Effects of Microwave and Ultrasonic-Assisted Aging on the Synthesis of H-ZSM-5 Nanozeolite and Its Catalytic Performance in Methanol Dehydration

2014 ◽  
Vol 12 (1) ◽  
pp. 355-362 ◽  
Author(s):  
Saeid Abbasian ◽  
Majid Taghizadeh
Keyword(s):  
Fixed Bed ◽  
Catalytic Performance ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Crystallization Time ◽  
Microwave Assisted ◽  
Ultrasonic Assisted ◽  
Ft Ir ◽  
Static Conditions ◽  
Ultrasonic Stirring

Abstract H-ZSM-5 nanozeolite was hydrothermally synthesized under static conditions. Evaluation of hydrothermal synthesis of ZSM-5 was performed by treating the synthesis mixture using different aging processes, consist of ultrasonic, stirring, and microwave-assisted aging, prior to the conventional hydrothermal treatment. The catalytic performances of selected catalysts were studied for the dehydration of methanol to dimethyl ether (DME) in a fixed-bed reactor under the same operating conditions (T = 300°C, P = 1 atm, and WHSV = 26 h−1). The prepared samples were characterized by XRD, SEM, BET, NH3-TPD and FT-IR techniques. The results showed that ultrasonic and microwave-assisted aging shortened the crystallization time and reduced crystal size of the obtained products without having any considerable effects on their catalytic activities.

scholarly journals Catalytic Performance of Phosphorus Incorporated HZSM-5 in Coupling Transformation of Methanol with 1-butene to Propylene

2021 ◽  
Vol 72 (3) ◽  
pp. 33-44
Author(s):  
Haifeng Tian ◽  
Yongyong Nan ◽  
Jinlong Lv ◽  
Fei Zha ◽  
Xiaohua Tang ◽  
...  
Keyword(s):  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Molar Ratio ◽  
N2 Adsorption ◽  
Facile Hydrothermal Method ◽  
Phosphorus Species ◽  
Coupling Transformation ◽  
Ft Ir ◽  
Adsorption Desorption

Directly incorporated phosphorus species into the framework of HZSM-5 zeolite (H[P, Al]-ZSM-5) was successfully synthesized by the facile hydrothermal method. It was characterized by employing XRD, ICP-OES, SEM, FT-IR, N2 adsorption-desorption, NH3-TPD, XPS and TG-DTA, respectively. The effects of the phosphorus species content, temperature, WHSV, and the molar ratio of methanol/1-butene in coupling transformation of methanol with 1-butene to propylene catalyzed by H[P, Al]-ZSM-5 in a fixed bed reactor were studied systematically. Tests have suggested the acid content and specific surface area of H[P, Al]-ZSM-5 are reduced. Under the condition of reaction temperature at 550�Z, molar ratio of methanol/1-butene to 1.0, reaction pressure at 0.1 MPa and WHSV= 3.53 h-1, the P-modified HZSM-5 zeolite (with the P2O5 molar composition of 0.4 )the selectivity and yield of propylene are 35.6% and 32.5%, respectively.

scholarly journals Activity Evaluation of CoMo Nanoparticles Supported on Meso-microporous Composites in Dibenzothiophene Hydrodesulphurization

2019 ◽  
Vol 15 (1) ◽  
pp. 112-118
Author(s):  
Nastaran Parsafard ◽  
Mohammad Hasan Peyrovi ◽  
Zahra Mohammadian ◽  
Niloofar Atashi
Keyword(s):  
Activation Energy ◽  
High Surface ◽  
High Surface Area ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Ft Ir ◽  
Adsorption Desorption

CoMo-supported mesoporous catalysts were synthesized by 50 wt% of HZSM-5 and 50 wt% of FSM-16, KIT-6, and MCM-48. These catalysts were prepared by the wet-impregnation method and pre-sulfided with CS2. The catalytic performance was evaluated for HDS reaction of dibenzothiophene over a temperature range of 250-400 °C in a micro fixed-bed reactor under atmospheric pressure. The supported CoMo bimetallic catalysts were characterized by XRD, XRF, FT-IR, N2 adsorption-desorption, and SEM. The CoMo/KIT-6/HZSM-5 indicate higher activity than other catalysts at 400 °C for dibenzothiophene hydrodesulphurization. Also, the best selectivity to cyclohexylbenzene (CHB) is related to CoMo/FSM-16/HZSM-5. The activation energy was also calculated for all prepared catalysts for the conversions of less than 10%; according to which, the activation energy for CoMo/KIT-6/HZSM-5 is less than other catalysts (~21 kJ/mol) which can be related to the appropriate pore size and high surface area of the support. Copyright © 2020 BCREC Group. All rights reserved 

scholarly journals Kinetics study of CWPO of phenol wastewater over Cu-ZSM-5/PSSF catalysts prepared by ion-exchanged method

2021 ◽  
Author(s):  
Yanjie Wu ◽  
Huiping Zhang ◽  
Ying Yan
Keyword(s):  
Phenol Degradation ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Exchange Method ◽  
Initial Oxidation ◽  
Wet Peroxide Oxidation ◽  
Power Rate ◽  
Optimum Reaction ◽  
Ft Ir

Cu-ZSM-5 was prepared on the paper-like sintered stainless steel fibers (PSSF) by ion-exchange method for catalytic wet peroxide oxidation (CWPO) of phenol in a fixed bed reactor. The prepared Cu-ZSM-5/PSSF catalyst was characterized by SEM, BET, XRD, FT-IR and UV-vis, respectively. And the effects of different catalyst bed height, reaction temperature and feed flow rate on catalytic performance were investigated to obtain optimum reaction condition. Finally, the catalytic reaction kinetics analysis over Cu-ZSM-5/PSSF catalyst were carried out with the Power-rate Law Kinetic model. The experimental results showed that the reaction order was the first-order reaction, and the activation energy of the oxidation reaction was Ea=72.9 kJ/mol. The initial oxidation rate equation (−rA0=5.36×108 e−72994/RT CA) was obtained for phenol degradation using Cu-ZSM-5/PSSF catalyst.

CO2 valorization into synthetic natural gas (SNG) using a Co–Ni bimetallic Y2O3 based catalysts

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Radwa A. El-Salamony ◽  
Sara A. El-Sharaky ◽  
Seham A. Al-Temtamy ◽  
Ahmed M. Al-Sabagh ◽  
Hamada M. Killa
Keyword(s):  
Reaction Mechanism ◽  
Natural Gas ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Synthetic Natural Gas ◽  
Methanation Reaction ◽  
Co2 Valorization

Abstract Recently, because of the increasing demand for natural gas and the reduction of greenhouse gases, interests have focused on producing synthetic natural gas (SNG), which is suggested as an important future energy carrier. Hydrogenation of CO2, the so-called methanation reaction, is a suitable technique for the fixation of CO2. Nickel supported on yttrium oxide and promoted with cobalt were prepared by the wet-impregnation method respectively and characterized using SBET, XRD, FTIR, XPS, TPR, and HRTEM/EDX. CO2 hydrogenation over the Ni/Y2O3 catalyst was examined and compared with Co–Ni/Y2O3 catalysts, Co% = 10 and 15 wt/wt. The catalytic test was conducted with the use of a fixed-bed reactor under atmospheric pressure. The catalytic performance temperature was 350 °C with a supply of H2:CO2 molar ratio of 4 and a total flow rate of 200 mL/min. The CH4 yield was reached 67%, and CO2 conversion extended 48.5% with CO traces over 10Co–Ni/Y2O3 catalyst. This encourages the direct methanation reaction mechanism. However, the reaction mechanism over Ni/Y2O3 catalyst shows different behaviors rather than that over bi-metal catalysts, whereas the steam reforming of methane reaction was arisen associated with methane consumption besides increase in H2 and CO formation; at the same temperature reaction.

scholarly journals Performance Analysis of TiO2-Modified Co/MgAl2O4 Catalyst for Dry Reforming of Methane in a Fixed Bed Reactor for Syngas (H2, CO) Production

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3347
Author(s):  
Arslan Mazhar ◽  
Asif Hussain Khoja ◽  
Abul Kalam Azad ◽  
Faisal Mushtaq ◽  
Salman Raza Naqvi ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Dry Reforming ◽  
Fixed Bed Reactor ◽  
Dry Reforming Of Methane ◽  
Catalyst Stability ◽  
Feed Ratio ◽  
Catalyst Loading ◽  
Impregnation Method

Co/TiO2–MgAl2O4 was investigated in a fixed bed reactor for the dry reforming of methane (DRM) process. Co/TiO2–MgAl2O4 was prepared by modified co-precipitation, followed by the hydrothermal method. The active metal Co was loaded via the wetness impregnation method. The prepared catalyst was characterized by XRD, SEM, TGA, and FTIR. The performance of Co/TiO2–MgAl2O4 for the DRM process was investigated in a reactor with a temperature of 750 °C, a feed ratio (CO2/CH4) of 1, a catalyst loading of 0.5 g, and a feed flow rate of 20 mL min−1. The effect of support interaction with metal and the composite were studied for catalytic activity, the composite showing significantly improved results. Moreover, among the tested Co loadings, 5 wt% Co over the TiO2–MgAl2O4 composite shows the best catalytic performance. The 5%Co/TiO2–MgAl2O4 improved the CH4 and CO2 conversion by up to 70% and 80%, respectively, while the selectivity of H2 and CO improved to 43% and 46.5%, respectively. The achieved H2/CO ratio of 0.9 was due to the excess amount of CO produced because of the higher conversion rate of CO2 and the surface carbon reaction with oxygen species. Furthermore, in a time on stream (TOS) test, the catalyst exhibited 75 h of stability with significant catalytic activity. Catalyst potential lies in catalyst stability and performance results, thus encouraging the further investigation and use of the catalyst for the long-run DRM process.

Modeling of a Fixed-Bed Reactor for the Production of Phthalic Anhydride

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Amir Rahimi ◽  
Sogand Hamidi
Keyword(s):  
Phthalic Anhydride ◽  
Fixed Bed ◽  
Tubular Reactor ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Conversion Degree ◽  
Reactor Length ◽  
Reactor Temperature ◽  
Reported Data ◽  
Reactor Pressure

In this study, the performance of a fixed–bed tubular reactor for the production of phthalic anhydride is mathematically analyzed. The conversion degree and reactor temperature values are compared with the measured one in a tubular reactor applied in Farabi petrochemical unit in Iran as well as reported data in the literature for a pilot plate. The comparisons are satisfactory. The effects of some operating parameters including reactor length, feed temperature, reactor pressure, and existence of an inert in the catalytic bed are investigated. The optimum value of each parameter is determined on the basis of the corresponding operating conditions.

scholarly journals Enhanced Phenol Tert-Butylation Reaction Activity over Hierarchical Porous Silica-Alumina Materials

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1098
Author(s):  
Ling Xu ◽  
Fan Wang ◽  
Zhi Xiu ◽  
Limei Duan ◽  
Zongrui Liu ◽  
...  
Keyword(s):  
Physical Adsorption ◽  
Porous Silica ◽  
Mesoporous Structure ◽  
Catalytic Performance ◽  
Crystallization Time ◽  
Hydrothermal Conditions ◽  
Transmission Electron ◽  
Hierarchical Porous ◽  
Silica Alumina ◽  
Ft Ir

Hierarchical aluminum-silicon materials have been successfully prepared by mixing pre-crystallization of silica-alumina sol and citric acid under hydrothermal conditions. The influence of pre-crystallization time on the micro-mesoporous structure is studied using Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), N2 physical adsorption, and high-resolution transmission electron microscopy (HRTEM). The catalytic performance of hierarchical silica-alumina material is evaluated by alkylation of phenol with tert-butanol. The results show that the silica-alumina materials with a pre-crystallization time of 16 h show micro-mesoporous structure and excellent catalytic activity.

scholarly journals Hierarchical H-ZSM5 zeolites based on natural kaolinite as a high-performance catalyst for methanol to aromatic hydrocarbons conversion

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ahmad Asghari ◽  
Mohammadreza Khanmohammadi Khorrami ◽  
Sayed Habib Kazemi
Keyword(s):  
Pore Size ◽  
Aromatic Hydrocarbons ◽  
High Performance ◽  
Low Cost ◽  
Direct Synthesis ◽  
Fixed Bed ◽  
Methanol Conversion ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Good Prospect

AbstractThe present work introduces a good prospect for the development of hierarchical catalysts with excellent catalytic performance in the methanol to aromatic hydrocarbons conversion (MTA) process. Hierarchical H-ZSM5 zeolites, with a tailored pore size and different Si/Al ratios, were synthesized directly using natural kaolin clay as a low-cost silica and aluminium resource. Further explored for the direct synthesis of hierarchical HZSM-5 structures was the steam assisted conversion (SAC) with a cost-effective and green affordable saccharide source of high fructose corn syrup (HFCS), as a secondary mesopore agent. The fabricated zeolites exhibiting good crystallinity, 2D and 3D nanostructures, high specific surface area, tailored pore size, and tunable acidity. Finally, the catalyst performance in the conversion of methanol to aromatic hydrocarbons was tested in a fixed bed reactor. The synthesized H-ZSM5 catalysts exhibited superior methanol conversion (over 100 h up to 90%) and selectivity (over 85%) in the methanol conversion to aromatic hydrocarbon products.

Preparation and Performance of Several Non-Precious Metal Oxides Catalysts for the Low Temperature SCR of NOx with NH3

2011 ◽  
Vol 356-360 ◽  
pp. 1528-1534
Author(s):  
Wei Fang Dong
Keyword(s):  
Low Temperature ◽  
Metal Oxides ◽  
Flue Gas ◽  
Precious Metal ◽  
Catalytic Reduction ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Low Temperature Scr ◽  
Scr Of Nox

A series of non-precious metal oxides catalysts were prepared for low-temperature selective catalytic reduction (SCR) of NOx with NH3 in a fixed bed reactor. The catalytic performance was evaluated by the removal efficiency of NOx and N2selectivity which were respectively detected by flue gas analyzer and flue gas chromatograph. Furthermore, the components of gas products from the above experiments were analysed with 2010 GC-MS. The results illustrated that the MnO2exhibited the highest NOx conversion to 95.46% and the highest selectivity of N2to 100% at temperature of 393K, then followed ZrO2, Al2O3and Fe2O3.

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