Three-phase modeling and optimization of benzene alkylation in commercial catalytic reactors

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Donya Danesh ◽  
Mohammad Farsi ◽  
Mohammad Reza Rahimpour
Keyword(s):  
Production Capacity ◽  
Solid Catalyst ◽  
Process Conditions ◽  
Catalytic Reactors ◽  
Benzene Alkylation ◽  
Conventional Condition ◽  
Liquid Phases ◽  
Decision Variables ◽  
Three Phase ◽  
Simulation Results

Abstract The main object of this research is heterogenous modeling of benzene alkylation in three phase reactors based on the mass and energy balance equations by coupling the kinetic and equilibrium models and optimization the process conditions to enhance production capacity. In the first step, the alkylation reactors are simulated considering a three-phase model including heat and mass transfer resistances in the solid catalyst, gas and liquid phases. To prove the accuracy of developed model and adopted assumptions, the simulation results are compared with the plant data. Based on the simulation results, the benzene conversion and ethylbenzene selectivity in the alkylation reactors are 15.03 and 94.60% at the conventional condition. In the second step, considering the temperature of inlet streams to the reactors as decision variables, an optimization problem is formulated to maximize the ethylbenzene production rate as the objective function. Based on the simulation results, applying optimal condition on the system improves the ethylbenzene production by 1.33% at the same ethylene conversion compared to the conventional condition.

Modeling of the Catalytic Distillation Process for the Synthesis of Ethyl Cellosolve Using A Three-Phase Nonequilibrium Model

2002 ◽  
Vol 1 (1) ◽  
Author(s):  
Yuxiang Zheng ◽  
Flora T. T. Ng ◽  
Garry L. Rempel
Keyword(s):  
Theoretical Plate ◽  
Solid Catalyst ◽  
Catalytic Distillation ◽  
Nonequilibrium Model ◽  
Liquid Phases ◽  
Three Phase ◽  
Model Predictions ◽  
Plant Data ◽  
Model Equations ◽  
Good Agreement

The catalytic distillation (CD) process for the synthesis of ethyl cellosolve from ethanol and ethylene oxide on molecular sieve catalyst NKC-01 in a 200 mm CD pilot column was simulated using the three-phase nonequilibrium model which was developed in our laboratory. The main feature of this model is that the actual rates for transport and reaction are used and the stage efficiency or HETP (height equivalent to a theoretical plate) is not required. The effect of multicomponent mass and heat transfer between vapor and liquid phases as well as between liquid and solid (catalyst) phases was taken into account according to the Maxwell-Stefan equations. The Newton-Raphson method was used to solve the model equations. The simulation profiles of the temperature and composition along the column are in good agreement with the pilot CD plant data obtained for the synthesis of ethyl cellosolve. Good agreement between model predictions and experimental data is also obtained for the yield and selectivity of the ethyl cellosolve. This model could be extended to simulate other CD processes and commercial scale CD plants.

Modification of Claus Sulfur Recovery Unit by Isothermal Reactors to Decrease Sulfur Contaminant Emission: Process Modeling and Optimization

2018 ◽  
Vol 14 (2) ◽  
Author(s):  
H. Ghahraloud ◽  
M. Farsi ◽  
M.R. Rahimpour
Keyword(s):  
Fixed Bed ◽  
Recovery Process ◽  
Coolant Temperature ◽  
Inlet Temperature ◽  
Sulfur Recovery ◽  
Catalytic Reactors ◽  
Steady State Condition ◽  
Conventional Process ◽  
Decision Variables ◽  
Simulation Results

Abstract Due to environmental limitations and issues, the main goal of this research is modification of conventional Claus sulfur recovery process to decreases sulfur contaminant emission. In this regard, two environmentally friendly alternatives are proposed based on the isothermal concept in reactors. Since Claus reaction is exothermic and reversible, the adiabatic fixed bed reactors in the catalytic section of Claus process are substituted by the isothermal reactors. The furnace and catalytic reactors are modeled based on the mass and energy conservation laws at steady state condition. To prove accuracy of the developed model, the simulation results of conventional process are compared with the available plant data. Then, the optimal condition of modified processes are calculated considering sulfur recovery as the objective function using the Genetic algorithm as a useful method in global optimization. The attainable decision variables are inlet temperature of furnace and reactors, coolant temperature, feed split fraction and air flow rate in the furnace. The simulation results show that H2S conversion in the proposed cases increases about 1.87 % and 1.78 % compared to the conventional process. Generally, the main advantages of proposed structures are higher sulfur recovery and lower sulfur contaminant emission such as COS and CS2 emission.

Control and Optimization of a Three Phase Industrial Hydrogenation Reactor

2004 ◽  
Vol 2 (1) ◽  
Author(s):  
Mylene Cristina Rezende ◽  
Aline Carvalho Costa ◽  
Rubens Maciel Filho
Keyword(s):  
Dynamic Behavior ◽  
Challenging Behavior ◽  
Dynamic Matrix Control ◽  
Catalytic Reactors ◽  
Control Structures ◽  
Dynamic Matrix ◽  
Liquid Phases ◽  
Three Phase ◽  
Hydrogenation Reactor ◽  
Matrix Control

Three phase catalytic reactors are very important industrial reactors with complex steady state and dynamic behavior. In fact, the interaction among the gas, solid and liquid phases with the kinetic, mass and heat transfer mechanisms lead the system to have a challenging behavior. That is the case for the o-cresol hydrogenation to obtain 2-methyl-cyclohexanol, which is carried out in a three phase catalyst slurry reactor. A determinist mathematical model was developed using the mass and energy conservation equations for each phase, so that a system of differential equations is generated. In order to identify some suitable control structures an extensive dynamic behavior analysis was carried out. The controller implemented was a multivariable predictive controller based on the philosophy of Dynamic Matrix Control (DMC). The problem of optimization was solved through non-linear programming making use of the Successive Quadratic Programming (SQP) algorithm.

scholarly journals Non-conventional Cascade Multilevel Inverter with Lower Number of Switches by Using Multilevel PWM

2021 ◽  
Vol 17 (1) ◽  
pp. 1-13
Author(s):  
Adala Abdali ◽  
Ali Abdulabbas ◽  
Habeeb Nekad
Keyword(s):  
High Voltage ◽  
High Power ◽  
Power Loss ◽  
Output Voltage ◽  
Lower Number ◽  
Multilevel Inverter ◽  
Three Phase ◽  
Multi Level ◽  
Simulation Results ◽  
Circuit Configuration

The multilevel inverter is attracting the specialist in medium and high voltage applications, among its types, the cascade H bridge Multi-Level Inverter (MLI), commonly used for high power and high voltage applications. The main advantage of the conventional cascade (MLI) is generated a large number of output voltage levels but it demands a large number of components that produce complexity in the control circuit, and high cost. Along these lines, this paper presents a brief about the non-conventional cascade multilevel topologies that can produce a high number of output voltage levels with the least components. The non-conventional cascade (MLI) in this paper was built to reduce the number of switches, simplify the circuit configuration, uncomplicated control, and minimize the system cost. Besides, it reduces THD and increases efficiency. Two topologies of non-conventional cascade MLI three phase, the Nine level and Seventeen level are presented. The PWM technique is used to control the switches. The simulation results show a better performance for both topologies. THD, the power loss and the efficiency of the two topologies are calculated and drawn to the different values of the Modulation index (ma).

Prototype of an Electric Drive Elevator

2017 ◽  
Vol 0 (0) ◽  
Author(s):  
M. Gaiceanu ◽  
S. Epure ◽  
C. R. Dache ◽  
S. Ciuta
Keyword(s):  
Electric Drive ◽  
Induction Machine ◽  
Power Converter ◽  
Experimental Platform ◽  
Electric Drive System ◽  
Ac Power ◽  
Three Phase ◽  
Chain Transmission ◽  
Simulation Results ◽  
Quality Features

Abstract The research purpose of the authors is reducing the energy consumption of the main worldwide consumer - the electric motors- by useful utilization of the input energy through the Regenerative Electric Drive System having also the power quality features. The prototype of the electric elevator consists mainly of two trolley: one serve for the active load, and the other as counterweight, gearbox, power converter, induction machine and chain transmission. The elevator is driven by using 4kW three-phase induction machine through AC-AC power converter and has the capacity of 450 kg. The numerical simulation results and the experimental platform are shown.

Qualitative simulation of organization quality specific immune decision-making of manufacturing enterprises based on QSIM algorithm simulation

2021 ◽  
pp. 1-18
Author(s):  
Qiang Liu ◽  
Xiaoli Qu ◽  
Danyu Zhao ◽  
Yu Guo
Keyword(s):  
Decision Making ◽  
Simulation Method ◽  
Engineering Management ◽  
Decision Variable ◽  
Science And Engineering ◽  
Qualitative Simulation ◽  
Manufacturing Enterprises ◽  
Decision Variables ◽  
Organization Quality ◽  
Simulation Results

Quality is the core of the enterprise, strengthening organization quality specific immune is the key channel. Organization quality specific immune belongs to science and engineering management field, QSIM qualitative simulation method that refer to computational simulation algorithm is widely used in the science and engineering management field, QSIM qualitative simulation method can solve science and engineering management issues effectively. In this study, qualitative simulation QSIM theory is used to analyze and reason the organization quality specific immune decision of manufacturing enterprises. Combined with the pressure-state-response framework, the management mechanism of organization quality specific immune is analyzed according to state variables, decision variables, system variables and environment variables, and further the qualitative simulation rules for organization quality specific immune decision-making are set according to the causal relationships among variables of organization quality specific immune. This study sets organization quality monitor, organization quality defense and organization quality memory as the decision variables, uses QSIM algorithm for simulating organization quality specific immune decision-making reasoning, compares with the influences of single decision variable and multi-decision variables on organization quality specific immune system through simulation results. Simulation results indicate that QSIM algorithm simulation can be used to simulate and reason organization quality specific immune decision-making in order to help manufacturing enterprises reasonably enhance organization quality specific immune performance and quality performance through three decision variables of organization quality monitor, organization quality defense and organization quality memory. The simulation results will provide new revelation for organization quality specific immune decision-making of manufacturing enterprises.

Multiphase Reactions and Reactors

2001 ◽  
Author(s):  
L. K. Doraiswamy
Keyword(s):  
Liquid Phase ◽  
Solid Phase ◽  
Complete Classification ◽  
Catalytic Reactions ◽  
Two Phase ◽  
Multiphase Reactions ◽  
Liquid Phases ◽  
Three Phase ◽  
Solid Form

The first three chapters of this part dealt with two-phase reactions. Although catalysts are not generally present in these systems, they can be used in dissolved form in the liquid phase. This, however, does not increase the number of phases. On the other hand, there are innumerable instances of gas-liquid reactions in which the catalyst is present in solid form. A popular example of this is the slurry reactor so extensively employed in reactions such as hydrogenation and oxidation. There are also situations where the solid is a reactant or where a phasetransfer catalyst is immobilized on a solid support that gives rise to a third phase. A broad classification of three-phase reactions and reactors is presented in Table 17.1 (not all of which are considered here). This is not a complete classification, but it includes most of the important (and potentially important) types of reactions and reactors. The thrust of this chapter is on reactions and reactors involving a gas phase, a liquid phase, and a solid phase which can be either a catalyst (but not a phasetransfer catalyst) or a reactant, with greater emphasis on the former. The book by Ramachandran and Chaudhari (1983) on three-phase catalytic reactions is particularly valuable. Other books and reviews include those of Shah (1979), Chaudhari and Ramachandran (1980), Villermaux (1981), Shah et al. (1982), Hofmann (1983), Crine and L’Homme (1983), Doraiswamy and Sharma (1984), Tarmy et al. (1984), Shah and Deckwer (1985), Chaudhari and Shah (1986), Kohler (1986), Chaudhari et al. (1986), Hanika and Stanek (1986), Joshi et al. (1988), Concordia (1990), Mills et al. (1992), Beenackers and Van Swaaij (1993), and Mills and Chaudhari (1997). Doraiswamy and Sharma (1984) also present a discussion of gas-liquid-solid noncatalytic reactions in which the solid is a reactant. In Chapter 7 we saw how Langmuir-Hinshelwood-Hougen-Watson (LHHW) models are normally used to describe the kinetics of gas-solid (catalytic) or liquid-solid (catalytic) reactions, and in Chapters 14 to 16 we saw how mass transfer between gas and liquid phases can significantly alter the rates and regimes of these two-phase reactions.

scholarly journals A Combined RMS-MEAN Value Approach for an Inverter Open-Circuit Fault Detection

2019 ◽  
Vol 63 (3) ◽  
pp. 169-177
Author(s):  
Mohamed Amine Khelif ◽  
Azeddine Bendiabdellah ◽  
Bilal Djamal Eddine Cherif
Keyword(s):  
Fault Detection ◽  
Induction Machines ◽  
Mean Value ◽  
Open Circuit ◽  
Major Research ◽  
Three Phase ◽  
Paper Work ◽  
The Mean ◽  
Simulation Results ◽  
Structural Failures

Currently, with the power electronics evolution, a major research axis is oriented towards the diagnosis of converters supplying induction machines. Indeed, a converter such as the inverter is susceptible to have structural failures such as faulty leg and/or open-circuit IGBT faults. In this paper, the detection of the faulty leg and the localization of the open-circuit switch of an inverter are investigated. The fault detection technique used in this work is based essentially upon the monitoring of the root mean square (RMS) value and the calculation of the mean value of the three-phase currents. In the first part of the paper work, the faulty leg is detected by monitoring the RMS value of the three-phase currents and comparing them to the nominal value of the phase current. The second part, the open-circuit IGBT fault is localized simply by knowing the polarity of the calculated mean value current of the faulty phase. The work is first accomplished using simulation work and then the obtained simulation results are validated by experimental work conducted in our LDEE laboratory to illustrate the effectiveness, simplicity and rapidity of the proposed technique.

Simulation of the micro-injection moulding process: effect of the thermo-rheological status on the morphology

2011 ◽  
Vol 225 (4) ◽  
pp. 224-238 ◽  
Author(s):  
T Nguyen-Chung ◽  
C Löser ◽  
G Jüttner ◽  
T Pham ◽  
M Obadal ◽  
...  
Keyword(s):  
Injection Moulding ◽  
Process Conditions ◽  
Transfer Coefficients ◽  
Moulding Process ◽  
Micro Injection Moulding ◽  
Mould Filling ◽  
Injection Moulding Process ◽  
Moulding Machine ◽  
Simulation Results ◽  
Micro Cavity

The software package Moldflow Plastics Insights was used to simulate the filling of a micro-cavity by considering precise material data and accurate boundary conditions. Experiments were carried out on an accurately controlled micro-injection moulding machine (formicaPlast) for providing important parameters to verify the simulation results and improve the accuracy of the simulation. Based on the relationship between the cavity pressure and the mould-filling ratio, the heat transfer coefficients can be appropriately determined for different process conditions. Finally, the transient thermo-rheological results were analysed with regard to their influence on the morphology of semi-crystalline (PP) micro-injection moulded parts, which not only give rise to the mechanisms of the morphological formation but also verify the quality of the simulation results.

Realization of Fixed Switching Frequency Direct Power Control for Three-Phase AC/DC Converter

2013 ◽  
Vol 385-386 ◽  
pp. 1216-1219
Author(s):  
Yun Liang Wang ◽  
Yong Le Zhao
Keyword(s):  
Power Control ◽  
Pulse Width Modulation ◽  
Control Strategies ◽  
Modulation Method ◽  
Switching Frequency ◽  
Direct Power ◽  
Direct Power Control ◽  
Three Phase ◽  
Simulation Results ◽  
Virtual Flux

This paper presents fixed switching frequency direct power control (FSF-DPC) for three-phase AC/DC converter. Sensorless control strategies based on virtual-flux can optimize the performance of the system. In this paper, realization of pulse width modulation method for FSF-DPC is presented. The simulation results show that the system running performance is good.

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