IMM micromixer

Yoshida and coworkers also developed a microreaction system for cation pool-initiated polymerization [62]. Significant control of the molecular weight distribution (Mw/Mn) was achieved when N-acyliminium ion-initiated polymerization of butyl vinyl ether was carried out in a microflow system (an IMM micromixer and a microtube reactor). Initiator and monomer were mixed using a micromixer, which was connected to a microtube reactor for the propagation step. The polymerization reaction was quenched by an amine in a second micromixer. The tighter molecular weight distribution (Mw/M = 1.14) in the microflow system compared with that of the batch system (Mw/M > 2) was attributed to the very rapid mixing and precise control of the polymerization temperature in the microflow system. 

The effect of the flow rate on molecular weight distribution (Table 14.1, runs 4-6) indicates the importance of mixing, because it is known that mixing efficiency decreases with decrease in flow rate in the IMM micromixer [44]. Reaction temperature is also important for controlling molecular weight distribution. Mw/M increases with increase in the temperature (mns 4, 7,8 and 9). Anyway, a high level of... 

More recently, Lowe and coworkers reported a detailed study on the addition of secondary amines to ethyl acrylate and acrylonitrile using a continuous microreaction process based on an IMM micromixer and tabular reactor [16]. In the best case, space-time yields (g/ml h) for the microflow system were much higher than those for the batch system, by a factor of 650. 

A microreactor was also applied to this reaction. The slit interdigital micromixer was purchased from IMM (Mainz, Germany). The width of the interdigital channels is 25 pm. HPLC pumps were used to feed the two reaction solutions. One is a mixture of Boc-AMP and 1.2 molar equivalents of r-BocaO. The other is a 50% aqueous KOH solution. The microreactor was immersed in a temperature controlled cooling bath at 15 °C. The product was quenched with an acid, and samples were taken for HPLC analysis. 

A nitroglycerine microprocessing plant, developed by IMM for the Chinese class-A company Xi an, is an example of the smart scaled-out concept, showing that just one caterpillar micromixer is sufficient for the continuous production of pharmaceutical-degree nitroglycerine, with a throughput of approximately 15 kg/h (Thayer 2006). 

Figure 4 Micromixers, (a) Interdigital structure of a multilamination micromixer. (b) Principle of split-and-recombine static micromixers. (Source IMM.)...

Figure 4.42 High-pressure interdigital micromixer made of steel (by courtesy of IMM).

Examination of the same mannosylation was performed by using the integrated microfluidic and batch systems as described earlier for microfluidic a-sialylation by the N-acetylated imidate 15 [19]. The Comet X-01 micromixer utilized for this case has a channel width of 500 pm (Fig. 8.5) because the micromixing with IMM mixer... 

When a T-shaped mixer is used, the product selectivity is essentially the same as for the macrobatch reactor (Scheme 6.4). The use of the YM-1 mixer, a splitting-and-recombination-type micromixer (see Chapter 7), increases the selectivity, however, a significant amount of dialkylation product is still produced. The use of the IMM multilamination-type micromixer results in excellent selectivity of the monoalkylation product. The amount of dialkylation product is very small. Therefore, the product selectivity strongly depends on the manner of mixing. 

In the case of Y- or T-shaped micromixers, a decrease in the channel width to shorten mixing time leads to a decrease of production volume per unit time. To solve this problem interdigital multilamination micromixers have been developed. In this type of micromixer, two fluids are separated into many small narrow streams, which are arranged to contact each other alternately. The mixing takes place at interfaces of such sub-streams by molecular diffusion. The IMM (Institute of Microtechnik Mainz) single... 

In interdigital multilamination micromixers, the small thickness of the lamellae leads to short diffusion paths, resulting in fast mixing. Further thinning of the liquid lamellae should lead to shorter diffusion paths and faster mixing. The IMM single mixer applied this concept by shrinking the channel width in the slit. A further extension of this concept leads to the... 

Yoshida et al. also demonstrated the effect of mixing on alkylation yields and selectivity by using an efficient multilamination micromixer (supplied by IMM channel width = 25 pm) and a T-mixer (500 pm). 

Figure 4.22 Y-type jet generated by a jet micromixer. (Adapted from Ref [39] (Courtesy Fraunhofer ICT-IMM, Germany.)...

Mae et al. proposed a micromixer based on repeated splitting and recombination and demonstrated its application for extraction using an emulsion (abbreviated as YM-1) [30]. A soap-free emulsion with a diameter of the order of 1pm can be produced in a short contact time of 0.1 s. The maximum production capacity of a single mixer is 200tyr , which is sufficient for the industrial production of fine chemicals and pharmaceutical compounds. Figure 12.8 shows the results for the extraction of phenol from dodecane into water using the YM-1 and an IMM mixer. 

Although it is not a gas-phase but a solution-phase reaction, Fukase and coworkers employed microflow systems for the acid-catalyzed dehydration of allylic alcohols to give dienes. The microfluidic dehydration effectively took place at 80 °C using p-TsOH as a catalyst and THF and toluene as solvents. Both an IMM standard micromixer and a PTFE (Teflon) Comet XOl reactor performed the dehydration successfully [6]. 

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