Residence time characteristic of Taylor reacting flow in a microchannel reactor

Herein, an in-situ visual method was developed to determine the residence time characteristic of a typical gas-liquid Taylor reacting flow in a microchannel reactor. Nitrobenzene hydrogenation was chosen as a reference heterogeneous reaction. The obtained results demonstrated the feasibility of the proposed in-situ visual method in determining the real residence time. The real residence time variation along with the flow distance is inherently related to the local nitrobenzene and hydrogen reactants consumption and mass transfer performance. The increase in residence time was initially accelerated due to rapid hydrogen consumption at the upstream. Then, ascribed to the gradually exhausted nitrobenzene, the deteriorated mass transfer resulted in the residence time being proceeded almost linearly increase along the flow direction at the downstream. Besides, the effects of both initial nitrobenzene concentration and liquid flow rate were also explored. This work reveals the intrinsic interaction between the residence time characteristic and catalytic reaction.