توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Liquid–Liquid Equilibria of Binary Polymer Solutions Using a Free–Volume UNIQUAC–NRF Model
نویسنده(ها): ، ، ،
اطلاعات انتشار: نهمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۱۲
In this work, a free–volume model based on the UNIQUAC–NRF model developed by Haghtalab and Asadollahi was proposed. While the combinatorial part of the proposed model for activity coefficient takes the same form as that of the entropic free–volume (entropic–FV) model, the residual part is similar to that of in the UNIQUAC–NRF model. The proposed model, i.e., the FV–UNIQUAC–NRF model overcomes the main
shortcoming of the original UNIQUAC–NRF model in predicting the lower critical solution temperature (LCST) for polymer solutions. The proposed model was applied to correlate the experimental data of Liquid–Liquid Equilibria (LLE) for various binary polymer solutions. The results obtained from the FV–UNIQUAC–NRF model were compared with those obtained from the FV–UNIQUAC model. The results of the proposed model show that the FV–UNIQUAC–NRF model can accurately correlate the experimental data for LLE of polymer solutions studied in this work. Another clear advantage of the proposed model is its capability in predicting the LCST for binary polymer solutions.<\div>

۲Dynamic investigation of solid propellant combustion in a rocket motor chamber
نویسنده(ها): ، ،
اطلاعات انتشار: یازدهمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۱۳
This study considers dynamic investigation of combustion phenomena in a Solid Propellant Rocket Motor (SPRM). Gas dynamic in combustion chamber and effluent nozzle has been studies by solving governing equations (mass, energy and momentum balances). In the modeling, spread of flame and variation of mass added from propellant surface into the gas stream are considered. The governing equations, which were in Euler form, were solved numerically by applying Modified Mac–Carmak method. Pressure, temperature and velocity distributions were found
as a function of time and axial distance. The results were validated by experimental data of a typical rocket motor. Effects of various factors on combustion were evaluated. The proposed model can be easily modified and used for other solid propellants even with low aluminum content.<\div>

۳Solubility of Carbon Dioxide in Benzene, Toluene and normal Heptane at high–pressures
نویسنده(ها): ، ، ،
اطلاعات انتشار: یازدهمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۱۳
The distinguished properties of Supercritical Fluids have been noticed to produce small–sized, nano and micro, particles. One of the most common fluid in such researches has been CO2. It is essential to predict the amount of solubility of CO2 in the solvents which often are industrially used. In this work the amount of solubility of CO2 at high pressures (400–1020 psig) in Benzene, Toluene, normal.Heptane and the mixture of Toluene–normal.Heptanes has been studied. Using the experimental results, the adjustable parameter (Kij) of Peng– Robinson(1976)EOS for each pair of materials has been adjusted. The tests has been done at 20’C and 32.50’C and Kij is adjusted for each pair of CO2–solvent. The maximum error for this adjusted PR–Model is 3.42%. Thus the Adjusted PRModel based on experimental data, can be used in order to predict the solubility of CO2 in those organic solvents. The results have shown that increasing pressure for each system increases the
solubility of CO2 in organic solvent. For the region above than nearly 600 psig the solubility is strictly increased for all the experimented systems; in these regions the composition of liquid phase is mostly CO2.<\div>

۴Correlation and Prediction of Solubility of CO2 in Amine Aqueous Solutions
نویسنده(ها): ، ، ، ، ، ، ، ، ،
اطلاعات انتشار: Iranian Journal of Chemistry and Chemical Engineering (IJCCE)، بيست و نهم،شماره۱(پياپي ۵۳)، ۲۰۱۰، سال
تعداد صفحات: ۱۴
The solubility of CO2 in the primary, secondary, tertiary and sterically hindered amine aqueous solutions at various conditions was studied. In the present work, the Modified Kent–Eisenberg (M–KE), the Extended Debye–Hückel (E–DH) and the Pitzer models were employed to study the solubility of CO2 in amine aqueous solutions. Two explicit equations are presented to evaluate the concentration of H+ as well as the equilibrium constants of protonation reactions for the tertiary and sterically hindered amine aqueous solutions. Using the M–KE model, the equilibrium constants of protonation reactions of amines were correlated in terms of temperature, CO2 partial pressure and amine concentration. Also the E–DH and Pitzer models were used to correlate the solubility of CO2 in MDEA aqueous solution. The binary interaction parameters for the models studied in this work as well as the parameters for the equilibrium constants of protonation reactions were obtained using the Davidon–Fletcher–Powell (DFP) minimization method. The results show that the M–KE, E–DH and the Pitzer models can accurately predict the corresponding experimental data. Although the solubility data for CO2 in amine aqueous solutions have been reported in the literature to a large extent, accurate data are required to model the CO2 absorption process. Therefore, two criteria for the tertiary and sterically hindered amines were presented using the M–KE model to screen the experimental data.

۵Correlation of Viscosity of Aqueous Solutions of Alkanolamine Mixtures Based on the Eyring's Theory and Wong–Sandler Mixing Rule
نویسنده(ها): ، ، ، ، ، ، ،
اطلاعات انتشار: Iranian Journal of Chemistry and Chemical Engineering (IJCCE)، سي و دوم،شماره۲(پياپي ۶۶)، ۲۰۱۳، سال
تعداد صفحات: ۱۰
A viscosity model، based on Eyring’s absolute rate theory combined with a cubic PR equation of state and Wong–Sandler mixing rule، has been proposed in order to correlate viscosities of aqueous solutions of alkanolamine mixtures at atmospheric pressure and different temperatures. In the proposed method، the energy and size parameters in studied Equation of State (EoS) have been obtained using the Wong – Sandler (WS) mixing rule combined with the NRTL and Wilson Gibbs equations. The NRTL and Wilson parameters for aqueous solutions of alkanolamine mixtures have been correlated using measured viscosity data at atmospheric pressure and different temperatures. The overall average deviation between the experimental and calculated viscosities of studied aqueous solutions of alkanolamine mixtures using Wilson model is 0.92%.
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