Effect of surface modification on parallel flow in microchannel with guideline structure

A parallel multiphase flow provides simple phase separation of product mixture at the end of a microreactor and hence, reduces the requirements for post-treatment unit operations. Surface modification by silanization was introduced to improve organic-aqueous two phase parallel flow in a microchannel made of glass with guideline structure. The effect of surface modification on water-toluene flow pattern in the microchannel was investigated using computational fluid dynamics (CFD). With the modified surface, the interface was fixed near the centerline of the microchannel. In addition, the fluids were kept in their own lines since feeding and needed less time to stabilize. The flow pattern transition between slug and parallel flow could take place at a lower flow rate for the microchannel with modified surface. By varying the flow rate ratio, the interface position could be adjusted. Finally, the effect of channel width on the interface position was demonstrated.

• The organic-aqueous parallel flow in a microchannel with guideline structure was studied using computational fluid dynamics. • The surface modification by silanization was proposed to improve the flow in the microchannel. • The slug-parallel flow pattern transition could take place at a lower flow rate for the surface modified microchannel.