Particle-image-velocimetry measurements in organic liquid multiphase systems for an optimal reactor design and operation

Abstract

Hydrodynamic features are very important to find an optimal reactor design for the hydroformylation of long-chain alkenes. For this purpose, and for the validation of theoretical reactor concepts, velocity measurements in a model reactor system are necessary. Due to the difficult reaction conditions found in reality (toxic thermomorphic organic solvent system, high pressure, high temperature, limited fields of view in typically used model reactors) such measurements are not an easy task. In this work, comparative particle-image-velocimetry (PIV) measurements have been used to find out if (1) the substitution of the solvent with water, and (2) reducing operation pressure still lead to similar results. For this purpose, PIV measurements have been performed in a stirred tank reactor under reaction conditions (organic solvents, high pressure, high temperature), but also with water at reduced pressure levels. It is found that pressure (as expected) and also the employed solvents do not have a significant influence on the observed flow structures, although density and viscosity are rather different. Therefore, further systematic experiments are now carried out in a model reactor, completely built out of glass, with water filling, and at atmospheric pressure. A complete hydrodynamic characterization is thus possible, opening the door for optimization of the resulting hydrodynamic field and for detailed comparisons with theoretical reactor design as well as numerical predictions.