Estimation of Reaction Kinetic Parameters by Local Online Experimentation

In the control of chemical reactors, it is important to know the kinetic parameters of the reaction with good precision. The traditional approach is to try to estimate them from laboratory experiments or from plant records, where variations due to control to disturbances may occur. However, this may happen only sporadically in the plant history because the reactor is at steady state for long periods of time. It would be advantageous to online, so that the estimation of the kinetic parameters could be made more accurately and independently of plant changes. This paper presents such a method which may be applicable to most industrial reactors. A test reactor is installed in parallel to the main stream and a little side stream to this reactor is taken from the main reactor stream at any point. In the simplest possible case, the side stream is led to a batch reactor where the reaction kinetics may be followed very closely. From the batch results it is possible to infere the kinetic parameters and even the order and mechanisms of the reactions. Such parameters shown here are the parameters in the Arrhenius type rate expression, the order and the heat of the reaction.