Mixtures Of Triethylene Glycol Research Articles

Theoretical and experimental ultrasonic velocities Comparison of binary mixtures of triethylene glycols and glycerol at different temperatures

The densities and sound velocities of binary mixtures of triethylene glycol are measured at different temperatures and at frequency of 2 MHz over entire range of mole fraction. Various theoretical models, such as Nomoto, Impedance, Junjie, Van Dael and Vangeel, have been used to measure theoretical ultrasonic velocities. The average percentage error was estimated and the chi-square fitness test was also used to check the validity of theoretical models. The variance from the experimental results is interpreted in terms of molecular interactions between the components of the binary mixtures.

Measurement of density, viscosity and surface tension of tri-ethylene glycol + 1,3-propanediamine mixtures & their computational chemistry and spectral analysis

For liquid and liquid mixtures, density (ρ), viscosity (η) and surface tension (γ) are seen as important basic data. This research reported the data of ρ, η and γ for the binary mixture of tri-ethylene glycol (TEG) + 1,3-propanediamine (PDA) at p = .1 MPa and T = (293.15 to 318.15) K within the whole molar fraction range, finding the maximum of η and γ values when the mole fraction of TEG was x1 ≈ 0.65. After that, excess molar volume (VmE), viscosity deviation (Δη), and surface tension deviation (Δγ) were carefully calculated, and the minimum VmE values and the maximum Δγ values were obtained when the molar fraction of TEG was at x1 ≈ 0.50; however, the maximum Δη values shifted from x1 ≈ 0.60 to x1 ≈ 0.66. And then, the Redlich-Kister (R-K) equation fitting was performed on above parameters to evaluate the coefficient and standard deviation, apparent molar volumes (Vφ, 1 and Vφ, 2) and partial molar volumes (V1¯ and V2¯). Meanwhile, Gaussian 09 software was used to further analyze the intermolecular force and to calculate the dissociation energy and bond length of the mixture, and the interaction of PDA with TEG were discussed on the basis of FTIR, UV–Vis and FLS spectral technologies. The results showed that there were hydrogen-bond interactions between the nitrogen atoms in PDA and the hydroxyl hydrogen atoms in TEG.

Evaluation of pulmonary toxicity of benzalkonium chloride and triethylene glycol mixtures using in vitro and in vivo systems.

Benzalkonium chloride (BAC) is a widely used disinfectant/preservative, and respiratory exposure to this compound has been reported to be highly toxic. Spray‐form household products have been known to contain BAC together with triethylene glycol (TEG) in their solutions. The purpose of this study was to estimate the toxicity of BAC and TEG mixtures to pulmonary organs using in vitro and in vivo experiments. Human alveolar epithelial (A549) cells incubated with BAC (1‐10 μg/mL) for 24 hours showed significant cytotoxicity, while TEG (up to 1000 μg/mL) did not affect cell viability. However, TEG in combination with BAC aggravated cell damage and inhibited colony formation as compared to BAC alone. TEG also exacerbated BAC‐promoted production of reactive oxygen species (ROS) and reduction of glutathione (GSH) level in A549 cells. However, pretreatment of the cells with N‐acetylcysteine (NAC) alleviated the cytotoxicity, indicating oxidative stress could be a mechanism of the toxicity. Quantification of intracellular BAC by LC/MS/MS showed that cellular distribution/absorption of BAC was enhanced in A549 cells when it was exposed together with TEG. Intratracheal instillation of BAC (400 μg/kg) in rats was toxic to the pulmonary tissues while that of TEG (up to 1000 μg/kg) did not show any harmful effect. A combination of nontoxic doses of BAC (200 μg/kg) and TEG (1000 μg/kg) promoted significant lung injury in rats, as shown by increased protein content and lactate dehydrogenase (LDH) activity in bronchoalveolar lavage fluids (BALF). Moreover, BAC/TEG mixture recruited inflammatory cells, polymorphonuclear leukocytes (PMNs), in terminal bronchioles and elevated cytokine levels, tumor necrosis factor α (TNF‐α), and interleukin 6 (IL‐6) in BALF. These results suggest that TEG can potentiate BAC‐induced pulmonary toxicity and inflammation, and thus respiratory exposure to the air mist from spray‐form products containing this chemical combination is potentially harmful to humans.

Prediction of the phase behavior of BTEX and alkane hydrocarbons in the presence of Tri-Ethylene Glycol (TEG) solvent

ABSTRACTA computational framework according to the CPA Equation of state by considering hydrogen bonding association and solvation effects has been proposed for accurate prediction of phase behavior of complex mixtures of triethylene glycol (TEG), BTEX aromatic hydrocarbons (benzene, toluene, ethylbenzene, and o-xlylene) and alkanes (methane, ethane, propane). The overall average absolute deviation between the predicted and measured phase compositions, regarding 150 data points is about 2.40% suggesting the accuracy of the presented approach. The presented model can be used for accurate design of BTEX containing natural gas dehydration plants in petroleum industry.

Thermophysical and transport properties of binary mixtures containing triethylene glycol and alcohols at different temperatures

Densities and viscosities have been measured for the binary mixtures of triethylene glycol with + 2-propanol, 2-butanol and 2-pentanol over the entire range of mole fraction at T = 293.15–323.15 K. From experimental data, the excess molar volume, thermal expansion coefficient, excess thermal expansion coefficient and deviation in viscosity were calculated. The experimental results have been discussed in terms of molecular interactions and formation of molecular complexes between unlike molecules. Influence of temperature and carbon chain length of alcohols on mentioned properties was discussed. Moreover, the friction theory coupled with PC-SAFT equation of state was applied to produce the viscosities of pure data and binary mixtures.

Synthesis and optical properties of nanosheet-based rh-In2O3 microflowers by triethylene glycol-mediated solvothermal process

A new synthesis route for the construction of corundum nanosheet-based In2O3 microflowers is presented in this study. InOOH was firstly prepared by a solvothermal process using In(NO3)3·xH2O as a precursor, urea as a precipitant, and a mixture of triethylene glycol and water as the solvent at 200°C for 18h. The corundum nanosheet-based In2O3 microflowers were then obtained by calcining the obtained InOOH at 450°C under ambient atmosphere. The products were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Raman and photoluminescence spectroscopy. The effects of solvent and urea on the fabrication of nanosheet-based corundum In2O3 microflowers were investigated and a self-assembly and transformation mechanism is proposed to explain the formation of the hierarchical nanostructures. The corundum nanosheet-based In2O3 microflowers show strong PL emission at 550nm.

A Triethylene Glycol–Water System: A Study of the TEG Regeneration Processes in Natural Gas Dehydration Plants

Natural gas pipeline transportation requires very low water content in the gas stream in order to avoid condensation or hydrate formation. To reach this goal, when triethylene glycol is used to dehydrate natural gas, after the absorption step, triethylene glycol must be regenerated to levels substantially above 98.5–99.0% by weight available from atmospheric distillation of glycol-water mixtures. In order to regenerate triethylene glycol to higher purity levels, some of the methods used require a stripping gas, a solvent, or to perform the distillation under vacuum. Another method to perform a further dehydration of triethylene glycol is the use of a water exhauster, known as Coldfinger, where the vapor in equilibrium with the liquid to be dehydrated is continuously condensed and removed. In the first part of this work, measurements of boiling temperatures are reported for binary mixtures of triethylene glycol and water at pressures of 50, 100, 200, and 400 mmHg. The experimental data obtained were correlated by employing the NRTL model, with temperature-dependent parameters, to express activities in the liquid phase. The fitted NRTL parameters were then used in the Hysys process simulator to perform a process simulation of a natural gas dehydration plant, provided both with a Coldfinger water exhauster and a conventional stripping column for triethylene glycol regeneration.

Liquid viscosities, excess properties, and viscous flow thermodynamics of triethylene glycol + water mixtures at T = (298.15, 303.15, 308.15, 313.15, and 318.15) K

This paper reports measurements of densities and viscosities for the binary mixtures of triethylene glycol (TEG) + water as a function of composition at T = (298.15, 303.15, 308.15, 313.15, and 318.15) K. Densities were measured using a capillary pycnometer and viscosities were determined with an Ubbelohde capillary viscometer. The experimental results are compared with data published in the literatures. From the experimental data, including density and viscosity values, the excess molar volumes V m E, and viscosity deviations Δν, the calculated results are fitted to a Redlich–Kister equation to obtain the coefficients and estimate the standard deviations between the experimental and calculated quantities. The values of V m E are negative in the whole composition range, whereas the values of Δν are positive over the major composition range. From the kinematic viscosity data, enthalpy of activation for viscous flow (ΔH ⁎) and entropy of activation for the viscous flow (ΔS ⁎) were calculated.

Temperature change from isenthalpic expansion of aqueous triethylene glycol mixtures for natural gas dehydration

In natural gas dehydration units, rich TEG solutions are decompressed before the TEG regeneration stage and the direction of the temperature change during the decompression has been debated. The temperature change from an isenthalpic expansion from (7000 kPa to 440 kPa was measured for the following aqueous mixtures: pure water, 99% pure triethylene glycol (TEG), aqueous TEG (99 wt% TEG + 1% water), aqueous TEG saturated with methane, aqueous TEG saturated with n-pentane, and aqueous TEG saturated with n-heptane. In all cases, the temperature increased upon expansion with the magnitude of the temperature change ranging from 1.4 K for pure water to 2.4 K for TEG. A simple equation of state model predicted the correct direction for the temperature change and the predicted values were within ±1 K of the experimental data.

Experimental and predicted excess molar enthalpies of some working pairs for absorption cycles

In this work, the measured excess molar enthalpies of absorption heat pump working pairs (refrigerant + absorbent), viz. water + mono-, di- and tri-ethylene glycol, water + glycerol, and ethanol + di- and tri-ethylene glycol mixtures are presented at 298.15 K and ambient pressure using a Setaram Calvet C80 calorimeter. The experimental results are represented and correlated by a Redlich–Kister type equation. Modeling of the excess enthalpies has been performed using the UNIFAC molecular group-contribution method, and UNIQUAC Gibbs energy model. In addition, the data and results are used to predict the Gibbs energy of all binary systems. This allows a preliminary evaluation of the suitability of the binary systems as heat pump working pairs.

Intermolecular interactions and properties of mixtures of triethylene glycol with ethanol and isopropyl alcohol

Density and viscosity of solutions formed in the systems triethylene glycol-ethanol and triethylene glycol-isopropyl alcohol were studied in the full concentration range at 20, 40, 50, and 60°C. The thermodynamic activation functions of viscous flow were calculated. The contribution of specific interactions to these functions was determined.

Extraction of aromatic hydrocarbons from reformates with mixtures of triethylene glycol and sulfolane

Results are presented of a seven-stage counterflow extraction of C6–C8 aromatic hydrocarbons from the reformate of the gasoline fraction with a mixed extracting agent composed of triethylene glycol, sulfolane, and water, containing 37.6–57.6 wt % sulfolane.

Extraction of toluene and xylenes from the toluene-xylene fraction of the reforming catalyzate with mixtures of triethylene glycol with sulfolane

Seven-stage counterflow extraction of aromatic hydrocarbons from the toluene-xylene fraction of the reforming catalysate with sulfolane and its mixtures with triethylene glycol was studied. A liquid-liquid phase equilibrium diagram is presented for a pseudoternary system that includes saturated and aromatic hydrocarbons of the toluene-xylene fraction of the reformate and a mixed extractive agent composed of triethylene glycol, sulfolane, and water (48.1: 48.1: 3.8 wt %).

Density, Viscosity, and Thermal Conductivity of Aqueous Ethylene, Diethylene, and Triethylene Glycol Mixtures between 290 K and 450 K

The density, viscosity, and thermal conductivity of ethylene glycol + water, diethylene glycol + water, and triethylene glycol + water mixtures were measured at temperatures ranging from 290 K to 450 K and concentrations ranging from 25 mol % glycol to 100 mol % glycol. Our data were generally in agreement with the limited data available in the literature and were correlated using simple empirical expressions and the generalized corresponding states principle (GCSP). The GCSP method, with two adjustable parameters for each property, offers the potential for judicious extrapolation of density and transport property data for all glycol + water mixtures.

Evaluation of the local composition model for VLE of binary mixtures of triethylene glycol with methane, water and benzene

AbstractThis work evaluated the predictive accuracy of the local composition model (LCM) formulation developed by Li et al. (1986) for four binary, vapor‐liquid equilibria (VLE) mixtures. The four components comprising these mixtures were benzene, triethylene glycol (TEG), water and methane, while the mixtures examined in this work were the benzene‐TEG, water‐TEG, methane‐TEG and methane‐benzene systems. The Khan‐Chung‐Lee‐Starling (KCLS) equation of state developed by Chung et al. (1984) was used with the LCM to predict the VLE behavior of these systems. The accurate results obtained in this work may be applied to the design of natural gas dehydration processes.

The Finkelstein Reaction in Acetonitrile–Glycol Mixtures. An Approach by a Concurrent Monodentate and Bidentate Solvation Model of the Halide Ion

Abstract The rate constant of the reaction of methyl iodide with the bromide ion showed a characteristic dependence on the composition of solvent mixtures. In five solvent mixtures, i.e., acetonitrile–ethylene glycol, –1,2-propanediol, –1,3-butanediol, –1,4-butanediol, and –2,3-butanediol, its dependence was fairly well reproduced by the theoretical equations derived on the basis of the concept of the concurrent monodentate and bidentate solvation of the halide ion by glycol. In contrast, the rate constants in acetonitrile–diethylene glycol and –triethylene glycol mixtures were better reproduced by the modified theoretical equations allowing for a self-association of glycol.