Multiphase flow processing in microreactors combined with heterogeneous catalysis for efficient and sustainable chemical synthesis

Catalytic Transformation of Biomass Derivatives to Value‐Added Chemicals and Fuels in Continuous Flow Microreactors

“…Thus, the choice of solvent for performing a certain biomass transformation should be considered carefully. [179,180] Microreactors carry out chemical reactions in a continuous flow mode. However, to recover organic products from water may require energy intensive separation procedures (e. g., extraction, stripping or distillation), in view of the process economics and/ or the environmental aspects with waste water disposal.…”

“…[179,180,194,195] Solid catalysts can be incorporated by either coating the inner wall of the microchannel with a thin (ca. [179,180,194,195] Solid catalysts can be incorporated by either coating the inner wall of the microchannel with a thin (ca.…”

“…[179,180,194,195] Solid catalysts can be incorporated by either coating the inner wall of the microchannel with a thin (ca. [180,194,195] Wall-coated microreactors have the advantage that the same (multiphase) flow pattern as in empty ones (e. g., slug flow) can be maintained ( Figure 3D). [180,194,195] Wall-coated microreactors have the advantage that the same (multiphase) flow pattern as in empty ones (e. g., slug flow) can be maintained ( Figure 3D).…”

“…Catalysts should have a particle diameter well below the microchannel diameter in order to form an effective packing structure and a good reactant flow distribution over the bed, and can be retained by filters ( Figures 3E and 3F) or inert particles (e. g., glass beads; Figure 2E). [180] Moreover, the flow maldistribution might occur (e. g., due to wall-channeling, wettability difference between particles and the microreactor wall), [196] which may adversely affect mass transfer and reaction performance. For instance, when introducing an upstream gasliquid slug flow, liquid-dominated slug flow could be observed in the packed bed, which is characterized by a liquid flow through the particle interstitial voids and most of the catalyst bed, with elongated bubbles moving through the voids (Figure 3F).…”

Highly Selective Continuous Flow Hydrogenation of Cinnamaldehyde to Cinnamyl Alcohol in a Pt/SiO2 Coated Tube Reactor

“…Much lower conversion and selectivity were found compared with the performance of the catalyst-coated tube reactor. The likely reasons are the mass transfer limitations, broad residence time distribution associated with the possibility of liquid channeling [60][61][62]. A combination of excellent catalytic activity, stability and selectivity in a tube reactor is promising for innovator pharma applications which are at gram to kilogram scale.…”