Design of Multivariable Control Loops for Distillation Columns Using Digital Simulaton

1988 ◽  
pp. 222-224
Author(s):  
Ch Hille ◽  
M. Wagner
Keyword(s):  
Multivariable Control ◽  
Distillation Columns ◽  
Control Loops

Software to Improve Control System in an Ethanol Distillation Process

2013 ◽  
Vol 827 ◽  
pp. 169-175
Author(s):  
André Ribeiro Lins de Albuquerque ◽  
Cecília Sosa Arias Peixoto ◽  
Luiz Teruo Kawamoto Júnior ◽  
Georgea Duarte ◽  
Jones Erni Schmitz ◽  
...  
Keyword(s):  
Production Condition ◽  
Production Capacity ◽  
Maximum Energy ◽  
Raw Material ◽  
Control Mode ◽  
Control Solution ◽  
Distillation Columns ◽  
Operational Conditions ◽  
Control Loops ◽  
Energy Economy

This work has developed a predictive control solution based on specific models for the process of ethanol distillation. The advantages of such control are relative to the prediction of the consequences of the disturbances by the model, thus enabling the control action to be done in a previous manner, resulting in the minimization of the variables fluctuation controlled by the process. This results in, among other advantages, energy economy, in the improvement of the ethanol produced and in the increasing production capacity. Another desirable characteristic in this control mode is its capacity to act in non-linear systems as is the case of the distillation columns. Finally, it must be noted that with the application of an advanced control solution, as proposed in this study, it becomes viable, in a second moment, for the ethanol plants to operate in multiple operational conditions, such as: 1) maximum energy economy (scarcity of raw material, for example) and: 2) maximum production condition (for situations with excess of materials to be distilled). The models developed in this project will consist of purely empirical models. Several tests will be done in the different types of models to measure the precision and robustness. The proposed control strategy demonstrated be able to control selected control loops adequately. Steam savings and reduction of product losses were observed.

Expert multivariable control. 2. Application of EMC to two-product distillation columns

1990 ◽  
Vol 29 (3) ◽  
pp. 389-403 ◽  
Author(s):  
Vassilios K. Tzouanas ◽  
William L. Luyben ◽  
Christos Georgakis ◽  
Lyle H. Ungar
Keyword(s):  
Multivariable Control ◽  
Distillation Columns

scholarly journals An Advanced Control System for Turbofan Engine: Multivariable Control and Fuzzy Logic (Application to the M88-2 Engine)

1995 ◽  
Author(s):  
Alain Garassino
Keyword(s):  
Fuzzy Logic ◽  
Control Systems ◽  
Performance Index ◽  
Multivariable Control ◽  
Outer Loop ◽  
Turbofan Engine ◽  
Stall Margin ◽  
Control Loops ◽  
Advanced Control ◽  
Fuzzy Supervisor

The search for better performance of present and future turbofan engine involves an increase on the number of variable geometries and thus of control loops. As we can not or do not want to disregard the interaction between loops any more, the future control systems will therefore be multivariable. The aim of the architecture of multivariable control presented here is to optimize a performance index during transients. This architecture consists of an inner loop which optimizes the performance index taking in account the limitations, an outer loop which brings the nominal steady-state offsets to zero and a trajectory which allows to take into account the topping schedule limitation. This basic architecture can be improved by fuzzy supervisor. Indeed, two control outputs are generated according to the description above: - the first one optimizes the thrust and does not care very much about LP stall margin limitation, - the second one optimizes again the thrust and strongly takes low pressure stall margin limitation into account. The fuzzy logic then allows to do a compromise between these two control outputs according to the engine state. Simulation results showing the efficiency of the method are given.

Expert multivariable control. 3. Extension of EMC to three-product side-stream distillation columns

1990 ◽  
Vol 29 (3) ◽  
pp. 404-415 ◽  
Author(s):  
Vassilios K. Tzouanas ◽  
William L. Luyben ◽  
Christos Georgakis ◽  
Lyle H. Ungar
Keyword(s):  
Multivariable Control ◽  
Distillation Columns ◽  
Side Stream

scholarly journals Comparing Composition Control Structures for Kaibel Distillation Columns

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 218 ◽  
Author(s):  
Yang Yuan ◽  
Kejin Huang ◽  
Haisheng Chen ◽  
Xing Qian ◽  
Lijing Zang ◽  
...  
Keyword(s):  
Control Systems ◽  
Distillation Column ◽  
Tight Control ◽  
Distillation Columns ◽  
Control Structures ◽  
Control Loops ◽  
Composition Control ◽  
Equipment Investment ◽  
Quaternary Mixture ◽  
Operation Cost

Although Kaibel distillation columns are superior to conventional distillation sequences owing to smaller equipment investment and operation cost, they display high nonlinearity and this greatly increases the difficulty of achieving their tight control. To overcome this problem, four decentralized composition control structures, i.e., the CSR/QR, CSR/B, CSD/QR, and CSD/B structures, are proposed and compared based on the control of a Kaibel distillation column fractionating a methanol/ethanol/propanol/butanol quaternary mixture. These four composition control structures all include five composition control loops. While the four of them are employed to maintain the purity of the top, upper sidestream, lower sidestream, and bottom products, the remaining one is employed to minimize the energy consumption of the Kaibel distillation column by maintaining the composition of propanol at the first stage of the prefractionator. Dynamic simulation results show the CSR/QR and CSR/B structures can tightly maintain the purity of the controlled products with a small overshoot and short settling time after facing various disturbances in feed conditions, but the CSD/QR and CSD/B structures lead to oscillatory responses (the latter even shows divergent responses under individual disturbances). At the end of the article, some effective guides for developing composition control systems are given.

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