DYNAMIC MODELING OF CATALYTIC 3-PHASE REACTORS

Dynamic models were developed for three phase slurry and trickle bed r eactors operating in non-isothermal conditions. The model equations fo r the gas, liquid and catalyst phases consisted of parabolic partial d ifferential equations (PDE) and ordinary differential equations (ODE), which were converted to ODEs using finite difference approximations f or the spatial derivatives. The ODEs were solved by a stiff ODE solver (LSODE) using the backward difference method. The numerical strategy proved to be reliable. The reactor simulation programs were included i n a flowsheet simulator. The use of the programs was illustrated with two case studies: oxidation of SO2 and hydrogenation of toluene. The e xample simulations showed that the dynamic approach provides a meaning ful path to the steady state of the reactor and gives valuable informa tion of the reaction dynamics.