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Developing a mathematical model for reforming of glycerol towards a comparative evaluation of the liquid vs. gas phase medium
, Article International Journal of Hydrogen Energy ; Volume 44, Issue 49 , 2019 , Pages 26764-26772 ; 03603199 (ISSN) ; Kazemeini, M ; Larimi, A ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Glycerol might be converted into hydrogen through a catalytic reforming process. In order to design an effective route, the choice of reaction conditions and in particular its medium considered yet a crucial issue still needing further investigations. In this research, a mathematical model of reforming processes in vapor (i.e., steam reforming (SR) and liquid phase (i.e.; aqueous phase reforming (APR)) were developed. This was performed in terms of understudying effects of parameters including the reactor diameter, catalyst morphology (i.e., particle size) and mass flow rate on the glycerol conversion. Then, a superior reaction medium in terms of these variables was determined. For data...
Pt nanoparticles decorated Bi-doped TiO2 as an efficient photocatalyst for CO2 photo-reduction into CH4
, Article Solar Energy ; Volume 211 , 15 November , 2020 , Pages 100-110 ; Khorasheh, F ; Larimi, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Pt@Bi-TiO2 photocatalysts with different Bi (0–5 wt%) and Pt (0–2 wt%) contents were prepared by a two-step sol-gel and photo-deposition technique and were used in photo-reduction of CO2. The synthesized catalysts were characterized by X-ray powder diffraction (XRD), UV–Vis diffuse reflectance spectroscopy (DRS), scanning and transmission electron microscopy (SEM and TEM), nitrogen sorption measurement (BET), Raman spectroscopy, Electron paramagnetic resonance (EPR) spectroscopy and photoluminescence spectroscopy (PL). CO2 photo-reduction results revealed that the introduction of Bi into TiO2 structure and subsequent loading of Pt on its surface significantly increased the methane yield....
Biodiesel production via transesterification of canola oil in the presence of Na–K doped CaO derived from calcined eggshell
, Article Renewable Energy ; Volume 163 , 2021 , Pages 1626-1636 ; 09601481 (ISSN) ; Khorasheh, F ; Larimi, A ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
CaO derived from calcined eggshell was doped with Na–K by wet impregnation method and the effect of different Na/K molar ratios was investigated on biodiesel production from canola oil. The catalysts were characterized by X-ray Powder Diffraction (XRD), Brunauer–Emmett–Teller (BET), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and Thermogravimetric (TGA) analyses. FAME yields were determined by Gas Chromatography-Mass Spectrometry (GC-MS). The Na–K/CaO catalyst with Na/K molar ratio of 1 showed the highest FAME yield of 97.6% at optimum reaction conditions. Structural investigation of materials revealed that FAME yield was proportional to the number of basic sites on...
Aqueous phase reforming of glycerol using highly active and stable Pt0.05CexZr0.95-xO2 ternary solid solution catalysts
, Article Applied Catalysis A: General ; Volume 523 , 2016 , Pages 230-240 ; 0926860X (ISSN) ; Kazemeini, M ; Khorasheh, F ; Sharif University of Technology
Elsevier
2016
Abstract
The aqueous phase reforming (APR) of glycerol is an attractive yet challenging pathway to convert abundant biomass into value added hydrogen. Pt catalysts have received attention due to their ability to produce hydrogen-rich gas under APR conditions. In this work, the conversion of glycerol into hydrogen is demonstrated using Pt0.05CexZr0.95-xO2 (x = 0, 0.29, 0.475, 0.66 and 0.95) solid solution catalysts. Both characteristic (XRD, BET, H2-TPR, CO-chemisorption, TEM and XPS) and reactivity measurements were used to investigate the activity of the catalysts. Results indicated that reactivity depended on the Ce/Zr ratio, which in turn affected the Pt oxidation state, active metal dispersion...
Highly selective doped Pt[sbnd]MgO nano-sheets for renewable hydrogen production from APR of glycerol
, Article International Journal of Hydrogen Energy ; Volume 41, Issue 39 , 2016 , Pages 17390-17398 ; 03603199 (ISSN) ; Kazemeini, M ; Khorasheh, F ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
A series of M-doped Pt[sbnd]MgO (M = Pd, Ir, Re, Ru, Rh and Cr) sheet-shaped nano-catalysts were synthesized by the controlled co-precipitation method. The effects of M-doping on both the physicochemical and the chemisorption characteristics of Pt[sbnd]MgO catalysts were examined. The performance of the catalysts for the aqueous phase reforming (APR) of glycerol was also investigated. The APR activity of Pt[sbnd]M[sbnd]MgO catalysts depended on the type of the M dopant used. The APR activity varied in the following order: Rh > Pd > Cr > Ir > undoped ≈ Ru > Re, with the Rh-promoted catalyst having an activity of about one order of magnitude higher than the Re-promoted catalyst at 250 °C. It...
Aqueous-phase reforming of glycerol for production of alkanes over Ni/CexZr1-xO2 nano-catalyst: Effects of the support's composition
, Article Renewable Energy ; Volume 108 , 2017 , Pages 417-424 ; 09601481 (ISSN) ; Kazemeini, M ; Larimi, A. S ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
The aqueous phase reforming (APR) reaction of glycerol considered to be environmentally green. It converted polyols into value added products including; H2 and alkanes. Ni species known for its capability of producing alkane-rich gas under the APR process conditions might be utilized for this purpose. In this research, the conversion of glycerol into alkanes demonstrated using 10wt% Ni/CexZr1-xO2 (with x = 0, 0.3, 0.5, 0.7 and 1) catalysts. In order to better understand the behavior of these materials, they were evaluated physio-chemically through the; XRD, BET, H2-TPR, H2-Chemisorption and TEM analyses. Moreover; performances of the synthesized materials were determined through their...
Production of renewable hydrogen through aqueous-phase reforming of glycerol over Ni/Al2O3–MgO nano-catalyst
, Article International Journal of Hydrogen Energy ; Volume 43, Issue 2 , 2018 , Pages 614-621 ; 03603199 (ISSN) ; Kazemeini, M ; Larimi, A ; Maleki, H ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
In this study, a series of Ni nano-catalysts supported on Al2O3 and MgO were prepared through the co-precipitation technique. Effects of the Al/Mg ratio on physicochemical characteristics of Ni/Al2O3–MgO catalysts were examined. Moreover, catalytic performance was investigated in order to determine the optimum catalyst for H2 production in aqueous phase reforming (APR) of glycerol. It was revealed that, the APR activity of synthesized catalysts strongly depended on the aforementioned ratio. In addition, it was observed that, the catalytic activity of Ni/MgO and Ni/Al2O3 samples were both lower than that of the corresponding mixed oxide supports. Furthermore, it was shown that, amongst the...
Ni-Bi co-doped TiO2 as highly visible light response nano-photocatalyst for CO2 photo-reduction in a batch photo-reactor
, Article Journal of CO2 Utilization ; Volume 41 , October , 2020 ; Ghotbi, C ; Khorasheh, F ; Larimi, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Photocatalytic reduction of CO2 is considered as a promising strategy for production of a wide range of renewable hydrocarbon fuels by solar energy. In this investigation, a series of Ni and Bi doped TiO2 catalysts with different Ni and Bi contents were synthesized by the conventional sol-gel method and tested for CO2 photoreduction under visible light irradiation. Synthesized nano-photo-catalysts were characterized by XRD, FESEM, TEM, DRS, PL, FTIR and BET analyses. BET results indicated that the doping of Ni or/and Bi in the TiO2 framework resulted in BET specific surface area increment with respect to pure TiO2. DRS analysis showed that Ni doped TiO2, Bi doped TiO2, and co-doped samples...
Multiphase modeling of powder flow in an ejector of solar-driven refrigeration system by eulerian-lagrangian approach
, Article Nanotechnology Applications for Solar Energy Systems ; 2023 , Pages 313-336 ; 978-111979123-2 (ISBN); 978-111979114-0 (ISBN) ; Najafi, A ; Larimi, M ; Parhizkari, M ; Sharif University of Technology
wiley
2023
Abstract
The ejectors are the type of vacuum or pressure-based pump widely applicable in power engineering, thermal systems, and new solar-driven refrigeration systems. Streams inside the ejectors are complex, and it is not easy to describe the best possible flows and design by considering different hydrothermal properties. Nowadays, nanofluids are considered as a method for increasing the heat transfer rate in heat pipes, heat exchangers, and different parts of solar-driven systems which these progress reported and categorized in literature. In this study, the design parameters and optimization of an ejector for a solar-based refrigeration system, for generation vacuum, and consequently, maximum...
Transesterification of canola oil and methanol by lithium impregnated CaO–La2O3 mixed oxide for biodiesel synthesis
, Article Journal of Industrial and Engineering Chemistry ; Volume 47 , 2017 , Pages 399-404 ; 1226086X (ISSN) ; Kazemeini, M ; Larimi, A. S ; Khorasheh, F ; Sharif University of Technology
2017
Abstract
CaO–La2O3 mixed oxides were synthesized by co-precipitation coupled with Li doping through wet impregnation. These were used as catalysts for transesterification of canola oil and methanol toward biodiesel production. To determine the structure and morphology of the prepared catalysts, they were characterized by the XRD, FESEM, BET, and basic strength measurements. Under optimum reaction conditions of methanol/oil molar ratio of 15:1, 5 wt% catalyst at 65 °C, 96.3% conversion was obtained in 2.5 h of reaction duration. Moreover, the catalyst demonstrated a rather high stability where reuse of up to five cycles without significant loss of performance observed. © 2016 The Korean Society of...
Renewable hydrogen production by ethylene glycol steam reforming over Al2O3 supported Ni-Pt bimetallic nano-catalysts
, Article Renewable Energy ; Volume 128 , 2018 , Pages 188-199 ; 09601481 (ISSN) ; Khorasheh, F ; Sharif University of Technology
2018
Abstract
The steam reforming of ethylene glycol, a simple model compound for biomass-derived liquids, is considered to be an environmentally green process for producing renewable hydrogen. Both Pt and Ni species are known for their catalytic activity under steam reforming reaction conditions. In this investigation, alumina supported Ni-Pt bimetallic catalysts (X wt% Ni-Y wt% Pt/Al2O3 named XNi-YPt) were employed for steam reforming of ethylene glycol. The prepared catalysts were characterized by XRD, BET, H2-TPR, H₂-Chemisorption, and TEM. It was observed that Ni/Pt ratio strongly affected the redox behavior, BET surface area, and particle size of the samples that in turn affected their catalytic...
Renewable hydrogen production over Pt/Al₂O₃ nano-catalysts: Effect of M-promoting (M=Pd, Rh, Re, Ru, Ir, Cr)
, Article International Journal of Hydrogen Energy ; Volume 44, Issue 16 , 2019 , Pages 8243-8251 ; 03603199 (ISSN) ; Khorasheh, F ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Xwt% Pt/Al 2 O 3 (X = 1, 3, 5, 8, 10) and 5 wt% Pt-1wt% M/AlO 3 (M = Pd, Rh, Re, Ru, Ir, Cr) catalysts were prepared, characterized and tested for aqueous phase reforming of pure and crude glycerol. Results show drastic dependence of catalytic performance of catalysts on both the active metal loading and the type of applied promoters. 5 wt% was the best Pt loading and Pt[sbnd]Rh/Al₂O₃ shows the best catalytic activity which has the highest hydrogen production rate (mmol/g cat h −1 ) and selectivity (89%) in continuous aqueous phase reforming of 10 wt% pure glycerol solution
Carbonaceous supports decorated with Pt–TiO2 nanoparticles using electrostatic self-assembly method as a highly visible-light active photocatalyst for CO2 photoreduction
, Article Renewable Energy ; Volume 145 , January , 2020 , Pages 1862-1869 ; Khorasheh, F ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Supported Pt–TiO₂ photocatalysts on carbonaceous supports were synthesized by the electrostatic self-assembly method to study CO₂ photoreduction to produce CH₄. Catalytic activities of the prepared photocatalysts were correlated with the particle size and dispersion of the active metal, which in turn depended on the type of carbonaceous support used, varying in the order of multi-walled carbon nanotubes (MWCNT) > Single-walled carbon nanotubes (SWCNT) > reduced graphene oxide > activated carbon. Generally, all catalysts were highly photoresistant with less than 5% loss of activity in terms of CH₄ yield. Pt–TiO₂/multi-walled carbon nanotubes exhibited better catalytic activity compared with...
Numerical and experimental analysis of drug inhalation in realistic human upper airway model
, Article Pharmaceuticals ; Volume 16, Issue 3 , 2023 ; 14248247 (ISSN) ; Babamiri, A ; Biglarian, M ; Ramiar, A ; Tabe, R ; Inthavong, K ; Farnoud, A ; Sharif University of Technology
MDPI
2023
Abstract
The demand for a more efficient and targeted method for intranasal drug delivery has led to sophisticated device design, delivery methods, and aerosol properties. Due to the complex nasal geometry and measurement limitations, numerical modeling is an appropriate approach to simulate the airflow, aerosol dispersion, and deposition for the initial assessment of novel methodologies for better drug delivery. In this study, a CT-based, 3D-printed model of a realistic nasal airway was reconstructed, and airflow pressure, velocity, turbulent kinetic energy (TKE), and aerosol deposition patterns were simultaneously investigated. Different inhalation flowrates (5, 10, 15, 30, and 45 L/min) and...
Computational investigation of stenosis in curvature of coronary artery within both dynamic and static models
, Article Computer Methods and Programs in Biomedicine ; Volume 185 , 2020 ; Momeni Larimi, M ; Hassanzadeh Afrouzi, H ; Moshfegh, A ; Toghraie, D ; Javadzadegan, A ; Rostami, S ; Sharif University of Technology
Elsevier Ireland Ltd
2020
Abstract
Background and Objective: Blood flow variation during cardiac cycle is the main mechanism of atherosclerotic development which is dependent on. Methods: The present work mainly tends to investigate stenosis effect in dynamic curvature of coronary artery. This paper presents numerical investigations on wall shear stress profiles in three-dimensional pulsatile flow through curved stenotic coronary arteries for both static and dynamic model. In order to do so, three-dimensional models related to the curved arteries with two degrees of stenosis (30% and 50%). Results: Lower amount of wall shear stress is found near the inner wall of artery distal to the plaque region (stenosis) and in both...
Production of Biodiesel Using Calcite Stone as Support Catalyst
, M.Sc. Thesis Sharif University of Technology ; Khorasheh, Farhad (Supervisor) ; Larimi, Afsanehsadat (Supervisor)
Abstract
The aim of this study is developing and investigating heterogeneous catalysts based on natural calcite for the transesterification of canola oil and methanol in order to produce biodiesel as a renewable and alternative fuel for fossil fuels. At first calcite was calcined at high temperature to decompose calcium carbonate to calcium oxide. Afterward, Mg-Zr/CaO catalysts were prepared with mass ratio of 2:1 Mg:Zr and different weight percent(2.5, 5,7.5 and 10 wt%) on calcite supported by impregnation method. In order to characterized synthesized catalysts used different analysis such as energy dispersive X-ray (EDX) spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy...
Production of Biodiesel Using Eggshell as Catalyst
, M.Sc. Thesis Sharif University of Technology ; Khorasheh, Farhad (Supervisor) ; Larimi, Afsaneh Sadat (Supervisor)
Abstract
The aim of this project is to investigate and synthesize CaO-based nanocatalysts derived from chicken eggshell calcination with alkali metals and sodium-potassium compounds promoters used in the transesterification reaction of canola oil and methanol. Sections of this thesis include the synthesis of nanocatalysts, catalyst characterization tests, and investigation of reaction under optimal conditions. Two groups of catalysts containing different weight percentages of alkali metals based on CaO and 1 %wt sodium-potassium based on CaO with different weight percentages of these two elements were synthesized by wet impregnation method and used in the reaction under optimum condition. Catalyst...
Effect of Selected Promotors on the Electrocatalytic Performance in Oxygen Evolution Reaction
, M.Sc. Thesis Sharif University of Technology ; Ghotbi, Cyrus (Supervisor) ; Larimi, Afsaneh Sadat (Supervisor)
Abstract
During the last few decades, efforts have been made to replace fossil fuels with clean and non-absorbent energy sources. One of the promising strategies is energy production by hydrogen storage using water splitting. For this purpose, different methods of using light, heat and electricity are provided. Electrolysis of water with a simple environment such as very high purity of hydrogen produced, controllable, device, no need for high temperature and pressure in the reactor and huge potential for industrial applications has been very much considered. Water electrolysis consists of two reactions: reduction of water to hydrogen (HER) and oxidation of water to oxygen (OER). The second reaction...
Synthesis and Evaluation of Nanostructured Magnetic Photocatalysts for Oxidation Desulfurization of Liquid Fuels
, M.Sc. Thesis Sharif University of Technology ; Ghotbi, Sirous (Supervisor) ; Larimi, Afsaneh Sadat (Supervisor)
Abstract
In recent decades, desulfurization processes have become necessary to reduce environmental pollution due to fuel sulfur emissions. In this research, in order to photocatalytic oxidation desulfurization of liquid fuel, a model fuel (normal octane) under visible light irradiation of 250 W sodium lamp, using H2O2 oxidant and methanol solvent in the presence of BMO/Fe@MIL(x%) composite. BMO and Fe@MIL were investigated. From the tests, X-ray diffraction, scanning and transmission electron microscope imaging, absorption and desorption of nitrogen gas, infrared spectrometer-Fourier transform, visible-ultraviolet reflection spectroscopy, optical radiation spectroscopy and vibration magnetometer in...
Oxidation Desulfurization of Liquid Fuels Using TiO2-based Photocatalysts
, M.Sc. Thesis Sharif University of Technology ; Khorasheh, Farhad (Supervisor) ; Larimi, Afsaneh Sadat (Supervisor)
Abstract
Due to the increasing consumption of fuel, the use of new methods with high efficiency to remove sulfur from fossil fuels is felt more than ever. Hydrogenation and oxidation of sulfur organic matter, such as thiophenes, is an old method of desulfurization of liquid fuels. Using a photocatalyst, everything can be done in an environment that is very low cost. In this study, the photocatalytic elimination of dibenzothiophene was investigated. For this purpose, carbon-doped thiamine dioxide was used as the photocatalytic base, which is synthesized by hydrothermal method. This method is the same source of titanium and carbon. To increase the performance of the catalyst, platinum metal was loaded...