System Identification of a Nonlinear CSTR

This project simulates a nonlinear Continuous Stirred Tank Reactor (CSTR) and identifies a transfer function model from step-response data.

Objective

The objective is to obtain a linear dynamic model relating cooling water flow rate to reactor temperature around a nominal operating point.

System

The nonlinear CSTR model includes:

• Component mole balances
• Energy balance
• Arrhenius reaction kinetics
• Cooling water heat transfer model

It is based in the example 9-4 "Startup of a CSTR", from Fogler's book "Elements of Chemical Reaction Engineering".

Workflow

1. Define process parameters.
2. Simulate the nonlinear CSTR model.
3. Apply a step change in cooling water flow.
4. Generate input-output data.
5. Estimate a transfer function using MATLAB System Identification Toolbox.
6. Compare nonlinear and identified model responses.

Main files

• main.m: main simulation script.
• cstr_ode.m: nonlinear CSTR model.
• parameters_cstr.m: process parameters.
• inputs.m: input step function.
• system_ident.m: transfer function estimation.

Tools

MATLAB, Control System Toolbox, System Identification Toolbox.