Ali Mohsenipour - Academia.edu (original) (raw)

Papers by Ali Mohsenipour

The Canadian Journal of Chemical Engineering

Russian Journal of Physical Chemistry A, 2015

In this work, we identify a simple method for predicting transport properties of fluids over wide... more In this work, we identify a simple method for predicting transport properties of fluids over wide ranges of temperatures and pressure. In this respect, the capability of several equations of state (EOS) and second virial coefficient correlations to predict transport properties of fluids including carbon dioxide, methane and argon using modified Enskog theory (MET) is investigated. The transport properties in question are viscosity and thermal conductivity. The results indicate that the SRK EOS employed in the modified Enskog theory outperforms other equations of state. The average absolute deviation was found to be 12.2 and 18.5% for, respectively, the calculated thermal conductivity and viscosity using the MET.

Journal of Molecular Liquids, 2016

A molecular thermodynamic-based approach has been previously employed to correlate the surface te... more A molecular thermodynamic-based approach has been previously employed to correlate the surface tension of ionic liquids (ILs). This paper aims to calculate further property of ILs, the solubility parameter of 27 ILs having imidazolium, pyrrolidinium, pyridinium, phosphonium, piperidinium and ammonium cations by the help of that approach along with an ion contribution-based equation of state (EOS). The proposed model calculates the internal pressure of ILs using a statistical mechanical expression and subsequently their solubility parameters through a simple relation. In this respect, contributions to internal pressure from the hard-sphere repulsion, Lennard-Jones dispersion force, and columbic interactions are considered and assumed to be additive in the development of the model. The performance of the proposed model is checked against the literature solubility parameters of ILs over temperature range within 298-358 K. The proposed model has a sound basis of statistical-mechanics which incorporates contributions arising from the hard-sphere repulsion, Lennard-Jones dispersion forces. Further, the electrostatic interaction is taken into account using the mean spherical approximation (MSA). The outcomes of our model are also compared with those obtained based on the vaporization enthalpies and molar volumes, for which their values are available in literature. Generally, the new molecular model represents accurately the solubility parameters of studied ILs with uncertainty of the order of ±2.33%. The miscibility of some non-polar and polar hydrocarbons in ILs is also investigated by the use of their solubility parameters and Flory-Huggins interaction parameter.

lthough extensive research work has been carried out on the drag reduction behavior of polymers a... more lthough extensive research work has been carried out on the drag reduction behavior of polymers and surfactants alone, little progress has been made on the synergistic effects of combined polymers and surfactants. A number of studies have demonstrated that certain types of polymers and surfactants interact with each other to form surfactant-polymer complexes. The formation of such complexes can cause changes in the solution properties and may result in better drag reduction characteristics as compared with pure additives. A series of drag-reducing surfactants and polymers were screened for the synergistic studies. The following two widely used polymeric drag reducing agents (DRA) were chosen: a copolymer of acrylamide and sodium acrylate (referred to as PAM) and polyethylene oxide (PEO). Among the different types of surfactants screened, a cationic surfactant octadecyltrimethylammonium chloride (OTAC) and an anionic surfactant Sodium dodecyl sulfate (SDS) were selected for the syner...

Computer Methods and Programs in Biomedicine

Journal of Energy Resources Technology

In this paper, a new compositional mechanistic wellbore model, including gas lifting parameters, ... more In this paper, a new compositional mechanistic wellbore model, including gas lifting parameters, is presented. In the governing equations of this model, new terms for mass transfer between phases and the enthalpy of phase change, which are important in non-isothermal gas lift systems, have been considered. These terms have been ignored in some recent research studies and subsequent results show that by ignoring them, serious errors may arise. In the current research study, using a mechanistic drift-flux approach, the pressure distribution in a wellbore was modeled. To verify the new simulator, the results were compared with those of commercial simulators. They were also verified against the phase behavior analysis of the fluid flowing in the wellbore. In addition, in order to show the novel aspects of the new simulator, the results of the presented simulator were compared with the results of a recently proposed model found in the literature. It was concluded that neglecting phase ch...

Noncentral indefinite quadratic expressions in possibly non-singular normal vectors are represent... more Noncentral indefinite quadratic expressions in possibly non-singular normal vectors are represented in terms of the difference of two positive definite quadratic forms and an independently distributed linear combination of standard normal random variables. This result also ap-plies to quadratic forms in singular normal vectors for which no general representation is currently available. The distribution of the positive definite quadratic forms involved in the representations is approximated by means of gamma-type distributions. We are also considering general ratios of quadratic forms, as well as ratios whose denominator involves an idempotent matrix and ratios for which the quadratic form in the denominator is positive definite. Additionally, an approximation to the density of ratios of quadratic expressions in singular normal vectors is being proposed. The results are applied to the Durbin-Watson statistic and Burg's estimator, both of which are expressible as ratios of quadrat...

Handbook of Surface and Colloid Chemistry, Fourth Edition, 2015

Industrial & Engineering Chemistry Research, 2013

Heat and Mass Transfer, 2009

It is the purpose of this paper to extract unlike intermolecular potential energies of five carbo... more It is the purpose of this paper to extract unlike intermolecular potential energies of five carbon dioxidebased binary gas mixtures including CO 2-He, CO 2-Ne, CO 2-Ar, CO 2-Kr, and CO 2-Xe from viscosity data and compare the calculated potentials with other models potential energy reported in literature. Then, dilute transport properties consisting of viscosity, diffusion coefficient, thermal diffusion factor, and thermal conductivity of aforementioned mixtures are calculated from the calculated potential energies and compared with literature data. Rather accurate correlations for the viscosity coefficient of afore-cited mixtures embracing the temperature range 200 K \ T \ 3273.15 K is reproduced from the present unlike intermolecular potentials energy. Our estimated accuracies for the viscosity are to within ±2%. In addition, the calculated potential energies are used to present smooth correlations for other transport properties. The accuracies of the binary diffusion coefficients are of the order of ±3%. Finally, the unlike interaction energy and the calculated low density viscosity have been employed to calculate high density viscosities using Vesovic-Wakeham method. List of symbols A* Ratio of collision integrals a D Constant a a Constant a g Constant a k Constant B* Ratio of collision integrals b Impact parameter (m) b D Constant b a Constant b g Constant b k Constant C* Ratio of collision integrals c D Constant c a Constant c g Constant D ij Binary diffusion coefficient (m 2 /s) d a Constant d g Constant d k Constant E* Ratio of collision integrals e a Constant F* Ratio of collision integrals f D Higher order correction factor for the diffusion f a Constant f g Higher order correction factor for the viscosity G Inversion function h Plank's constant (Js) k Boltzman constant (J/K) k T

Fuel Processing Technology, 2014

ABSTRACT Flotation and leaching methods were used to remove ash and sulfur from bitumen by sulfur... more ABSTRACT Flotation and leaching methods were used to remove ash and sulfur from bitumen by sulfuric acid. The bitumen samples had sulfur content of 9.6% (6.74% in the pyrite sulfur form) and 30% ash. All the experiments were done under aeration rate of 4 L/min using pine oil and gasoline as frother and collector agents, respectively. The factors studied were including the amounts of collector and frother agents, pH, solid weight percentage in the pulp, stirrer speed, and particle size. The bitumen samples with dimensions less than 0.5 mm were crushed. The flotation experiments were performed in a 3-L Denver laboratory flotation cell to ease the ash and sulfur removal. The optimum condition for plant operation were; foaming (50 gr/t), collector (1 kg/t), impeller speed of 1200 rpm, pH = 7, pulp containing 5% of solid, particle size of 100 mesh, and flotation time of 3 min. In these circumstances, 52.9% of pyrite sulfur (e.g.; 36.45% of total sulfur) and 43% of ash were removed. With the approach of leaching using sulfuric acid, the organic and pyrite sulfur removal were 7% and 13%, respectively. Combination of these two methods (in optimal conditions), removed up to 47% of the total sulfur and 61% of ash through bitumen sample. In the next step of study Artificial Neural Networks (ANN) was employed to model the ash and sulfur removals data obtained by flotation method. A network consisting of two layers of six and nine neurons in the hidden layer were considered. Meanwhile learning algorithm Levenberg–Marquardt (LM) was used. In neural network models “Tansig” and “Purelin”, transfer functions for hidden and output layers were applied, respectively. Very low error in the network estimation confirmed validity of the obtained networks for further analysis and optimization. Moreover, process optimization were carried out by using ANN to predict the best operating conditions, which resulted in the maximum percentage of ash and pyrite sulfur removal from bitumen. The maximum percentage of ash was estimated by ANN to be 42.39% under the following operational conditions; foaming amount of 50.5gr/t, the collector amount of 1.12 kg/t, impeller speed of 1200 rpm, pH = 7.5, pulp equal to 5% of solid, particle size of 110 mesh, and flotation time of 3 min. The maximum percentage of pyrite sulfur removal was estimated by ANN to be 52.15% under the following operational conditions; foaming amount of 50gr/t, the collector amount of 1.4 kg/t, impeller speed of 1200 rpm, pH = 7, pulp equal to 5% of solid, particle size of 100 mesh, and flotation time of 3 min.

Energy & Fuels, 2011

“Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted... more “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to ...

Chemical Engineering Communications, 2013

The Canadian Journal of Chemical Engineering, 2013

Turbulent drag reduction behaviour of a mixed nonionic polymer/cationic surfactant system was stu... more Turbulent drag reduction behaviour of a mixed nonionic polymer/cationic surfactant system was studied in a pipeline flow loop to explore the synergistic effects of polymeric and surfactant drag reducing additives. The nonionic polymer used was polyethylene oxide (PEO) at three different concentrations (500, 1000, and 2000 ppm). The surfactant used was cationic octadecyltrimethylammonium chloride (OTAC) at concentration levels of 1000 and 2500 ppm. Sodium salicylate (NaSal) was used as a counter-ion for the surfactant at a molar ratio of 2 (MR = Salt/OTAC = 2). Relative viscosity and surface tension were measured for different combinations of PEO and OTAC. While the relative viscosities demonstrated a week interaction between the polymer and the surfactant, the surface tension measurements exhibited negligible interaction. The pipeline results show a considerable synergistic effect, that is, the mixed polymer-surfactant system gives a significantly higher drag reduction (lower friction factors) as compared with pure polymer or pure surfactant. The addition of surfactant to the polymer always enhances drag reduction. However, the synergistic effect in mixed system is stronger at low polymer concentrations and high surfactant concentrations.

The Canadian Journal of Chemical Engineering, 2013

Although extensive research work has been carried out on the drag reduction (DR) behaviour of pol... more Although extensive research work has been carried out on the drag reduction (DR) behaviour of polymers and surfactants alone, little progress has been made on the synergistic effects of combined polymers and surfactants. In this work, the interactions between drag-reducing anionic polymer (copolymer of acrylamide and sodium acrylate, referred to as PAM) and drag-reducing cationic surfactant (octadecyltrimethylammonium chloride, OTAC) are studied. Solutions are prepared using both deionised (DI) water and tap water. The measurement of the physical properties such as electrical conductivity and viscosity are used to determine the surfactant-polymer interactions. The addition of surfactant to the polymer solution has a significant effect on the properties of the system. The critical micelle concentration (CMC) of the mixed surfactant-polymer system is found to be different from that of the surfactant alone. With the addition of surfactant to a polymer solution, a substantial decrease in the viscosity occurs. The observed changes in the viscosity of mixed polymer-surfactant system are explained in terms of the changes in the extension of polymeric chains, resulting from polymer-surfactant interactions. The anionic PAM chains tend to collapse upon the addition of cationic OTAC. The pipeline flow behaviour of PAM/OTAC mixtures is found to be consistent with the bench scale results. The DR ability of PAM is reduced upon the addition of OTAC. At low concentrations of PAM, the effect of OTAC on the DR behaviour is more pronounced. The DR behaviour of polymer solutions is strongly influenced by the nature of water (DI or tap).

The Canadian Journal of Chemical Engineering

Russian Journal of Physical Chemistry A, 2015

In this work, we identify a simple method for predicting transport properties of fluids over wide... more In this work, we identify a simple method for predicting transport properties of fluids over wide ranges of temperatures and pressure. In this respect, the capability of several equations of state (EOS) and second virial coefficient correlations to predict transport properties of fluids including carbon dioxide, methane and argon using modified Enskog theory (MET) is investigated. The transport properties in question are viscosity and thermal conductivity. The results indicate that the SRK EOS employed in the modified Enskog theory outperforms other equations of state. The average absolute deviation was found to be 12.2 and 18.5% for, respectively, the calculated thermal conductivity and viscosity using the MET.

Journal of Molecular Liquids, 2016

A molecular thermodynamic-based approach has been previously employed to correlate the surface te... more A molecular thermodynamic-based approach has been previously employed to correlate the surface tension of ionic liquids (ILs). This paper aims to calculate further property of ILs, the solubility parameter of 27 ILs having imidazolium, pyrrolidinium, pyridinium, phosphonium, piperidinium and ammonium cations by the help of that approach along with an ion contribution-based equation of state (EOS). The proposed model calculates the internal pressure of ILs using a statistical mechanical expression and subsequently their solubility parameters through a simple relation. In this respect, contributions to internal pressure from the hard-sphere repulsion, Lennard-Jones dispersion force, and columbic interactions are considered and assumed to be additive in the development of the model. The performance of the proposed model is checked against the literature solubility parameters of ILs over temperature range within 298-358 K. The proposed model has a sound basis of statistical-mechanics which incorporates contributions arising from the hard-sphere repulsion, Lennard-Jones dispersion forces. Further, the electrostatic interaction is taken into account using the mean spherical approximation (MSA). The outcomes of our model are also compared with those obtained based on the vaporization enthalpies and molar volumes, for which their values are available in literature. Generally, the new molecular model represents accurately the solubility parameters of studied ILs with uncertainty of the order of ±2.33%. The miscibility of some non-polar and polar hydrocarbons in ILs is also investigated by the use of their solubility parameters and Flory-Huggins interaction parameter.

lthough extensive research work has been carried out on the drag reduction behavior of polymers a... more lthough extensive research work has been carried out on the drag reduction behavior of polymers and surfactants alone, little progress has been made on the synergistic effects of combined polymers and surfactants. A number of studies have demonstrated that certain types of polymers and surfactants interact with each other to form surfactant-polymer complexes. The formation of such complexes can cause changes in the solution properties and may result in better drag reduction characteristics as compared with pure additives. A series of drag-reducing surfactants and polymers were screened for the synergistic studies. The following two widely used polymeric drag reducing agents (DRA) were chosen: a copolymer of acrylamide and sodium acrylate (referred to as PAM) and polyethylene oxide (PEO). Among the different types of surfactants screened, a cationic surfactant octadecyltrimethylammonium chloride (OTAC) and an anionic surfactant Sodium dodecyl sulfate (SDS) were selected for the syner...

Computer Methods and Programs in Biomedicine

Journal of Energy Resources Technology

In this paper, a new compositional mechanistic wellbore model, including gas lifting parameters, ... more In this paper, a new compositional mechanistic wellbore model, including gas lifting parameters, is presented. In the governing equations of this model, new terms for mass transfer between phases and the enthalpy of phase change, which are important in non-isothermal gas lift systems, have been considered. These terms have been ignored in some recent research studies and subsequent results show that by ignoring them, serious errors may arise. In the current research study, using a mechanistic drift-flux approach, the pressure distribution in a wellbore was modeled. To verify the new simulator, the results were compared with those of commercial simulators. They were also verified against the phase behavior analysis of the fluid flowing in the wellbore. In addition, in order to show the novel aspects of the new simulator, the results of the presented simulator were compared with the results of a recently proposed model found in the literature. It was concluded that neglecting phase ch...

Noncentral indefinite quadratic expressions in possibly non-singular normal vectors are represent... more Noncentral indefinite quadratic expressions in possibly non-singular normal vectors are represented in terms of the difference of two positive definite quadratic forms and an independently distributed linear combination of standard normal random variables. This result also ap-plies to quadratic forms in singular normal vectors for which no general representation is currently available. The distribution of the positive definite quadratic forms involved in the representations is approximated by means of gamma-type distributions. We are also considering general ratios of quadratic forms, as well as ratios whose denominator involves an idempotent matrix and ratios for which the quadratic form in the denominator is positive definite. Additionally, an approximation to the density of ratios of quadratic expressions in singular normal vectors is being proposed. The results are applied to the Durbin-Watson statistic and Burg's estimator, both of which are expressible as ratios of quadrat...

Handbook of Surface and Colloid Chemistry, Fourth Edition, 2015

Industrial & Engineering Chemistry Research, 2013

Heat and Mass Transfer, 2009

It is the purpose of this paper to extract unlike intermolecular potential energies of five carbo... more It is the purpose of this paper to extract unlike intermolecular potential energies of five carbon dioxidebased binary gas mixtures including CO 2-He, CO 2-Ne, CO 2-Ar, CO 2-Kr, and CO 2-Xe from viscosity data and compare the calculated potentials with other models potential energy reported in literature. Then, dilute transport properties consisting of viscosity, diffusion coefficient, thermal diffusion factor, and thermal conductivity of aforementioned mixtures are calculated from the calculated potential energies and compared with literature data. Rather accurate correlations for the viscosity coefficient of afore-cited mixtures embracing the temperature range 200 K \ T \ 3273.15 K is reproduced from the present unlike intermolecular potentials energy. Our estimated accuracies for the viscosity are to within ±2%. In addition, the calculated potential energies are used to present smooth correlations for other transport properties. The accuracies of the binary diffusion coefficients are of the order of ±3%. Finally, the unlike interaction energy and the calculated low density viscosity have been employed to calculate high density viscosities using Vesovic-Wakeham method. List of symbols A* Ratio of collision integrals a D Constant a a Constant a g Constant a k Constant B* Ratio of collision integrals b Impact parameter (m) b D Constant b a Constant b g Constant b k Constant C* Ratio of collision integrals c D Constant c a Constant c g Constant D ij Binary diffusion coefficient (m 2 /s) d a Constant d g Constant d k Constant E* Ratio of collision integrals e a Constant F* Ratio of collision integrals f D Higher order correction factor for the diffusion f a Constant f g Higher order correction factor for the viscosity G Inversion function h Plank's constant (Js) k Boltzman constant (J/K) k T

Fuel Processing Technology, 2014

ABSTRACT Flotation and leaching methods were used to remove ash and sulfur from bitumen by sulfur... more ABSTRACT Flotation and leaching methods were used to remove ash and sulfur from bitumen by sulfuric acid. The bitumen samples had sulfur content of 9.6% (6.74% in the pyrite sulfur form) and 30% ash. All the experiments were done under aeration rate of 4 L/min using pine oil and gasoline as frother and collector agents, respectively. The factors studied were including the amounts of collector and frother agents, pH, solid weight percentage in the pulp, stirrer speed, and particle size. The bitumen samples with dimensions less than 0.5 mm were crushed. The flotation experiments were performed in a 3-L Denver laboratory flotation cell to ease the ash and sulfur removal. The optimum condition for plant operation were; foaming (50 gr/t), collector (1 kg/t), impeller speed of 1200 rpm, pH = 7, pulp containing 5% of solid, particle size of 100 mesh, and flotation time of 3 min. In these circumstances, 52.9% of pyrite sulfur (e.g.; 36.45% of total sulfur) and 43% of ash were removed. With the approach of leaching using sulfuric acid, the organic and pyrite sulfur removal were 7% and 13%, respectively. Combination of these two methods (in optimal conditions), removed up to 47% of the total sulfur and 61% of ash through bitumen sample. In the next step of study Artificial Neural Networks (ANN) was employed to model the ash and sulfur removals data obtained by flotation method. A network consisting of two layers of six and nine neurons in the hidden layer were considered. Meanwhile learning algorithm Levenberg–Marquardt (LM) was used. In neural network models “Tansig” and “Purelin”, transfer functions for hidden and output layers were applied, respectively. Very low error in the network estimation confirmed validity of the obtained networks for further analysis and optimization. Moreover, process optimization were carried out by using ANN to predict the best operating conditions, which resulted in the maximum percentage of ash and pyrite sulfur removal from bitumen. The maximum percentage of ash was estimated by ANN to be 42.39% under the following operational conditions; foaming amount of 50.5gr/t, the collector amount of 1.12 kg/t, impeller speed of 1200 rpm, pH = 7.5, pulp equal to 5% of solid, particle size of 110 mesh, and flotation time of 3 min. The maximum percentage of pyrite sulfur removal was estimated by ANN to be 52.15% under the following operational conditions; foaming amount of 50gr/t, the collector amount of 1.4 kg/t, impeller speed of 1200 rpm, pH = 7, pulp equal to 5% of solid, particle size of 100 mesh, and flotation time of 3 min.

Energy & Fuels, 2011

“Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted... more “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to ...

Chemical Engineering Communications, 2013

The Canadian Journal of Chemical Engineering, 2013

Turbulent drag reduction behaviour of a mixed nonionic polymer/cationic surfactant system was stu... more Turbulent drag reduction behaviour of a mixed nonionic polymer/cationic surfactant system was studied in a pipeline flow loop to explore the synergistic effects of polymeric and surfactant drag reducing additives. The nonionic polymer used was polyethylene oxide (PEO) at three different concentrations (500, 1000, and 2000 ppm). The surfactant used was cationic octadecyltrimethylammonium chloride (OTAC) at concentration levels of 1000 and 2500 ppm. Sodium salicylate (NaSal) was used as a counter-ion for the surfactant at a molar ratio of 2 (MR = Salt/OTAC = 2). Relative viscosity and surface tension were measured for different combinations of PEO and OTAC. While the relative viscosities demonstrated a week interaction between the polymer and the surfactant, the surface tension measurements exhibited negligible interaction. The pipeline results show a considerable synergistic effect, that is, the mixed polymer-surfactant system gives a significantly higher drag reduction (lower friction factors) as compared with pure polymer or pure surfactant. The addition of surfactant to the polymer always enhances drag reduction. However, the synergistic effect in mixed system is stronger at low polymer concentrations and high surfactant concentrations.

The Canadian Journal of Chemical Engineering, 2013

Although extensive research work has been carried out on the drag reduction (DR) behaviour of pol... more Although extensive research work has been carried out on the drag reduction (DR) behaviour of polymers and surfactants alone, little progress has been made on the synergistic effects of combined polymers and surfactants. In this work, the interactions between drag-reducing anionic polymer (copolymer of acrylamide and sodium acrylate, referred to as PAM) and drag-reducing cationic surfactant (octadecyltrimethylammonium chloride, OTAC) are studied. Solutions are prepared using both deionised (DI) water and tap water. The measurement of the physical properties such as electrical conductivity and viscosity are used to determine the surfactant-polymer interactions. The addition of surfactant to the polymer solution has a significant effect on the properties of the system. The critical micelle concentration (CMC) of the mixed surfactant-polymer system is found to be different from that of the surfactant alone. With the addition of surfactant to a polymer solution, a substantial decrease in the viscosity occurs. The observed changes in the viscosity of mixed polymer-surfactant system are explained in terms of the changes in the extension of polymeric chains, resulting from polymer-surfactant interactions. The anionic PAM chains tend to collapse upon the addition of cationic OTAC. The pipeline flow behaviour of PAM/OTAC mixtures is found to be consistent with the bench scale results. The DR ability of PAM is reduced upon the addition of OTAC. At low concentrations of PAM, the effect of OTAC on the DR behaviour is more pronounced. The DR behaviour of polymer solutions is strongly influenced by the nature of water (DI or tap).