A. Shariati - Academia.edu (original) (raw)
Papers by A. Shariati
One of the main reactions that can be used to reduce greenhouse gases emissions is Reverse Water ... more One of the main reactions that can be used to reduce greenhouse gases emissions is Reverse Water Gas Shift (RWGS) reaction. Through this reaction CO2 is converted to CO to produce beneficial chemicals such as methanol. In this paper Mo/Al2O3 catalyst was prepared and then promoted with Ni ions through impregnation method to produce Ni-Mo/Al2O3 catalyst. The structures of the catalysts were studied using XRD, XRF and TEM techniques. Activity, selectivity and stability of both catalysts were investigated in a batch reactor and the results indicate that addition of Ni promoter to Mo/Al2O3 catalyst increased its activity and CO selectivity. Ni-Mo/Al2O3 showed acceptable catalytic stability during RWGS reaction. As a whole Ni-Mo/Al2O3 can be a suitable candidate for methanol production process from CO2 using RWGS reaction. [A. Gharibi Kharaji, A. Shariati. Selectivity and Performance of Ni-Mo/γ-Al2O3 Catalyst for Methanol Production with Reverse Water Gas Shift (RWGS) Reaction. J Am Sci ...
Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2016
ABSTRACT Dimethyl ether is a clean and economical fuel alternative for petrodiesel. It can also b... more ABSTRACT Dimethyl ether is a clean and economical fuel alternative for petrodiesel. It can also be used as a substitute for chlorofluorocarbons and propellant sprays. As a chemical intermediate, it can be used to produce gasoline, ethylene, and other aromatic chemicals. In the present study, dehydration of methanol to dimethyl ether was investigated in an adiabatic fixed bed flow microreactor using the nanosize synthesized zeolite catalyst (H-ZSM-5) with hydrothermal crystallization method at different operating conditions. The structure of the synthesized zeolite catalyst was studied using X-ray diffraction, NH3-temperature programmed desorption, scanning electron microscopy, and Brunauer-Emmett-Teller techniques. The synthesized catalyst with silica to aluminum ratio of 67.7 showed high crystallinity and high surface area. The activity test also showed that the maximum yield of reaction was observed at a temperature range of 240 to 250○C and weight hourly space velocity of 15 h−1. At a temperature above 270○C more by-products were produced.
Industrial & Engineering Chemistry Research, 2016
Turbulent nonpremixed combustion of rapeseed methyl ester (RME) in a free shear swirl air flow wa... more Turbulent nonpremixed combustion of rapeseed methyl ester (RME) in a free shear swirl air flow was modeled by solving the governing conservation equations of mass, momentum, energy, and equations representing the droplet breakup, dispersion, movements, vaporization, and the combustion (i.e., formation, reaction and transport of gaseous species) and then validated via experimentations. A surrogate combustion mechanism for RME including 419 reactions and 101 species was employed for handling the combustion chemistry. The flamelet concept is used to relate the instantaneous composition of gaseous species to the mixture fraction. The turbulent gas mixture velocity across the flame was numerically resolved by Reynold Average Navier–Stokes (RANS) and the turbulence fluctuations of scalar variables (i.e., mixture fraction, heat loss, and scalar dissipation) is averaged and taken into account by weighting with an assumed shape probability density function (PDF). The heat radiation was modeled via discrete ordinat...
Chemical Engineering & Technology
Petroleum Science and Technology
Chemical Engineering Journal
Chemical Engineering Research and Design
International Journal of Hydrogen Energy
Clean Technologies and Environmental Policy
Journal of Dispersion Science and Technology
Chemical Engineering & Technology
Energy Sources, Part A: Recovery, Utilization, and Environmental Effects
Chemical Product and Process Modeling
The kinetics study, modeling, simulation and optimization of water gas shift reaction were perfor... more The kinetics study, modeling, simulation and optimization of water gas shift reaction were performed in a catalytic fixed bed reactor. The renowned empirical power law rate model was used as rate equation and fitted to experimental data to estimate the kinetics parameters using gPROMS. A good fit between predicted and experimental CO conversion data was obtained. The validity of the kinetic model was then checked by simulation of plug flow reactor which shows a good agreement between experimental and predicted values of the reaction rate. Subsequently, considering axial dispersion, a homogeneous model was developed for simulation of the water-gas shift reactor. The simulation results were also validated by checking the pressure drop of the reactor as well as the mass concentration at equilibrium. Finally, a multi-objective optimization was conducted for water-gas shift reaction in order to maximize hydrogen formation and carbon monoxide conversion, whereas the reactor volume to be m...
Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2015
ABSTRACT Biodiesel, also known as a biofuel usually produced from vegetable oil, has a potential ... more ABSTRACT Biodiesel, also known as a biofuel usually produced from vegetable oil, has a potential to replace petroleum biodiesel partially or totally. Currently, a question is being raised whether biodiesel has the properties like diesel fuel and if it is well nominated for diesel replacement. This study intends to compare the properties of methyl ester (biodiesel) of soy bean, sunflower, corn, rice bran, olive, and grape seed together and with petroleum-based diesel fuel in order to investigate whether biodiesels with different vegetable oil origins are good candidates for diesel replacement in the near future. In this study, biodiesels are made through alkali-based transesterification with methanol and potassium hydroxide. Properties, such as specific gravity, viscosity, gross heating value, Cetane number, and flash point, are obtained with distinct ASTM standards. Results state that, except for viscosity, other properties of biodiesels and diesel fuel are comparable to each other.
Journal of Molecular Liquids, 2016
One of the main reactions that can be used to reduce greenhouse gases emissions is Reverse Water ... more One of the main reactions that can be used to reduce greenhouse gases emissions is Reverse Water Gas Shift (RWGS) reaction. Through this reaction CO2 is converted to CO to produce beneficial chemicals such as methanol. In this paper Mo/Al2O3 catalyst was prepared and then promoted with Ni ions through impregnation method to produce Ni-Mo/Al2O3 catalyst. The structures of the catalysts were studied using XRD, XRF and TEM techniques. Activity, selectivity and stability of both catalysts were investigated in a batch reactor and the results indicate that addition of Ni promoter to Mo/Al2O3 catalyst increased its activity and CO selectivity. Ni-Mo/Al2O3 showed acceptable catalytic stability during RWGS reaction. As a whole Ni-Mo/Al2O3 can be a suitable candidate for methanol production process from CO2 using RWGS reaction. [A. Gharibi Kharaji, A. Shariati. Selectivity and Performance of Ni-Mo/γ-Al2O3 Catalyst for Methanol Production with Reverse Water Gas Shift (RWGS) Reaction. J Am Sci ...
Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2016
ABSTRACT Dimethyl ether is a clean and economical fuel alternative for petrodiesel. It can also b... more ABSTRACT Dimethyl ether is a clean and economical fuel alternative for petrodiesel. It can also be used as a substitute for chlorofluorocarbons and propellant sprays. As a chemical intermediate, it can be used to produce gasoline, ethylene, and other aromatic chemicals. In the present study, dehydration of methanol to dimethyl ether was investigated in an adiabatic fixed bed flow microreactor using the nanosize synthesized zeolite catalyst (H-ZSM-5) with hydrothermal crystallization method at different operating conditions. The structure of the synthesized zeolite catalyst was studied using X-ray diffraction, NH3-temperature programmed desorption, scanning electron microscopy, and Brunauer-Emmett-Teller techniques. The synthesized catalyst with silica to aluminum ratio of 67.7 showed high crystallinity and high surface area. The activity test also showed that the maximum yield of reaction was observed at a temperature range of 240 to 250○C and weight hourly space velocity of 15 h−1. At a temperature above 270○C more by-products were produced.
Industrial & Engineering Chemistry Research, 2016
Turbulent nonpremixed combustion of rapeseed methyl ester (RME) in a free shear swirl air flow wa... more Turbulent nonpremixed combustion of rapeseed methyl ester (RME) in a free shear swirl air flow was modeled by solving the governing conservation equations of mass, momentum, energy, and equations representing the droplet breakup, dispersion, movements, vaporization, and the combustion (i.e., formation, reaction and transport of gaseous species) and then validated via experimentations. A surrogate combustion mechanism for RME including 419 reactions and 101 species was employed for handling the combustion chemistry. The flamelet concept is used to relate the instantaneous composition of gaseous species to the mixture fraction. The turbulent gas mixture velocity across the flame was numerically resolved by Reynold Average Navier–Stokes (RANS) and the turbulence fluctuations of scalar variables (i.e., mixture fraction, heat loss, and scalar dissipation) is averaged and taken into account by weighting with an assumed shape probability density function (PDF). The heat radiation was modeled via discrete ordinat...
Chemical Engineering & Technology
Petroleum Science and Technology
Chemical Engineering Journal
Chemical Engineering Research and Design
International Journal of Hydrogen Energy
Clean Technologies and Environmental Policy
Journal of Dispersion Science and Technology
Chemical Engineering & Technology
Energy Sources, Part A: Recovery, Utilization, and Environmental Effects
Chemical Product and Process Modeling
The kinetics study, modeling, simulation and optimization of water gas shift reaction were perfor... more The kinetics study, modeling, simulation and optimization of water gas shift reaction were performed in a catalytic fixed bed reactor. The renowned empirical power law rate model was used as rate equation and fitted to experimental data to estimate the kinetics parameters using gPROMS. A good fit between predicted and experimental CO conversion data was obtained. The validity of the kinetic model was then checked by simulation of plug flow reactor which shows a good agreement between experimental and predicted values of the reaction rate. Subsequently, considering axial dispersion, a homogeneous model was developed for simulation of the water-gas shift reactor. The simulation results were also validated by checking the pressure drop of the reactor as well as the mass concentration at equilibrium. Finally, a multi-objective optimization was conducted for water-gas shift reaction in order to maximize hydrogen formation and carbon monoxide conversion, whereas the reactor volume to be m...
Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2015
ABSTRACT Biodiesel, also known as a biofuel usually produced from vegetable oil, has a potential ... more ABSTRACT Biodiesel, also known as a biofuel usually produced from vegetable oil, has a potential to replace petroleum biodiesel partially or totally. Currently, a question is being raised whether biodiesel has the properties like diesel fuel and if it is well nominated for diesel replacement. This study intends to compare the properties of methyl ester (biodiesel) of soy bean, sunflower, corn, rice bran, olive, and grape seed together and with petroleum-based diesel fuel in order to investigate whether biodiesels with different vegetable oil origins are good candidates for diesel replacement in the near future. In this study, biodiesels are made through alkali-based transesterification with methanol and potassium hydroxide. Properties, such as specific gravity, viscosity, gross heating value, Cetane number, and flash point, are obtained with distinct ASTM standards. Results state that, except for viscosity, other properties of biodiesels and diesel fuel are comparable to each other.
Journal of Molecular Liquids, 2016