Feedforward Variable Structural Proportional-Integral-Derivative for Temperature Control of Polymerase Chain Reaction

This thesis deals with the combined utilisation of a reaction calorimeter, the RC1 ® commercialisedby Mettler Toledo and equipped with a 2 L glass reactor, and the heat transfer dynamics modellingof industrial reactors. By doing so, the temperature evolution of the reaction medium of full scaleequipment during a chemical process can be forecast already at laboratory scale. Thus, theselectivity, quality and safety issues arising during the transfer of a new process, respectively theoptimisation of an existing one, from the laboratory to the production scale are earlier detected andmore correctly apprehended. It follows that the proposed methodology is a process developmenttool aiming to accelerate the rate at which innovative processes can be introduced into the market,and for which the global safety can be guaranteed.Chapter 3 of the thesis devotes to the heat transfer dynamics modelling of industrial reactors. Tothis intention, heating/cooling experiments have been performed at plant scale. First, it consistedin filling up the industrial reactor with a measured quantity of a solvent with known physical andchemical properties (typically water or toluene). Second, after a stabilisation phase at lowtemperature, the setpoint of the liquid was modified to a temperature about 20 °C below its boilingpoint, followed by a stabilisation phase at high temperature. Then, the setpoint was changed to avalue about 20 °C higher than the fusion point, again followed by a stabilisation phase at lowtemperature. During the experiment, the solvent and jacket temperatures are measured andregistered. The stirrer revolution speed or the liquid amount are changed, and the wholemeasurement cycle repeated. Not only the heat transfer between the utility fluid and the reactionmedium was modelled, but also the thermal dynamics of the jacket itself. Nine industrial reactorshave been characterised, their sizes ranging from 40 L to 25 m

Scale-down approach: chemical process optimisation using reaction calorimetry for the experimental simulation of industrial reactors dynamics

To meet the technical demands of temperature control in medical air insulation blanket, a closed loop system of temperature control is put forward, in which the hardware circuit is mainly composed of temperature sensor, MCU and RS232 communication module etc. Through changing the work time of the electrically heated wire via controlling the turn-on time of the thyristor by the PWM technique and adaptive fuzzy PID technique, the air temperature from the outlet of the insulation blanket's gasbag is automatically adjusted and controlled. The whole control process is divided into two stages: the duty cycle of the electrically heated wire's work time is set to be 100% at the initial auto adjustment stage, and then is determined by a relevant control variable during the stage of adaptive fuzzy PID algorithm control when the air temperature rises up to a certain range, hence the air temperature is regulated. The MATLAB simulation based on the control method shows that the adaptive fuzzy PID algorithm control is superior to conventional PID control due to the former excellent adaptability, robustness and the steady-state accuracy.

A new approach for temperature control of medical air insulation blanket

Due to highly nonlinear, complexity, variability and uncertainty that batch polymerization processes involve, the control of batch polymerization processes offers attractive and challenging problems for control community. This paper introduces the characteristics of the processes and reviews the progress in the computer control and application of advanced process control for batch polymerization reactors in recent years. Special attention is focused on predictive control, adaptive control and fuzzy control. It is shown that there is a huge gap between industry and research practices.

A survey of advanced control for batch polymerization reactors

Partial state reference model adaptive control of batch and fed-batch chemical reactors

PID adaptive control of the temperature in batch and semi-batch chemical reactors

Batch and semi-batch chemical reactors are extensively used in polymer, fine chemical and pharmaceutical industries. The temperature control is of fundamental importance from product quality and reproductibility points of view. It is then necessary to improve the automation of these plants which are typically controlled using standard PID controllers. An autotuning PID controller is proposed and evaluated by application to a batch and semi-batch pilot plant reactor to investigate advanced control techniques. The involved control design is derived in the spirit of the partial state reference model adaptive control (PSRMAC) approach within the delta operator formulation. PSRMAC is mainly motivated by its suitable tracking capability when only a crude knowledge about the plant to be controlled is available. The delta operator formualtion is particularly motivated by the convergence of the performances to their continuous time counterpart as well as its numerical robustness when the sampling is required to be...

E. Miklovičová

Papers

PID adaptive control of the temperature in batch and semi-batch chemical reactors

Partial state reference model adaptive control of batch and fed-batch chemical reactors

Adaptive linear quadratic control of batch and semi-batch cehmical reactors within the delta operator formulation