Liquid-Liquid Test Reactions to Characterize 2-Phase-Mixing in Microchannels

Multiphase flow is often found in chemical engineering, food processing, or analytics. First contacting and droplet generation as well as coalescence and re-dispersion have high importance for the flow characteristics. In all processes, the channel geometry, fluid properties, and flow velocity determine the flow regime, droplet size, and interfacial area. The hydrolysis of alkyl acetates in organic phase with sodium hydroxide NaOH in the aqueous phase is investigated as flexible test reaction for mass transfer and interfacial area. For right design of the characteristic time for mass transfer, the alkyl group is chosen from ethyl, isopropyl or n-butyl, which differ in water solubility, diffusivity and rate constant. The consumption of NaOH is used for calculation of specific area and related mass transfer coefficient. Different channel geometries are characterized and design considerations are conducted.