Modeling mesoscale reactors for the production of fine chemicals

• We modeled mesoscale reactors with 1-d dispersion, 2-d colaminar feeds, and 3-d Y-junction CFD approaches.
• We extended the traditional 1-d dispersion model to include effects from sample loops and feed tubing.
• We demonstrated regions where the 1-d dispersion model applies and compared the results against batch gather kinetic results.

Flow based synthesis at the mesoscale level allows precise control over process conditions (such as temperature and mixing), and offers advantages such as reduced processing times, higher reproducibility, and enhanced selectivity compared to batch reactors. Precise heat and mass transfer control allows for safer operations when using toxic or explosive materials or for highly exothermic reactions. We present a simple transient one-dimensional (1-d) dispersion model to analyze mesoscale reactors. The conversions predicted by the 1-d dispersion model matched well with conversions predicted by a two-dimensional (2-d) colaminar model. A computational fluid dynamics simulation (CFD) of a 120° Y-junction leads to a lower conversion at higher Damköhler numbers. Estimation of the kinetic parameters for the reaction between sodium azide and 2-phenylethylbromide demonstrated excellent agreement between the 1-d dispersion model and rates generated using a standard batch experiment.