scholarly journals Toward the Sustainable Synthesis of Propanols from Renewable Glycerol over MoO3-Al2O3 Supported Palladium Catalysts

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 385 ◽  
Author(s):  
Shanthi Samudrala ◽  
Sankar Bhattacharya
Keyword(s):  
Catalytic Activity ◽  
Palladium Catalysts ◽  
Fixed Bed ◽  
Value Added ◽  
High Strength ◽  
Acid Sites ◽  
Fixed Bed Reactor ◽  
High Catalytic Activity ◽  
Impregnation Method ◽  
Glycerol Conversion

The catalytic conversion of glycerol to value-added propanols is a promising synthetic route that holds the potential to overcome the glycerol oversupply from the biodiesel industry. In this study, selective hydrogenolysis of 10 wt% aqueous bio-glycerol to 1-propanol and 2-propanol was performed in the vapor phase, fixed-bed reactor by using environmentally friendly bifunctional Pd/MoO3-Al2O3 catalysts prepared by wetness impregnation method. The physicochemical properties of these catalysts were derived from various techniques such as X-ray diffraction, NH3-temperature programmed desorption, scanning electron microscopy, 27Al NMR spectroscopy, surface area analysis, and thermogravimetric analysis. The catalytic activity results depicted that a high catalytic activity (>80%) with very high selectivity (>90%) to 1-propanol and 2-propanol was obtained over all the catalysts evaluated in a continuously fed, fixed-bed reactor. However, among all others, 2 wt% Pd/MoO3-Al2O3 catalyst was the most active and selective to propanols. The synergic interaction between the palladium and MoO3 on Al2O3 support and high strength weak to moderate acid sites of the catalyst were solely responsible for the high catalytic activity. The maximum glycerol conversion of 88.4% with 91.3% selectivity to propanols was achieved at an optimum reaction condition of 210 ∘ C and 1 bar pressure after 3 h of glycerol hydrogenolysis 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.

scholarly journals Tungsten Oxide-Modified SSZ-13 Zeolite as an Efficient Catalyst for Ethylene-To-Propylene Reaction

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 553
Author(s):  
Mansurbek Urol ugli Abdullaev ◽  
Sungjune Lee ◽  
Tae-Wan Kim ◽  
Chul-Ung Kim
Keyword(s):  
Tungsten Oxide ◽  
Fixed Bed ◽  
Acid Sites ◽  
Fixed Bed Reactor ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Efficient Catalyst ◽  
X Ray ◽  
Propylene Selectivity ◽  
Temperature Programmed

Among the zeolitic catalysts for the ethylene-to-propylene (ETP) reaction, the SSZ-13 zeolite shows the highest catalytic activity based on both its suitable pore architecture and tunable acidity. In this study, in order to improve the propylene selectivity further, the surface of the SSZ-13 zeolite was modified with various amounts of tungsten oxide ranging from 1 wt% to 15 wt% via a simple incipient wetness impregnation method. The prepared catalysts were characterized with several analysis techniques, specifically, powder X-ray diffraction (PXRD), Raman spectroscopy, temperature-programmed reduction of hydrogen (H2-TPR), temperature-programmed desorption of ammonia (NH3-TPD), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and N2 sorption, and their catalytic activities were investigated in a fixed-bed reactor system. The tungsten oxide-modified SSZ-13 catalysts demonstrated significantly improved propylene selectivity and yield compared to the parent H-SSZ-13 catalyst. For the tungsten oxide loading, 10 wt% loading showed the highest propylene yield of 64.9 wt%, which was 6.5 wt% higher than the pristine H-SSZ-13 catalyst. This can be related to not only the milder and decreased strong acid sites but also the diffusion restriction of bulky byproducts, as supported by scanning transmission electron microscopy-energy dispersive X-ray spectroscopy (STEM-EDS) observation.

Research on the Catalytic Activity of MnyCezOx/TiO2 for Ethyl Acetate Oxidation

2013 ◽  
Vol 781-784 ◽  
pp. 308-311 ◽  
Author(s):  
Xin Li ◽  
Wei Su ◽  
Qi Bin Xia ◽  
Zhi Meng Liu
Keyword(s):  
Catalytic Activity ◽  
Ethyl Acetate ◽  
High Activity ◽  
Fixed Bed ◽  
Space Velocity ◽  
Fixed Bed Reactor ◽  
Impregnation Method ◽  
Acetate Oxidation ◽  
Acetate Concentration ◽  
Molar Ratios

Manganese and cerium based catalysts with different Mn/Ce molar ratios prepared by impregnation method for ethyl acetate oxidation. The activity tests of the samples were performed in a fixed-bed reactor. The effect of gas hourly space velocity (GHSV) and ethyl acetate concentration on the catalytic activity of the catalyst were also investigated. The results showed that these catalysts had high activity for the catalytic oxidation of ethyl acetate, of which the catalyst Mn0.9Ce0.1Ox/TiO2exhibitedthe bestactivity, and the temperature required for 90% conversion of ethyl acetate was at 216 °C. The catalyst Mn0.9Ce0.1Ox/TiO2still maintained high activity in the range of GHSV (16,500 to 48,500 h-1) and ethyl acetate concentration (4526 to 7092 mg/m3). In additional, experiments for measuring stability of Mn0.9Ce0.1Ox/TiO2were carried out, and experimental results showed that the good stability of Mn0.9Ce0.1Ox/TiO2was kept after it has run for 25 hours.

Comparative study of catalytic conversion of glycerol, a by-product of transesterification, to cyclic hydrocarbons using MCM-22, ZSM-5 and alumina

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sandeep Kumar ◽  
Dinesh Kumar ◽  
Neeru Anand ◽  
Vinay Shah
Keyword(s):  
Rate Constant ◽  
Reaction Rate ◽  
Fixed Bed ◽  
Liquid Product ◽  
Value Added ◽  
Fixed Bed Reactor ◽  
High Yield ◽  
Esterification Reaction ◽  
Glycerol Conversion ◽  
Ms Analysis

Abstract Recently chemical consumption has increased due to the growth of human population and industrialization. Depleting fuel reserves and increase in chemicals rise has led and researcher to focus on alternative bio based chemicals. Glycerol which is produced as a major byproduct from the trans-esterification reaction of fatty acids for producing biodiesel has been used in this work for conversion to value added products. Conversion of glycerol in presence of alumina, MCM-22 (pure silica based mesoporous catalyst) and ZSM-5 (Si-Al based catalyst) is investigated at different temperature and catalyst weight in a fixed bed reactor. The conversion of glycerol was found to be maximum in presence of alumina whereas maximum liquid products were obtained with ZSM-5. GC/MS analysis confirmed the production of Furan compounds in higher fraction with both alumina as well as ZSM-5 showing the importance of acid sites for the glycerol conversion to higher hydrocarbons. The GC/MS analysis of liquid product obtained in presence of catalyst was also observed with high area% of unconverted glycerol. The order is as follow 54% (MCM-22) > 44% (ZSM-5) > 42.2% (Alumina). For the investigation of the conversion for varying catalyst weight (0–3 g with 0.5 g weight difference), reaction temperature were varied between 450 and 550 °C. Different values of n = 0, 1, 2 etc. were used for the fitting of the respective plot. A change in reaction rate and the rate constant indicated that with the change of temperature, reaction rate was increased. The rate constant value obtained between 0.09 and 0.12 h−1. In all cases 450 °C and catalyst weight of 2.5 g was obtained as optimum for higher liquid yield. TGA analysis of spent catalyst also showed that alumina give high yield (∼50% by weight) of coke as compared to ZSM-5 and MCM-22.

scholarly journals Ni–Cu High-Loaded Sol–Gel Catalysts for Dehydrogenation of Liquid Organic Hydrides: Insights into Structural Features and Relationship with Catalytic Activity

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2017
Author(s):  
Yuliya Gulyaeva ◽  
Maria Alekseeva (Bykova) ◽  
Olga Bulavchenko ◽  
Anna Kremneva ◽  
Andrey Saraev ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Sol Gel ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Structural Features ◽  
Atomic Ratio ◽  
Fixed Bed Reactor ◽  
High Catalytic Activity ◽  
Wide Range ◽  
Structure Reactivity Relationship

The heightened interest in liquid organic hydrogen carriers encourages the development of catalysts suitable for multicycle use. To ensure high catalytic activity and selectivity, the structure–reactivity relationship must be extensively investigated. In this study, high-loaded Ni–Cu catalysts were considered for the dehydrogenation of methylcyclohexane. The highest conversion of 85% and toluene selectivity of 70% were achieved at 325 °C in a fixed-bed reactor using a catalyst with a Cu/Ni atomic ratio of 0.23. To shed light on the relationship between the structural features and catalytic performance, the catalysts were thoroughly studied using a wide range of advanced physicochemical tools. The activity and selectivity of the proposed catalysts are related to the uniformity of Cu distribution and its interaction with Ni via the formation of metallic solid solutions. The method of introduction of copper in the catalyst plays a crucial role in the effectiveness of the interaction between the two metals.

scholarly journals The Effect of Aluminum Source on Performance of Beta-Zeolite as a Support for Hydrocracking Catalyst

2018 ◽  
Vol 13 (3) ◽  
pp. 543
Author(s):  
Mina Hadi ◽  
Hamid Reza Aghabozorg ◽  
Hamid Reza Bozorgzadeh ◽  
Mohammad Reza Ghasemi
Keyword(s):  
Fixed Bed ◽  
Diffraction Method ◽  
Acid Sites ◽  
Fixed Bed Reactor ◽  
Beta Zeolite ◽  
Impregnation Method ◽  
Gas Oil ◽  
Hydrocracking Catalyst ◽  
Silica Alumina ◽  
Temperature Programmed

In this paper, three different kinds of aluminum sources (sodium aluminate, aluminum sulfate and aluminum isopropylate) were used for preparing of nano beta-zeolite. The as synthesized zeolites were mixed with the as prepared amorphous silica-alumina to produce the supports for hydrocracking catalyst. The prepared supports were used for preparation of NiMo/silica alumina-nano beta-zeolite by impregnation method. The influence of the aluminum source for preparation of beta-zeolite on the performance of the prepared catalysts has been studied. The samples were thoroughly characterized by X-Ray diffraction method (XRD), field emission-scanning electron microscopy (FE-SEM), N2 adsorption-desorption isotherms (BET), temperature programmed desorption (TPD) and temperature programmed reduction (TPR) methods. The catalysts performance was evaluated by vacuum gas oil (VGO) hydrocracking at 390 oC in a fixed bed reactor. The XRD patterns showed that the beta-zeolite samples obtained from the present methods were pure and highly crystalline and the crystal size of the prepared zeolites were in nanometer scale. Crystallite size of nano beta-zeolite synthesized by aluminum isopropylate [Al(iPrO)3] was smaller than those of prepared by the other aluminum sources. The catalyst containing this zeolite with higher surface area (231 m2/g) and more available acid sites (1.66 mmol NH3/g) possessed higher activity and selectivity to gas oil (71.9 %). Copyright © 2018 BCREC Group. All rights reservedReceived: 25th April 2018; Revised:22nd July 2018; Accepted: 29th July 2018How to Cite: Hadi, M., Aghabozorg, H.R., Bozorgzadeh, H.R., Ghasemi, M.R. (2018). The Effect of Aluminum Source on Performance of Beta-Zeolite as a Support for Hydrocracking Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (3): 543-552 (doi:10.9767/bcrec.13.3.2570.543-552)Permalink/DOI: https://doi.org/10.9767/bcrec.13.3.2570.543-552 

Activity of Copper and Nickel Loaded on HZSM-5Zeolite Based Catalyst for Steam Reforming of Glycerol to Hydrogen

2014 ◽  
Vol 699 ◽  
pp. 504-509
Author(s):  
Hafizah Abdul Halim Yun ◽  
Ramli Mat ◽  
Tuan Amran Tuan Abdullah ◽  
Mahadhir Mohamed ◽  
Anwar Johariand Asmadi Ali
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Fixed Bed ◽  
Operating Conditions ◽  
Zeolite Catalysts ◽  
Fixed Bed Reactor ◽  
Molar Ratio ◽  
Hydrogen Yield ◽  
Impregnation Method ◽  
Glycerol Conversion

The study focuses on hydrogen production via glycerol steam reforming over copper and nickel loaded on HZSM-5 zeolite based catalyst. The catalysts were prepared by using different loading amount of copper (0-10wt%) and nickel (0-10wt%) on HZSM-5 zeolite catalysts through wet impregnation method and was characterized by X-Ray Diffraction (XRD). The performances of catalysts were evaluated in terms of glycerol conversion and hydrogen production at 500°C using 6:1 of water to glycerol molar ratio (WGMR) in a tubular fixed bed reactor. All the catalysts had achieved more than 85% of glycerol conversion except that of 5%Cu loaded on HZSM-5 catalyst. The addition of nickel into 5% Cu/HZSM-5 catalyst had increased the hydrogen yield. Similar trend was observed when copper was added into Ni/HZSM-5 catalyst but using copper loaded on HZSM-5 alone was unable to produce hydrogen compared to using nickel catalyst alone. It showed that copper acted as a promoter for hydrogen production. It was established that a 5wt% of Cu with 10wt% of Ni loaded on HZSM-5 catalyst showed significant improvement in terms of hydrogen yield and gaseous product compositions at selected operating conditions.

scholarly journals Oleylamine-modified impregnation method for the preparation of a highly efficient Ni/SiO2 nanocatalyst active in the partial oxidation of methane to synthesis gas

2017 ◽  
Vol 23 (2) ◽  
pp. 259-267
Author(s):  
Davarani Hosseini ◽  
Hassan Hashemipour ◽  
Alireza Talebizadeh
Keyword(s):  
Partial Oxidation ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Partial Oxidation Of Methane ◽  
Fixed Bed Reactor ◽  
High Catalytic Activity ◽  
Impregnation Method ◽  
Oxidation Of Methane ◽  
Temperature Programmed ◽  
H2 Yield

In this research, a novel modified wet impregnation method has been successfully developed to synthesize 5% Ni/SiO2 nanocatalyst with high catalytic activity and stability for the partial oxidation of methane. Oleylamine was used as a capping agent in the impregnation solution to improve Ni dispersion and interaction with silica surfaces. The product was analyzed and characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, N2 physisorption measurement and transmission electron microscopy (TEM) and temperature- -programmed H2 reduction (H2-TPR). Partial oxidation of methane over the modified catalyst was performed in a continues-flow fixed-bed reactor under atmospheric pressure at 700?C. The modified catalyst showed 91% CH4 conversion, 86% H2 yield and 95% CO selectivity, and these results almost remained constant within 5 h reaction on stream. The excellent catalytic performance of the catalyst was reasonably attributed to the small and uniform distribution of Ni nanoparticles on the support, and structural characterization confirmed this conclusion.

scholarly journals Acidity effects of K promoted Co-based catalyst with NH4OH addition of the impregnation solution for Fischer-Tropsch synthesis

2019 ◽  
Vol 268 ◽  
pp. 07001
Author(s):  
Zaky Al Fatony ◽  
Yosi Febriani ◽  
IGBN Makertihartha ◽  
Melia Laniwati Gunawan ◽  
Subagjo
Keyword(s):  
Catalyst Activity ◽  
Fixed Bed ◽  
Product Distribution ◽  
Acid Sites ◽  
Weak Acid ◽  
Tropsch Synthesis ◽  
Fixed Bed Reactor ◽  
Impregnation Method ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis

Fischer-Tropsch synthesis (FTS) with cobalt-based catalyst has been developed to produce wax as a feedstock for further catalytic cracking. During catalyst preparation, NH4OH was added to the salt nitrate precursor to investigate the influence on catalyst acidity. Catalysts were prepared by the dry impregnation method and characterized by XRD, BET and NH3-TPD analyses. These properties were correlated with activity and selectivity of the catalyst. Activity tests showed CO and H2 conversion were in the range of 36.4% to 80.3% and 34.2% to 74.1% respectively. The cobalt particle size measurements exhibited 7.6-8.5 nm. The presence of weak acid sites on catalyst with large surface area and pore size is mainly responsible for obtaining high yields of C5+ hydrocarbon due to suppression of cracking properties. The product distribution showed a higher selectivity to C5+ in the range of 53.57% to 96.5%. In this study, FTS was evaluated by using fixed-bed reactor at 20 bar, 250 C, and WHSV of 1500 ml/g.cat/h-1.

scholarly journals Dehydrogenation of Cyclohexanol to Cyclohexanone Over Nitrogen-doped Graphene supported Cu catalyst

2020 ◽  
Vol 15 (2) ◽  
pp. 568-578
Author(s):  
Alyaa. K. Mageed ◽  
Dayang A. B. Radiah ◽  
A. Salmiaton ◽  
Shamsul Izhar ◽  
Musab Abdul Razak ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Chemical Reduction ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Impregnation Method ◽  
Nitrogen Doped ◽  
Reduced Graphene ◽  
Cu Catalyst ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

In this study, the dehydrogenation of cyclohexanol to cyclohexanone over nitrogen-doped reduced graphene oxide (N-rGO) Cu catalyst has been reported. The N-rGO support was synthesized by chemical reduction of graphite oxide (GO). The synthesized N-rGO was used as a support to prepare the Cu/N-rGO catalyst via an incipient wet impregnation method. The as-prepared support and the Cu/N-rGO catalyst were characterized by FESEM, EDX, XRD, TEM, TGA, and Raman spectroscopy. The various characterization analysis revealed the suitability of the Cu/N-rGO as a heterogeneous catalyst that can be employed for the dehydrogenation of cyclohexanol to cyclohexanone. The catalytic activity of the Cu/N-rGO catalyst was tested in non-oxidative dehydrogenation of cyclohexanol to cyclohexanone using a stainless-steel fixed bed reactor. The effects of temperature, reactant flow rate, and time-on-stream on the activity of the Cu/N-rGO catalyst were examined. The Cu/N-rGO nanosheets show excellent catalytic activity and selectivity to cyclohexanone. The formation of stable Cu nanoparticles on N-rGO support interaction and segregation of Cu were crucial factors for the catalytic activity. The highest cyclohexanol conversion and selectivity of 93.3% and 82.7%, respectively, were obtained at a reaction temperature of 270 °C and cyclohexanol feed rate of 0.1 ml/min. Copyright © 2020 BCREC Group. All rights reserved 

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