scholarly journals Robust generic model feedback under model uncertainties: Application of a tubular reactor for the treatment of industrial plating wastewater

2008 ◽  
Vol 6 (03) ◽  
Author(s):  
Ricardo Aguilar-López ◽  
Ricardo Acevedo-Gómez ◽  
Marí­a Isabel Neria González ◽  
Alma Rosa Domí­nguez-Bocanegra
Keyword(s):  
Flow Reactor ◽  
Laboratory Data ◽  
Plug Flow ◽  
Tubular Reactor ◽  
Generic Model ◽  
Model Uncertainties ◽  
Kinetic Rate ◽  
Integral Action ◽  
The Stability ◽  
Plating Wastewater

The goal of this work is to describe the design of a feedback controller to regulate the Hexavalent chromium (Cr (VI)) concentration in industrial plating wastewater in a tubular reactor. Cr(VI) is a major pollutant present in industrial wastewaters common to the metal and mineral processing as well as to plating industries. For control purposes, a dynamic model of a plug flow reactor with dispersion is developed in the form of partial differential equations (PDE) via applying classical conservation principles; this model is experimentally corroborated using laboratory data. The proposed controller is based on uncertainty observer to infer unknown terms as diffusive transport and Cr(VI) kinetic rate; also Generic Model Controller (GMC) is coupled with this estimation methodology to provide robustness against model uncertainties. The controller leads to nonlinear PID plus double integral action, where the tuning rules are given in terms of the observer and GMC gains. A theoretical frame is given in order to show the stability properties of the closed-loop system under the proposed controller. Numerical simulation illustrates performance of the methodology proposed; a comparison with observer based I/O linearizing controller and a well tuned PID controller is done, which allows concluding that the observer based Generic Model Controller exhibits better performance.

scholarly journals Kinetic study of hydrolysis of ethyl acetate using caustic soda

2018 ◽  
Vol 7 (4) ◽  
pp. 1995 ◽  
Author(s):  
Mostafa Ghobashy ◽  
Mamdouh Gadallah ◽  
Tamer T.El-Idreesy ◽  
M. A.Sadek ◽  
Hany A.Elazab
Keyword(s):  
Caustic Soda ◽  
Ethyl Acetate ◽  
Flow Reactor ◽  
Design Method ◽  
Plug Flow ◽  
Tubular Reactor ◽  
Acid Base ◽  
Chemical Reaction Kinetics ◽  
Hydrolysis Of

We report here, the hydrolysis of ethyl acetate by using caustic soda which is followed by means of conductance measurements which is widely used in chemical industry. The main aim of this research is to study the parameters of production of ethyl acetate by chemical reaction kinetics using an anion ion-exchange acting as a catalyst and acid-base titrations. The reaction of ethyl acetate and sodium hydroxide (caustic-soda) is done in a plug-flow reactor (steady-state tubular reactor) under the effect of different parameters including temperature, concentration and flow-rate, which allows the determination of activation energy and rate constants, due to large number of experiments. Factorial design method is used for the calculations of the experiment. It was determined that the order of the reaction is a second-order reaction.  

Comparison of Raschig Ring Packing Pattern via Mean Resident Time using CFD Particle Tracing Technique: Dry Methane Reforming for Case Study

2018 ◽  
Author(s):  
Nattaporn Chutichairattanaphum ◽  
Phavanee Narataruksa ◽  
Karn Pana-Suppamassadu ◽  
Sabaithip Tungkamani ◽  
Chaiwat Prapainainar ◽  
...  
Keyword(s):  
Flow Reactor ◽  
Flow Behavior ◽  
Plug Flow ◽  
Tubular Reactor ◽  
Packed Bed ◽  
Methane Reforming ◽  
Particle Tracing ◽  
Raschig Ring ◽  
Resident Time

This paper aims to study the effect of raschig ring packing patterns using Computational Fluid Dynamics (CFD). CFD module of particle tracing was established to measure particles diffusing through the packed bed. The support raschigs catalyst was modeled in three patterns within a tubular reactor – namely, vertical staggered, chessboard staggered and reciprocal staggered pattern. A case study of Dry Methane Reforming (DMR) was investigated at 600°C, 1 atm. The study of Mean Resident Time (MRT) and E(t) function were investigated to identify the packing pattern performance. The results showed that the minimum value of the E(t), which means the flow behavior, was close to ideal plug flow behavior. MRT can be used to systematically identify the deviation from the ideal plug flow reactor of the three different packing patterns.

scholarly journals Digital Twins for Continuous mRNA Production

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1967
Author(s):  
Heribert Helgers ◽  
Alina Hengelbrock ◽  
Axel Schmidt ◽  
Jochen Strube
Keyword(s):  
Flow Reactor ◽  
Continuous Production ◽  
Effective Means ◽  
Plug Flow ◽  
Tubular Reactor ◽  
In Vitro Transcription ◽  
Stirred Tank ◽  
Parameter Determination ◽  
Messenger Ribonucleic Acid

The global coronavirus pandemic continues to restrict public life worldwide. An effective means of limiting the pandemic is vaccination. Messenger ribonucleic acid (mRNA) vaccines currently available on the market have proven to be a well-tolerated and effective class of vaccine against coronavirus type 2 (CoV2). Accordingly, demand is presently outstripping mRNA vaccine production. One way to increase productivity is to switch from the currently performed batch to continuous in vitro transcription, which has proven to be a crucial material-consuming step. In this article, a physico-chemical model of in vitro mRNA transcription in a tubular reactor is presented and compared to classical batch and continuous in vitro transcription in a stirred tank. The three models are validated based on a distinct and quantitative validation workflow. Statistically significant parameters are identified as part of the parameter determination concept. Monte Carlo simulations showed that the model is precise, with a deviation of less than 1%. The advantages of continuous production are pointed out compared to batchwise in vitro transcription by optimization of the space–time yield. Improvements of a factor of 56 (0.011 µM/min) in the case of the continuously stirred tank reactor (CSTR) and 68 (0.013 µM/min) in the case of the plug flow reactor (PFR) were found.

Quadrotor Position Control Using Cascaded Adaptive Integral Backstepping Controllers

2014 ◽  
Vol 565 ◽  
pp. 98-106 ◽  
Author(s):  
Younes Al Younes ◽  
Ahmad Drak ◽  
Hassan Noura ◽  
Abdelhamid Rabhi ◽  
Ahmed El Hajjaji
Keyword(s):  
Position Control ◽  
Control Technique ◽  
Test Results ◽  
Model Uncertainties ◽  
Second Stage ◽  
Integral Action ◽  
Modeling Errors ◽  
The Stability ◽  
Adaptation Law ◽  
Two Stages

This paper proposes a nonlinear control technique to control the position of the Qball-X4 quadrotor using a cascaded methodology of two Adaptive Integral Backstepping Controllers (AIBC). The nonlinear algorithm uses the principle of Lyapunov methodology in the backstepping technique to ensure the stability of the vehicle, and utilizes the integral action to eliminate the steady state error that caused by the disturbances and model uncertainties, as well as, the adaptation law will estimate the modeling errors caused by assumptions in simplifying the complexity of the quadrotor model. The algorithm goes through two stages of cascaded AIBCs; the first stage aims to stabilize the attitude and the altitude of the quadrotor, and the second stage feeds the first stage with the desired attitude values to control the position of the quadrotor.Flight test results show that the proposed algorithm is capable of controlling the position of the nonlinear quadrotor model.

Surface Modification of Nanocrystalline Zeolite X and Its Application as Catalyst in Synthesis of Cumene in a Packed Bed Flow Reactor: A Kinetic Study

2017 ◽  
Vol 16 (2) ◽  
Author(s):  
Ruchika Thakur ◽  
Sanghamitra Barman ◽  
Gopinath Halder
Keyword(s):  
Crystal Size ◽  
Flow Reactor ◽  
Plug Flow ◽  
Fixed Bed ◽  
Packed Bed ◽  
Product Distribution ◽  
Ceric Ammonium Nitrate ◽  
Zeolite X ◽  
Kinetic Rate ◽  
Nano Crystalline

AbstractIn the present investigation, synthesis of cumene by transalkylation of 1, 4 DIPB with benzene was studied over cerium modified nano crystalline zeolite X in a fixed bed plug flow reactor. Nano crystalline zeolite X was synthesized and characterized by XRD, SEM, TPD, EDS and FTIR. A series of nanocrystalline zeolite X (MX4, MX6, MX10) modified with ceric ammonium nitrate of different concentrations (4 %, 6 %, 10 %) was used for synthesis of cumene. MX10zeolite was proved to be the most active catalyst over which 27.12 % yield of cumene was obtained at temperature 553K, benzene/1, 4 DIPB mole ratio of 7.5 and space time-10.54 kg h/kmol. Reduction of crystal size (100–500 nm) in MX10increases surface area (633m2/gm) and thereby increases cumene yield. A kinetic rate equation was developed from the product distribution pattern following Langmuir–Hinshelwood approach. Kinetic parameters were estimated by nonlinear regression analysis. The activation energy for transalkylation and isomerisation reaction was found to be 88.86 kJ/mol and 99.04 kJ/mol respectively.

scholarly journals Design and Control of Glycerol-tert-Butyl Alcohol Etherification Process

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Elena Vlad ◽  
Costin Sorin Bildea ◽  
Grigore Bozga
Keyword(s):  
Flow Reactor ◽  
Plug Flow ◽  
Extractive Distillation ◽  
Butyl Alcohol ◽  
Balance Model ◽  
Distillation Columns ◽  
Control Structures ◽  
Amberlyst 15 ◽  
Plantwide Control ◽  
The Stability

Design, economics, and plantwide control of a glycerol-tert-butyl alcohol (TBA) etherification plant are presented. The reaction takes place in liquid phase, in a plug flow reactor, using Amberlyst 15 as a catalyst. The products' separation is achieved by two distillation columns where high-purity ethers are obtained and a section involving extractive distillation with 1,4-butanediol as solvent, which separates TBA from the TBA/water azeotrope. Details of design performed in AspenPlus and an economic evaluation of the process are given. Three plantwide control structures are examined using a mass balance model of the plant. The preferred control structure fixes the fresh glycerol flow rate and the ratio glycerol + monoether : TBA at reactor-inlet. The stability and robustness in the operation are checked by rigorous dynamic simulation in AspenDynamics.

scholarly journals Design of a Bench-Scale Tubular Reactor Similar to Plug Flow Reactor for Gas-Phase Kinetic Data Generation-Illustration with the Pyrolysis of Octanoic Acid

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2270
Author(s):  
Julien Gornay ◽  
Edouard Plasari ◽  
Jean-François Portha ◽  
Pierre-Alexandre Glaude ◽  
Francis Billaud ◽  
...  
Keyword(s):  
Gas Phase ◽  
Kinetic Data ◽  
Octanoic Acid ◽  
Flow Reactor ◽  
Dispersion Coefficient ◽  
Plug Flow ◽  
Tubular Reactor ◽  
Data Generation ◽  
Bench Scale ◽  
Axial Dispersion Coefficient

The material described in this article deals with waste conversion into energy vectors by pyrolysis, steam cracking, or oxidation of liquid biomass, carried out at small to medium scale. The design of a bench-scale experimental setup devoted to gas phase kinetic data generation in a tubular reactor under laminar regime close to plug flow is detailed based on a very simple approach. Validation of the designed bench-scale setup was successfully carried out within the context of octanoic acid pyrolysis by generating kinetic data with satisfactory measurement repeatability and material balances. The key to this positive result is that axial dispersion coefficient is much smaller in gas-phase than in liquid-phase, thus allowing the designed small sized tubular reactor to be close to the plug flow reactor. Such a feature of the axial dispersion coefficient is not well known by the wider public. Besides, octanoic acid was selected as surrogate for carboxylic acids because of their key role in various industrial applications (combustion of ethyl biodiesel; production of biofuel and biosourced chemicals).

A stochastic model for two-station hydraulics exhibiting transient impact

1997 ◽  
Vol 36 (5) ◽  
pp. 19-26 ◽  
Author(s):  
J. L. Jacobsen ◽  
H. Madsen ◽  
P. Harremoès
Keyword(s):  
Parameter Estimation ◽  
Flow Reactor ◽  
Deterministic Model ◽  
Plug Flow ◽  
Stochastic Methods ◽  
Sewer System ◽  
Statistical Tool ◽  
Water Level Variation ◽  
Deterministic Description ◽  
Linear Reservoir

The objective of the paper is to interpret data on water level variation in a river affected by overflow from a sewer system during rain. The simplest possible, hydraulic description is combined with stochastic methods for data analysis and model parameter estimation. This combination of deterministic and stochastic interpretation is called grey box modelling. As a deterministic description the linear reservoir approximation is used. A series of linear reservoirs in sufficient number will approximate a plug flow reactor. The choice of number is an empirical expression of the longitudinal dispersion in the river. This approximation is expected to be a sufficiently good approximation as a tool for the ultimate aim: the description of pollutant transport in the river. The grey box modelling involves a statistical tool for estimation of the parameters in the deterministic model. The advantage is that the parameters have physical meaning, as opposed to many other statistically estimated, empirical parameters. The identifiability of each parameter, the uncertainty of the parameter estimation and the overall uncertainty of the simulation are determined.

Efficient Production of Light Olefin Based on Methanol Dehydration: Simulation and Design Improvement

2020 ◽  
Vol 23 ◽  
Author(s):  
S. Majid Abdoli ◽  
Mahsa Kianinia
Keyword(s):  
Dimethyl Ether ◽  
Flow Reactor ◽  
New Technology ◽  
Plug Flow ◽  
Light Olefins ◽  
Efficient Production ◽  
Actual Process ◽  
Light Olefin ◽  
Aspen Hysys ◽  
Improved Design

Background: Ethylene, propylene, and butylene as light olefins are the most important intermediates in the petrochemical industry worldwide. Methanol to olefins (MTO) process is a new technology based on catalytic cracking to produce ethylene and propylene from methanol. Aims and Objective: This study aims to simulate the process of producing ethylene from methanol by using Aspen HYSYS software from the initial design to the improved design. Methods: Ethylene is produced in a two-step reaction. In an equilibrium reactor, the methanol is converted to dimethyl ether by an equilibrium reaction. The conversion of the produced dimethyl ether to ethylene is done in a conversion reactor. Changes have been made to improve the conditions and get closer to the actual process design done in the industry. The plug flow reactor has been replaced by the equilibrium reactor, and the distillation column was employed to separate the dimethyl ether produced from the reactor. Result and Conclusion: The effect of the various parameters on the ethylene production was investigated. Eventually, ethylene is

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