Research Projects

Chemical processing in micro and meso-scale reactors has become attractive to carry out reactions involving multiple phases due to the advantages of high interfacial area density, high rate of mass transfer, potential to achieve high heat removal rates, minimizing wastage, better control and safety. In two-phase gas-liquid and liquid-liquid flow, slug or Taylor flow is the preferred regime of operation due to its ability to segment the flow and provide intense mixing in each slug. Similarly, slurry Taylor flow in three-phase gas-liquid-solid or liquid-liquid solid flow can overcome the limitation of handling solid particle in microreactors. The issue of poor mixing in microreactors due to laminar flow can be addressed by making the flow path curved and generating secondary flow induced mixing. The yield and selectivity in a reactor is a function of residence time distribution. The residence time distribution and hold-up of different phases depend on the flow regime. It is therefore important to develop a comprehensive understanding of the flow regimes map in such channels over a range of flow and channel geometric parameters. The data available in the literature for two-phase flow in mini and microchannels are generally for inert or immiscible two-phase systems only making the information of limited use for the microreactor design. Therefore, there is a need to understand the deviation in the flow regime maps when compared with those for diffusive or reacting systems. This project aims to develop quantitative understanding of flow regime map, phase hold up, film thickness distribution of two and three phase flow, residence time distribution for reactive and non-reactive systems in curved tubes of size ranging from submillimeter scale to centimeter scale. The experimental data, understanding of the physical phenomena and simple phenomenological models developed through a synergistic combination of experimental and computational techniques would be of great help to the designers of micro chemical processing systems and microfluidic devices.