Modeling of gas-liquid reactors. Isothermal semibatch and continuous stirred tank reactors

A computer code for the simulation of isothermal stirred gas-liquid reactors, both continuous and semibatch, has been developed. The models are constituted of two moduli. The first one describes the diffusion-reaction processes at the gas-liquid interphase, and is based on the film model. This modulus is the same for all reactors. The second one describes the time evolution (semibatch reactor) or the steady state behavior (continuous reactor) of the composition of the bulk liquid and gas phases, which depends on the specific reactor configuration and fluodynamics. The simulation code has been developed for the most general case, involving any type of kinetic scheme and reaction rate expressions, evaporation of volatile liquid components, recycle of condensed liquid from the condenser, etc. Specific numerical algorithms have been implemented for the solution of the mathematical models in all possible operating conditions. All fluodynamic and transport parameters are evaluated internally using selected semi-empirical relations derived from the literature. Thus the required input data to the computer code involve only the physicochemical properties of the involved chemical species and the kinetic parameters involved in the reaction rate expressions. The performance of the simulation models has been tested by comparison with experimental data for two processes of practical interest: catalytic oxidation of p-xylene and photochemical chlorination of p-xylene. (C) 1997 Elsevier Science Ltd.