Modelling catalytic combustion in monolith reactors - challenges faced

When searching for a design concept in which a catalytic combustor is utili sed, or looking for areas where improvements can be made to an existing des ign, then mathematical modelling is an important tool. However, models are only as good as the way in which the physico-chemical processes are modelle d and the quality of the physical and chemical parameters (e.g. kinetic exp ressions, physical properties) acquired for use in the models. When selecti ng a basis for a model, there are many questions that need to be asked and answered by the developer of the chemical reaction engineering model of the catalytic combustor. Many challenges arise from having to make decisions o n compromises that need to be made, and in recognising the consequences of such action. Examples of such challenges are outlined and, for some, clues are offered as to where the answers may lie. The examples include challenge s in: the selection of appropriate kinetic expressions, recognition of the role that intraphase diffusion may play, the choice of pressure for catalyt ic kinetic and pilot scale studies, the selection of heat and mass transfer correlations, and the modelling of transients. (C) 1999 Elsevier Science B .V. All rights reserved.