Hydrodynamics And Mass Transfer In Membrane Microreactor And Application To Pervaporation-Esterification Coupling Process

Process intensification is important and difficult in the research of chemical engineering at present. The technology of chemical process intensification, which is aimed at making the factory layout more reasonable and compact with significantly reduced energy consumption, waste and by-products, could be achieved through greatly decreasing the size of production equipment, simplifying the technological process and reducing the amount of device. There will be an important theoretical significance and application value to develop new reaction separation-coupling techniques and devices for chemical process intensification.Micro-structured chemical system provides a new technology and method for reaction which is safer, more efficient and environmentally friendly. Moreover, the membrane technology can improve the process through the coupling of reaction and separation, which could be strengthened by combining microfluidic technology with membrane separation for new membrane reactor. However, little research has been done into the theory research of micro reaction and separation process. It is necessary to do a further research on the fluid flow and mass transfer in order to strengthen the coupling of reaction and separation process in MMR.First, the microfluid flow was investigated in rectangular microchannels. The effect of wetting properties of fluid and the channel wall on flow was investigated through both visual experiments and simulation calculation. After analyzing the extrusion force, shear force and the interfacial tension under different flow patterns in microchannles, it was found that the velocity of continuous phase was closely related to the shear force, and the velocity of two phases was closely related to the flow pattern. As a result, the control of a variety of flow pattern (such as laminar flow, column dispersion flow, droplets dispersed flow, etc.) can be realized. We found that the dominant force changed under different flow pattens. It provided a research basis for the flow pattern in MMR.Secondly, the permeation performance was investigated under different conditions in MMR. The effect of temperature, water concentration and velocity was investigated. The semi-empirical model was established according to series resistance model and dissolution-diffusion mechanism. It provided a theoretical basis for the MMR to combine with the coupling of the reaction and separation.Moreover, the flow modeling in MMR was established based on the theories of flow patterns in microchannel, and was solved through the finite Fourier transform. The modeling was evaluated through pervaporation dehydration process. The two-component diffusion modeling in MMR was established based on the flow modeling. The water concentration at the outlet was calculated through the modeling and compared with the experimental result. The basic theory of fluid flow under microscale was enriched.Finally, the intensification on coupling of pervaporation and esterification reaction in MMR is analyzed based on the flow and mass transfer. The conversion in MMR was much higher than that in the conventional membrane reactor under the same condition. The MMR system is helpful to prevent catalyst from poisoning and deactivation.