Dynamic response and parameter estimation in a two-phase continuous flow stirred tank reactor

Abstract

Based on a three-parameter model, the dynamic response of an isothermal two-phase continuous flow stirred tank reactor with a first-order chemical reaction occurring in uniform spherical catalyst particles was obtained analytically by using the method of Laplace transforms. Three modes of input perturbation are specifically considered in the solution: step change, impulse, and the sudden introduction of catalyst into the reactor. In all cases, it was found that the time domain solution can be divided into three cases by a critical Thiele modulus. This critical Thiele modulus also divides the reactor dynamics into two different responses when the catalyst particles, which are filled with inert liquid initially, are introduced into the reactor at time zero. In terms of the dimensional form, this critical Thiele modulus relates the rate constant with the inlet liquid flow rate and other parameters except for the liquid—solid mass transfer coefficient and intraparticle coefficient. This makes it possible to determine the rate constant directly from the experiments, even though mass transfer resistances are coexistent, by simply manipulating the inlet liquid flow rate.