Cumene is used as precursor for production of many organic chemicals and as
thinner in paints & lacquers. Its production process involves one of the
large-scale manufacturing processes with complex kinetics. Different
classical control strategies have been implemented and compared for the
cumene reactor in this process. As a system with large degrees of freedom a
novel approach for extracting the state space model from the COMSOL
Multiphysics implementation of the system is adopted here. Internal Modern
Control (IMC) based PI and PID controllers are derived for the system. To
derive the controller setting the system is reduced to the FOPDT and SOPDT
model structure using Skogestad half rules. The integral time is modified to
obtain the excellent set point tracking and faster disturbance rejection.
From the analysis it can be stated that PI controller suits more for this
specific process. Particle Swarm Optimization (PSO) algorithm, an
evolutionary computation technique is also used to tune the PI settings. The
PI controllers with IMC, Zeigler Nichols and PSO tuning are compared and it
can be concluded that PSO PI controller settles at 45s without any
oscillations and settles down faster for the disturbance of magnitude 0.5
applied at t=800s, through it is computationally intensive compared to other
controller strategies.