, ethane, propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, hydrogen, oxygen, carbon monoxide, water, hydrogen sulfide, helium, and argon. Over the entire composition range, GERG-2008 covers the gas phase, liquid phase, supercritical region, and vapor–liquid equilibrium states for mixtures of these components. The normal range of validity of GERG-2008 includes temperatures from (90 to 450) K and pressures up to 35 MPa where the most accurate experimental data of the thermal and caloric properties are represented to within their accura...

872 citations


Journal ArticleDOI
TL;DR: In this paper, the authors measured and correlated the solubilities of (Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetic acid in different pure solvents and binary mixtures of water + (ethanol, methanol, or glycol).
Abstract: Article commenting on an article titled, "Measurement and correlation of solubilities of (Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetic acid in different pure solvents and binary mixtures of water + (ethanol, methanol, or glycol)," published in March 2011.

216 citations


Journal ArticleDOI
TL;DR: In this paper, the experimental refractive index and the predicted polarizability normalized in terms of the molar volume of the room-temperature ionic liquids were found to be correlated.
Abstract: Refractive index, an optical property, and liquid density were measured for 17 types of room-temperature ionic liquids at various temperatures. Ab initio calculations were performed to yield theoretical polarizability of the respective ionic liquid composing ions. A highly linear correlation was found between the experimental refractive index and the predicted polarizability normalized in terms of the molar volume. This suggests that the electronic polarization of the ionic liquid composing ions predominantly contributes to the refractive index of the room-temperature ionic liquids.

191 citations


Journal ArticleDOI
TL;DR: In this article, the ability of activated carbon which was produced by chemical activation using zinc chloride from tea industry wastes (TIWAC) to adsorb phenol molecules from aqueous solution was tested by equilibrium, kinetic, and thermodynamic parameters.
Abstract: The ability of activated carbon which was produced by chemical activation using zinc chloride from tea industry wastes (TIWAC) to adsorb phenol molecules from aqueous solution was tested by equilibrium, kinetic, and thermodynamic parameters. Phenol adsorption on TIWAC took place with a high yield at pH values in the range 4 to 8. The optimum contact period was observed as 4.0 h and from the adsorption graphs plotted as a function of time; it was established that phenol adsorption on TIWAC conformed more to a pseudosecond-order kinetic model. Additionally, it was determined that the adsorption rate is controlled by intraparticle diffusion as well as film diffusion. It was established that phenol adsorption on TIWAC can be better defined by the Langmuir adsorption model and its adsorption capacity was 142.9 mg·g–1 from the linear Langmuir equation. Temperature had an adverse effect on adsorption yield, and hence, the adsorption process was exothermic in our case. Moreover, increasing electrolyte concentrati...

186 citations


Journal ArticleDOI
TL;DR: In this paper, the tetrahydrofuran (THF) + CH4, THF + CO2, CH4+ CO2+ CH4 hydrates were investigated over wide ranges of temperature, pressure, and concentration.
Abstract: The hydrate phase equilibrium behaviors of tetrahydrofuran (THF) + CH4, THF + CO2, CH4 + CO2, and THF + CO2 + CH4 were investigated over wide ranges of temperature, pressure, and concentration. The dissociation conditions of THF + CH4 and THF + CO2 hydrates were shifted to lower pressures and higher temperatures from the dissociation boundaries of pure CH4 and pure CO2 hydrates. X-ray diffraction results revealed that the CH4 + CO2 and THF + CO2 + CH4 hydrates prepared from a CH4/CO2 (50:50) gas mixture formed structure I and II clathrate hydrates, respectively. Raman measurements provided detailed information regarding the cage occupancy of CH4 and CO2 molecules encaged in the hydrate frameworks. For the CH4 + CO2 hydrates, the concentrations of CO2 in the hydrate phase were higher than those in the vapor phase. In contrast, for the THF + CO2 + CH4 hydrates, the concentrations of CO2 in the hydrate phase were lower than those in the vapor phase.

177 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated quantitatively the solubility properties of a number of unsubstituted metal phthalocyanines with various metal atoms such as Co, Cu, Fe, Mg, Mn, Ni, Sn, and Zn.
Abstract: We investigated quantitatively the solubility properties of a number of unsubstituted metal phthalocyanines with various metal atoms such as Co, Cu, Fe, Mg, Mn, Ni, Sn, and Zn. We studied three categories of solvents: conventional solvents, ionic liquids, and acids. The conventional liquids comprised 20 typical representatives from acetone to toluene. We tested two ionic liquids and five acids. For each solution we measured the molar absorption coefficient and the saturation concentration (or estimated these values if the solubility was too low). The absorption coefficients and saturation concentrations were derived from UV–vis absorption measurements of the Q-band. The solution spectra are presented and discussed as well as the chemical properties (stability) of the solutions.

161 citations


Journal ArticleDOI
TL;DR: In this article, the interfacial tension between carbon dioxide and aqueous solutions of the mixed salt system (0.864 NaCl + 0.136 KCl) with total salt molalities between (098 and 4.95) mol·kg−1.
Abstract: We report the interfacial tension between carbon dioxide and aqueous solutions of the mixed salt system (0.864 NaCl + 0.136 KCl) with total salt molalities between (0.98 and 4.95) mol·kg–1. The measurements were made at temperatures between (298 and 473) K at various pressures up to 50 MPa by means of imaging a pendant drop of CO2-saturated brine surrounded by a water-saturated CO2 phase. The expanded uncertainties at 95 % confidence are 0.05 K in temperature, 70 kPa in pressure, and for interfacial tension γ, the larger of 0.016γ and 0.6 mN·m–1. The results of the study indicate that the interfacial tension increases linearly with the molality of the salt solution. An empirical equation has been developed to represent the present results as a function of temperature, pressure, and molality with an expanded uncertainty of 1.6 mN·m–1.

151 citations


Journal ArticleDOI
TL;DR: In this article, four thermophysical properties, specifically, density, viscosity, refractive index, and surface tension, were determined for five acetate-based ionic liquids, and additional properties, such as the isobaric thermal expansion coefficient, the surface entropy and enthalpy, and the critical temperature, were further estimated.
Abstract: Ionic liquids (ILs) with improved hydrogen-bonding acceptor abilities, such as acetate-based compounds, have shown great potential for CO2 capture and biomass dissolution. In this context, the knowledge of the thermophysical properties of acetate-based fluids is essential for the design and scale-up of related processes. However, at this stage, acetate-based ILs are still poorly characterized. In this work, four thermophysical properties, specifically, density, viscosity, refractive index, and surface tension, were determined for five acetate-based ILs. Both protic and aprotic ILs were investigated, namely, N,N-dimethyl-N-ethylammonium acetate, 1-ethylimidazolium acetate, 1-ethyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium acetate, and 1-butyl-1-methylpyrrolidinium acetate. From the temperature dependence of the measured properties, additional properties, such as the isobaric thermal expansion coefficient, the surface entropy and enthalpy, and the critical temperature, were further estimated.

149 citations


Journal ArticleDOI
TL;DR: In this article, the adsorbents were characterized by Fourier transform infrared (FTIR) spectra to confirm that chitosan was successfully immobilized on alumina, and some functional groups were successfully introduced into the surface of alumina after modification.
Abstract: Alumina, a support material, was loaded with chitosan to form a chitosan/alumina composite (CA) and was utilized for removing sulfonated azo-dye methyl orange (MO) from aqueous media in this study. The adsorbents were characterized by Fourier transform infrared (FTIR) spectra to confirm that chitosan was successfully immobilized on alumina, and some functional groups were successfully introduced into the surface of alumina after modification. The effects of pH, the amount of adsorbent, initial concentration, time, and temperature were studied in batch experiments. The experimental data were analyzed by Langmuir and Freundlich adsorption isotherms. Thermodynamic parameters such as ΔGo, ΔHo, and ΔSo have also been evaluated, and it has been found that the sorption process was spontaneous and exothermic in nature. Pseudofirst-order and pseudosecond-order kinetic models were used to fit the experimental data. Kinetic parameters, rate constants, equilibrium adsorption capacities, and related correlation coeffi...

145 citations


Journal ArticleDOI
TL;DR: In this paper, the self-diffusion coefficients, D, of lithium, anions, and solvents in four binary-solution electrolytes of EC, DEC, and propylene carbonate (PC) were measured by 1H, 7Li, and 19F NMR spectroscopy from (353 to 243) K or above freezing for seven solution electrolytes.
Abstract: The self-diffusion coefficients, D, of lithium, anions, and solvents in four binary-solution electrolytes of ethylene carbonate (EC)–diethyl carbonate (DEC) and three single-solution electrolytes of EC, DEC, and propylene carbonate (PC) including 1 M LiPF6 were measured by 1H, 7Li, and 19F NMR spectroscopy from (353 to 243) K or above freezing for seven solution electrolytes. In the single DEC electrolyte, DLi and DPF6 had almost the same values at every temperature, whereas DLi was smaller than DPF6 in the EC and PC solutions. In the binary EC–DEC electrolytes, as the ratio of EC increased, DLi gradually became smaller, while DPF6 remained almost unchanged in the temperature range studied. At 303 K, the degree of ion dissociation α was evaluated from the ionic conductivity, DLi and DPF6. The α value increased from 0.17 to 0.71 as the EC ratio increased from (0 to 100) %.

139 citations


Journal ArticleDOI
TL;DR: In this article, the thermal expansion coefficient of two selected ionic liquids (ILs), 1-butyl-3-methylimidazolium bis(trifluoro-methylsulfonyl)imide, [bmim][NTf2], and 1- butyl-1-methylpyrrolidinium bis (triffluoromethyl-sulfononyl), were determined in the temperature range from (293.15 to 353.15) K.
Abstract: Densities of two selected ionic liquids (ILs), 1-butyl-3-methylimidazolium bis(trifluoro-methylsulfonyl)imide, [bmim][NTf2], and 1-butyl-1-methylpyrrolidinium bis(trifluoromethyl-sulfonyl)imide, [bmpyr][NTf2], were determined in the temperature range from (293.15 to 353.15) K. From the experimental density values, the thermal expansion coefficient was calculated. The specific conductivity was measured in the range from (303.15 to 353.15) K. Our experimental results were compared with available literature data. Also, viscosity of these ionic liquids was measured from room temperature up to 353.15 K. Using the obtained data, the temperature effect on the viscosity was analyzed. Since there are limited literature data on physicochemical properties of ionic liquids, data obtained in this study can provide valuable contributions for better understanding of ILs behavior.

Journal ArticleDOI
TL;DR: In this article, a review of different aspects concerning several binary and multicomponent systems of CO2-sterically hindered amine-based absorbents essential for the design and operation of absorption equipment is presented.
Abstract: The gas absorption process for CO2 separation from gas streams is of high interest in various applications in chemical, oil, and gas industries, as well as in environmental protection. The choice of a certain amine (single or blended amine) for CO2 capture is mainly based on the absorption capacity, reaction kinetics, and regenerative potential and facility. The application of sterically hindered amines in gas-treating technology offers absorption capacity, absorption rate, and degradation resistance advantages over conventional amines for CO2 removal from gases. The aim of this review is to bring an update of different aspects concerning several binary and multicomponent systems of CO2-sterically hindered amine-based absorbents essential for the design and operation of absorption equipment (physical properties like density, viscosity, vapor pressure, heat capacity and heat of absorption, CO2 and amine diffusivity, CO2 absorption capacity and kinetics, regeneration capability).

Journal ArticleDOI
TL;DR: In this article, the experimental data of viscosity and density for six binary mixtures of water (methanol or ethanol) with an ionic liquid, 1-butyl-3-methylimidazolium dimethylphosphate ([BMIM][DMP]) or 1-ethyl-3methyloridazolate (EMIM]-DMP), were measured in the temperature range of (293.15 to 333.15) K at atmospheric pressure using a viscometer and densimeter.
Abstract: The experimental data of viscosity and density for six binary mixtures of water (methanol or ethanol) with an ionic liquid, 1-butyl-3-methylimidazolium dimethylphosphate ([BMIM][DMP]) or 1-ethyl-3-methylimidazolium dimethylphosphate ([EMIM][DMP]), were measured in the temperature range of (293.15 to 333.15) K at atmospheric pressure using a viscometer and densimeter. The solution behavior of the mixtures is discussed in terms of the variation of the excess viscosity and excess volume with temperatures and compositions. It is found that both excess volume and viscosity of the mixtures studied show a negative deviation from the ideal solution behavior, and the viscosity of the mixtures decreases drastically with the increase of temperatures and mole fractions of solvents. The excess volume of the binary mixtures is quite low, in the range of (1.0 to 1.9) cm3·mol–1; moreover, it shows a monotonic decrease with increasing temperature for the aqueous solution of ILs and a reverse trend for the IL solutions of ...

Journal ArticleDOI
TL;DR: In this article, an experimental evaluation of the kinetics and equilibrium capacities of pure fluids as a fast and effective means to screen an adsorbent's gas separation potential is described.
Abstract: An experimental evaluation of the kinetics and equilibrium capacities of pure fluids as a fast and effective means to screen an adsorbent's gas separation potential is described. Equilibrium adsorption capacities for pure N2, CH4, and CO2 have been determined using a Micromeritics ASAP2020 sorption analyzer, for three commercially available zeolites: natural chabazite, H+ mordenite, and Linde 4A molecular sieve over the temperature range from (248 to 302) K and pressure range from (0.001 to 120) kPa. Toth models were regressed to the equilibrium data for each gas and used to generate inferred equilibrium selectivity maps over a wider range of temperature and pressure for the purpose of targeting any future mixture measurements. For each gas, the rate of adsorption at 100 kPa was measured as a function of temperature and used with a linear driving force model to calculate mass transfer coefficients. In most cases the ratio of the mass transfer coefficients for each pair of gases was close to unity and did ...

Journal ArticleDOI
TL;DR: A series of choline carboxylate ionic liquids (ILs) have been synthesized by neutralization of CHO2 solution with acetic, propanoic, butanoate, and hexanoate salts at temperatures from (293.15 to 353.15) K.
Abstract: A series of choline carboxylate ionic liquids (ILs) have been synthesized by neutralization of choline hydroxide solution with acetic, propanoic, butanoic, pivalic, and hexanoic acids. The salts so obtained were characterized by NMR spectroscopy, thermal methods, and elemental analysis. Key physical properties (density, viscosity, and refractive index) were measured for the propanoate, butanoate, and hexanoate salts at temperatures from (293.15 to 353.15) K. The densities were used to estimate the molecular volumes, standard entropies, crystal lattice energies, and thermal expansion coefficients. All five choline carboxylates were found to have cytotoxicities (IC50 values) above 10 mM toward the human breast cancer cell line, MCF-7, indicating they are much less toxic than common imidazolium-based ILs.

Journal ArticleDOI
TL;DR: In this article, the adsorption of reactive blue 4 (RB4) and acid red 183 (AR183) on a multiwall carbon nanotube (MWCNT) was investigated in single and binary dye systems.
Abstract: The adsorption of reactive blue 4 (RB4) and acid red 183 (AR183) on a multiwall carbon nanotube (MWCNT) was investigated in single and binary dye systems. The MWCNT presented a higher adsorption of RB4 than AR183 in single and binary dye systems, due to stronger interactions. In single dye solutions, adsorption capacities of the MWCNT for RB4 and AR183 at 25 °C are (69 and 45) mg·g–1, respectively. The higher temperature resulted in lower adsorption of the dyes on the MWCNT. In binary dye solutions, RB4 and AR183 showed competitive adsorption, resulting in RB4 adsorption but desorption of AR183 on the MWCNT. RB4 adsorption capacity in binary dye systems was also reduced to 56 mg·g–1 at 25 °C. The interaction of the dyes with MWCNT was found to be dominated by electrostatic attraction.

Journal ArticleDOI
TL;DR: In this article, the phase diagram of CO2 + ammonium bromide double hydrate is presented and the visualization of TBAB hydrates with and without CO2 is also discussed.
Abstract: Tetra-n-butyl ammonium bromide (TBAB) is an attractive additive to form hydrates that can incorporate specific guest molecules, such as CO2, and the phase diagram of CO2 + TBAB double hydrate is important to the formation and dissociation of hydrate. In this work, experimental equilibrium data of CO2 + TBAB hydrate are presented in the pressure range of (0.3 to 4.4) MPa and in the temperature range of (279 to 292) K at mass fraction w = 0.05, 0.10, 0.19, 0.32, and 0.55. Meanwhile, the visualization of TBAB hydrates with and without CO2 is also presented and discussed.

Journal ArticleDOI
Wei-Guo Xu1, Long Li1, Xiaoxue Ma1, Jie Wei1, Wen-Bin Duan1, Wei Guan1, Jia-Zhen Yang1 
TL;DR: In this article, a series of air and water stable ionic liquids (ILs) based on tetrafluoroborate, [Cnmim][BF4]-n = 2,3,4,5,6, 1-alkyl-3-methylimidazolium tetraflamboroborate) in the temperature range of (298.15 to 338.15 ± 0.02) K were measured.
Abstract: The values of density, surface tension, and refractive index were measured for a classic series of air and water stable ionic liquids (ILs) based on tetrafluoroborate, [Cnmim][BF4](n = 2,3,4,5,6)(1-alkyl-3-methylimidazolium tetrafluoroborate) in the temperature range of (298.15 to 338.15 ± 0.02) K. In terms of Glasser’s theory, the standard molar entropy and lattice energy of the ILs were calculated. Using Kabo’s method, the molar enthalpy of vaporization of the IL, ΔlgHm0 (298 K), was estimated. According to the interstice model, the thermal expansion coefficient of ILs [Cnmim][BF4] (n = 2,3,4,5,6), α, were calculated, and in comparison with experimental value, their magnitude order is in good agreement. To test this new concept of ionic parachor, [BF4]− was chosen as a reference ion and its individual value of ionic parachor was determined in terms of extrathermodynamic assumption. Then, using ionic parachor of [BF4]−, the ionic parachors for all corresponding imidazolium cations, [Cnmim]+, were calcula...

Journal ArticleDOI
TL;DR: In this article, the solubility of CO2 in solvent poly(ethylene glycols) (PEGs) with molecular weights of 150, 200, 300, and 400 were measured over the range of pressure from (100 to 1200) kPa and temperature from (303.15 to 333.15) K.
Abstract: The solubilities of CO2 in solvent poly(ethylene glycols) (PEGs) with molecular weights of 150, 200, 300, and 400 were measured over the range of pressure from (100 to 1200) kPa and temperature from (303.15 to 333.15) K. Henry's constant was obtained by linear fitting of the experimental data, and thermodynamic properties of solutions were calculated from the correlation of Henry's constant. It indicates that the solubility of CO2 increases with increasing molecular weights of PEGs. Henry's constant based on mole fraction and the molality of CO2 in PEG400 vary from (4.78 to 7.09) MPa and (1.56 to 2.48) MPa·kg·mol–1 from (303.15 to 333.15) K, respectively.

Journal ArticleDOI
Ruijuan Qu1, Hongxia Liu, Mingbao Feng1, Xi Yang1, Zunyao Wang1 
TL;DR: In this article, the first-order ionization constant for the most likely ionization path of the most stable conformations in each group of isomers was obtained with the self-consistent reaction field (SCRF) method.
Abstract: Anthraquinone and polyhydroxylated anthroquinones (PHOAQs) have been studied at the B3LYP/6-311G** level using the Gaussian 09 program. The isodesmic reactions were designed to calculate the standard enthalpy of formation (ΔfHθ) and standard Gibbs energy of formation (ΔfGθ) for PHOAQ congeners. Two kinds of intramolecular hydrogen bonds exist in PHOAQs, and the isodesmic reactions of isomerization were used to determine the intramolecular hydrogen bond energy. The Atoms in Molecules (AIM) 2000 program (version 1.0) was used to study the characteristics of the hydrogen bonds. Relations of Sθ, ΔfHθ, and ΔfGθ with the number and position of hydroxyl substitution (NPHOS) were also discussed. How the intramolecular hydrogen bond influences ionization was investigated, and the first-order ionization constant for the most likely ionization path of the most stable conformations in each group of isomers was obtained with the self-consistent reaction field (SCRF) method.

Journal ArticleDOI
TL;DR: In this paper, a third-order Redlich-Kister equation and a linear relationship with the temperature was used to measure surface tension of CO2 loaded aqueous MEA solutions at temperatures from (298.15 to 413.15) K.
Abstract: Densities in liquid solutions of monoethanolamine (MEA) and water have been measured at temperatures from (298.15 to 423.15) K. The mass fraction of MEA ranged from 0.3 to 1.0. Excess volumes were correlated by a Redlich–Kister equation. The model uses a third-order Redlich–Kister equation and a linear relationship with the temperature. Densities of CO2 loaded aqueous MEA solutions were measured at temperatures from (298.15 to 413.15) K. The mass fraction of MEA was 0.3, 0.4, 0.5, and 0.6. Molar volumes of CO2 loaded aqueous MEA solutions were correlated by the equations from the literature. Polynomial equations are in turn used to correlate the parameters with the temperature. Surface tensions of aqueous MEA solutions were measured at temperatures from (303.15 to 333.15) K. The mass fraction of MEA ranged from 0 to 1.0. The experimental surface tension data were correlated with temperature and mole fraction, respectively.

Journal ArticleDOI
TL;DR: In this paper, the water absorbance of biodiesel and biodiesel-diesel fuel blends evaluating the temperature and blend ratio parameters was determined through experiments and experiments were conducted to determine the water absorption.
Abstract: Biodiesel has a higher affinity toward moisture content than petroleum diesel, and the water retaining capacity of biodiesel is higher than diesel. The water content in fuels can be classified in free, emulsionated, and soluble water. High water content in biodiesel and diesel can cause problems such as water accumulation and microbial growth in fuel tanks and transportation equipment. Currently, there is a lack of information on water absorbance in biodiesel and biodiesel/diesel blends. Experiments were conducted to determine the water absorbance of biodiesel and biodiesel–diesel fuel blends evaluating the temperature and blend ratio parameters. Soluble water in biodiesel ranged from (1500 to 1980) mg·kg–1 in the temperature range of (283.15 to 323.15) K, which was 10 to 15 times higher than diesel. Results also showed that, at constant relative humidities, biodiesel absorbed 6.5 times more moisture than diesel. The presence of free and/or emulsionated water in biodiesel and blends was determined through...

Journal ArticleDOI
TL;DR: A new low global warming potential (GWP) fluid hydrochlorofluoroolefin trans-isomer of 1-chloro-3, 3,3,3-trifluoro-propene (HCFO-1233zd(E)) has been developed in this article.
Abstract: A new low global warming potential (GWP) fluid hydrochlorofluoroolefin trans-isomer of 1-chloro-3,3,3-trifluoro-propene (HCFO-1233zd(E)) has been developed in our laboratory. HCFO-1233zd(E) has a very short atmospheric lifetime of 26 days and a global warming potential (GWP) of less than 5 (Wong et al., http://www.honeywell-solsticelba.com.product-info/environmental-regulatory/#atmospheric-impact, 2012). This makes it an excellent environmentally friendly candidate for many applications including refrigeration, foam expansion agents, and as solvents. In this work we have presented our measurements of physical properties like the boiling point, critical temperature, vapor pressure, liquid density, and surface tension of HCFO-1233zd(E). We have also provided our calculated ideal gas heat capacity at constant pressure using quantum mechanical theory. Temperature-dependent properties are correlated with standard forms of equations and described in the paper.

Journal ArticleDOI
TL;DR: In this paper, the densities and refractive indices of binary mixtures containing 1-butyl-3-methylimidazolium tetrafluoroborate with water and monoethanolamine are measured at a temperature range of (293.15 to 353.15) K and within the whole range of composition.
Abstract: The densities and refractive indices of binary mixtures containing 1-butyl-3-methylimidazolium tetrafluoroborate with water and monoethanolamine are measured at a temperature range of (293.15 to 353.15) K and within the whole range of composition. Excess molar volumes are deduced from the measured physical properties and correlated using Redlich–Kister polynomial equations. The excess molar volumes are positive for the entire mole fraction range, and the details are discussed. The thermal expansion coefficients are also derived from the measured density values.

Journal ArticleDOI
TL;DR: In this article, the surface area and microporous volumes were calculated using the Dubinin-Radushkevitch (D-R) equation based on CO2 adsorption at 273 K.
Abstract: We prepared several different surfaces and pore volumes on small pore zeolites by hydrothermal synthesis and ion exchange (Li+, Na+, and Ca2+) based on three basic gas diameter grade structures of zeolites: KFI (0.39 × 0.39 nm), CHA (0.38 × 0.38 nm), and LEV (0.36 × 0.48 nm), which were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and elemental analysis. The surface area and microporous volumes were calculated using the Dubinin–Radushkevitch (D-R) equation based on CO2 adsorption at 273 K. The CHA was synthesized with a lower Si/Al ratio, and the surfaces and microporous volumes were changed greatly by ion exchange. KFI had a higher Si/Al ratio, and the scope of the surface could be kept smaller. Focusing on the CO2, CH4, and N2 adsorption isotherms at high pressure (1 MPa), we found that the samples were exchanged by Li+ and Na+ with bigger surfaces and greater adsorption volumes. The orifice diameter was very important in the sieving of CO2 and N2 or CO2 and CH4, while N...

Journal ArticleDOI
TL;DR: In this article, the densities of MgCl2(aq), CaCl2 (aq), KI(aq, NaCl, KCl, AlCl3, and AlCl4 were reported at temperatures between (283 and 472) K and pressures up to 68.5 MPa.
Abstract: We report the densities of MgCl2(aq), CaCl2(aq), KI(aq), NaCl(aq), KCl(aq), AlCl3(aq), and the mixed salt system [(1 – x)NaCl + xKCl](aq), where x denotes the mole fraction of KCl, at temperatures between (283 and 472) K and pressures up to 68.5 MPa. The molalities at which the solutions were studied were (1.00, 3.00, and 5.00) mol·kg–1 for MgCl2(aq), (1.00, 3.00, and 6.00) mol·kg–1 for CaCl2(aq), (0.67, 0.90, and 1.06) mol·kg–1 for KI(aq), (1.06, 3.16, and 6.00) mol·kg–1 for NaCl(aq), (1.06, 3.15, and 4.49) mol·kg–1 for KCl(aq), (1.00 and 2.00) mol·kg–1 for AlCl3(aq), and (1.05, 1.98, 3.15, and 4.95) mol·kg–1 for [(1 – x)NaCl + xKCl](aq), with x = 0.136. The measurements were performed with a vibrating-tube densimeter calibrated under vacuum and with pure water over the full ranges of pressure and temperature investigated. An analysis of uncertainties shows that the relative uncertainty of density varies from 0.03 % to 0.05 % depending upon the salt and the molality of the solution. An empirical correlat...

Journal ArticleDOI
TL;DR: In this article, the density, speed of sound, and refractive index of eight binary systems (water + ionic liquid) were measured, along the whole composition range, at T = (288.15 to 308.15) K and atmospheric pressure.
Abstract: In this paper, the density, speed of sound, and refractive index of eight binary systems (water + ionic liquid) were measured, along the whole composition range, at T = (288.15 to 308.15) K and atmospheric pressure. All binary mixtures were completely miscible in water at the studied temperatures. The ionic liquids used in this work are constituted by different cations (imidazolium, pyridinium and pyrrolidinium) and anions (trifluoromethanesulfonate, dicyanamide, methylsulfate, or ethylsulfate). From the experimental data, excess molar volumes and excess molar isentropic compressions were calculated and satisfactorily fitted using the Redlich–Kister equation. Finally, the effect of the ions and temperature on the physical and excess properties was analyzed and discussed. The obtained results show that the physical and excess properties studied in this work are dependent on water content, temperature, and structure of the ILs, especially of the anion.

Journal ArticleDOI
Abstract: Density, rheological properties, and conductivity of a homologous series of ammonium-based ionic liquids N-alkyl-triethylammonium bis{(trifluoromethyl)sulfonyl}imide were studied at atmospheric pressure as a function of alkyl chain length on the cation, as well as of the temperature from (293.15 to 363.15) K. From these investigations, the effect of the cation structure was quantified on each studied properties, which demonstrated, as expected, a decrease of the density and conductivity, a contrario of an increase of the viscosity with the alkyl chain length on the ammonium cation. Furthermore, rheological properties were measured for both pure and water-saturated ionic liquids. The studied ionic liquids were found to be Newtonian and non-Arrhenius. Additionally, the effect of water content in the studied ionic liquids on their viscosity was investigated by adding water until they were saturated at 293.15 K. By comparing the viscosity of pure ionic liquids with the data measured in water-saturated samples...

Journal ArticleDOI
TL;DR: In this paper, a new experimental apparatus based on an equilibrium cell with a constant volume allowing the measurement of carbon dioxide solubility is presented, and the liquid phase composition at the thermodynamic equilibrium is determined by an analytical method (ion chromatography) and a static synthetic method.
Abstract: New experimental solubility data for carbon dioxide in pure water and in aqueous solution containing sodium hydroxide in the temperature range (293.15 to 393.15) K and pressures up to 5 MPa are presented in this work. A new experimental apparatus based on an equilibrium cell with a constant volume allowing the measurement of carbon dioxide solubility is presented. The liquid phase composition at the thermodynamic equilibrium is determined by an analytical method (ion chromatography) and a static synthetic method. The CO2 + water system is used to validate the experimental apparatus; therefore data obtained are compared with literature data.

Journal ArticleDOI
TL;DR: In this article, the ternary system ethanol + water + ethylene glycol and its three constituent binary mixtures were measured at 101.3 kPa using a modified Rogalski-Malanoski equilibrium still.
Abstract: Isobaric vapor–liquid equilibria were measured for the ternary system ethanol + water + ethylene glycol and its three constituent binary mixtures at 101.3 kPa using a modified Rogalski–Malanoski equilibrium still. The thermodynamic consistency of experimental binary data was checked using the point and area tests. The experimental binary data were then correlated by the Wilson, nonrandom two-liquid (NRTL), and universal quasichemical activity coefficient (UNIQUAC) equations. The ternary vapor–liquid equilibria data were predicted using the binary parameters for the three equations with good accuracy. The selectivity of ethylene glycol as entrainer for the separation of the azeotropic system ethanol + water by extractive distillation was discussed using the NRTL parameters.