Modeling of the Phase behavior of light (C2 & C3) olefins in liquid phase epoxidation systems and experimental determination of gas/liquid mass transfer coefficients

Abstract

Conventional technologies for the selective epoxidation of olefins such as ethylene and propylene to form their corresponding epoxides are either non selective and/or produce much waste. A novel biphasic process for the epoxidation of olefins has been developed by the researchers at Center for Environmentally Beneficial Catalysis (CEBC), employing environmentally benign substances (catalyst methyltrioxorhenium, oxidant aqueous H2O2) dissolved in a suitable solvent (determined to be methanol). HYSYS® software was used to study the phase behavior and generate quantitative data on the solubility of gaseous olefins in the liquid phase which aided in the optimization of the reaction conditions. A detailed stirred tank reactor model was developed to estimate the gas/liquid mass transfer coefficient which was determined to be 0.14 sec-1 at 1000 rpm which ensured operation outside the diffusion limited region. Inerts such as N2 and CO2 can be used to mitigate the flammability envelope of these highly flammable gases.