Binary Mixtures Of Ethylene Glycol Research Articles

Experimental study on the effect of modified heated surfaces on the heat transfer performance of deionized water and ethylene glycol binary mixtures

ABSTRACT With the development of modern industry, the demand for environmentally friendly working fluids is gradually increasing. Although binary mixtures have low global warming potential, their boiling heat transfer performance is generally lower than that of pure components. To enhance their applications in boiling heat transfer, it is of great research significance to improve the boiling heat transfer coefficient (HTC) of binary mixtures by changing the characteristics of the heated surface. This article used a mixture of 30% ethylene glycol and deionized water as the working fluid to experimentally study the effect of a series of modified heated surfaces on their boiling heat transfer performance. Including heated surfaces with different roughness polished with 320#, 800#, and 2000# sandpapers, heated surfaces covered with TiO2 and Al2O3 nanoparticle coatings with varying diameters of nano particles, and two state-of-art types of microstructure heated surfaces. The experimental results indicated that most modified heated surfaces can improve the boiling performance of the working fluid. Among them, the heated surfaces that changed the roughness due to sandpaper polishing had the least improvement effect on HTC. The microstructure surfaces had the best performance in HTC improvement. The reason for this phenomenon is that the microstructure not only changes the roughness of the heated surface but also increases the heat transfer area. Although nanoparticle coatings enhanced the heat transfer performance, the TiO2 nanoparticle coatings showed better performance than Al2O3, which may be related to the stability of nanoparticle coatings.

Investigation of Heat Transfer Performance in Deionized Water–Ethylene Glycol Binary Mixtures during Nucleate Pool Boiling

Pool boiling heat transfer is recognized as an exceptionally effective method, widely applied across various industries. The adoption of non-azeotropic binary mixtures aligns with the environmental objectives of modern industrial development and enhances the coefficient of performance (COP) in numerous systems. Therefore, investigating the boiling heat transfer characteristics of these mixtures is crucial to improving their industrial usability. In this study, mixtures of ethylene glycol and deionized water (EG/DW) in varying concentrations were chosen as the working fluids. A comprehensive experimental setup was developed, followed by a series of experiments to assess their pool boiling performance. Simultaneously, the thermophysical parameters of these mixtures underwent detailed examination and analysis. The research revealed that the concentration of EG in the mixture markedly affects its thermal properties and temperature glide, both of which are crucial in influencing the heat transfer coefficient. Additionally, six established heat transfer coefficient prediction correlations, primarily designed for pure fluids, have been employed. However, their application to non-azeotropic mixtures under experimental conditions revealed significant deviations. To address this issue, the present study modified existing correlations with the temperature slip characteristics of non-azeotropic mixtures. This process involved recalibrating the wall superheat values in the correlations to reflect the local temperature differential at the boiling point, thereby customizing them for application to non-azeotropic mixtures. The modified correlations highlighted the unique behaviors of non-azeotropic mixtures in boiling heat transfer, demonstrating improved compatibility with these mixtures in a deviation within a permissible 20% range compared with experimental results.

Volumetric Properties and Viscosities for 1-Ethyl-3-methylimidazolium Ethyl Sulfate and Ethylene Glycol Binary Mixture from 293.15 K to 343.15 K at Atmospheric Pressure

Volumetric Properties and Viscosities for 1-Ethyl-3-methylimidazolium Ethyl Sulfate and Ethylene Glycol Binary Mixture from 293.15 K to 343.15 K at Atmospheric Pressure

An experimental study on thermal efficiency of hybrid GO/MWCNTs nanoparticles suspended in a binary mixture of ethylene glycol and water

Energy consumption has a demand growth across the globe due to modernization. However, the use of fossil fuels is creating a huge impact on climate change and has made it essential to harvest solar renewable energy technology. The heat transfer fluid plays an important role in maintaining the optimum temperature of the panel by removing the heat absorbed and transferring to the thermal energy storage medium. Due to the poor thermal conductivity and thermal degradation of conventional heat transfer fluids such as water, ethylene glycol and oil, these pose limitations to be utilised in solar energy technology systems. Thus, to overcome this problem, a hybrid nanofluid is used to boost the thermal conductivity and degradation temperature. However, the addition of hybrid nanoparticles further enhances the thermo-physical properties of the fluids. In this present study, GO/MWCNTs hybrid nanoparticles (0.01 – 0.2 wt%) were dispersed in hybrid base fluid (EG/water) in the ratio of 40:60. The finding shows that for visual stability, MWCNT sediment was faster compared to GO while, hybrid GO/MWCNT, showed higher stability compared to the single nanoparticle. The TGA results show the higher thermal degradation temperature at 0.05 wt% of pure GO, pure MWCNT and hybrid GO/MWCNT with thermal degradation of 122.74 ℃, 118.93 ℃ and 119.26 ℃ respectively. The use of nanofluids acts as a clean fuel for electricity production and decreases CO2 emission, which can further promote sustainable development goals.

Thermal conductivity of ethylene glycol and water binary mixtures at evaluated temperature and pressure

Binary mixtures of ethylene glycol and water are widely used as working fluids in many areas, and the study of thermal conductivity is crucial in the determination of the heat transfer properties of related systems. In this paper, the thermal conductivity of these binary mixtures at a series of ethylene glycol concentrations (0 to 100 wt%) is measured experimentally using a transient hot-wire system at evaluated temperature and pressure range from 293–533 K and 0.1–15.0 MPa. Moreover, the experimental data are fitted into an equation as a function of temperature, pressure, and concentration, the average absolute deviation and maximum deviation between fitted values and experimental data are 0.29 % and 1.05 %, respectively, which shows that this equation describes our data very well. Furthermore, available experimental data in the literature are collected and the comparisons between literature data and our data are analyzed, our data agree well with most literature data. This work is expected to promote the use of binary mixtures of ethylene glycol and water as heat transfer working fluids in industries.

Insight into molecular interactions and structural changes of ethyl lactate and (tri/tetra)-ethylene glycol binary mixture: A thermophysical and spectral depiction

The current work deals with the analysis of the molecular interactions amongst the binary systems formed by significant solvents with environment friendly characteristics. The density (ρ) and refractive index (nD) of pure liquids and mixtures containing L-Ethyl Lactate (EL) + Tri-Ethylene Glycol (TrEG) or Tetra-Ethylene Glycol (TeEG) over the entire composition have been measured at four equidistant temperatures from T/(K) = 298.15 to 313.15 and pressure p/(MPa) = 0.1. Based on the experimental data, calculation of derived properties (excess molar volumes (VmE), partial molar volumes (V¯m), excess partial molar volumes (V¯mE), deviations in refractive index (ΔϕnD) and deviations in molar refraction (ΔϕRM)) was done. The consequent properties were fitted to the Redlich-Kister polynomial equation to recognize the interaction coefficients and standard deviations. The obtained outcomes were examined theoretically through Prigogine-Flory-Patterson (PFP) theory and Graph theory to elucidate the non-ideal behaviour of investigated mixtures. The theoretical interpretations were found to be in harmony with experimental observations. Spectroscopic data from UltraViolet (UV) and Fourier Transform InfraRed (FT-IR) analysis ascertains the dominance of solute-solvent interactions in mixed state hereby supporting the experimental and theoretical analysis.

Density, viscosity and excess properties of binary mixtures of ethylene glycol and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide

Densities and viscosities of binary mixtures of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [bmim][NTf2], with ethylene glycol (EG) were measured at atmospheric pressure and from 293.15 K to 338.15 K with a step increment of 5 K. A first-order polynomial and Vogel-Fulcher-Tammann (VFT) equation were described using experimental values to estimate the densities and viscosities of the mixtures, respectively. The excess molar volume, viscosity, and Gibbs energy of activation for viscous flow have been calculated and fitted to the Redlich-Kister equation. Besides, the thermal expansion coefficients and partial and apparent molar volumes of [bmim][NTf2] and EG in their binary mixtures have been reported.

Liquefaction and chemical composition of walnut shells

AbstractThe cultivation of walnut (Juglans regiaL.) for the exploitation of the fruit has been increasingly recognized worldwide; therefore, it is important to valorize a large amount of biomass from walnut shells (WS), where liquefaction may play an important role. This work intends to contribute to an improved understanding of the best uses for this material. The assays were made with a binary mixture of ethylene glycol and glycerol (1:1 v/v) as solvents, catalyzed by sulfuric acid. The tested parameters were as follows: particle size >0.420–0.177 mm, temperature 140–200°C, and reaction time between 15 and 60 min. The initial dried material, the liquefied material, and the resulting solid residue were analyzed by FTIR-ATR for polyol characterization. The results showed that WS are mostly composed of lignin with 35.0% and polysaccharides, 30.0% cellulose and 24.9% hemicelluloses. High-lignin content indicated that WS might be used as a bio-fuel or adhesives. Extractives represent 10.2% with almost half (4.6%) of polar extractives. The best conditions to attain the optimal liquefaction yield were 160°C, 30 min, and 0.420–0.250 mm particle size, for the tested parameters. FTIR spectrum of the liquefied material is very different from the original material, and solid residue spectra seem to indicate that there is higher liquefaction of polysaccharides when compared with lignin since there is a higher absorption at 1,600 cm−1and lower absorption at 1,040 cm−1and that liquefied compounds are probably in smaller molecules.

Entropy Generation Analysis on MHD Flow with a Binary Mixture of Ethylene Glycol and Water Based Silver-Graphene Hybrid Nanoparticles in Automotive Cooling Systems

The present work is focused on the flow and transfer of heat analysis of the silver-graphene with a binary mixture of ethylene glycol (EG) and water (0:100, 20:80 and 40:60 vol %) based hybrid nanofluids. Flow formulation is developed by considering the effect of magnetic field, stagnation point flow, Joule heating and viscous dissipation. Heat exchanger plays an important role because of the increasing demand for efficient cooling systems in automotive industries. Proper transforms lead to highly nonlinear differential systems, which are solved through shooting procedure with fourth order R-K (Runge-Kutta) method. The results of numerous control parameters for both silver-graphene nanoparticles are graphically shown and discussed in detail. The current numerical work is qualified through comparative study with the formerly published results for a special case. The heat transfer rate is higher with lower Ec values and higher ϕ1 and ϕ2 values.

Manganese Fluoride Nanoparticles Synthesized by Microwave Irradiation Using Ionic Liquid–Ethylene Glycol Mixtures: Room-Temperature Photoluminescence, Crystalline Phase, and Morphology

The facile and rapid microwave-assisted method has been demonstrated to be effective in synthesizing manganese fluoride (MnF2) nanoparticles in binary mixtures of ethylene glycol and imidazolium-based ionic liquid containing fluorine, within a minute, without any surfactant and stabilizer. The effect of volume ratio of an ionic liquid in the binary mixtures with ethylene glycol and the length of the alkyl chain of imidazolium on the morphologies and crystalline structures of MnF2 was investigated. Two types of crystalline phases MnF2, P42/mnm rutile and P4̅2m space group, were synthesized depending on the volume ratio of EMIM BF4. The morphologies of rutile MnF2 clearly varied depending on what kind of ionic liquid was used in the synthesis. MnF2 nanoparticles and spherical nanoclusters assembled by nanospheres were synthesized when the used ionic liquid was OMIM BF4 and EMIM BF4, respectively. Clear room temperature photoluminescence (PL) spectra of MnF2 nanoparticles were observed at ambient pressure. The change of PL spectra depending on the crystalline phase was also observed. In this study, we report that the microwave-assisted method using ethylene glycol–ionic liquid binary mixtures is proper for synthesizing high-quality MnF2 nanoparticles with controllable crystalline phase and morphology.

Prediction of drug solubility in ethylene glycol + water mixtures using generally trained cosolvency models

This work reports the results obtained from the generally trained versions of Yalkowsky and Jouyban-Acree models for prediction of drugs' solubility in binary mixtures of ethylene glycol + water at different temperatures. To achieve a full predictive model, the Abraham solvation solute parameters are combined with the Jouyban-Acree and Jouyban-Acree-van't Hoff models. In this respect, the solubility data sets of 14 drugs with various polarities and structural features in aqueous ethylene glycol mixtures are collected from literature and correlated with the above-mentioned models, the overall mean relative deviation values for the back-calculated drug's solubility indicating the generally trained models have an acceptable performance in solubility prediction and can be useful in pharmaceutical industry.

Ultrasonic Velocities of Binary Mixtures of Homologous Series of Ethylene Glycol and Glycerol at Different Temperatures: A Comparative Study

Abstract The densities and ultrasonic velocities of binary mixtures of ethylene glycol and glycerol 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 compute theoretical ultrasonic velocities. The average percentage error has been calculated and chi-square test for goodness of fit has also been to check the validity of theoretical models. The deviation from experimental results is interpreted in terms of molecular interactions among the components of the binary mixtures.

Ethylene Glycol as Entrainer in 1-Propanol Dehydration: Scrutiny of Physicochemical Properties of Ethylene Glycol+1-Propanol Binary Mixture at Different Temperatures

Density (ρ), and dielectric permittivity (ε) of the binary mixture of ethylene glycol + 1- propanol have been determined as a function of mole fraction of ethylene glycol at T = (298, 308 and 313)K. These measurements have been employed to compute thermodynamic properties like molar volume (V), and molar polarization (P) of the liquid mixtures. Excess properties such as VE, εE and PE for the binary mixture have also been calculated at different temperatures. In order to calculate the standard deviations of the excess properties, Redlich – Kister polynomial equation was used. The negative and positive values of the excess properties predicted the type and strength of molecular interactions between the components in the binary mixture.The excess molar volume for the mixture at all temperatures is found to be negative. The εE values for ethylene glycol + 1-propanol has been found to be negative at 298K and but positive values are obtained at 308 and 313K. The divergent magnitudes of εE values at different temperatures have been attributed to different strengths of hydrogen bond interactions as well as alignments of net dipoles.

Енергоощадний режим роботи ректифікаційної колони зневоднення етиленгліколю

The article offers theoretical analysis of the possibility of using in the distillation column for dehydration of ethylene glycol of several streams of coolant, which has different temperature to reduce energy costs for ethylene glycol production. The directions for the literary review of modern research were selected: optimization in the design and operation of the distillation column, reduction of energy costs during rectification, methods for assessing the energy efficiency of the rectification process. The purpose of the article is to analyze the efficiency of the modernization of the distillation column to reduce energy costs for ethylene glycol production. Cost reduction is possible due to the use of heat carriers of different temperature potentials. For the purpose of estimating the amount of energy savings, a model is used, where the column is provided with thermal energy produced by a heat pump. The proposed model of heat exchange in the distillation column takes into account the internal convective heat exchange between the reflux condenser and the vat residue and the external heat exchange that is realized by the heat pump. In the proposed model, the heat pump operates on the ideal Carnot cycle, consumes mechanical energy and transfers thermal energy from the reflux condenser to the residue, increasing the temperature potential columns. The simplifications for the model solution are formulated and substantiated, an example of calculating the energy efficiency of the rectification process of a binary mixture of ethylene glycol with water is given, dependence of energy efficiency on the temperature of the alternative heat carrier flow is obtained. It is concluded that there is an extreme of theoretical relative economy of energy costs in the column of dehydration of ethylene glycol from the temperature value of the second heat carrier flow.

Solubility of sildenafil citrate in the binary mixtures of ethylene glycol and water at different temperatures

The aim of this work is to investigate the solubility behavior of sildenafil citrate (SC) in the binary mixtures of ethylene glycol and water at different temperatures in the range of 293.2–313.2 K. The generated data are correlated with some linear and non-linear cosolvency models including the van't Hoff, the double log-log, the mixture response surface, Yalkowsky, Jouyban-Acree, Jouyban-Acree-van't Hoff, and the modified Wilson models. The mean relative deviations (MRD%) of the back-calculated solubility for each applied models are computed as an accuracy criterion. Density data measured for SC saturated mixtures as another physico-chemical property are also correlated with the Jouyban-Acree model and the results are discussed. Furthermore, apparent thermodynamic properties for SC dissolution process are computed by using van't Hoff and Gibbs equations.

Optimal Performance Evaluation of Energy Efficient Residential Air Conditioning System with Nanofluid-based Intercooler using Taguchi-based Response Surface Methodology

Air conditioning is viewed as a major energy consuming area in domestic and industrial applications. However energy conservation is effectively possible in air conditioners by employing an intercooler with nanofluids, which can consequently reduce the compressor load. This paper presents an investigative report on the performance of proposed energy efficient air conditioning system. A binary mixture of ethylene glycol (C2H6O2) and water is used as the base fluid in the shell and coil type heat exchanger (SCHE). The volume concentration of C2H6O2 in base fluid, type of suspended nano particles (Al2O3 and MgO), flow rate of nanofluid at shell side of intercooler and the volume fraction of nano particles are chosen for experimentation designed using Taguchi L18 orthogonal array. The coefficient of performance (COP) of the nanofluid-based domestic air conditioner is estimated as the performance index (response). Quadratic model and response surface plots are generated to observe the effects of inputs on the COP. The nano particles of MgO (0.75%v/v), suspended in a binary mixture with 28.65% C2H6O2 is found to improve the system performance (COP) at a nanofluid flow rate of 2.42 LPM.

Solubilities of Dilute SO2 in the Binary System of Glycol and Dimethylsulfoxide

The solubility of SO2 in binary mixtures of ethylene glycol (EG) and dimethylsulfoxide (DMSO), a potential candidate for use as the scrubbing liquid for the absorption of SO2 from flue gas, are lacking in the literature. The paper presents solubility data of dilute SO2 in these inexpensive solvent mixtures at T = (303.15, 308.15, and 313.15) K and p = 122.66 kPa. The solubilities of dilute SO2 in the mixtures increases gradually with increasing concentration of DMSO and decreasing temperature. The solubility of SO2 is linearly proportional to the experimental pressure. Meanwhile, the Henry’s law constants (H x ), dissolution enthalpy changes, dissolution entropy changes, and dissolution Gibbs energy changes were also obtained from the solubility data of SO2 in the mixtures. The experimental results demonstrate that the binary system of EG and DMSO is a promising alternative in SO2 separation processes due to its excellent absorption and regeneration performance.

Structural, dielectric and conductivity behaviours of cetyltrimethylammonium bromide/ethylene glycol-based quenched lyotropic mesophases

ABSTRACTThe present study highlights the effect of quenching on the structural, textural and dielectric dynamics of cetyltrimethylammonium bromide/ethylene glycol binary mixtures of varying concentrations 30:70, 50:50 and 75:25 wt.%. No mesomorphism is seen in the as-prepared binary mixtures as X-ray diffraction and polarisation optical microscopy studies reveal the crystalline-like structures for the studied concentrations. With the effect of quenching, lyotropic hexagonal phase is obtained at 30:70, 50:50 wt.% concentration; however, mixture with higher 75:25 wt.% concentrations exhibit crystalline-like phase. The obtained hexagonal lyotropic phases restrain the mesomorphism up to ≈340 K and then show crystalline-like structures with the further increase in the temperature. Dielectric and relaxation behaviours of hexagonal lyotropic phases are presented in this study. The relaxation parameters of lyotropic phases are also discussed. Interestingly, the hexagonal lyotropic phases obtained for 30:70 and 50:50 wt.% concentrations exhibit ac conductivity of the order of 10–5 S/m, which can be seen as a significant result of this study.

Solubilization of lamotrigine using Tween 80 and ethylene glycol or propylene glycol

Micellar medium as solubilization technique is an influential approach for solubilization of drugs with high hydrophobicity. In the current work, the effects of Tween 80 as a nonionic surfactant on the solubilities of lamotrigine in binary mixtures of ethylene glycol+water and propylene glycol+water at 298K are investigated. To measure solubility of lamotrigine a lab-made setup was employed. This setup applies a synthetic-based method to measure the solubility of the candidate drugs using a three-step procedure to check the solution saturation point. Measured solubility data points were fitted to the common cosolvency models and then back-calculated solubilities were used to calculate the mean percentage deviation (MPD) as an accuracy measure of the models. The obtained MPDs for back-calculated and predicted solubilities using Jouyban-Acree model were 4.0 and 6.9%, respectively.

Lifshitz phase: the microscopic structure of aqueous and ethanol mixtures of 1,n-diols.

We study binary mixtures of ethylene glycol and 1,3-propandiol with water or ethanol using computer simulations. Despite strong hydrogen bonding tendencies between all these molecules, we find that these mixtures are surprisingly homogeneous, in contrast to the strong micro-heterogeneity found in aqueous ethanol mixtures. The aqueous diol mixtures are found to be close to ideal mixtures, with near-ideal Kirkwood-Buff integrals. Ethanol-diol mixtures show weak non-ideality. The origin of this unexpected randomness is due to the fact that the two hydrogen bonding hydroxyl groups of the 1,n-diol are bound by the neutral alkyl bond, which prevents the micro-segregation of the different types of hydroxyl groups. These findings suggest that random disorder can arise in the presence of strong interactions - in contrast to the usual picture of random disorder due to weak interactions between the components. They point to the important role of molecular topology in tuning concentration fluctuations in complex liquids. We propose and justify herein the name of Lifshitz phases to designate such types of disordered systems.