acetate RD process is shown in Fig. 4.1. The catalytic packing used in the present study was Katapak-S with an Amberlyst ion-exchange catalyst. Experiments were carried out both at the laboratory scale [6] and the semi-industrial scale [4].

Two major classes of modeling concepts, the equilibrium stage and the rate-based approach, were tested. The chemical reaction is assumed to occur only in the liquid phase. A survey of the four models used is given in Fig. 4.2. Three variants of the equilibrium stage model were considered. In the simplest model (Model 1) the RD column is modeled as a countercurrent multistage process with physical and chemical equilibrium on each stage. In Model 2 the assumption of chemical equilibrium is dropped and the reaction on each stage is described by second-order bulk reaction kinetics. Model 3 was developed to take into account the residence time behavior of the liquid flow in the packing. For this goal the reaction zone is described by a relatively large number of stages, or, in terms of reaction modeling, stirred tank reactors. Neither phase nor chemical equilibrium is reached

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