Hydrodynamics and liquid–solid mass transfer in micropacked bed reactors with copper foam packing

Efficient and continuous furfural hydrogenation to furfuryl alcohol in a micropacked bed reactor

“…This is because the perturbation of N 2 intensifies the liquid–solid mass transfer process and thus increases the reaction rate. 44 And when the gas flow rate was further increased, the effect of the gas flow rate on the FA yield was not significant (entries 2, 6 and 7). Meanwhile, the hydrogen donor isopropanol exhibited better performance compared to 2-butanol, which was consistent with the phenomenon observed by Zhu et al 45 A possible reason for this phenomenon is that isopropanol has a lower viscosity (0.339 mPa s) compared to 2-butanol (0.680 mPa s) under the same conditions, resulting in a smaller mass transfer resistance.…”

External Mass Transfer Performance Studies in a Micropacked Bed Reactor with Pd/PDA/Nickel Foam

“…According to Figure b, ( ka ) OV showed proportionality with gas and liquid superficial velocities under identical operating temperature and pressure conditions. The main reason is that the increase of the liquid superficial velocities improves the liquid holdup of the μPBRs, thus increasing the effective gas–liquid and liquid–solid interfacial area. , At the same time, the increase in fluid superficial velocity can enhance the gas–liquid–solid interphase perturbation and raise the gas–liquid–solid mass transfer coefficients k OV . The effect of the pore size of the nickel foam on ( ka ) OV is given in Figure c.…”

“…Based on our previous studies, the high k GL a GL of μPBRs with foam packing was 0.047−0.38 s −1 and the pressure drop was one-tenth of that of μPBRs with solid particles. 16,17 The coating materials that combine the active component and support nickel foam are a critical factor in the multiphase catalyst hydrogenation reaction. Many inorganic or organic coating materials are used to increase the specific surface area of the foam packing and to enhance the loading of the active components.…”

Local and global gas–liquid mass transfer in a micro‐packed bed reactor utilizing a noninvasive colorimetric technique

“…Zhang et al 18 constructed the automated platform for gas–liquid mass transfer measurement of the μPBR with glass bead packing via CO 2 absorption into methyl diethanolamine solution (MDEA) and proposed the predicting correlation for mass‐transfer coefficient. Sang et al 19,20 adopted the MDEA‐CO 2 system and copper dissolution technique to assess gas–liquid and liquid–solid mass transfer performances in the μPBRs with foam packing and used the NaOH‐CO 2 system to investigate gas–liquid effective interfacial area 21 . In addition, our group employed the hydrogenation of α‐methylstyrene system in the μPBR with Pd catalysts to obtain the external mass transfer performance of gas–liquid–solid reaction 22 .…”

“…In the above-mentioned studies, all results were obtained and calculated by variation of reactor inlet and outlet gas/liquid concentrations, representing the average values of mass transfer performance in the whole μPBR. [17][18][19][20][21][22][23] Nevertheless, the local differences of gasliquid flow behavior existed because of the sophisticated inner status inside the μPBR, 24 which induced the heterogeneous mass transfer in temporal and spatial dimensions possibly. The study of local mass transfer performance contributed to improve all-around understanding and guide the reactor optimization.…”