Advancement in experimental and computational methods for optimizing and scaling up continuous reactors

This PhD thesis presents the experimental and numerical study of an tubular equipment for turbulent gas-liquid mixing, mass transfer and separation in continuous processes, implementing process intensification principles in the chemical industry. The experimental part consists in the fluid dynamics characterization of the equipment considering single- and two-phase flow at different regimes and configurations of Kenics Static Elements (KSE). Non-invasive techniques, such as Digital Image Analysis, Electrical Resistance Tomography, Particle Image Velocimetry and piezo-resistive pressure transducers, are used to obtain characterization and validation data. The numerical part is focused on the development of a robust computational tool for the design of the equipment, starting from a single-phase model of the liquid flow in the equipment, to the final two-phase model coupled with Population Balance Modeling and gas-liquid mass transfer. Finally, the constructed numerical model is used to explore a gas-absorption application in a pipeline equipped with combination of mixing KSE units followed by separation KSE units, which ensures efficient gas dispersion and separation in the same equipment. The results obtained experimentally evidence the effect of the KSE in terms of energy consumption, bubble size and gas hold-up. The interfacial area is significantly enhanced in the mixing configurations due bubble size reduction and gas dispersion. From the numerical side, good agreement is reached for the single-phase model compared with power consumption and experimental velocity profiles. From the two-phase flow an acceptable prediction of the model is reached in terms of changes in the flow pattern using different KSE configurations, power consumption and bubble size distributions. Finally, in the gas absorption application, 20 % of the CO2 was absorbed by the liquid phase, and comparing with the same process application in bubble columns and stirred tanks, important increments in the rate of absorption and coefficient of mass transfer are achieved.