Search

In this work, a two-stage packed bed scrubber was designed and optimized for purification of industrial waste gas containing ammonia at a concentration of 1400 mg m-3. Basic material balance equations, equilibrium data, and the generalized pressure drop correlation were used for the calculation. For the analysis of different configurations, Katmar software was utilized, which uses the generalized pressure drop correlation in order to calculate the scrubber diameter based on the allowable pressure drop and proximity to flooding conditions. It was found that optimal results are achieved in a two-stage device, using 70 vol.% sulfuric acid for chemisorption of ammonia. Pall rings, 50 mm in size and made of polypropylene, were selected as a column packing. Performances of scrubbers of three column diameters (i.e., Dc=2; 2.1 and 2.2 m) were analyzed. From the aspect of the liquid phase flow, the column diameter of 2 m provides satisfactory results. According to the packing specifications, the pressure drop through the packing layer would be about 900 Pa. It was found that the pressure gradient, and therefore the total pressure drop in the column decreases with increasing the column diameter. However, as the diameter of the column increases, the minimum flow rate of the liquid phase required to wet the packed bed increases, so the required liquid flow rate increases. Taking into account all of the analyzed process parameters, as well as the required purification degree of the waste gas, the optimal configuration of the device was proposed.

Copyright of Chemical Industry / Hemijska Industrija is the property of Association of Chemical Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Different deep eutectic solvents (DESs) of triethanolamine (TEOA) and oxalic acid (OA), glacial acetic acid (AA), L-(+)-lactic acid (LA), oleic acid (OLA), glycerol (G), ethylene glycol (EG), propylene glycol (PEG), choline chloride (ChCl) or 1,3-dimethylurea (DMU) were prepared and characterized regarding their physicochemical (density, viscosity, electrical conductivity, refractive index, coefficient of volume expansion, molecular volume, lattice energy and heat capacity) properties over the temperature range of 293.15–363.15 K at 101.325 kPa. For all tested DESs, the density, viscosity and refractive index decreased with rising temperature, while the electrical conductivity increased. The temperature dependence of viscosity and electrical conductivity are described by the Vogel–Tamman–Fulcher equations. The viscosity and molar conductivity, which exhibited a linear behaviour, were correlated by the fractional Walden rule. Besides, the Fourier transform infrared spectroscopy (FTIR) was used to study the functional groups of these DESs while thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) provided the information about their stability. The tested DESs of TEOA possess desirable properties for use in various industrial processes, such as extractions, separations, chemical technology and biotechnology.

Copyright of Chemical Industry / Hemijska Industrija is the property of Association of Chemical Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

SAFT equations of state have been widely used for the determination of different thermo-physical and phase equilibria properties. In order to use these equations as predictive models it is necessary to calculate the model parameters. In this work CK-SAFT and PC-SAFT equations of state were applied for the correlation of pure compounds densities in the wide ranges of temperature and pressure (288.15–413.15 K and 0.1–60 MPa, respectively). The calculations of densities for n-hexane, n-heptane, n-octane, toluene, dichloromethane and ethanol, under high pressure conditions, were performed with the new sets of parameters determined in this paper by CK-SAFT and PC-SAFT. Very good agreement between experimental and calculated density values was achieved, having absolute average percentage deviations lower than 0.5 %. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. OI 172063]

In this paper, the Prigogine–Flory–Patterson (PFP) theoretical model and the extended real association solution (ERAS) model for the prediction of the excess molar volumes of 17 binary sets of alcohols (methanol, ethanol, propan-1-ol, butan-1-ol, butan-2-ol and pentan-1-ol) with benzene, chlorobenzene, acetonitrile, hexan-1-amine and n-heptane were tested at 298.15 K and atmospheric pressure. The binary sets contained 333 experimental data points for 11 different compounds. The ERAS model demonstrated better correlative characteristics for binary mixtures comparing to PFP model. The ERAS model is successfully applied on all binary systems except ethanol + benzene and propan-1-ol + benzene. PFP model gave less satisfactory results for all systems except butan-1-ol + hexan-1-amine, for which obtained results were acceptable. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172063]

The ability of non-toxic and biodegradable deep eutectic solvent (DES) choline chloride + DL-malic acid in mole ratio 1:1, for the breaking of the azeotropes heptane + methanol and toluene + methanol by means of liquid– –liquid extraction was evaluated. Ternary liquid–liquid equilibrium experiments were performed at 298.15 K and at atmospheric pressure. Densities, viscosities and refractive indices of DES + methanol and water + DES systems were experimentally determined over a wide temperature range and at atmospheric pressure. Additionally, the viscosities of DES + glycerol mixture were - determined at temperatures up to 363.15 K to check how much the addition of glycerol decreases high viscosities of DES. The results indicate that the addition of small amounts of water or glycerol as a third component significantly decreases the viscosity of the investigated deep eutectic solvent. Based on the selectivity and distribution ratio values, the extraction ability of the investigated deep eutectic solvent, in comparison with the conventionally used solvents, yields promising results. Non-random two-liquid (NRTL) and universal quasichemical (UNIQUAC) models were satisfactorily applied for correlation of experimental phase equilibrium data for two ternary mixtures. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172063]

The most common model of linear economy is currently unsustainable, from the economic, energy and ecological aspects. The enormous increase in human needs for various products and energy has led to a reduction in raw material reserves, on the one hand, and the accumulation of waste, on the other. Therefore, it is necessary to widely adopt the circular economy model, where waste is treated as a raw material, with the idea of achieving zero waste production without use of virgin raw materials. In that sense, in this work food and agricultural waste was used to obtain liquid and solid biofuels. Used cooking oil was used as a raw material in the production of biodiesel, while the waste shell of a hen's egg served as the source of a catalyst for the reaction. Glycerine, as a side product of the chemical reaction, was mixed with agricultural and woody biomass in the production of enriched pellets. The fuels obtained in this way were thermodynamically characterized. For biodiesel and glycerine, the density and viscosity at atmospheric pressure and temperatures were measured, while for the mixtures of crude glycerine and biomass, the calorific value was determined. The obtained products show promising characteristics as potential energy source. [ABSTRACT FROM AUTHOR]

Experimental density r, refractive index nD and viscosity h data of three binary systems of poly(ethylene glycol) diacrylate (PEGDA) + ethanol, + 1-propanol, and + 1-butanol were measured at eight temperatures from (288.15 to 323.15) K, with temperature step of 5 K, and at atmospheric pressure. The experimental data were correlated as a function of PEGDA mole fraction and temperature. Densities and refractive indices of the investigated mixtures could be fitted well with exponential function vs. composition, including temperature dependence of parameters, while in the case of viscosities polynomial function fits well over a mixture’s composition. In the case of temperature correlation, all three properties (ρ, lnη and nD) exhibit linear trend. The viscosity modeling was performed using four models: UNIFAC-VISCO, ASOG-VISCO, Mc-Allister and Teja-Rice. For application of UNIFAC-VISCO model interaction parameters of following groups were determined: CH2=CH/CH3, CH2=CH/CH2, CH2=CH/OH, CH2=CH/CH2O and CH2=CH/COO. Also, in the same way binary interaction parameters used in ASOG-VISCO of the following groups were determined: CH2=CH/CH2, CH2=CH/OH, CH2=CH/CH2O and CH2=CH/COO. [Projekat Ministarstva nauke Republike Srbije, br. 172063]

Densities data of n-hexane, toluene and dichloromethane at temperatures 288.15-413.15 K and at pressures 0.1-60 MPa, determined in our previous work, were fitted to the modified Tait equation of state. The fitted temperature-pressure dependent density data were used to calculate the derived properties: the isothermal compressibility, the isobaric thermal expansivity, the difference between specific heat capacity at constant pressure and at constant volume and the internal pressure, over the entire temperature and pressure intervals specified above. In order to assess the proposed modeling procedure, a comparison of the obtained values for the isothermal compressibility and the isobaric thermal expansivity with the corresponding literature data were performed. The average absolute percentage deviations for isothermal compressibility were: for n-hexane 2.01-3.64%, for toluene 0.64-2.48% and for dichloromethane 1.81-3.20%; for the isobaric thermal expansivity: for n-hexane 1.31-4.17%, for toluene 0.71-2.45% and for dichloromethane 1.16-1.61%. By comparing the obtained deviations values with those found in the literature it can be concluded that the presented results agree good with the literature data. [Projekat Ministarstva nauke Republike Srbije, br. 172063]

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]

In this work an apparatus for density measurements in the compressed liquid regions was presented. This installation is based on the use of the DMA HP density measuring cell and the DMA 5000 densimeter (both instruments are products of Anton Paar, Gratz, Austria). Calibration of DMA HP cell was performed by applying the classical method where a vacuum, water and n-decane were recommended to be used as calibration fluids. To test the capabilities of the set-up, the densities of n-hexane, toluene and dichloromethane were measured in the temperature interval 288.15 to 413.15 K and the pressure range 0.1-60 MPa. The obtained results were compared with the corresponding values found in the literature. Depending on the literature selected for comparison (the temperature and pressure ranges available) the average absolute percentage deviations were: for n-hexane 0.03-0.10%; for toluene 0.04-0.08% and for dichloromethane 0.02-0.03%. A deeper insight into the results of this work shows that most of them are in a good agreement with the literature values; higher discrepancies are remarked in the vicinity of the ends of the temperature and pressure ranges. [Projekat Ministarstva nauke Republike Srbije, br. 172063]

Viscosities and refractive indices of three binary systems, acetone+1-propanol, acetone+1,2-propanediol and acetone+1,3-propanediol, were measured at eight temperatures (288.15, 293.15, 298.15, 303.15, 308.15, 313.15, 318.15, 323.15)K and at atmospheric pressure. From these data viscosity deviations and deviations in refractive index were calculated and fitted to the Redlich-Kister equation. The viscosity modelling was done by two types of models: predictive UNIFAC-VISCO and ASOG VISCO and correlative Teja-Rice and McAlister equations. The refractive indices of binary mixtures were predicted by various mixing rules and compared with experimental data. [Projekat Ministarstva nauke Republike Srbije, br. 172063]

The excess molar volumes of twenty two binary mixtures containing various groups of organic compounds: alcohols (ethanol, 1-propanol, 1,2-propanediol, 1,3-propanediol and glycerol), ketone (acetone), ester (butyl lactate), lactam (N-methyl-2-pyrrolidone), PEGs (PEG 200, PEG 400) and aromatics (benzene, toluene and pyridine) were predicted from the refractive index data, using three types of equations coupled with several mixing rules for refractive index calculations: the Lorentz-Lorenz, Dale-Gladstone, Eykman, Arago-Biot, Newton, and Oster. The obtained results were analysed in terms of the applied equation and mixing rule and the nature of interactions between the mixtures’ components. [Projekat Ministarstva nauke Republike Srbije, br. 172063]

Densities, refractive indices and viscosities of the binary mixtures of dimethyl phthalate (or dimethyl adipate) + tetrahydrofuran have been measured at eight temperatures (288.15 to 323.15 K) and atmospheric pressure. All measurements were performed using an Anton Paar DMA 5000 digital vibrating-tube densimeter, Anton Paar RXA 156 refractometer and Anton Paar SVM 3000/G2 digital Stabinger viscometer, respectively. From the experimental densities, refractive indices and viscosities, the excess molar volumes, VE, deviations of refractive indices, DnD, and viscosity deviations, Dh, were calculated. [Projekat Ministarstva nauke Republike Srbije, br. 172063]

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, ηE, excess free energies of activation of a viscous flow,

In our previous review an attempt has been made to relate the volumetric effects involved in the binary mixtures of normal and branched alcohols. This paper summarized some selected research activities of various authors related to complex molecular structure appearing in leading international journals. The main aim was better understanding of complex structure of different non-electrolyte mixtures with no alcohols, which are the most frequently present in chemical, petrochemical and related industries. The influence of the basic physical, chemical and structural effects of considerably chosen type of various binary and ternary mixtures was analyzed. These contributions are of primary importance for determination and modelling of thermodynamic, transport and other properties. [Projekat Ministarstva nauke Republike Srbije, br. 172063]

An attempt has been made to relate the volumetric effects involved in the binary mixtures of normal and branched alcohols and various components (aromatics, halo and nitroaromatics and haloaliphatics) with the molecular interactions of unlike molecules. This review is a condensation of research activities developed in recent years as results of a better understanding of volumetric behavior and a stronger insight into the complex structure of those mixtures. The influence of important contributions of a physical, chemical and geometrical nature that change excess molar volume, VE (positive, sigmoidal, negative) is considered and explained in detail. It appears that the balance between these contributions is quite sensitive to the behavior of the alcohol molecules in contact with the chosen compounds.

Densities of binary mixtures of 1-propanol, or 2-butanol, or 1-pentanol + cyclohexylamine were measured at temperatures from 288.15 to 313.15 K and atmospheric pressure, while the densities for the system 2-methyl-2-propanol + cyclohexylamine were measured at temperatures from 303.15 to 323.15 K and atmospheric pressure. All measurements were performed using an Anton Paar DMA 5000 digital vibrating-tube densimeter. From the experimental densities, the excess molar volumes, VE, were calculated.

Although many cubic equations of state coupled with van der Waals-one fluid mixing rules including temperature dependent interaction parameters are sufficient for representing phase equilibria and excess properties (excess molar enthalpy HE, excess molar volume VE, etc.), difficulties appear in the correlation and prediction of thermodynamic properties of complex mixtures at various temperature and pressure ranges. Great progress has been made by a new approach based on CEOS/GE models. This paper reviews the last six-year of progress achieved in modelling of the volumetric properties for complex binary and ternary systems of non-electrolytes by the CEOS and CEOS/GE approaches. In addition, the vdW1 and TCBT models were used to estimate the excess molar volume VE of ternary systems methanol + chloroform + benzene and 1-propanol + chloroform + benzene, as well as the corresponding binaries methanol + chloroform, chloroform + benzene, 1-propanol + chloroform and 1-propanol + benzene at 288.15-313.15 K and atmospheric pressure. Also, prediction of VE for both ternaries by empirical models (Radojković, Kohler, Jackob-Fitzner, Colinet, Tsao-Smith, Toop, Scatchard, Rastogi) was performed.

The simultaneous correlation of VLE and excess properties (HE, cPE) for diether + n-alkane systems was performed in our previous paper by the cubic equation of state which incorporates the activity coefficient model (CEOS/GE).With the same aim, in the present work, a completely different approach based on a polynomial equation (Kohler model) was considered. This method gave results on the same systems which could be estimated as being comparable to GEOS/GE models for the simultaneous correlation of two and with considerably improved fits, of three properties.

The NpT - Gibbs ensemble Monte Carlo computer simulation method was applied to predict the vapour-liquid equilibrium (VLE) behavior of the binary systems ethane + pentane at 277.55 K and 310.95 K, ethane + hexane at 298.15 K, propane + methanol at 313.15 K and propane + ethanol at 325.15 K and 425.15 K. The optimized potentials for the liquid simulating (OPLS) model were used to describe the interactions of alkanes and alcohols. The simulated VLE predictions are compared with experimental data available for the pressure and phase composition of the analyzed binary systems. The agreement between the experimental data and the simulation results is found to be generally good, although slightly better for system in which both components were nonpolar.