Materials synthesize and production
Volume 10, Issue 2 , April 2013, , Pages 81-86
Transport Phenomena,
Volume 8, Issue 2 , April 2011, , Pages 81-97
Transport Phenomena,
Volume 7, Issue 3 , July 2010, , Pages 81-87
Separation Technology,
Sh. Houshyar; M. Torab-Mostaedi; S. M. A. Moosavian; Seyed Hamed Mousavi; M. Asadollahzadeh
Volume 14, Issue 3 , August 2017, , Pages 82-95
Abstract
The droplet size distribution in the column is usually represented as the average volume to surface area, known as the Sauter mean drop diameter. It is a key variable in the extraction column design. A study of the drop size distribution and Sauter-mean drop diameter for a liquid-liquid extraction column ...
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The droplet size distribution in the column is usually represented as the average volume to surface area, known as the Sauter mean drop diameter. It is a key variable in the extraction column design. A study of the drop size distribution and Sauter-mean drop diameter for a liquid-liquid extraction column has been presented for a range of operating conditions and three different liquid-liquid systems. The effects of rotor speed, and dispersed and continuous phase velocities on drop size are investigated. Drop size distribution are appropriately described using the normal and log-normal probability density functions. The mathematical approach is used to determine the constant parameters in these functions and to provide the fit of the experimental data with them. and empirical expressions are derived to predict the parameters of the distribution curve as a function of operating variables, and physical properties of the systems. Good agreement between the prediction and experiments was achieved for all investigated operating conditions. An empirical correlation is also proposed to predict the Sauter-mean drop diameter with mean deviation of 9.8%.
Reaction Engineering, Kinetics and Catalysts,
S. A. Hosseini
Volume 14, Issue 2 , 2017, , Pages 83-90
Abstract
Two Cu-Co and Co3O4 oxides were synthesized by the conventional sol-gel auto-combustion and their physical-chemical properties were characterized by XRD, FTIR, SEM, TPR and XPS. The XRD results indicated that copper-cobalt oxide appeared in a mixture form of Cu0.15Co2.85O4 spinel and CuO phases, whereas ...
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Two Cu-Co and Co3O4 oxides were synthesized by the conventional sol-gel auto-combustion and their physical-chemical properties were characterized by XRD, FTIR, SEM, TPR and XPS. The XRD results indicated that copper-cobalt oxide appeared in a mixture form of Cu0.15Co2.85O4 spinel and CuO phases, whereas the cobalt oxide exhibited in the pure form of Co3O4 spinel. The FTIR approved the formation of the spinel structure in the both samples. The SEM results showed that both oxides are as nanoparticles. Application of the same synthesis conditions for both samples let to obtain samples with different purity. The results of temperature program reduction (TPR) revealed that Cu-Co nano oxide is more reducible at lower temperatures. The copper-cobalt oxide exhibited the higher activity that the Co3O4 in catalytic combustion of toluene, which is explained by its higher reducibility at the reaction conditions and by a possible synergistic effect between Cu-Co oxide and CuO particles.
Petroleum and Reservoir Engineering
F. S. Shariatmadar; Sh. Ghanbari Pakdehi; M. A. Zarei
Volume 13, Issue 1 , January 2016, , Pages 84-97
Abstract
Examination of the available ignition delay time data and correlations in the case of methane, butane, heptane, decane, kerosene, Jet-A and ethylene fuels, allowed the derivation and recommendation of standard equations for this property. In this study, a new accurate substance dependent equation for ...
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Examination of the available ignition delay time data and correlations in the case of methane, butane, heptane, decane, kerosene, Jet-A and ethylene fuels, allowed the derivation and recommendation of standard equations for this property. In this study, a new accurate substance dependent equation for ignition delay time as a function of pressure, number of carbon atoms, mixture equivalence ratio, fuel mole fraction and temperature has been developed to estimate ignition delay time of some hydrocarbon fuels. With the presented model, ignition delay time has been calculated and compared with the data reported in literature. The accuracy of the obtained model has been compared to the mostly used predictive models and the comparison indicated that the proposed correlation provides more accurate results than other models used in the previous works.
Reaction Engineering, Kinetics and Catalysts,
Volume 7, Issue 1 , January 2010, , Pages 87-94
Transport Phenomena,
Volume 6, Issue 3 , July 2009, , Pages 88-98
Abstract
Electro-Hydrodynamics (EHD) spray is an important process in many engineering operations such as ink-jet printing, spray drying and atomization (liquid jet in air), dispersion and emulsification (liquid jet in liquid). In this work the method of electrospray was employed to form droplets from a high ...
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Electro-Hydrodynamics (EHD) spray is an important process in many engineering operations such as ink-jet printing, spray drying and atomization (liquid jet in air), dispersion and emulsification (liquid jet in liquid). In this work the method of electrospray was employed to form droplets from a high viscous sodium-alginate solution using constant DC voltage. The droplets were cured in calcium chloride solution to produce solid beads. The main objective was to extend the knowledge of EHD spray to high viscous and non-Newtonian liquids (1000-5000 mPa.s). However, the effects of electric field strength, nozzle diameter, flow rate and concentration of liquid were specifically investigated on the size of the beads. Among the parameters studied, voltage had a pronounced effect on the size of the beads as compared to the flow rate, the nozzle diameter and the concentration of alginate liquid. The size of beads was reduced to a minimum value by increasing the voltage in the range of 0-10 kV. However, within the middle part of this range, an unstable transition occurred from the dripping mode to the jet mode where the size distribution was wide. Increasing the height of fall of the droplets improved the sphericity of the beads, because of the increase of flight time for the droplets to relax before gelation.
Materials synthesize and production
E. Gomaa; A. Negm; R. Abou Qurn
Volume 14, Issue 4 , December 2017, , Pages 90-99
Abstract
The redox behavior cobalt chloride was studied voltammetrically in presence and absence of L- Carrageenan (LK) natural polymer using glassy carbon electrodes in 0.1 M KCl supporting electrode. Scan rates are studied for the redox behaviors for CoCl2 alone or in presence of L- Carrageenan (LK) natural ...
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The redox behavior cobalt chloride was studied voltammetrically in presence and absence of L- Carrageenan (LK) natural polymer using glassy carbon electrodes in 0.1 M KCl supporting electrode. Scan rates are studied for the redox behaviors for CoCl2 alone or in presence of L- Carrageenan (LK) natural polymer. Stability constants for the interaction of cobalt ions with L - Carageenan (LK) natural polymer are evaluated. All mechanisms are discussed.The redox behavior cobalt chloride was studied voltammetrically in presence and absence of L- Carrageenan (LK) natural polymer using glassy carbon electrodes in 0.1 M KCl supporting electrode. The interaction of CoCl2 with L-Carrageenan (LK) has been studied using cyclic voltammetry technique in the potential range (+1.5 to -1.0) V at different scan rates in water at 292.15 oK using KCl (0.1M) as supporting medium and glassy carbon as a working electrode. The study is valuable for evaluating the thermodynamic properties [3-18]. The cobalt ions used show two oxidation peak at 0.02 and 0.06 V and two reduction peaks at 0 and -0.7 V These two peaks corresponding to the oxidation of cobalt zero valent to monovalent and then the oxidation of cobalt monovalent to divalent cobalt Scan rates are studied for the redox behaviors for CoCl2 alone or in presence of L- Carrageenan (LK) natural polymer. Stability constants for the interaction of cobalt ions with L - Carageenan (LK) natural polymer are evaluated. All mechanisms are discussed.
Reaction Engineering, Kinetics and Catalysts,
P. Rashidi Zonouz; M.E. Masoumi; A. Niaei; A. Tarjomannejad
Volume 15, Issue 2 , May 2018, , Pages 91-102
Abstract
In this paper, catalytic oxidation of CO over the LaFe1-xCuxO3 (x= 0, 0.2, 0.4, 0.6) perovskite-type oxides was investigated. The catalysts were synthesized by sol-gel method and characterized by XRD, BET, FT-IR, H2-TPR and SEM methods. The catalytic activity of catalysts was tested in catalytic oxidation ...
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In this paper, catalytic oxidation of CO over the LaFe1-xCuxO3 (x= 0, 0.2, 0.4, 0.6) perovskite-type oxides was investigated. The catalysts were synthesized by sol-gel method and characterized by XRD, BET, FT-IR, H2-TPR and SEM methods. The catalytic activity of catalysts was tested in catalytic oxidation of CO. XRD patterns confirmed the synthesized perovskites to be single-phase perovskite-type oxides. The synthesized perovskite catalysts show high activity in the range of reaction temperature (50 - 300 ºC). The substitution of Cu in B-site of the perovskite catalysts enhanced their catalytic activity for CO oxidation. Among different synthesized perovskite catalysts, LaFe0.6Cu0.4O3 has the highest activity: nearly complete elimination of CO was achieved at 275 ºC with this catalyst. Kinetic studies for CO oxidation were performed based on power law and Mars-van Krevelen mechanisms. According to kinetic calculations, the most probable mechanism is the MKV-D (dissociative adsorption of oxygen) which can predict the experimental data with correlation coefficient of R2 > 0.995.
Transport Phenomena,
Volume 11, Issue 2 , April 2014, , Pages 92-102
Biomedical and Biotechnology,
Volume 12, Issue 4 , October 2015, , Pages 93-100
Abstract
Antioxidants have an important role in control and prevention of dangerous diseases like cancers, but instability and high solubility of the antioxidants are major challenges of pharmaceutical researchers. Thus, using a suitable carrier for an antioxidant can enhance the antioxidant stability and protect ...
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Antioxidants have an important role in control and prevention of dangerous diseases like cancers, but instability and high solubility of the antioxidants are major challenges of pharmaceutical researchers. Thus, using a suitable carrier for an antioxidant can enhance the antioxidant stability and protect it from reacting with the other existing molecules in the blood circulation. Mesoporous silica nanoparticles (MSNs) have been widely used as a carrier for therapeutic applications because of their suitable biological properties. This study attempts to improve the surface properties and increase antioxidant loading by functionaliztion of MSNs with 3-aminopropyltriethoxysilane (AP-MSNs) via post- synthesis grafting method. Synthesized nanoparticles were characterized by Scanning electron microscopy (SEM), Zetasizer and Fourier transform infrared spectroscopy (FTIR). Gallic acid (GA) was loaded into AP-MSNs. To optimize GA loading capacity, two effective parameters: GA concentration and embedding time were investigated. So different concentrations of GA in EtOH (1-50 mg/mL) were prepared and sampling was done in 24 and 48 h. Results showed that the best GA loading capacity was obtained at a concentration of 40 mg/mL in 48 h. The maximum GA loading capacity and entrapment efficiency were obtained 46 and 20%, respectively, determined by spectrophotometry and high-performance liquid chromatography (HPLC) analysis.
Reaction Engineering, Kinetics and Catalysts,
M. E. Zeynali; H. Abedini; H. R. Sadri
Volume 15, Issue 4 , November 2018, , Pages 93-104
Abstract
DEB dehydrogenation reaction was conducted to produce divinylbenzene (DVB) and ethylvinylbenzene (EVB). The effects of temperature, catalyst weight and time factor on the performance of the dehydrogenation reactor were investigated experimentally. Temperature was varied from 550º C up to 600 º ...
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DEB dehydrogenation reaction was conducted to produce divinylbenzene (DVB) and ethylvinylbenzene (EVB). The effects of temperature, catalyst weight and time factor on the performance of the dehydrogenation reactor were investigated experimentally. Temperature was varied from 550º C up to 600 º C. Temperature affect the conversion of DEB to DVB significantly. The mole fraction of DEB in the outlet of the reactor is reducing up to 580 º C, but further increase in temperature up to 600 º C does not decrease the mole fraction of DEB in the outlet of the reactor. Catalyst weight was varied from 10 gr up to 40 gr. The results showed that the trends of EVB+DVB production and DEB consumption are identical at various catalyst weights. To obtain optimum time factor for the DEB dehydrogenation process experiments were conducted at various time factors. The results showed that the optimum time factor for DVB as a desired product is 825 gr/hr.mole. . The data and information provided in this research can be used for scale-up and optimization purposes.
Reaction Engineering, Kinetics and Catalysts,
S.E Mousavi; H. Pahlavanzadeh; M. khani; H. Ale ebrahim; A. Mozaffari
Volume 15, Issue 3 , September 2018, , Pages 94-107
Abstract
The catalytic reduction of sulfur dioxide with methane to form elemental sulfur has been studied. Al2O3, Cu-Al2O3 and Ni-Al2O3 were examined as catalysts and their performances were compared in terms of SO2 conversion and selectivity. Performance of the catalyst extremely enhanced when nickel and copper ...
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The catalytic reduction of sulfur dioxide with methane to form elemental sulfur has been studied. Al2O3, Cu-Al2O3 and Ni-Al2O3 were examined as catalysts and their performances were compared in terms of SO2 conversion and selectivity. Performance of the catalyst extremely enhanced when nickel and copper were added as promoters. The effects of temperature, SO2/CH4 molar ratio, and reaction time on SO2 reduction were studied. The operating temperature range was 550–800 °C and it was observed that the reaction is strongly temperature dependent. At temperatures lower than 700 °C, Al2O3-Cu (10%) catalyst showed the best performance of all the catalysts. But, at 700° and higher, performances of Al2O3-Cu (10%) and Al2O3-Ni(10%) catalysts were similar. Complete conversion and selectivity (more than 99.5%) was achieved by Al2O3-Cu (10%) and Al2O3-Ni(10%) catalyst, at 750 °C. Effect of molar feed ratio of SO2/CH4= 1-3 was studied and stoichiometric feed ratio showed the best performance. Also, investigation of reaction time for Al2O3-Cu(10%) and Al2O3-Ni(10%) catalysts showed a good long-term stability for SO2 reduction with methane.
Materials synthesize and production
A. Ghaderi; S. Abbasi; F. Farahbod
Volume 12, Issue 3 , July 2015, , Pages 96-105
Abstract
The aim of the current research is concentrated on the synthesis of the different nanoparticles such as SnO2 and ZnO nanoparticles and SnO2-ZnO hybrid via sol gel method to investigate their photocatalytic applications for removal of methyl orange pollutant in water. Therefore, ZnCl2 and SnCl2.2H2O were ...
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The aim of the current research is concentrated on the synthesis of the different nanoparticles such as SnO2 and ZnO nanoparticles and SnO2-ZnO hybrid via sol gel method to investigate their photocatalytic applications for removal of methyl orange pollutant in water. Therefore, ZnCl2 and SnCl2.2H2O were used as ZnO and SnO2 source respectively. The samples were characterized by X-ray diffraction (XRD) spectroscopy, Fourier transform infrared spectroscopy (FTIR) and UV-Vis spectroscopy. XRD results revealed that the crystalline structure of SnO2 and ZnO nanoparticles were formed. FTIR analysis confirmed the presence of ZnO and SnO2 nanoparticles. Optical properties of samples measured using UV-Vis spectrophotometer and the achieved results demonstrated that the photocatalytic activity ofSnO2-ZnO hybrid for the degradation of methyl orange is higher than that of SnO2 nanoparticles and lower than that of ZnO nanoparticles. Weight fraction dependence study also showed that the degradation of methyl orange dye increases with weight fraction. The experimental results revealed that after 35 min UV light irradiation, the photocatalytic degradation of MO using 0.5 g ZnO, hybrid of ZnOSnO2 and SnO2 nanoparticles reached to 99.35%, 92.14% and 87.91%, respectively. In addition, maximum removal efficiency of MO was related to the suspension containing of 0.5 g of ZnO hybrid equal to 99.35%.
Transport Phenomena,
Leila Omidvar Langroudi; hassan pahlavanzadeh; sara nanvakenari
Volume 13, Issue 4 , November 2016, , Pages 96-112
Abstract
This study introduces an experimental and theoretical investigation of the performance of a proposed air dehumidification system using a nanofluid of γ-alumina nano-particles in LiBr/H2O as a desiccant. Comparative experiments organized using a central composite design were carried out to evaluate ...
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This study introduces an experimental and theoretical investigation of the performance of a proposed air dehumidification system using a nanofluid of γ-alumina nano-particles in LiBr/H2O as a desiccant. Comparative experiments organized using a central composite design were carried out to evaluate the effects of six numerical factors (air velocity, desiccant flow rate, air humidity ratio, desiccant solution concentration, air temperature, desiccant temperature) and one categorical factor (adding nano-particles) on outlet air humidity ratio and outlet air temperature as responses. Reduced quadratic models were derived for each response. The results revealed that the concentration of LiBr/H2O solution and air temperature had the largest effect on outlet air humidity ratio and outlet air temperature, respectively. It was found that the average increase in mass transfer rate was 12.23% and heat transfer rate was 13.22% when γ-alumina nano-particles (0.02% wt) were added to the LiBr/H2O solution. The average increase in mass transfer coefficient was 22.73% and heat transfer coefficient was 26.51%.
Reaction Engineering, Kinetics and Catalysts,
F. Mohammadi; M. Rahimi; A. Parvareh; M. Feyzi
Volume 15, Issue 1 , February 2018, , Pages 102-114
Abstract
In the present study, Choline hydroxide (ChOH) as an ionic liquid catalyst was used for transesterification of soybean oil into biodiesel in a microchannel reactor. The effects of three variables i.e. reaction temperature, catalyst dosage and total flow rate on fatty acid methyl ester (FAME) content ...
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In the present study, Choline hydroxide (ChOH) as an ionic liquid catalyst was used for transesterification of soybean oil into biodiesel in a microchannel reactor. The effects of three variables i.e. reaction temperature, catalyst dosage and total flow rate on fatty acid methyl ester (FAME) content (wt. %) were optimized using Box–Behnken experimental design. In order to predict the FAME content a quadratic polynomial model was obtained. The optimal conditions from the model were reaction temperature of 53.53 °C, catalyst dosage of 2.6 wt. % and total flow rate of 11.82 mL/min. At these conditions, the predicted FAME content was 96.45 wt.% and the experimental FAME content was obtained 97.6 wt. %. The proximity of the experimental results and predicted values showed that the regression model issignificant. Using the ionic liquid catalyst in the studied microreactor for transesterification leads to diminish the reaction time to the order of seconds compared to conventional batch systems. In addition, the reusability of ChOH catalyst was investigated. The results revealed that the catalyst had perfect utility after several runs without much loss in the activity.
Modeling and Simulation
A. Sinkakarimi; A. Ghadi
Volume 16, Issue 2 , June 2019, , Pages 103-118
Abstract
Computational fluid dynamics (CFD) is a powerful numerical tool that is becoming widely used to simulate many processes in the industry. In this work study of the stirred tank with 7 types of concave blade with CFD was presented. In the modeling of the impeller rotation, sliding mesh (SM) technique was ...
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Computational fluid dynamics (CFD) is a powerful numerical tool that is becoming widely used to simulate many processes in the industry. In this work study of the stirred tank with 7 types of concave blade with CFD was presented. In the modeling of the impeller rotation, sliding mesh (SM) technique was used and RNG-k-ε model was selected for turbulence. Power consumption in various speeds in the single phase, mean tangential, radial and axial velocities in various points, effects of disc diameter and thickness and mixing time were investigated. The optimum concave impeller was selected and the effect of tracer feed position and probe location was investigated on it. Results suggested that power consumption is exactly depending on impellers scale and geometry, was in a good agreement with the experimental data and in turbulent flow is relatively independent of Reynolds number. Power number increases with increasing disc diameter for both concave and Rushton and concave´s power is relatively independent on disc thickness but increasing it decreases Rushton´s power. The data revealed that the power number was 2.3±0.3 for blade angle 40° whereas for blade 25°, 50° and 55° respectively 43% lower and 57% and 43% higher.
A. Jahanban-Esfahlan; R. Jahanban-Esfahlan; M. Tabibiazar; L. Roufegarinejad; R. Amarowicz
Abstract
The shell of walnut fruit is an agricultural byproduct generated in considerable amounts upon the processing of fruit to obtain its valuable kernel. Walnut is recognized as an appreciated tree nut belonging to the Juglandaceae family. The fruit is mainly composed of a kernel, seed coat, shell, and husk. ...
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The shell of walnut fruit is an agricultural byproduct generated in considerable amounts upon the processing of fruit to obtain its valuable kernel. Walnut is recognized as an appreciated tree nut belonging to the Juglandaceae family. The fruit is mainly composed of a kernel, seed coat, shell, and husk. In recent years, the shell portion of walnut fruit has been widely used in the development of different high–value materials. In this regard, high carbon and low ash contents of the walnut shell (WS) make it a suitable material and inexpensive waste agricultural product for the activated carbon (AC) preparation. In this review, recent developments in the preparation of AC from the shell of walnut fruit and the characterization methods are highlighted. Additionally, the applications of AC mainly in the removal of different hazardous materials such as heavy metals (HMs) ions, dyes as well as pharmaceuticals and other dangerous materials are comprehensively discussed.
Separation Technology,
P. Abbasi; k. Shayesteh; v. vahidfard; M. Hosseini
Abstract
In an Iranian zinc smelter plant, nickel and cadmium are removed from the electrolyte solution at the cold purification stage with the help of zinc powder. This study tries to investigate the optimal conditions for the removal of these impurities through the response surface methodology by examining ...
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In an Iranian zinc smelter plant, nickel and cadmium are removed from the electrolyte solution at the cold purification stage with the help of zinc powder. This study tries to investigate the optimal conditions for the removal of these impurities through the response surface methodology by examining the effects of effective parameters on the process. The results of the experiments showed that cadmium was cemented by zinc powder much more conveniently than nickel. The interplay of parameters showed that increasing the concentration of zinc powder can reduce the time and temperature of the entire reaction. It also neutralized the effect of the changes of pH and mixing speed. The optimum conditions for the simultaneous removal of nickel and cadmium were obtained at 75 °C, the pH of 4.5, the residence time of 45 min, the mixing speed of 500 rpm, and 2 g/l of zinc powder. Under optimal conditions, more than 99 % of nickel and cadmium were removed from the electrolyte solution.
Biomedical and Biotechnology,
Sh. mashayekhiyan; M. Jahanshahi; M. Jafarkhani; K. Entezari; M. Niazi; H. Kabir
Abstract
Electrospun nanofiber is one of the promising alternatives for use in tissue engineering and drug delivery due to its controllable characteristics. However, choosing an appropriate biomaterial for a specific tissue regeneration plays a significant role in fabricating functional tissue-engineered ...
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Electrospun nanofiber is one of the promising alternatives for use in tissue engineering and drug delivery due to its controllable characteristics. However, choosing an appropriate biomaterial for a specific tissue regeneration plays a significant role in fabricating functional tissue-engineered constructs. Heart extracellular matrix (ECM)-derived electrospun nanofiber which mimic the physicochemical and structural characteristics of cardiac tissue is advantageous for cardiac tissue engineering. In this study, acellular calf heart ECM has been investigated as a potential biomaterial to be electrospun in a novel combination with poly vinyl pyrrolidone (PVP), gelatin (Gel) and polycaprolactone (PCL) for cardiac tissue engineering. The obtained fibers were aligned, uniform, and bead free. After fabrication, the scaffolds were cross-linked in glutaraldehyde vapor to become mechanically stronger and dissoluble in the aqueous environments. Considering surface topography, biocompatibility, hydrophilicity, and mechanical properties, the fabricated hybrid electrospun ECM/PVP/Gel/PCL fibers can be proposed as a biomimetic scaffold for heart tissue engineering applications.
R. Parvizsedghy; M. Alibolandi; S. M. Sadrameli
Abstract
Vegetable oils are proved as valuable feedstocks in the biofuel production. Some common issues of cracking of vegetable oils–as an effective method for the biofuel production- are related to the glycerol decomposition during the cracking process. Transesterification, which can remove glycerol from ...
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Vegetable oils are proved as valuable feedstocks in the biofuel production. Some common issues of cracking of vegetable oils–as an effective method for the biofuel production- are related to the glycerol decomposition during the cracking process. Transesterification, which can remove glycerol from vegetable oil molecules, is performed before the thermal cracking to adjust the problems. This study has been aimed at surveying the efficiency of transesterification and the thermal cracking integration to produce bio-gasoline and bio-oil from castor oil. In transesterification, methanol as alcohol and KOH as catalyst were used, and the catalyst concentration, reaction temperature, and alcohol to oil ratio were effective variables. Statistical studies demonstrated the interactions among parameters and the yield of the methyl ester production as 96.7 % under the optimized conditions. Results showed that in the thermal cracking two parameters, of the feed flowrate and temperature, influenced the product yield significantly without any interaction. Under the optimum conditions, to maximize the bio-gasoline production, 28 % of bio-gasoline and 88.6 % of bio-oil were produced. The lack of acrolein, as a toxic component, the negligible amount of the generated water in the product, the high octane number, the significant amount of the heat of combustion of bio-gasoline, and being in criteria of standard gasoline as per ASTM D4814 for the distillation curve and RVP of bio-gasoline, were the great advantages of the cracking of the transesterified caster oil. Therefore, the bio-gasoline produced via the thermochemical conversion of castor oil could be used as a fuel for spark-ignition engines or as an octane enhancer with gasoline, i.e., by adding 10 % of bio-gasoline to the refinery gasoline, the octane number increased from 95 to 105.
H. Abedin
Abstract
In this study, the effect of light wavelength on growth rate and lipid production of Synechocystis was investigated. Continuous cultivation system was used to have uniform cell density and avoid self-shading in order to obtain more precise results. Based on previous studies, red light is more efficient ...
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In this study, the effect of light wavelength on growth rate and lipid production of Synechocystis was investigated. Continuous cultivation system was used to have uniform cell density and avoid self-shading in order to obtain more precise results. Based on previous studies, red light is more efficient than other colors in the visible spectrum for cultivation of Synechocystis; however, the optimum wavelength in red light spectrum remains still unknown. In order to determine the most efficient wavelength of red light, five different wavelengths including 600, 635, 660, 670, and 730 nm were used for growing Synechocystis in a chemostat setup. The results revealed that 635 nm was the most efficient wavelength for cultivation of Synechocystis in terms of both biomass production yield and growth rate. These findings can be attributed to the existence of phycocyanin, the principal light-harvesting supercomplex in Synechocystis, which absorbs maximally at around 620 nm. The results also indicated that cell size and fatty acid profile of Synechocystis were almost the same for different light wavelengths; however, the maximum light was absorbed at 635 nm.
Reaction Engineering, Kinetics and Catalysts,
Nemat Alimohammadi; Sohrab Fatthi
Abstract
In the presented research, the selective hydrogenation of benzene in a mixture of benzene and normal heptane (5 vol % of benzene) over different kinds of heterogeneous catalysts was investigated. For this purpose, a series of catalysts with various supports such as Pd/ZSM-5, Pd/13X and Pd/ was ...
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In the presented research, the selective hydrogenation of benzene in a mixture of benzene and normal heptane (5 vol % of benzene) over different kinds of heterogeneous catalysts was investigated. For this purpose, a series of catalysts with various supports such as Pd/ZSM-5, Pd/13X and Pd/ was developed. To prepare Pd supported catalysts, the modification of supports was conducted by a specified amount of palladium nitrate in the aqueous solution. Experimental catalyst evaluation tests were performed in the catalyst assessment set-up. The characterizations of the physicochemical properties of the prepared catalysts were performed by XRD, NH₃-TPD and BET. It can be found that the conversion of benzene was promoted under the optimized reaction conditions of 200 °C, 1 MPa, H2/HC = 1.3 (molar ratio) and the weight hourly space velocity (WHSV) = 25 hr-1. Among these catalysts, Pd/13X exhibited the maximum conversion of benzene (90 %) and the minimum light-cut production under the optimum conditions. The study on the stability of catalysts shows that, the decline activity of Pd/13X catalyst is more than that of the other catalysts (from 90 % to 81 %) in the specified 20 h time on stream, but so far the activity of this catalyst is the highest in comparison with that of other catalysts at the end of the defined time (20 h).
Separation Technology,
H. Aasadi; O. Alizadeh; A. Ramazani; F. Dorosti
Abstract
The Mixed Matrix Membrane (MMM) concept consists of incorporating suitable polymers with inorganic or organic fillers. The majority of polymeric membranes maintain a trade-off between permeation and selectivity, which restricts their development in separation applications. In this paper, less reviewed ...
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The Mixed Matrix Membrane (MMM) concept consists of incorporating suitable polymers with inorganic or organic fillers. The majority of polymeric membranes maintain a trade-off between permeation and selectivity, which restricts their development in separation applications. In this paper, less reviewed challenges on development of MMMs, such as the preparation of mix-matrix resistant membranes for industrial gas separation applications, as well as the use of appropriate and compatible fillers for different types of polymers were discussed. The MMMs comprising Metal Organic Framework (MOF) fillers were extensively studied. The importance of MOFs includes finely tunable structures, excellent compatibility with polymer matrices, and molecular sieve action. MMMs are considered promising structures that combines the advantages of polymeric and inorganic membranes. They exhibit the potential to upgrade the separation performance of pure polymer membranes using filler materials, whereas the cost remains relatively lower than that of pure inorganic membranes. The development of novel filler materials makes a substantial contribution in terms of role-playing.