The intensification of rapid reactions in multiphase systems using slug flow in capillaries

Abstract

A multiphase microreactor based upon the use of slug flow through a narrow channel has been developed. The internal circulation, which is stimulated within the slugs by their passage along the channel, is responsible for a large enhancement in the interfacial mass transfer and the reaction rate. Mass transfer performance data has been obtained for a glass chip-based reactor in a 380 microm wide channel by monitoring the extraction of acetic acid from kerosene slugs as they moved along the reactor channel. Finally, the data was compared with that provided from other inter-phase contacting techniques.

Novel synthesis of thick wall coatings of titania supported Bi poisoned Pd catalysts and application in selective hydrogenation of acetylene alcohols in capillary microreactors

“…Microreactors have many advantages over traditional large-scale chemical reactors: the small dimensions of microreactors facilitate mass-and heat-transfer, small reaction volume allows the handling of hazardous or expensive chemicals safely and high-pressure reactions to be carried out with inexpensive equipment, hence significant process intensification is possible with microreactor technology. [8][9][10][11][12][13][14] In heterogeneous catalytic reactions however, the advantages of microreactors are offset by the problem of catalyst introduction into the reactor. A convenient laboratory practice to use packed-bed reactors, i.e.…”

“…27 This method was applied to obtain a 5-20 μm thick coating inside shorter (0.3 m) reactors 28 or a thin coating (90 nm) inside 10-m long reactors. 23,29 Another derivative of the dip-coating method, the fill-and-dry method, can be used to obtain [10][11][12][13][14][15][16][17][18][19][20] μm thick catalytic coatings inside short reactors. [30][31][32] However, the essential component of these methods, solvent evaporation, requires years to remove solvent from a longer (5 m) reactor according to estimations performed using Stefan's equation, 33 Fig.…”

Optimising Terpene Synthesis with Flow Biocatalysis

“…In a segmented flow system, the interfacial area between the two liquids is exquisitely controlled by the size of the solvent segments 7. Many researchers, including us, have utilised this to enhance mixing and accelerate reactions 8.…”

Membrane-Based, Liquid–Liquid Separator with Integrated Pressure Control

“…The separator achieved three stages of extraction ( Figure 8) when extracting acetone from either toluene or water. This was expected since the high mass transfer rates in slug flow 21,22 ensured that equilibrium was achieved before separation at each stage. Since extraction and separation occur independently, this system could be scaled to a large number of stages with † TABLE OF CONTENTS GRAPHIC …”

“…[14][15][16][17][18][19] Among the separation techniques available to organic chemists, liquidliquid separations are becoming more popular. 20 The small length scales encountered in continuous systems on the microscale and milliscale improve the extraction rate due to higher mass transfer coefficients, 21,22 but present challenges for separation as surface forces dominate over the traditionally used gravity force. 23 Several solutions have reported including parallel flow, [24][25][26] settling tanks, 27,28 selectively wetting channels, [29][30][31] centrifugation, 13,32 and microfiltration membranes.…”