Counteracting Catalyst Deactivation in Methane Aromatization with a Two Zone Fluidized Bed Reactor

The upgrading of bio-oil by catalytic transformation upon acidic catalysts is aimed at adapting its composition to that of conventional fuel, or at obtaining petrochemical raw materials, such as olefins and aromatics. A further alternative of growing interest for bio-oil upgrading is catalytic reforming for obtaining H2. The viability of any of these alternatives requires minimizing both the plugging problems that arise in the reactor when the bio-oil is fed and the rapid deactivation of the catalyst, which are associated with the thermal degradation of the lignocellulosic components. In this paper, the catalytic transformation of bio-oil (obtained by fast pyrolysis of vegetable biomass) in a fluidized bed reactor upon a Ni-HZSM-5 zeolite catalyst has been studied, and special attention has been paid to the design of the feed preheating zone. Operation in a single-unit (U-shaped steel tube) for the thermal treatment of the bio-oil (in the downward zone of the U-tube) and its catalytic transformation (in a fluidized bed located in the upward zone of the U-tube) has been compared with operation in a two-unit system, where both steps are carried out in separate units connected through a thermostated line (U-shaped tube for thermal treatment, followed by a fluidized bed reactor for catalytic transformation). It has been proven that a separate step of thermal treatment prior to the catalytic transformation notably improves the global process of bio-oil upgrading. Firstly, it contributes to minimizing coke deposition on the acidic catalyst, mainly the deposition of "thermal" coke (which is associated with the thermal degradation of the bio-oil components at high temperatures), leading to an important attenuation of catalyst deactivation. Secondly, the bio-oil components degraded in the thermal treatment can subsequently be subjected to another upgrading treatment (by steam activation or pyrolysis) in order to obtain a high quality char, which involves upgrading the entire bio-oil.

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Preparation of Mo/HZSM-5/Bentonite Catalyst for Methane Aromatization in a Fluidized Bed Reactor

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2017-0081 ◽

2017 ◽

Vol 15 (5) ◽

Cited By ~ 1

Author(s):

J Lasobras ◽

J.A Medrano ◽

J Soler ◽

J Herguido ◽

M Menéndez ◽

...

Keyword(s):

Fluidized Bed ◽

Mechanical Stability ◽

Active Material ◽

Fluidized Bed Reactor ◽

Added Value ◽

Fluidized Bed Reactors ◽

Thermal Treatments ◽

Methane Aromatization ◽

Catalyst Synthesis ◽

Aromatization Reaction

Abstract Methane aromatization is a promising technology for the transformation of natural gas to added-value products. The main objective of this work was to obtain a catalyst with suitable performance and good mechanical stability for methane aromatization reaction in fluidized bed reactors. The selected catalyst was Mo/H-ZSM-5/bentonite mixture. Mo/ZSM-5 was chosen as the active material, since it provides good selectivity to aromatics but the particle size of the zeolite was too small for operation in a fluidized bed and a binder was needed. We prepared two series of catalysts with two different zeolites. We tested several heating velocities (1, 7 and 10 °C min‒1) in the different stages of catalyst synthesis. Methane conversion and selectivity to aromatic products improved when using gentle thermal treatments, increasing 2% and 10%, respectively, for the best catalyst tested.

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Methane Aromatization in a Fluidized Bed Reactor: Parametric Study

Frontiers in Energy Research ◽

10.3389/fenrg.2019.00008 ◽

2019 ◽

Vol 7 ◽

Cited By ~ 1

Author(s):

Javier Lasobras ◽

Jaime Soler ◽

Javier Herguido ◽

Miguel Menéndez ◽

Alonso Jimenez ◽

...

Keyword(s):

Fluidized Bed ◽

Parametric Study ◽

Fluidized Bed Reactor ◽

Methane Aromatization

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Fast Pyroylysis of Polyolefin Waste over Cracking Catalysts for Producing Hydrocarbon Fuels Using a Fluidized-bed Reactor

International Journal of Chemical Reactor Engineering ◽

10.1515/1542-6580.3053 ◽

2012 ◽

Vol 10 (1) ◽

Author(s):

Dr. Ta-Tung Wei ◽

Prof. Yeuh-Hui Lin

Keyword(s):

Fluidized Bed ◽

Catalyst Deactivation ◽

Ambient Pressure ◽

Carbon Number ◽

Fluidized Bed Reactor ◽

Acid Sites ◽

Carbon Number Distribution ◽

Product Mixture ◽

Number Distribution ◽

Mcm 41

Abstract A mixture of post-commercial polyolefin waste (PE/PP/PS) was pyrolyzed over various micro- and mesoporous catalysts using a fluidized-bed reactor operating isothermally at ambient pressure. The yield of volatile hydrocarbons with zeolitic nano-catalysts (n-ZSM-5 > n-MOR > n-USY) were higher than with non-zeolitic catalysts (MCM-41 > ASA). MCM-41 with large mesopores and ASA with weaker acid sites resulted in a highly olefinic product mixture with a wide carbon number distribution, whereas n-USY yielded a saturate-rich product mixture with a wide carbon number distribution and substantial coke levels. A novel developed model based on kinetic and mechanistic considerations which take into account chemical reactions and catalyst deactivation for the catalytic degradation of commingled polyolefin waste has been investigated. This model represents the benefits of product selectivity for the chemical composition such as alkanes, alkenes, aromatics and coke in relation to the performance and the particle size selection of the catalyst used as well as the effect of the fluidizing gas and reaction temperature.

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HETEROGENEOUS PHOTO-FENTON DEGRADATION OF QUINOLINE WITH A NOVEL INTERNAL CIRCULATING FLUIDIZED-BED REACTOR

Environmental Engineering and Management Journal ◽

10.30638/eemj.2016.228 ◽

2016 ◽

Vol 15 (9) ◽

pp. 2119-2126

Author(s):

Hong You ◽

Ran Zhang ◽

Ting Liu ◽

Donghai Wu ◽

Weiming Wang

Keyword(s):

Fluidized Bed ◽

Circulating Fluidized Bed ◽

Fluidized Bed Reactor

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Removal of microcystin-LR from drinking water with TiO2-coated activated carbon

Water Science & Technology Water Supply ◽

10.2166/ws.2004.0088 ◽

2004 ◽

Vol 4 (5-6) ◽

pp. 21-28

Author(s):

S.-C. Kim ◽

D.-K. Lee

Keyword(s):

Drinking Water ◽

Activated Carbon ◽

Synergistic Effect ◽

Fluidized Bed ◽

Continuous Flow ◽

High Surface ◽

High Surface Area ◽

Fluidized Bed Reactor ◽

Exterior Surface ◽

Tio2 Particles

TiO2-coated granular activated carbon was employed for the removal of toxic microcystin-LR from water. High surface area of the activated carbon provided sites for the adsorption of microcystin-LR, and the adsorbed microcystin-LR migrated continuously onto the surface of TiO2 particles which located mainly at the exterior surface in the vicinity of the entrances of the macropores of the activated carbon. The migrated microcystin-LR was finally degraded into nontoxic products and CO2 very quickly. These combined roles of the activated carbon and TiO2 showed a synergistic effect on the efficient degradation of toxic microcystin-LR. A continuous flow fluidized bed reactor with the TiO2-coated activated carbon could successfully be employed for the efficient photocatalytic of microcystin-LR.

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Influence of Seeding Conditions on Initial Biofilm Development during the Startup of Anaerobic Fluidized Bed Reactors

Water Science & Technology ◽

10.2166/wst.1989.0219 ◽

1989 ◽

Vol 21 (4-5) ◽

pp. 157-165 ◽

Cited By ~ 2

Author(s):

F. Ehlinger ◽

J. M. Audic ◽

G. M. Faup

Keyword(s):

Fluidized Bed ◽

Future Development ◽

Protein Concentration ◽

Specific Activity ◽

Fluidized Bed Reactor ◽

Fluidized Bed Reactors ◽

Support Material ◽

Biofilm Development ◽

Initial Biofilm

The characterization of the biofilm of an anaerobic fluidized-bed reactor was completed under standard conditions. The distribution of the fixed protein concentration depended on the level in the reactor. The protein concentration reached 1520 µg.g−1 of support at the top of the reactor and only 1200 µg.g−1 at the bottom after 504 hours of operation but the specific activity of the biofilm was 33×10−4 µM acetate.h−1.mg−1 proteins at the bottom and only 26×10−4 µM.h−1.mg−1 at the top. The efficiency of a fluidized bed reactor and the composition of the biofilm changed with an increase of the pH from 7 to 8.5 during the seeding of the support material. Future development of the biofilm and the specific activity of the support were affected.

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The Kinetics of Glucose Decomposition with Sulfate Reduction in the Anaerobic Fluidized Bed Reactor

Water Science & Technology ◽

10.2166/wst.1993.0092 ◽

1993 ◽

Vol 28 (2) ◽

pp. 135-144 ◽

Cited By ~ 3

Author(s):

S. Matsui ◽

R. Ikemoto Yamamoto ◽

Y. Tsuchiya ◽

B. Inanc

Keyword(s):

Sulfate Reduction ◽

Fluidized Bed ◽

Kinetic Equations ◽

Fluidized Bed Reactor ◽

Order Reaction ◽

First Order Reaction ◽

First Order ◽

Glucose Decomposition ◽

Reaction Equations ◽

Kinetics Of

Using a fluidized bed reactor, experiments on glucose decomposition with and without sulfate reduction were conducted. Glucose in the reactor was mainly decomposed into lactate and ethanol. Lactate was mainly decomposed into propionate and acetate, while ethanol was decomposed into propionate, acetate, and hydrogen. Sulfate reduction was not involved in the decomposition of glucose, lactate, and ethanol, but was related to propionate and acetate decomposition. The stepwise reactions were modeled using either a Monod expression or first order reaction kinetics in respect to the reactions. The coefficients of the kinetic equations were determined experimentally. The modified Monod and first order reaction equations were effective at predicting concentrations of glucose, lactate, ethanol, propionate, acetate, and sulfate along the beight of the reactor. With sulfate reduction, propionate was decomposed into acetate, while without sulfate reduction, accumulation of propionate was observed in the reactor. Sulfate reduction accelerated propionate conversion into acetate by decreasing the hydrogen concentration.

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