Intensification of multiphase reactions through the use of a microphase-II. Experimental

Abstract

The specific rates of alkaline hydrolysis of solid esters-2,4-dichlorophenyl benzoate, p-chlorophenyl benzoate and phenyl benzoate—in the presence of a second emulsified liquid phase were measured in a 67 mm i.d. mechanically agitated contactor. For 2,4-dichlorophenyl benzoate the above study was also carried out in microemulsions and allied micellar media. Significant enhancements in the specific rates of hydrolysis, as high as 29, were observed. The above data on solid-liquid systems, along with those of absorption of gases, namely, isobutylene, but-1-ene and propylene into emulsions of an additional liquid phase in aqueous sulfuric acid as well as microemulsions and various micellar solutions, published earlier, have been analysed with the unsteady state theory developed in Part I of this study. In some of the cases, where bulk concentration of the sparingly soluble reactant was finite, it was necessary to modify the original theory. The predicted values of the enhancement factor, for systems where macroemulsions were used, were found to be in good agreement with the experimental values of the enhancement in the specific rate. For the other cases, where a priori prediction was not possible the model equations provided a reasonable basis for correlation of data. The analysis of experimental data brings out clearly the importance of time dependent phenomenon like accumulation within the microphase and demonstrates the necessity of models based on unsteady state formulations for such cases.