Methods to delay deactivation of zeolites on furan acylation: continuous liquid-phase technology and solvent effects

RSC Advances ◽  
2015 ◽  
Vol 5 (125) ◽  
pp. 103695-103702 ◽  
Author(s):  
Yuannan Xiong ◽  
Wenqi Chen ◽  
Jianjun Ma ◽  
Zhihua Chen ◽  
Aiwu Zeng
Keyword(s):  
Liquid Phase ◽  
Acetic Anhydride ◽  
Solvent Effects ◽  
Food Additives ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Beta Zeolite ◽  
Commercial Importance

The continuous liquid phase acylation of furan with acetic anhydride over H-beta zeolite was carried out in a fixed-bed reactor. 2-acetylfuran is of considerable commercial importance due to its application in food additives and drug industries.

Modeling of aerated upflow fixed bed reactors for nitrification

1999 ◽  
Vol 39 (4) ◽  
pp. 85-92 ◽  
Author(s):  
J. Behrendt
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Liquid Phase ◽  
Gas Phase ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Bulk Liquid ◽  
Initial Value ◽  
Fixed Bed Reactors ◽  
Number Of Cells

A mathematical model for nitrification in an aerated fixed bed reactor has been developed. This model is based on material balances in the bulk liquid, gas phase and in the biofilm area. The fixed bed is divided into a number of cells according to the reduced remixing behaviour. A fixed bed cell consists of 4 compartments: the support, the gas phase, the bulk liquid phase and the stagnant volume containing the biofilm. In the stagnant volume the biological transmutation of the ammonia is located. The transport phenomena are modelled with mass transfer formulations so that the balances could be formulated as an initial value problem. The results of the simulation and experiments are compared.

scholarly journals Valuable Chemicals Derived from Pyrolysis Liquid Products of Spirulina platensis Residue

2019 ◽  
Vol 19 (3) ◽  
pp. 703 ◽  
Author(s):  
Siti Jamilatun ◽  
Budhijanto Budhijanto ◽  
Rochmadi Rochmadi ◽  
Avido Yuliestyan ◽  
Arief Budiman
Keyword(s):  
Polyaromatic Hydrocarbons ◽  
Food Additives ◽  
Fixed Bed ◽  
Liquid Product ◽  
Fixed Bed Reactor ◽  
Water Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Human Needs ◽  
Liquid Products ◽  
Interesting Alternative

With a motto of preserving nature, the use of renewable resources for the fulfillment of human needs has been seen echoing these days. In response, microalgae, a water-living microorganism, is perceived as an interesting alternative due to its easy-to-cultivate nature. One of the microalgae, which possess the potential for being the future source of energy, food, and health, is Spirulina plantesis. Aiming to identify valuable chemicals possibly derived from it, catalytic and non-catalytic pyrolysis process of the residue of S. plantesis microalgae has been firstly carried out in a fixed-bed reactor over the various temperature of 300, 400, 500, 550 and 600 °C. The resulting vapor was condensed so that the liquid product consisting of the top product (oil phase) and the bottom product (water phase) can be separated. The composition of each product was then analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). In the oil phase yield, the increase of aliphatic and polyaromatic hydrocarbons (PAHs) and the decrease of the oxygenated have been observed along with the increase of pyrolysis temperature, which might be useful for fuel application. Interestingly, their water phase composition also presents some potential chemicals, able to be used as antioxidants, vitamins and food additives.

scholarly journals Stable Continuous Production of γ-Valerolactone from Biomass-Derived Levulinic Acid over Zr–Al-Beta Zeolite Catalyst

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 678
Author(s):  
Clara López-Aguado ◽  
Marta Paniagua ◽  
Juan A. Melero ◽  
Jose Iglesias ◽  
Pablo Juárez ◽  
...  
Keyword(s):  
Levulinic Acid ◽  
Hydrogen Transfer ◽  
Zeolite Catalyst ◽  
Continuous Production ◽  
Catalyst Activity ◽  
Fixed Bed ◽  
Transfer Hydrogenation ◽  
Fixed Bed Reactor ◽  
Beta Zeolite ◽  
Thermal Regeneration

The one-pot conversion of biomass-derived platform molecules such as levulinic acid (LA) and furfural (FAL) into γ-valerolactone (GVL) is challenging because of the need for adequate multi-functional catalysts and high-pressure gaseous hydrogen. As a more sustainable alternative, here we describe the transfer hydrogenation of LA to GVL using isopropanol as a hydrogen donor over a Zr-modified beta zeolite catalyst in a continuous fixed-bed reactor. A stable sustained production of GVL was achieved from the levulinic acid, with both high LA conversion (ca. 95%) and GVL yield (ca. 90%), for over at least 20 days in continuous operation at 170 °C. Importantly, the small decay in activity can be advantageously overcome by the means of a simple in situ thermal regeneration in the air atmosphere, leading to a complete recovery of the catalyst activity. Key to this outstanding result is the use of a Zr-modified dealuminated beta zeolite with a tailored Lewis/Brønsted acid sites ratio, which can synergistically catalyze the tandem steps of hydrogen transfer and acid-catalyzed transformations, leading to such a successful and stable production of GVL from LA.

scholarly journals Agglomeration of Ti-SBA-15 with clays for liquid phase olefin epoxidation in a continuous fixed bed reactor

2008 ◽  
Vol 139 (3) ◽  
pp. 631-641 ◽  
Author(s):  
Juan A. Melero ◽  
Jose Iglesias ◽  
Javier Sainz-Pardo ◽  
Pilar de Frutos ◽  
Sandra Blázquez
Keyword(s):  
Liquid Phase ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Olefin Epoxidation

scholarly journals Turnover Rate of Metal-Catalyzed Hydroconversion of 2,5-Dimethylfuran: Gas-Phase Versus Liquid-Phase

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1171
Author(s):  
Hanan Althikrallah ◽  
Casper Kunstmann-Olsen ◽  
Elena F. Kozhevnikova ◽  
Ivan V. Kozhevnikov
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Furan Ring ◽  
Ambient Pressure ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Ring Cleavage ◽  
Phase Reaction ◽  
Liquid Phase Reaction ◽  
Phase Process

Hydroconversion (hydrogenation and hydrogenolysis) of biomass-derived furanic compounds giving furan ring-hydrogenation and ring-cleavage products attracts interest for sustainable production of chemicals and fuels. Here, the hydroconversion of 2,5-dimethylfuran (DMF), chosen as a model furanic compound, was investigated at a gas-solid interface over carbon-supported Pt, Pd, Rh and Ru metal catalysts in a fixed-bed reactor at 70–90 °C and ambient pressure. Pt/C was mainly active in ring cleavage of DMF to produce 2-hexanone as the primary product, followed by its hydrogenation to 2-hexanol and hexane. In contrast, Pd/C, Rh/C and Ru/C selectively hydrogenated the furan ring to 2,5-dimethyltetrahydrofuran (DMTHF). The turnover frequency (TOF) of metal sites in the gas-phase DMF hydroconversion was determined from zero-order kinetics in the absence of diffusion limitations. The TOF values decreased in the sequence Pt > Rh > Pd >> Ru, similar to the liquid-phase reaction. The TOF values for the gas-phase reaction were found to be one order of magnitude greater than those for the liquid-phase reaction. This indicates that the gas-phase process is potentially more efficient than the liquid-phase process. TOF values for hydroconversion of ring-saturated furan derivatives, tetrahydrofuran and DMTHF, on Pt/C, were much lower than those for DMF.

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 

Liquid phase propylene epoxidation with H2O2on TS-1/SiO2catalyst in a fixed-bed reactor: experiments and deactivation kinetics

2014 ◽  
Vol 90 (8) ◽  
pp. 1489-1496 ◽  
Author(s):  
Wenping Feng ◽  
Yaquan Wang ◽  
Guoqiang Wu ◽  
Yi Lin ◽  
Juan Xu ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Propylene Epoxidation ◽  
Deactivation Kinetics
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