On the interfacial mass transfer and the location of the chemical reactionin a fluid/fluid reacting system at elevated temperatures and pressures

In a two-phase (supercritical fluid-fluid) system, the rate of conversion o f a bimolecular reaction A + B --> AB reacting in the layer adjacent to the interface and in the bulk phase was determined. The mass transfer associat ed with the chemical reaction was measured in a stirred and thermostaticall y controlled cell varying reaction temperature, pressure and stirring speed . As model system, the Diels-Alder reaction between 9-hydroxymethylanthrace ne and maleic acid was chosen in the solvent pair supercritical propane/wat er. The cell was developed for high pressures and temperatures. The reactio n was monitored in both phases with on line UV-spectroscopy. The experiment al results are compared to simulated data obtained by using a film model. A n improved theoretical model describing the changes in concentration of the reactants in the two phases is presented. (C) 2001 Elsevier Science B.V. A ll rights reserved.