Abstracts

Quantitative modeling and characterization ofhydrodynamics and transport in multiphasemicroreactors

by Lu Ph Yang




Institution: MIT
Department:
Year: 2017
Keywords: Chemical Engineering.
Posted: 02/01/2018
Record ID: 2190642
Full text PDF: http://hdl.handle.net/1721.1/111378


Abstract

On-chip flow chemistry synthesis has advancedrapidly in recent years as a fast and effective means to discoverand screen suitable reaction candidates for continuous production.Among the many chemical reactions, multiphase reactions constitutea major category with important industrial applications, andmicroreactors have been shown to effectively enhance the efficiencyof such reactions. However, compared to single-phase flow chemistrysystems, many unknowns remain in the design, optimization andscale-up of multiphase microreactors - primarily due to the complexnature of the multiphase flow. Therefore, this work aims to obtainfundamental knowledge of the hydrodynamics, transport and reactionsin multiphase microreactors through a combination of computation,theory and characterization. Specifically, I studied five typicalmultiphase flow chemistry modules: the segmented flow microreactor,the post microreactor, the tube-in-tube microreactor, the capillarymicroseparator and the membrane microseparator. A series of C++solvers that simultaneously model multiphase hydrodynamics,transport and reactions on the microscale were developed andvalidated. Parallel computation with up to 128 cores were performedto accelerate simulation. Laser-induced fluorescence visualizationcombined with image analysis was used to systematically quantifykey features such as interfacial area and phase holdup. A varietyof analytic models were also developed to provide guidelines forenhanced reactor design. The integrated strategy elucidated thecomplex hydrodynamics and transport in microreactors with fullphysical details. The enhanced physical insight into multiphasemicroreactors would be crucial to predicting reactor performance,reducing experimental cost, and achieving reactorscale-up.Advisors/Committee Members: Klavs F. Jensen (advisor).