Chemical Engineering
Fateme Beiranvand; Seyed Hesam Najibi; Bahram Hashemi Shahraki
Abstract
A device is designed and constructed for measuring the equilibrium surface tension of water and a number of other solutions. The measured equilibrium surface tension of water, as a reference fluid, has good consistency with literature data. Moreover, the equilibrium surface tension of the aqueous solutions ...
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A device is designed and constructed for measuring the equilibrium surface tension of water and a number of other solutions. The measured equilibrium surface tension of water, as a reference fluid, has good consistency with literature data. Moreover, the equilibrium surface tension of the aqueous solutions of surfactants and polymer composed of sodium dodecyl sulphate (SDS), Triton CG-110, dimethyl di-dodecyl-ammonium bromide (DDAB), and polyethylene glycol (PEG) with different molecular weights of 200, 300, 400, and 600, as well as that of the ternary solutions of SDS/PEG/water, Triton CG-110/PEG/water, and DDAB/PEG/water at 293.15 K and atmospheric pressure are measured. The equilibrium surface tension of the aqueous solutions of PEG 600 are measured at 296.15 K because PEG 600 is solid at 293.15 K. The measured data are compared with the predictions of thermodynamic models, and the results show that Redlich-Kister (RK) model has the lowest error in predicting the experimental data.
Chemical Engineering
Kamalodin Momeni; Hesam Najibi Najibi; Mohammad T. Sadeghi
Abstract
In this work, the performance of four electrolyte models for prediction the osmotic and activity coefficients of different aqueous salt solutions at 298 K, atmospheric pressure and in a wide range of concentrations are evaluated. In two of these models, (electrolyte Non-Random Two-Liquid e-NRTL and Mean ...
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In this work, the performance of four electrolyte models for prediction the osmotic and activity coefficients of different aqueous salt solutions at 298 K, atmospheric pressure and in a wide range of concentrations are evaluated. In two of these models, (electrolyte Non-Random Two-Liquid e-NRTL and Mean Spherical Approximation-Non-Random Two-Liquid MSA-NRTL), association between ions of opposite charges for simplification purposes is ignored and in the other two ones, (Associative Mean Spherical Approximation-Non-Random Two-Liquid AMSA-NRTL and Binding Mean Spherical Approximation BiMSA) association and solvation effects are considered. The predictions of these four models for the osmotic and activity coefficients of electrolyte solutions at 298 K and atmospheric pressure are compared with the experimental data reported in the literature. This comparison includes, 28 different aqueous salt solutions including thio-cyanates, perchlorates, nitrates, hydroxides, quaternary ammonium salts and others. The results show, the performance of models that consider association effects are better than others especially for higher salt concentrations. However, the best performance belongs to BiMSA model which has some parameters with physical meaning.
Seyed Hesam Najibi; Hamid Darabi; Mohammad Javad Kamali
Abstract
Recently, due to the very good market in ethane as a feedstock for petrochemical complexes, there are some plans to make a deep ethane recovery from the gases produced in Iran southern fields. In this work, the feasibility of different technologies for deep ethane recovery from a specified feed gas produced ...
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Recently, due to the very good market in ethane as a feedstock for petrochemical complexes, there are some plans to make a deep ethane recovery from the gases produced in Iran southern fields. In this work, the feasibility of different technologies for deep ethane recovery from a specified feed gas produced in one of the Iran southern fields is reviewed. Three different processes are selected and simulated for the specified feed gas. These processes are compared from technical and economic viewpoints and the advantages and disadvantages are discussed. The results show that RSV and CRR processes are technically more feasible for high levels of ethane recovery (greater than 95%). The economic evaluations show that the CRR process is the most appropriate one for the feed gas specified in this study.
