Efficient and reversible separation of NH_(3) by deep eutectic solvents with multiple active sites and low viscosities

The efficient separation and collection of ammonia(NH_(3))during NH_(3) synthesis process is essential to improve the economic efficiency and protect the environment.In this work,ethanolammonium hydrochloride(EtOHACl)and phenol(PhOH)were used to prepare a novel class of deep eutectic solvents(DESs)with multiple active sites and low viscosities.The NH_(3) separation performance of EtOHACl+PhOH DESs was analyzed completely.It is figured out that the NH_(3) absorption rates in EtOHACl+PhOH DESs are very fast.The NH_(3) absorption capacities are very high and reach up to 5.52 and 10.74 mol·kg1 at 11.2 and 100.4 kPa under 298.2 K,respectively.In addition,the EtOHACl+PhOH DESs present highly selective absorption of NH_(3) over N_(2) and H_(2) and good regenerative properties after seven cycles of absorption/desorption.The intrinsic separation mechanism of NH_(3) by EtOHACl+PhOH DESs was further revealed by spectroscopic analysis and quantum chemistry calculations.

A Laboratory Study of the Effect of Temperature on Densities and Viscosities of Binary and Ternary Blends of Soybean Oil, Soy Biodiesel and Petroleum Diesel Oil

The depletion of world petroleum reserves and the increased environmental concerns have stimulated the search for alternative sources for petroleum based fuel. The possibility of using vegetable oils as fuel has been recognized, however, due to its high viscosities and low volatilities makes it inefficient for most combustion engines and thus the need to get them chemically altered or transesterified to obtain fatty alkyl esters of the oil (biodiesel). In this study, binary and ternary blends of biodiesel were produced and the effect of temperature on their viscosity and density was investigated. Biodiesel was produced from soybean oil by transesterification of the oil with methanol using potassium hydroxide as a catalyst at a temperature of 60℃ in a batch reactor. Binary and ternary blends of the soy-biodiesel were prepared with soy bean oil and petroleum diesel fuel, respectively. Viscosities and densities of the binary and ternary blends were measured at different temperatures of 20℃ to 90℃ as to determine the effect of temperature on viscosities and densities of the blends. The properties of the soy-biodiesel produced were compared with ASTM standard and found to be within the limits. The results show that the viscosities and densities of both the binary and ternary blends are temperature dependent. The viscosities of binary and ternary blends decreased nonlinearly with temperature, while their densities decreased linearly with temperature. The variation of temperature with viscosity and density of the blends was correlated and the polynomial equation offered the best correlation between temperature and viscosity, while linear equation gave the best correlation between temperature and density. In conclusion, the efficiency of binary and ternary blends of biodiesel in combustion engines is dependent on the viscosity and density of the blends which are invariably temperature dependent.

Densities and Viscosities of the Ionic Liquid [C4mim][PF6]＋ N,N-dimethylformamide Binary Mixtures at 293.15 K to 318.15 K

Viscosities and densities for 1-butyl-3-methylimidazolium hexafluorophosphate （[C4mim][PF6]） and N, N-dimethylformamide （DMF） binary mixtures have been measured at the temperature range from 293.15 K to 318.15 K. It is shown that the viscosities and densities decrease monotonously with temperature and the content of DMF. Various correlation methods including Arrhenius-like equation, Sedclon et al.＇s equation, Redlich-Kister equation with four parameters, and other empirical equations were applied to evaluate these experimental data. A model based on an equation of state Ior estimating the viscosity of mixtures containing ionic liquids were proposed by coupling with the excess Gibbs free energy model of viscosity, which can synchronously calculate the viscosity and the molar volume. The results show that the model gives a deviation of 8.29% for the viscosity, and a deviation of 1.05% for the molar volume when only one temperature-independent adjustable parameter is adopted. The correlation accuracy is further improved when two parameters or one temperature-dependent parameter is used.

Densities and viscosities for ionic liquids [BMIM][BF4] and [BMIM][Cl] and their binary mixtures at various temperatures and atmospheric pressure

The density and viscosity of 1-butyl-3-methylimidazolium tetrafluoroborate[BMIM][BF4]and 1-butyl-3-methylimidazolium chloride[BMIM][Cl]and their binary mixtures within the temperatures from 303.15 K to323.15 K and at ambient pressure were determined in this work.The temperature dependences of density and viscosity were satisfactorily described with the linear model and the Vogel-Tammann-Fulcher type equation,respectively.The molar volume and viscosity of binary IL mixtures were predicted through ideal mixing rules showing that almost null deviations for IL mixtures were observed and their mixing was remarkably close to linear ideal behavior in the molar volumes,while comparatively large errors in viscosity occurred.Additionally,the molar volume of the investigated pure ILs and their mixtures could well be predicted by a predictive model presented by Valderrama et al.(Fluid Phase Equilib.,275(2009)145).

Analysis of the rates of emulsification in intraocular silicone oil tamponades of differing viscosities

AIM:To investigate the rates of emulsification in silicone oil(SO)tamponades of differing viscosities used during pars plana vitrectomy(PPV)in the treatment of complicated vitreoretinal diseases.METHODS:This study was a prospective randomized clinical trial.Totally 290 cases with greater likelihoods of secondary detachment were included and randomly grouped into either Siluron 2000(n=143)or Siluron 5000(n=147)SO tamponades with 23-gauge PPV.Patient followups and data analyses were conducted 1,3,6,and 12 mo post-surgery.RESULTS:The time of the SO emulsification ranged from 1 to 17 mo,with a mean of 7.3±4.2 mo.The Siluron 5000 group showed a slower emulsification rate in comparison to the Siluron 2000 group.The Siluron 2000 group took a shorter time to show signs of emulsification,necessitating earlier SO removal.However,there were no significant differences in the occurrence of complications,including secondary retinal detachment,cataract,corneal abnormality,high intraocular pressure and hypotony.CONCLUSION:The Siluron 2000 SO tamponade shows a faster rate of emulsification than the Siluron 5000 SO,necessitating earlier removal.Both groups show similar results in terms of anatomical success and visual acuity outcome,and there is no significant difference between the SOs regarding the occurrence of complications.

A Generalized Correlation for Characterization of Lubricating Base-oils from Their Viscosities

Lubricating mineral base oils are normally extracted from lube-oil cuts with furfural solvent.Aromatic content in the raffinate phase from extraction process is an essential parameter that affects the quality of the lubricating base-oils.For determination of aromatic content by the usual ASTM D3238 method,density,refractive index and molecular weight of the raffinate are required.In this work,a new generalized correlation is developed for de-termination the aromatic content by using only the measured viscosity of lubricating oil.With a mole fraction of aromatic compounds,the kinematic viscosity may be obtained at any temperature between 60-100°C along with their molecular weight and refractive index.

Numerical investigation of variable viscosities and thermal stratification effects on MHD mixed convective heat and mass transfer past a porous wedge in the presence of a chemical reaction

An analysis is presented to investigate the effects of variable viscosities and thermal stratification on the MHD mixed convective heat and mass transfer of a viscous, incompressible, and electrically conducting fluid past a porous wedge in the presence of a chemical reaction. The wall of the wedge is embedded in a uniform nonDarcian porous medium in order to allow for possible fluid wall suction or injection. The governing boundary layer equations are written into a dimensionless form by similarity transformations. The transformed coupled nonlinear ordinary differential equations are solved numerically with finite difference methods. Numerical calculations up to the thirdorder level of truncation are carried out for different values of dimensionless parameters. The results are presented graphically, and show that the flow field and other quantities of physical interest are significantly influenced by these parameters. The results are compared with those available in literature, and show excellent agreement.

Calculation of Viscosities of Liquid Mixtures Using Eyring's Theory in Combination with Cubic Equations of State

Cubic equations of state (EOS) have been combined with the absolute rate theory of Eyring to calculate viscosities of liquid mixtures. A modified Huron-Vidal gE-mixing rule is employed in the calculation and in comparison with the van Laar and the Redlich-Kister-type mixing rule. The EOS method gives an accurate correlation of liquid viscosities with an overall average deviation less than 1% for 67 binary systems including aqueous solutions. It is also successful in extrapolating viscosity data over a certain temperature range using parameters obtained from the isotherm at a given temperature and in predicting viscosities of ternary solutions from binary parameters for either polar or associated systems.

Coalescence dynamics of two droplets of different viscosities in T-junction microchannel with a funnel-typed expansion chamber

The coalescence behavior of two droplets with different viscosities in the funnel-typed expansion chamber in T-junction microchannel was investigated experimentally and compared with droplet coalescence of the same viscosity.Four types of coalescence regimes were observed:contact non-coalescence,squeeze non-coalescence,two-droplet coalescence and pinch-off coalescence.For droplet coalescence of different viscosities,the operating range of non-coalescence becomes narrowed compared to the droplet coalescence of same viscosity,and it shrinks with increasing viscosity ratioηof two droplets,indicating that the difference in the viscosity of two droplets is conducive to coalescence,especially when1<η<6.Furthermore,the influences of viscosity ratio and droplet size on the film drainage time(Tdr)and critical capillary number(Ca)c)were studied systematically.It was found that the film drainage time declined with the increase of average droplet size,which abided by power-law relation with the size difference and viscosity ratio of the two droplets:Tdr~(ld)^(0.25±0.04)and Tdr~(η)^(﹣0.1±0.02).For droplet coalescence of same viscosity,the relation of critical capillary number with two-phase viscosity ratio and dimensionless droplet size is Cac=0.48λ^(0.26)l^(﹣2.64),while for droplet coalescence of different viscosities,the scaling of critical capillary number with dimensionless average droplet size,dimensionless droplet size difference and viscosity ratio of two droplets is Cac=0.11η^(﹣0.07)ls^(﹣2.23)l^(0.16)_(d).

Viscosities of Pure Water, Acetic Acid ＋ Water, and p-Xylene ＋ Acetic Acid ＋ Water at Different Temperature and Pressure

The viscosities of pure water,the acetic acid+water binary system,and the p-xylene+acetic acid+ water ternary system at different concentrations were determined with a rolling-ball viscometer at temperatures from 313.15 to 473.15 K and pressures from 0.10 to 3.20 MPa.The viscosity data were fitted by a correlation equation for the estimation of the mixture viscosities.The average absolute deviations(AAD)of the correlation for binary and ternary systems are 2.48%and 1.77%,respectively.

Densities and Viscosities of 1-butyl-3-methylimidazolium Hexafluorophosphate [bmim][PF6] ＋ CO2 Binary System： Determination and Correlation

A gas-dissolving device was designed and connected to the falling-body viscometer, which was used to determine the viscosities of liquids in our lab before. The equipment can be used to determine the gas composition, the densities and viscosities of the solution at the same time. The densities and viscosities of [bmim][PF6] ＋ CO2 binary system were determined in the temperature range of 313.2 to 413.2 K and pressure range of 5.0 to 25.0 MPa by the equipment. Then the viscosities of [bmim][PF6] ＋ CO2 binary system at constant temperature, constant pressure, and different temperature and pressure were correlated, respectively. For the correlation at different tempera- ture and different t3ressure for different concentration mixtures the average relative deviation ARD is 0.037.

Flow characteristics of liquid with pressure-dependent viscosities in microtubes

It is obvious that the pressure gradient along the axial direction in a pipe flow keeps constant according to the Hagen-Poiseuille equation. However, recent experiments indicated that the distribution of the pressure seemed no longer linear for liquid flows in microtubes driven by high pressure （1-30MPa）. Based on H-P equation with slip boundary condition and Bridgman＇s relation of viscosity vs. static pressure, the nonlinear distribution of pressure along the axial direction is analyzed in this paper. The revised standard Poiseuille number with the effect of pressure-dependent viscosity taken into account agrees well with the experimental results. Therefore, the dependence of the viscosity on the pressure is one of the dominating factors under high driven pressure, and is represented by an important property coefficient α of the liquid.

Calculation of Viscosities of Liquid Mixtures Using Eyring’s Theory in Combination with Cubic Equations of State

Cubic equations of state EOS have been combined with the absolute rate theory of Eyring to calculate viscosities of liquid mixtures. A modified Huron-Vidal gE-mixing rule is employed in the calculation and in com- parison with the van Laar and the Redlich-Kister-type mixing rule. The EOS method gives an accurate correlation of liquid viscosities with an overall average deviation less than 1% for 67 binary systems including aqueous solu- tions. It is also successful in extrapolating viscosity data over a certain temperature range using parameters obtained from the isotherm at a given temperature and in predicting viscosities of ternary solutions from binary parameters for either polar or associated systems.

Densities, conductivities, and viscosities of aqueous solutions of N-hexyl,methylpyrrolidinium bromide and N-butyl, methylpyrrolidinium bromide at different temperatures

The densities, conductivities, and viscosities were measured for ternary solutions of N-hexyl,methylpyrrolidinium bromide([PP1,6]Br)- N-butyl,methylpyrrolidinium bromide([PP1,4]Br)-H2 O and its binary subsystems [PP1,6]Br-H2 O and [PP1,4]Br-H2 O at(298.15, 303.15, 308.15, and 313.15) K, respectively. The results were used to test the predictability of the simple equations established for the prediction of density, conductivity,and viscosity of the mixed electrolyte solutions. The results show that the examined simple equations can offer good predictions for density, conductivity, and viscosity of the mixed ionic liquid solutions in terms of the corresponding properties of its binary subsystems of equal ionic strength.

Relationship between waxy crude viscosities and wax crystal microstructure

It is important and profound to quantitatively study the relation between rheology and microstructure for development of the microstructural mechanism of crude oil rheology and even for the waxy crude oil pipelining.However,due to the high complexity and irregularity of wax crystal morphology,quantitative characterization is hard to achieve.This has hampered further study on the rheology-microstructure relationship.A new approach combined the fractal geometry and the stereology theory is presented for quantifying the intricate wax crystal morphology and structure.Based on the characterization,the effects of microstructures and oil composition on the waxy crude viscosities are analyzed quantitatively.It further validates the previous qualitative research and enriches understanding into the microstructural mechanism of waxy crude oil rheology.

Densities and Viscosities of the Quaternary System Mannitol-Sorbitol- D-Glucose-H2O and Its Ternary Subsystems at 298.15K

To check the applicabilities of the simple density equation and viscosity equation in the semi-ideal solution theory to nonelectrolyte solutions, the densities and viscosities were measured for the quaternary system mannitol-sorbitol-D-glucose-HzO and its ternary subsystems mannitol-D-glucose-H2O and sorbitol-D-glucose-H2O at 298.15K. The results were used to test the applicability of the simple equations for the density and viscosity of the multicomponent nonelectrolyte solution. The agreements between the predicted and measured results are good.

Correlation of Viscosities for Alkane, Aromatic and Alcohol Family at High Pressure by Modified Tait Equation

A new model was proposed to calculate the viscosity of fluids under the pressure ranging from 0.1 to 110MPa by improving the Tait equation, in which the viscosity μ of liquids was linked with activation volume V. The model with two adjustable parameters a and fl was applied in calculating viscosities for alkane, aromatic and alcohol family at high pressure. Results show that calculated values of viscosity are in good agreement with the experimental ones, and the average relative deviations for alkanes, aromatics and alcohols are 0.56%, 0.31% and 0.66%, respectively. Besides, the errors correlated by the model proposed in this paper were equivalent to the ones from the pure empirical Tait equation, and obviously superior to those from Eyring equation.

PREDICTION OF VISCOSITIES OF LNG MIXTURES BY TWO CORRESPONDING STATES PRINCIPLES

The three parameter and shape factor corresponding states principle (CSP) are used respectively to predict the shear viscosities of LNG mixtures successfully.In the three parameter CSP calculation,only one adjustable interaction coefficient is required to characterize each binary system.When this coefficient is set as a unity,the three parameter CSP gives nearly the same extent of accuracy as the shape factor CSP,with the average absolute deviation between the calculated and experimental data ranging from 2% to 9%.However,when an optimized coefficient is introduced to the three parameter CSP,it may result in very accurate predictions,well within the accuracy of the experimental data with the deviation less than 3%.It is also found that the accuracy of the shape factor approach shows a tendency that the deviation increases with the increase of the densities of the LNG mixtures. [WT5”HZ〗

Densities, Viscosities and Related Properties for Binary Mixtures of Sulfolane + p-Xylene, Sulfolane + Ethylbenzene in the Temperature Range from 303.15K to 353.15K

Densities and viscosities of the binary systems of sulfolane + ethylbenzene, sulfolane + p-xylene have been experimentally determined in temperature interval 303.15-353.15 K and at atmospheric pressure for the whole composition range. The excess molar volumes and viscosity deviations were computed. The computed quantities have been fitted to Redlich-Kister equation. Excess molar volumes and viscosity deviation show a systematic change with increasing temperature. Two mixtures exhibit negative excess volumes with a minimum which occurs approximately at x = 0.5. The effect of the size, shape and interaction of components on excess molar volumes and viscosity deviations is discussed.