Influence of the reactive distillation column configuration on its performance: A computational study

2008 ◽  
Vol 62 (1) ◽  
Author(s):  
Zuzana Švandová ◽  
Jozef Markoš ◽  
L’udovít Jelemenský
Keyword(s):  
Flow Rate ◽  
Distillation Column ◽  
Reactive Distillation ◽  
Computational Study ◽  
Reaction System ◽  
Reflux Ratio ◽  
Feed Flow Rate ◽  
Butyl Ether ◽  
Dynamic Simulations ◽  
Tertiary Butyl

AbstractComparison of the performance of a reactive distillation column with three different hardware configurations is presented. As a reaction system the methyl tertiary-butyl ether (MTBE) synthesis has been chosen. The sieve tray columns with catalyst (encased inside wire gauze envelopes) placed along the liquid flow path differ in the number of reactive trays. The column simulations have been performed using the nonequilibrium model. The steady state behaviour of the three different hardware configurations was studied regarding the three input parameters; feed flow rate of methanol, feed flow rate of butenes, and reflux ratio. It has been shown that by varying the location of the methanol feed stage, the columns exhibit significantly different solution diagrams using the butenes feed flow rate as a continuation parameter. Using dynamic simulations, different perturbations of the manipulated variables were found to cause transitions between multiple steady states and these were also investigated. The major objective of this paper is to demonstrate the importance of the hardware choice in the performance of a reactive distillation column e.g. during the start-up or if occasional variations of the operating parameters occur.

scholarly journals Modeling Of A Reactive Distillation Column: Methyl Tertiary Butyl Ether (Mtbe) Simulation Studies

1970 ◽  
Vol 4 (2) ◽  
Author(s):  
Ismail Mohd Saaid Abdul Rahman Mohamed and Subhash Bhatia
Keyword(s):  
Distillation Column ◽  
Reactive Distillation ◽  
Relaxation Method ◽  
Differential Algebraic Equations ◽  
Operating Conditions ◽  
Integration Scheme ◽  
Algebraic Equations ◽  
Butyl Ether ◽  
Tertiary Butyl ◽  
Proposed Model

A process simulation stage-wise reactive distillation column model formulated from equilibrium stage theory was developed. The algorithm for solving mathematical model represented by sets of differential-algebraic equations was based on relaxation method. Numerical integration scheme based on backward differentiation formula was selected for solving the stiffness of differential-algebraic equations. Simulations were performed on a personal computer (PC Pentium processor) through a developed computer program using FORTRAN90 programming language. The proposed model was validated by comparing the simulated results with the published simulation results and with the pilot plant data from the literature. The model was capable of predicting high isobutene conversion for heterogeneous system, as desirable in industrial MTBE production process. The comparisons on temperature profiles, liquid composition profile and operating conditions of reactive distillation column also showed promising results. Therefore the proposed model can be used as a tool for the development and simulation of reactive distillation column.Keywords: Modeling, simulation, reactive distillation, relaxation method, equilibrium stage, heterogeneous, MTBE

scholarly journals Operability Analysis of MTBE Reactive Distillation Column using a Process Simulator

2009 ◽  
Vol 4 (3) ◽  
Author(s):  
Herry Santoso ◽  
Jie Bao ◽  
Peter L Lee
Keyword(s):  
Steady State ◽  
Process Design ◽  
Distillation Column ◽  
Reactive Distillation ◽  
Design Parameters ◽  
Hammerstein Model ◽  
Reflux Ratio ◽  
Tertiary Butyl ◽  
Highly Nonlinear ◽  
Process Simulator

It has been understood for decades that process operability does not depend entirely upon the control system but also on the inherent properties of the process itself. For example, the decision on the size of equipment or the use of a highly integrated process may have a significant impact on the overall operability. Ignoring operability during process design may lead to a very difficult to control process. In this paper, a dynamic operability analysis of a Methyl Tertiary Butyl Ether (MTBE) reactive distillation column is presented. The effects of two design parameters, i.e. the reboiler duty and the reflux ratio, on the operability of the reactive distillation system are studied. Process operability is defined as the ability of the process to return to the steady-state in spite of unknown but bounded disturbances. The nonlinearity of the process is represented using a Hammerstein model, which can be easily obtained during process design from the steady-state model combined with some limited information on the process dynamics. The recent operability analysis method proposed by Rojas et al. (2007) is extended such that it can be implemented conveniently as one extra step after the flowsheet simulation using a process simulator. Based on this approach, an optimal controller for this highly nonlinear process is determined by solving a linear matrix inequality (LMI) optimization problem.

Simulation of Methyl Tertiary Butyl Ether Production in Catalytic Distillation

2012 ◽  
Vol 263-266 ◽  
pp. 444-447
Author(s):  
Jin Nan Chen ◽  
Yu Chun Zhang ◽  
Xing Yong Sun
Keyword(s):  
Relative Error ◽  
Conversion Rate ◽  
Model Development ◽  
Methyl Tertiary Butyl Ether ◽  
Reflux Ratio ◽  
Distillation Process ◽  
Butyl Ether ◽  
Catalytic Distillation ◽  
Design Data ◽  
Tertiary Butyl

The software of the catalytic distillation process of methyl tertiary butyl ether was developed by using Process Simulation System Platform. The isobutylene conversion rate was calculated by using the catalytic distillation software. The relative error of isobutylene conversion rate between the simulation results and the design data from the China Petroleum Hohhot Petrochemical Co. was less than 5%. The relative error satisfies industrial design requirements. At present, enterprise workers use this software to learn how to operate the catalytic distillation process. The catalytic distillation software is further used to study the influence of reaction temperature and reflux ratio on the isobutylene conversion rate which can be used for future empirical model development and control studies.

scholarly journals Comparison of Different Synthesis Schemes for Production of Sodium Methoxide from Methanol and Sodium Hydroxide

2020 ◽  
Vol 24 (6) ◽  
pp. 63-77
Author(s):  
Natthiyar Aeamsuksai ◽  
Thirawat Mueansichai ◽  
Pongtorn Charoensuppanimit ◽  
Pattaraporn Kim-Lohsoontorn ◽  
Farid Aiouache ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Flow Rate ◽  
Sodium Methoxide ◽  
Distillation Column ◽  
Reactive Distillation ◽  
Flow Ratio ◽  
Total Energy Consumption ◽  
Pervaporation Membrane ◽  
Simulation Parameters

This research investigates the process simulation of sodium methoxide (NaOCH3) synthesis from methanol (CH3OH) and sodium hydroxide (NaOH) under three synthesis schemes: schemes A, B, and C. Scheme A consisted of one equilibrium reactor and two distillation columns, scheme B one reactive distillation column and one distillation column, and scheme C one reactive distillation column and pervaporation membrane. The simulation parameters included CH3OH/NaOH feed flow ratio (1.2-1.6), number of stages (5-30), bottom flow rate (1400-1600 kg/h), and feed stage location (5, 10, 15, 20, 21, 22, 23, and 24). The simulation parameters were varied to determine the optimal NaOCH3 synthetic conditions under different schemes with 0.01 wt% water content, maximum 45 wt% NaOCH3, and the lowest total energy consumption. The results showed that scheme C had the lowest total energy consumption (34.25 GJ/h) under the optimal synthetic condition of 1.4 for CH3OH/NaOH feed flow ratio, 25 for the number of stages, 1550 kg/h for the bottom flow rate, and the 24th feed stage location, with the NaOCH3 flow rate of 675 kg/h. Scheme C thus holds promising potential as an energy-efficient alternative for synthesis of NaOCH3. The novelty of this research lies in the use of pervaporation membrane in place of distillation column to separate CH3OH from water and to lower energy consumption and capital cost.

Reactive Divided Wall Distillation Column: Simulation and Experiment of Methyl Acetate Hydrolysis

2012 ◽  
Vol 468-471 ◽  
pp. 2785-2789 ◽  
Author(s):  
Yan Wang ◽  
He Xu Ma ◽  
Huai Gong Zhu ◽  
Wei Tang
Keyword(s):  
Methyl Acetate ◽  
Distillation Column ◽  
Reactive Distillation ◽  
Molar Ratio ◽  
Reflux Ratio ◽  
Liquid Distribution ◽  
Divided Wall Column ◽  
New Process ◽  
Simulation And Experiment ◽  
Complex Technology

As a combination of divided wall column (DWC) and reactive-distillation column, the reactive divided wall distillation column is a highly complex technology that reaction and separation can occur simultaneously, which can reduce the energy consumption and decrease the costs of captial and operation. This new process was simulated with PROⅡ software and mini plant experiments were implemented. In addition, we investigated the influences of reflux ratio, liquid distribution ratio and molar ratio of ester in water on the conversion rate of methyl acetate and the purity of the product respectively. It could be seen that the trend from experiments was suitable with simulation results.

scholarly journals Production of Butyric Anhydride Using Single Reactive Distillation Column with Internal Material Circulation

Processes ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 1 ◽  
Author(s):  
Guanghui Chen ◽  
Fushuang Jin ◽  
Xiaokai Guo ◽  
Shuguang Xiang ◽  
Shaohui Tao
Keyword(s):  
Acetic Anhydride ◽  
Butyric Acid ◽  
Distillation Column ◽  
Reactive Distillation ◽  
Reaction System ◽  
Total Annual Cost ◽  
Material Circulation ◽  
Butyric Anhydride ◽  
Better Than ◽  
Column Process

The traditional two-column reactive distillation (RD) process is used for the production of butyric anhydride, which is synthesized with butyric acid and acetic anhydride via a reversible reaction. In this work, a novel process with a single RD column (SRDC) is designed for the production of butyric anhydride, where the second distillation column for separating excess reactant is removed based on the boiling point profile of the reaction system. Two applications of the proposed SRDC process, namely SRDC with excess butyric acid or acetic anhydride circulating internally, are economically optimized, and the results show that both SRDC processes have a lower total annual cost (TAC) than the traditional two-column process. Furthermore, from the perspective of TAC, the application with an excess feed of butyric acid is better than the application with excess acetic anhydride. The developed technique may also be applied to retrofit other traditional two-column RD processes, where the overhead and bottom products are the lightest and heaviest components of the reaction system, respectively, and no azeotrope is involved in the RD column.

Neural - Wiener Model for Multivariable Methyl Tertiary Butyl Ether (MTBE) Reactive Distillation

2013 ◽  
Vol 284-287 ◽  
pp. 409-413
Author(s):  
Sudibyo Sudibyo ◽  
Muhamad Nazri Murat ◽  
Norashid Aziz
Keyword(s):  
Reactive Distillation ◽  
State Space Model ◽  
Nonlinear Behavior ◽  
Distillation Process ◽  
Wiener Model ◽  
Butyl Ether ◽  
Separation Processes ◽  
Tertiary Butyl ◽  
Highly Nonlinear ◽  
Reliable Model

MTBE is a chemical that can be used as anti-knock additive to replace lead additive (tetra ethyl lead) which can be efficiently produced using reactive distillation process. It has been established in the literature that MTBE reactive distillation poses a highly nonlinear behavior due to the combination of reaction and separation processes. A reliable model for predicting the behavior is required especially for the control purposes. In this work, a Neural Wiener model which is one of the available types of oriented block model was utilised to develop the MTBE reactive distillation model. The required data for the Neural Wiener model were generated using a validated Aspen dynamics model for the MTBE reactive distillation process. It is found that the Neural Wiener model is capable to predict the MTBE purity and isobutene conversion with accuracy of 98.55% and 96.95%, respectively. Those values are quantitatively better in comparison to the state space model which gives lower values for prediction accuracy of 87.86% and 82.90%, respectively.

Multiple steady states in a CSTR with total condenser: Comparison of equilibrium and nonequilibrium models

2006 ◽  
Vol 60 (6) ◽  
Author(s):  
Z. Švandová ◽  
J. Markoš ◽  
L’. Jelemenský
Keyword(s):  
Distillation Column ◽  
Dynamic Behaviour ◽  
Reactive Distillation ◽  
Steady States ◽  
Multiple Steady States ◽  
Reflux Ratio ◽  
Start Up ◽  
State Behaviour ◽  
Steady State Behaviour ◽  
Nonequilibrium Models

AbstractComparison of equilibrium and nonequilibrium models of a CSTR with total condenser focused on the multiple steady states and dynamic behaviour was carried out. The steady-state behaviour of the model system, MTBE synthesis from methanol and isobutene in a reactive distillation column, was studied in terms of the input parameters, i. e. feed flow rate of methanol or butenes, reflux ratio, and mass of catalyst. The dynamic behaviour of the system during the start-up was investigated and perturbations of manipulated variables were found to cause transitions between the parallel steady states.

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