25 research outputs found

    Prediction of thermophysical and transport properties of ternary organic non-electrolyte systems including water by polynomials

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    The description and prediction of the thermophysical and transport properties of ternary organic non-electrolyte systems including water by the polynomial equations are reviewed. Empirical equations of Radojković et al. (also known as Redlich-Kister), Kohler, Jacob-Fitzner, Colinet, Tsao-Smith, Toop, Scatchard et al. and Rastogi et al. are compared with experimental data of available papers appeared in well know international journals (Fluid Phase Equilibria, Journal of Chemical and Engineering Data, Journal of Chemical Thermodynamics, Journal of Solution Chemistry, Journal of the Serbian Chemical Society, The Canadian Journal of Chemical Engineering, Journal of Molecular Liquids, Thermochimica Acta, etc.). The applicability of empirical models to estimate excess molar volumes, VE, excess viscosities, Ī·E, excess free energies of activation of a viscous flow

    Effects of different mechanical treatments on structural changes of lignocellulosic waste biomass and subsequent Cu(II) removal kinetics

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    In this paper, the character of structural changes induced by different mechanical treatments to Prunus persica stones (PSs), and its subsequent effect on biosorption kinetics of Cu(II) were investigated. PSs were processed in vibratory disk mill (PS-V) and ultra-centrifugal mill (PS-C) and characterized by XRD, BET, SEM and FTIR spectroscopy. It was shown that PS-V was smaller and more reactive with less crystallinity index and hydrogen bond intensity compared to PS-C. In opposite, surface area of the PS-C was bigger than that of the PS-V. The total pore volume was about threefold, while the volume of micro pores was 9.29 times higher in PS-Cs than in PS-Vs. The kinetics of Cu(II) biosorption by both PSs was tested through various kinetic models: pseudo-first and pseudo-second order rate equations, Elovich equation, Boyd model, Weberā€“Morris and Uranoā€“Tachikawa intraparticle diffusion model. For both sample types, Cu(II) biosorption occurred through combination of intraparticle and film diffusion mechanism, while kinetic results were best described by the pseudo-second order kinetic model. At the same time, the results indicated that together with kinetic rate the biosorption capacity of PS-C (21.20 mg gāˆ’1) was higher than that of PS-V (16.30 mg gāˆ’1). Mechanical activation like crushing and grinding will change material particle size, specific surface area and porosity, as well as its crystallinity. However, this paper elucidates that such physical structural changes will impact on heavy metal ions removal efficiency. This investigation suggests that the type of size reduction in lignocellulosic biosorbent preparation plays a very important role in overall biosorption performance, so it should be carefully considered every time when the mechanical treatment of material is necessary to be applied

    Correlation of the liquid mixture viscosities

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    In this paper forty two selected correlation models for liquid mixture viscosities of organic compounds were tested on 219 binary and 41 ternary sets of experimental data taken from literature. The binary sets contained 3675 experimental data points for 70 different compounds. The ternary sets contained 2879 experimental data points for 29 different compounds. The Heric I, Heric-Brewer II, and Krishnan-Laddha models demonstrated the best correlative characteristics for binary mixtures (overall absolute average deviation < 2%). The Heric I, Heric-Brewer II, Krishnan-Laddha and Heric II models demonstrated the best correlative characteristics for ternary mixtures (overall absolute average deviation < 3%)

    Volumetric Properties, Viscosities, and Refractive Indices of the Binary Systems 1-Butanol + PEG 200, + PEG 400, and + TEGDME

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    Densities, viscosities, and refractive indices of three binary systems consisting of 1-butanol with polyethylene glycols of different molecular weights (PEG 200 and PEG 400) or tetraethylene glycol dimethyl ether (TEGDME) were measured at ten temperatures (288.15, 293.15, 298.15, 303.15, 308.15, 313.15, 318.15, 323.15, 328.15, and 333.15) K and atmospheric pressure. Densities of the selected binary mixtures were measured with an Anton Paar DMA 5000 digital vibrating U-tube densimeter, refractive indices were measured with an automatic Anton Paar RXA-156 refractometer, while for viscosity measurements, a digital Stabinger SVM 3000/G2 viscometer was used. From these data, excess molar volumes were calculated and fitted to the Redlich-Kister equation. The obtained results have been analyzed in terms of specific molecular interactions and mixing behavior between mixture components, as well as the influence of temperature on them. Viscosity data were also correlated by Grunberg-Nissan, Eyring-UNIQUAC, three-body McAlister, and Eyring-NRTL models

    A new group contribution model for prediction liquid hydrocarbon viscosity based on free-volume theory

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    In this paper a group contribution model for predicting the viscosity values of n-alkanes and iso-alkanes in the liquid phase based on Free-Volume Theory was developed. A database with 2129 experimental data with a temperature range up to 573.15 K and a pressure range up to 4000 bar was used to develop the model. The total weighted average percentage error is 4.894%. The model was tested on the next 472 experimental data with a temperature range up to 564.15 K and a pressure range up to 2019 bar and a mean percentage error that was obtained is 5.155%

    Energy integration of nitric acid production using pinch methodology

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    Pinch methodology was applied to the heat exchangers network (HEN) synthesis of nitric acid production. The integration is analyzed in two ways, and the results are presented as two different solutions: (i) the first solution is based on the original heat transfer equipment arrangement, (ii) in order to eliminate the shortages of the first solution the second HEN was obtained using process simulation with optimized process parameters. Optimized HEN, with new arrangement of heat exchangers, gave good results in energy and process optimization. [Projekat Ministarstva nauke Republike Srbije, br. P172063

    Liquid-liquid equilibria of the ternary systems water + C1 ā€“ C3 alcohols + dimethyl adipate at 298.15 K and atmospheric pressure: Experimental data and modeling

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    The aim of this study was to examine the possibility of using a green organic solvent, dimethyl adipate (DMA), as a separation agent in the extraction of different alcohols from aqueous solutions. For that purpose, the liquidā€“liquid equilibria (LLE) of four ternary systems were analytically determined at 298.15 K and atmospheric pressure using stirred and thermo-regulated cells: {water + methanol + dimethyl adipate (DMA)}, {water + ethanol + DMA}, {water + 1-propanol + DMA}, {water + 2-propanol + DMA}. Phase diagrams for these four ternary systems were obtained by determining a binodal curve and tie-lines data using a visual cloud-point method, but also gas chromatography. Distribution coefficients and separation factors were calculated for the immiscibility region. Hand and Othmer-Tobias correlations were used to examine the reliability of the tie-line data. In addition, the experimental ternary LLE data were correlated with the UNIversal QUAsiChemical (UNIQUAC) activity coefficient models. The obtained results showed that DMA is a suitable candidate for the extraction of methanol, ethanol, 1-propanol, and 2-propanol from water. With some alcohols, this potential is more noticeable than with others. The potential of DMA as a separation agent is increasing in the following sequence: methanol < ethanol < 2-propanol < 1-propanol, and that also could be noticed from the selectivity values that also increase in this sequence. The UNIQUAC model proved as successful in correlating the LLE data

    Thermodynamic study of triacetin or ethyl levulinate and alcohol binary mixtures

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    The subject of presented research is the study of liquid binary mixtures consisting of ester and alcohol combination; triacetin or ethyl levulinate, as one component, and ethanol or isobutanol, as second component. Thermodynamic and transport data were measured in the broad temperature range, T=(288.15/298.15ā€“323.15/333.15) K, and at atmospheric pressure, p = 0.1 MPa. All corresponding excess and deviation properties were calculated including the excess molar volume, viscosity deviation, refractive index deviation, isentropic compressibility deviation and excess molar Gibbs energy of activation of viscous flow, and correlated with the basic Redlich-Kister equation. The analysis of possible chemical interactions and structural effects taking place in the mixtures was led in the terms of ester structure, complexity of ester molecule and chain length and branching of the alcohol molecule. The thermodynamic analyses showed change of the sign of the excess molar volume depending on the alcohol present in the mixture. FT-IR spectra were recorded for all four systems for the compositions where maximum excess molar volumes are obtained to support the conclusions derived from the mixturesā€™ nonideal behaviour. In addition, modelling of viscosity is performed with the two- and three-parameter correlative models, as well as excess molar volume correlation with the Peng-Robinson equation of state and three-parameter van der Waals mixing rule
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