Behavior of a pilot plant fixed-bed reactor during catalyst deactivation

1986 ◽  
Vol 41 (4) ◽  
pp. 779-786 ◽  
Author(s):  
A. Baiker ◽  
D. Epple ◽  
A. Wokaun
Keyword(s):  
Pilot Plant ◽  
Catalyst Deactivation ◽  
Fixed Bed ◽  
Fixed Bed Reactor

scholarly journals Analysis and Model-Based Description of the Total Process of Periodic Deactivation and Regeneration of a VOx Catalyst for Selective Dehydrogenation of Propane

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1374
Author(s):  
Andreas Brune ◽  
Andreas Seidel-Morgenstern ◽  
Christof Hamel
Keyword(s):  
Catalyst Deactivation ◽  
Process Development ◽  
Coke Formation ◽  
Fixed Bed ◽  
Reaction Network ◽  
Fixed Bed Reactor ◽  
Side Reactions ◽  
Model Based ◽  
Total Process

This study intends to provide insights into various aspects related to the reaction kinetics of the VOx catalyzed propane dehydrogenation including main and side reactions and, in particular, catalyst deactivation and regeneration, which can be hardly found in combination in current literature. To kinetically describe the complex reaction network, a reduced model was fitted to lab scale experiments performed in a fixed bed reactor. Additionally, thermogravimetric analysis (TGA) was applied to investigate the coking behavior of the catalyst under defined conditions considering propane and propene as precursors for coke formation. Propene was identified to be the main coke precursor, which agrees with results of experiments using a segmented fixed bed reactor (FBR). A mechanistic multilayer-monolayer coke growth model was developed to mathematically describe the catalyst coking. Samples from long-term deactivation experiments in an FBR were used for regeneration experiments with oxygen to gasify the coke deposits in a TGA. A power law approach was able to describe the regeneration behavior well. Finally, the results of periodic experiments consisting of several deactivation and regeneration cycles verified the long-term stability of the catalyst and confirmed the validity of the derived and parametrized kinetic models for deactivation and regeneration, which will allow model-based process development and optimization.

Pilot plant studies on fixed bed reactor system for biomethanation of distillery spent wash

1992 ◽  
Vol 41 (1-2) ◽  
pp. 87-107 ◽  
Author(s):  
T. Nandy ◽  
S. N. Kaul ◽  
P. P. Pathe ◽  
C. V. Deshpande ◽  
R. A. Daryapurkar
Keyword(s):  
Pilot Plant ◽  
Fixed Bed ◽  
Reactor System ◽  
Fixed Bed Reactor ◽  
Spent Wash ◽  
Distillery Spent Wash

scholarly journals Hydrogen Generation from Catalytic Steam Reforming Bio-Oil Model Compound—Acetic Acid Employing Ni/attapulgite Catalysts Prepared with Different Preparation Methods

2016 ◽  
Author(s):  
Yishuang Wang ◽  
Mingqiang Chen ◽  
Tian Liang ◽  
Jie Yang ◽  
Zhonglian Yang ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Steam Reforming ◽  
Catalyst Deactivation ◽  
Hydrogen Generation ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Precipitation Method ◽  
Impregnation Method ◽  
Bio Oil ◽  
Catalytic Steam Reforming

In this research, catalytic steam reforming acetic acid derived from the aqueous portion of bio-oil for hydrogen production was investigated by using different Ni/ATC (Attapulgite Clay) catalysts prepared by precipitation, impregnation and mechanical blending methods. The fresh and reduced catalysts were characterized by XRD, N2 adsorption-desorption, TEM and H2-TPR. The comprehensive results demonstrated that the interaction between active metallic Ni and ATC carrier was significantly improved in Ni/ATC catalyst prepared by precipitation method, and in which the mean Ni particle size was the smallest (~13 nm) resulted in the highest metal dispersion (7.5%). The catalytic performance of the three catalysts was evaluated through the process of steam reforming of acetic acid in a fixed-bed reactor under atmospheric pressure at two different temperatures, such as 550 ℃ and 650 ℃. Results showed that the Ni/ATC (PM-N/ATC) prepared by precipitation method, achieved the highest H2 yield of ~82% and little lower acetic acid conversion efficiency of ~85% than that (~95%) of Ni/ATC (IM-NATC) prepared by impregnation method. In addition, the deactivation catalysts after reaction for 4 h were analyzed by XRD, TGA-DTG and TEM, which demonstrated that the catalyst deactivation was not caused by the amount of carbon deposition, but owed to the significant agglomeration and sintering of Ni particles in the carrier.

Optimal catalyst activity distribution in fixed-bed reactor with catalyst deactivation

1989 ◽  
Vol 54 (2) ◽  
pp. 375-387 ◽  
Author(s):  
Jozef Markoš ◽  
Alena Brunovská
Keyword(s):  
Catalyst Deactivation ◽  
Active Catalyst ◽  
Catalyst Activity ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Catalytic Reactor ◽  
Reactor Performance ◽  
Thiele Modulus ◽  
Activity Distribution ◽  
Parameter Ratio

In this paper the influence of the active catalyst location in a pellet on fixed-bed catalytic reactor performance is described. The optimal activity distribution as a function of an economic parameter (ratio of product and catalyst costs), Thiele modulus and Damkohler number is estimated.

Catalytic Wet Peroxide Oxidation Process for the Continuous Treatment of Polluted Effluents on a Pilot Plant Scale

2008 ◽  
Vol 11 (1) ◽  
Author(s):  
Fernando Martínez ◽  
M Isabel Pariente ◽  
Juan Antonio Melero ◽  
Juan Ángel Botas
Keyword(s):  
Pilot Plant ◽  
Fixed Bed ◽  
Pilot Scale ◽  
Fixed Bed Reactor ◽  
Continuous Treatment ◽  
Continuous Stirred Tank Reactor ◽  
Peroxide Oxidation ◽  
Wet Peroxide Oxidation ◽  
Pilot Plant Scale ◽  
Catalytic Wet Peroxide Oxidation

AbstractCatalytic Wet Peroxide Oxidation (CWPO) for the continuous treatment of a phenolic aqueous solution has been studied on a pilot scale process. The pilot plant has been designed by integration of a catalytic fixed bed reactor (FBR) with a continuous stirred tank reactor (CSTR). The CSTR is used as reservoir for the continuous delivering of a recirculation stream through the catalytic bed. The main part of phenol mineralization takes place by catalytic oxidation in the FBR. The mesoporous SBA-15 silica-supported iron oxide (Fe

Kinetic Modelling of Propane Dehydrogenation over a Pt–Sn/hierarchical SAPO-34 Zeolite Catalyst, Including Catalyst Deactivation

2017 ◽  
Vol 42 (4) ◽  
pp. 344-360
Author(s):  
Milad Komasi ◽  
Shohreh Fatemi ◽  
Seyed Hesam Mousavi
Keyword(s):  
Catalyst Deactivation ◽  
Kinetic Modelling ◽  
Coke Formation ◽  
Fixed Bed ◽  
Reaction Network ◽  
Normal Pressure ◽  
Fixed Bed Reactor ◽  
Propane Dehydrogenation ◽  
Coke Deposition ◽  
Formation Kinetic

Pt–Sn/hierarchical SAPO-34 was synthesised and kinetically modelled as an efficient and selective catalyst for propylene production through propane dehydrogenation. The kinetics of the reaction network were studied in an integral fixed-bed reactor at three temperatures of 550, 600 and 650 °C and weight hourly space velocities of 4 and 8 h−1 with a feed containing hydrogen and propane with relative molar ratios of 0.2, 0.5 and 0.8, at normal pressure. The experiments were performed in accordance with the full factorial experimental design. The kinetic models were constructed on the basis of different mechanisms and various deactivation models. The kinetics and deactivation parameters were simultaneously predicted and optimised using genetic algorithm optimisation. It was further proven that the Langmuir–Hinshelwood model can well predict propane dehydrogenation kinetics through lumping together all the possible dehydrogenation steps and also by assuming the surface reaction as the rate-determining step. A coke formation kinetic model has also shown appropriate results, confirming the experimental data by equal consideration of both monolayer and multilayer coke deposition kinetic orders and an exponential deactivation model.

scholarly journals Condensation By-Products in Wet Peroxide Oxidation: Fouling or Catalytic Promotion? Part II: Activity, Nature and Stability

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 518 ◽  
Author(s):  
Asunción Quintanilla ◽  
Jose L. Diaz de Tuesta ◽  
Cristina Figueruelo ◽  
Macarena Munoz ◽  
Jose A. Casas
Keyword(s):  
Catalyst Deactivation ◽  
Fixed Bed ◽  
Reaction Rates ◽  
Fixed Bed Reactor ◽  
Intrinsic Activity ◽  
Peroxide Oxidation ◽  
Air Oxidation ◽  
Carbonaceous Deposits ◽  
Wet Peroxide Oxidation ◽  
By Products

The deposition of condensation by-products onto the catalyst surface upon wet peroxide and wet air oxidation processes has usually been associated with catalyst deactivation. However, in Part I of this paper, it was demonstrated that these carbonaceous deposits actually act as catalytic promoters in the oxygen-assisted wet peroxide oxidation (WPO-O2) of phenol. Herein, the intrinsic activity, nature and stability of these species have been investigated. To achieve this goal, an up-flow fixed bed reactor packed with porous Al2O3 spheres was used to facilitate the deposition of the condensation by-products formed in the liquid phase. It was demonstrated that the condensation by-products catalyzed the decomposition of H2O2 and a higher amount of these species leads to a higher degree of oxidation degree The reaction rates, conversion values and intermediates’ distribution were analyzed. The characterization of the carbonaceous deposits on the Al2O3 spheres showed a significant amount of condensation by-products (~6 wt.%) after 650 h of time on stream. They are of aromatic nature and present oxygen functional groups consisting of quinones, phenols, aldehydes, carboxylics and ketones. The initial phenol concentration and H2O2 dose were found to be crucial variables for the generation and consumption of such species, respectively.

Methane Dry Reforming over Ni-Co/Al2O3: Kinetic Modelling in a Catalytic Fixed-bed Reactor

2017 ◽  
Vol 15 (6) ◽  
Author(s):  
Yacine Benguerba ◽  
Mirella Virginie ◽  
Christine Dumas ◽  
Barbara Ernst
Keyword(s):  
Catalyst Deactivation ◽  
Kinetic Modelling ◽  
Fixed Bed ◽  
Dry Reforming ◽  
Fixed Bed Reactor ◽  
Coke Deposition ◽  
Dry Reforming Of Methane ◽  
Reactor Model ◽  
Reverse Water Gas Shift ◽  
Different Temperatures

Abstract The dry reforming of CH4 was investigated in a catalytic fixed-bed reactor to produce hydrogen at different temperatures over supported bimetallic Ni-Co catalyst. The reactor model for the dry reforming of methane used a set of kinetic models: The Zhang et al model for the dry reforming of methane (DRM); the Richardson-Paripatyadar model for the reverse water gas shift (RWGS); and the Snoeck et al kinetics for the coke-deposition and gasification reactions. The effect of temperatures on the performance of the reactor was studied. The amount of each species consumed or/and produced were calculated and compared with the experimental determined ones. It was showed that the set of kinetic model used in this work gave a good fit and accurately predict the experimental observed profiles from the fixed bed reactor. It was found that reaction-4 and reaction-5 could be neglected which could explain the fact that this catalyst coked rapidly comparatively with other catalyst. The use of large amount of Ni-Co will lead to carbon deposition and so to the catalyst deactivation.

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