Modeling, simulation and control of a scheibel liquid-liquid contactor Part 1. Dynamic analysis and system identification

Farouk Mjalli, Nabil M. Abdel-Jabbar, John P. Fletcher

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

The liquid-liquid extraction process is well-known for its complexity and often entails intensive modeling and computational efforts to simulate its dynamic behaviour. However, rigorous mathematical models are usually impractical or are of limited usefulness for control system design. Therefore, there is a need to derive simpler models for this process. Reduced-order linear models can be derived through applying system identification on the input-output simulation data. As a first step, a rigorous model for dynamic simulation of an extraction process is developed. This model employs an improved detailed stage-wise mixing stage with backmixing and it takes into account the variation in hydrodynamics, mass transfer, and physical properties throughout the length of the extraction column. It also approximates end effects by incorporating two mixing stages at both ends in addition to calculation of mass transfer within calming zones through the use of a mass transfer weight factor. The model is validated with dynamic experimental data for a nine stage Scheibel extraction column of type I. The simulation model is shown to be accurate for prediction of process behaviour under different operating conditions. Dynamic analysis of the process is conducted on the developed rigorous simulation model. Then, system identification is applied to derive linear time-invariant reduced-order models, which relate the input process variables (agitator speed, solvent feed flowrate and concentration, feed concentration and flowrate) to the output process variables (raffinate concentration and extract concentration). The identified model predictions are found to be in a good agreement with the rigorous ones.

Original languageEnglish
Pages (from-to)541-553
Number of pages13
JournalChemical Engineering and Processing: Process Intensification
Volume44
Issue number5
DOIs
Publication statusPublished - Jan 1 2005

Fingerprint

Dynamic analysis
Identification (control systems)
Dynamical systems
Computer simulation
Liquids
Mass transfer
Hydrodynamics
Physical properties
Systems analysis
Mathematical models
Control systems

Keywords

  • Backflow model
  • Backmixing
  • Extraction dynamics
  • Liquid-liquid
  • Scheibel
  • Stagewise
  • System identification

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Energy Engineering and Power Technology
  • Industrial and Manufacturing Engineering

Cite this

Modeling, simulation and control of a scheibel liquid-liquid contactor Part 1. Dynamic analysis and system identification. / Mjalli, Farouk; Abdel-Jabbar, Nabil M.; Fletcher, John P.

In: Chemical Engineering and Processing: Process Intensification, Vol. 44, No. 5, 01.01.2005, p. 541-553.

Research output: Contribution to journalArticle

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