Development of a Kinetic Model for Modeling the Industrial VGO Hydrocracker Accompanied By Deactivation

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Azita Barkhordari ◽  
Shohreh Fatemi ◽  
Mahdi Daneshpayeh ◽  
Hossain Zamani
Keyword(s):  
Experimental Data ◽  
Kinetic Model ◽  
Catalyst Deactivation ◽  
Fixed Bed ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Wide Range ◽  
Silica Alumina ◽  
Parallel Reactions

Two types of kinetic modeling, continuous and discrete lump model were studied and compared in this research in order to model the industrial scale VGO hydrocracking process. The experimental data obtained from a pilot-scale fixed bed reactor over Ni-Mo/Silica-Alumina catalyst in a wide range of operating conditions was used for prediction and tuning the kinetic parameters using Genetic algorithm. In this study, the discrete lump model with four parallel reactions to four lumped products showed more convergence to the experimental data than the continuous lump model. Afterward, the discrete kinetic model was used to simulate the vacuum gas oil (VGO) industrial hydrocracking reaction accompanied by catalyst deactivation. The activity of the catalyst was taken as a time dependent variable and the first year of operational data were used to derive the deactivation parameter. The refinery test runs spanning over the last two and half years of operation were used to validate the model and interpret the simulation results. A comparison between the industrial and the predicted data showed that there is a good agreement between them and the presented model provides a reasonable fit to estimate the product yields of LPG, naphtha, kerosene, diesel.

Hydrogenation of Acetylene: Kinetic Studies and Reactor Modeling

2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Navid Mostoufi ◽  
Ali Ghoorchian ◽  
Rahmat Sotudeh-Gharebagh
Keyword(s):  
Experimental Data ◽  
Catalyst Deactivation ◽  
Fixed Bed ◽  
Kinetic Studies ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Reactor Modeling ◽  
Deactivation Rate Constant ◽  
Hydrogenation Reactor ◽  
Kinetics Of

The kinetics of acetylene hydrogenation has been studied in a fixed bed reactor of a commercial Pd/Al2O3 catalyst. The experiments were carried out at 30, 50 and 70 ºC with various feed compositions at atmospheric pressure. The experiments were repeated at 70 ºC in the presence of the used catalyst to determine the effect of the catalyst deactivation where the corresponding deactivation rate constant was determined in order to predict the activity of the catalyst during each run. Two well known kinetic models were used for a nearly similar catalyst to predict the experimental data of this work and none of them were found satisfactory. A new model was then proposed to fit the experimental data. The hydrogenation reactor was also simulated at industrial operating conditions with the proposed kinetics for both plug and dispersion flows. The results of these simulations were almost close to each other in most cases.

Kinetic Study of the Simultaneous Cracking of Paraffins and Methanol on HZSM-5 Zeolite Catalysts

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Diana Mier ◽  
Andrés Tomás Aguayo ◽  
Alaitz Atutxa ◽  
Ana G Gayubo ◽  
Javier Bilbao
Keyword(s):  
Kinetic Model ◽  
Catalyst Deactivation ◽  
Fixed Bed ◽  
Acid Catalyst ◽  
Product Distribution ◽  
Operating Conditions ◽  
Zeolite Catalysts ◽  
Fixed Bed Reactor ◽  
Light Olefins ◽  
Feed Temperature

A study has been carried out on the effect of acid catalyst properties and operating conditions (methanol/n-butane ratio in the feed, temperature, space time, time on stream) on the yield of light olefins (C2-C4) in the simultaneous cracking of n-butane and methanol. The operation has been carried out in an isothermal fixed bed reactor in the 400-575 °C range, using catalysts prepared based on HZSM-5 zeolites (with different Si/Al ratio), HY, Ni/HZSM-5 and SAPO-18. The results are evidence of a synergism between the transformation reactions of both reactants, whose consequence is an increase in the yield of olefins that correspond to the transformation of methanol and the cracking of n-butane. Furthermore, catalyst deactivation by coke is significantly attenuated compared to the corresponding transformation of methanol. Based on the effect of operating conditions on product distribution, a kinetic model is proposed by combining the schemes corresponding to the transformation of individual components.

Intrinsic Kinetics Study of CO Methanation on Ni-Mo-SiO2 Catalyst Prepared by Hydrothermal Method

2018 ◽  
Vol 921 ◽  
pp. 40-47
Author(s):  
Jia Ying Zhang
Keyword(s):  
Kinetic Model ◽  
Orthogonal Design ◽  
Fixed Bed ◽  
Reaction Network ◽  
Space Velocity ◽  
Operating Conditions ◽  
Least Square ◽  
Fixed Bed Reactor ◽  
Consecutive Reaction ◽  
Wide Range

A comprehensive kinetic model for methanation of syngas on Ni-Mo-SiO2catalyst was developed on a fixed bed reactor data. The CO and H2conversion, methane selectivity and yield were obtained in a wide range of operating conditions including 300 < T < 450°C, 1 < H2/CO <4 and 0.1 < P < 1.5 MPa with the total weight hourly space velocity (WHSV) of 60000 ml/h/g. A 6-step reaction scheme defined to the description of a reaction network that considers both catalytic and gas-phase as well as primary and consecutive reaction steps to predict the performance of the syngas methantion. Orthogonal design method was adopted to select test points with temperature, pressure and feed compositions as factors and the kinetic rates involved Langmuir – Hinshelwood equation kinetic model. The kinetic rate parameters were estimated using the Least Square Method by MATLAB. Comparing the experimental and model predicted data showed that presented model has a reasonable fit between the experimental data and the predicted values with average absolute relative deviation of ±9.8%.

Development and experimental validation of reactor kinetic model for catalytic cracking of eugenol, a potential bio additive fuel blend

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mythily Mani ◽  
Thyagarajan Thangavelu ◽  
Santhana Krishnan Perumal ◽  
Shanthi Kannan
Keyword(s):  
Kinetic Model ◽  
Real Time ◽  
Catalytic Cracking ◽  
Catalyst Deactivation ◽  
Fixed Bed ◽  
Integrated Model ◽  
Fixed Bed Reactor ◽  
Design Parameters ◽  
Exhaust Emission ◽  
Time Data

Abstract An integrated kinetic model representing catalytic cracking of eugenol in a fixed bed reactor is developed. Eugenol, a major component of clove oil can act as the most potential bio additive fuel for improving the diesel quality thereby reducing the exhaust emission of the engine. The proposed integrated model includes four lump kinetic model which is plugged with catalyst deactivation model. The reactor design parameters are also included in the integrated model. The effectiveness of the proposed integrated model is compared with the conventional kinetic models and the results are presented. The proposed integrated model is validated against the real time data obtained by conducting an experiment in a real time setup with MoS2(Ni2P) Al-SBA-15(10) as the catalyst. The advantages of the proposed integrated model are highlighted.

scholarly journals A Comprehensive Kinetic Model of Fischer-Tropsch Synthesis over Supported Cobalt Catalyst

2017 ◽  
Author(s):  
Reza Jalilzadeh ◽  
Mahmoud Moqadam
Keyword(s):  
Kinetic Model ◽  
Fixed Bed ◽  
Operating Conditions ◽  
Tropsch Synthesis ◽  
Fixed Bed Reactor ◽  
Molar Ratio ◽  
Rate Equations ◽  
Type Model ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis

A comprehensive kinetic model of the Fischer-Tropsch synthesis (FTS) is developed in a fixed bed reactor under operating conditions (temperature, 230&ndash;235&deg;C, pressure, 20&ndash;25 bar, gas hourly space velocity, 4000&ndash;5000 cm3(STP)/h/gcatalyst ,H2/CO feed molar ratio, 2.1) over a Co based catalyst. Reaction rate equations based on Eley-Rideal (ER) type model for initiation step and Langmuir-Hinshelwood-Hougen-Watson (LHHW) type model for propagation and termination steps of the FTS reactions have been considered and the readsorption of olefins were taken into account. The model that was reported in the literature was modified in order to explain many significant deviations from the ASF distribution. Optimum parameters have been obtained by Genetic Algorithms (GA). The calculated activation energies to produce n-paraffins and 1-olefins were in the range of 82.24 to 90.68 kJ/mol and 100.66 to 105.24 kJ/mol, respectively. The hydrocarbon distribution in FTS reactions was satisfactorily predicted particularly for paraffins.

Thermochemical equilibrium modeling approach for carbon-rich feedstock gasification validated against laboratory and large-scale experiments

2020 ◽  
Author(s):  
Christopher Otto ◽  
Thomas Kempka
Keyword(s):  
Synthesis Gas ◽  
Reactive Transport ◽  
Large Scale ◽  
Fixed Bed ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Equilibrium Modeling ◽  
Modeling Approach ◽  
Wide Range ◽  
Thermochemical Equilibrium

&lt;p&gt;In the present study, a pre-existing stoichiometric equilibrium model based on direct minimization of Gibbs free energy has been further developed and applied to estimate the equilibrium composition of synthesis gases produced by the gasification of carbon-rich feedstock (e.g., coal, municipal waste or biomass) in a fixed-bed reactor [1]. Our modeling approach is validated against thermodynamic models, laboratory gasification and demonstration-scale experiments reported in the literature. The simulated synthesis gas compositions have been found to be in good agreement under a wide range of different operating conditions. Consequently, the presented modeling approach enables an efficient quantification of synthesis gas compositions derived from feedstock gasification, considering varying feedstock and oxidizer compositions as well as pressures and temperatures. Furthermore, the developed model can be easily integrated with numerical flow and transport simulators to simulate reactive transport of a multi-componentgas phase.&lt;/p&gt;&lt;p&gt;[1] Otto and Kempka, Synthesis gas composition prediction for underground coal gasification using a thermochemical equilibrium modeling approach, Energies (in review)&lt;/p&gt;

scholarly journals Kinetics of Hydrogenation of Acetic Acid to Ethanol

2019 ◽  
Vol 31 (12) ◽  
pp. 2915-2923
Author(s):  
Qiang Chen ◽  
Xuebing Zhang ◽  
Shuxun Tian ◽  
Junying Long ◽  
Xiangkun Meng ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Kinetic Model ◽  
Reaction Temperature ◽  
Active Sites ◽  
Fixed Bed ◽  
Space Velocity ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Model Parameters ◽  
Intrinsic Kinetic

The intrinsic kinetic behaviour of catalytic hydrogenation of acetic acid in vapour phase was studied over a multi-metallic catalyst. The rate expression was derived from the sequence of elementary reaction steps based on a Langmuir-Hinshelwood-model involving two types of active sites. Experiments were carried out in a fixed bed reactor, which is similar to an isothermal integral reactor designed to excluding the negative effects of internal and external diffusion. The reaction conditions investigated were as follow:reaction temperature 275-325 ºC, reaction pressure1.5-3.0 MPa, liquid hourly space velocity (sv) 0.3-1.2 h-1, molar ratio of hydrogen to acetic acid (H/AC) 8:20. The results show that conversion of acetic acid increases with increasing the reaction temperature and pressure, but decreases with increasing the space velocity and H/AC. Furthermore, reducing the reaction pressure and increasing reaction temperature, space velocity and H/AC can improve the reaction selectivity of acetic acid to ethanol. The established kinetic model results agreed with experimental results. The relative difference between the calculated value and the experimental value is less than 6 %. The values of model parameters are consistent with the three thermodynamic constraints. The study provided evidence that the intrinsic kinetic model is suitable both mathematically and thermodynamically, and it could be useful in guiding reactor design and optimization of operating conditions.

Packed-Bed Reactor Performance Enhancement by Membrane Distributed Feed: The Case of Methanol Oxidative Dehydrogenation

2002 ◽  
Vol 752 ◽  
Author(s):  
Victor Diakov ◽  
Arvind Varma
Keyword(s):  
Oxidative Dehydrogenation ◽  
Membrane Reactor ◽  
Performance Enhancement ◽  
Fixed Bed ◽  
Packed Bed ◽  
Operating Conditions ◽  
Packed Bed Reactor ◽  
Fixed Bed Reactor ◽  
Reactor Performance ◽  
Wide Range

ABSTRACTFor methanol oxidative dehydrogenation to formaldehyde, the performance of the packed-bed membrane reactor (PBMR) is compared with that of the conventional fixed-bed reactor (FBR) over a wide range of operating conditions. The reaction was studied in three reactor configurations: the conventional FBR and the packed-bed membrane reactor, with either methanol (PBMR-M) or oxygen (PBMR-O) as the permeating component. The kinetics of methanol and formaldehyde partial oxidation reactions were determined and incorporated in a PBMR model. Both experimental data and model considerations demonstrate that the PBMR enhances reactant conversion and selectivity.Small oscillations in CO production were observed experimentally. Their amplitude was taken as a basis for comparison of packed-bed operation instability. The likely source of oscillatory behavior is the non-uniformity in reaction conditions along the reactor. It was found that membrane distributed feed, by providing a more uniform reactor operation, is an effective remedy from these instabilities.It is found, both by simulations and experimental observations, that relative reactor performance depends strongly on the operating conditions. Using formaldehyde yield as the basis for optimization, optimal reactor performances are determined to be in the order: PBMR-O > FBR > PBMR-M. Further PBMR productivity enhancement is possible by optimizing the membrane feed distribution pattern.

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.

Performance Characterization of a Twin Scroll Volute for Turbocharging Applications

2018 ◽  
Author(s):  
Carlo Cravero ◽  
Mario La Rocca ◽  
Andrea Ottonello
Keyword(s):  
Experimental Data ◽  
Scientific Literature ◽  
Aerodynamic Performance ◽  
Operating Conditions ◽  
Automatic Design ◽  
Cfd Model ◽  
Radial Turbine ◽  
Wide Range ◽  
Partial Admission

The use of twin scroll volutes in radial turbine for turbocharging applications has several advantages over single passage volute related to the engine matching and to the overall compactness. Twin scroll volutes are of increasing interest in power unit development but the open scientific literature on their performance and modelling is still quite limited. In the present work the performance of a twin scroll volute for a turbocharger radial turbine are investigated in some detail in a wide range of operating conditions at both full and partial admission. A CFD model for the volute have been developed and preliminary validated against experimental data available for the radial turbine. Then the numerical model has been used to generate the database of solutions that have been investigated and used to extract the performance. Different parameters and indices are introduced to describe the volute aerodynamic performance in the wide range of operating conditions chosen. The above parameters can be used for volute development or matching with a given rotor or efficiently implemented in automatic design optimization strategies.

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