Phase transfer catalysis in a microchannel: fluidic control of conversion and selectivity

Precise control over the segmented flow in a microchannel reactor offers an important tool for the optimization of reaction yield and productivity. The fluidic control over the reaction was demonstrated on the selective alkylation of benzyl cyanide to the monoalkylated product in a 250 µm microchannel reactor. The conversion of benzyl cyanide increased from 39.9% to 99.7% as a result of a 97% larger slug surface-to-volume ratio when the volumetric aqueous-to-organic phase flow ratio was raised from 1.0 to 6.1 at the same residence time. Conversion and selectivity in the microchannel reactor are both significantly larger than in a stirred reactor.