Chemistry Reference
In-Depth Information
Selected examples of microreactor devices. (A) Silicon microreactor.
8a
Reproduced by permission of the Royal Society of Chemistry. (B) Teflon
stack microreactor with integrated ultrasonication and heating for solids
handling reactions.
8b
(C) PFA capillary microreactor.
8c
(D) Microcapillary
assembly for high-temperature and -pressure applications with two HPLC
pumps (1), capillary microreactor immersed in a heating bath (2), cooling
zone (3), sample collection (4) and back-pressure regulator (5).
8d
(E) micro packed-bed reactor for biphasic reaction conditions.
8e
Figure 13.1
(F)
Capillary microreactor for photochemical reactions.
8f
Table 13.1 Advantages and disadvantages of continuous flow microreactors.
Advantages
Disadvantages
Excellent mixing (high mass transfer)
Handling of solids
Fast heating (high heat transfer)
Lack of engineering skills
Safety of operation
Initial investment cost
Novel process windows
Multidisciplinary
Precise control over reaction parameters
Scale-up potential
Reaction automation (self-optimization)
Use of in situ spectroscopic tools
Integrated multistep syntheses
expensive microreactors made of silicon or stainless steel. One of the
greatest issues in micro flow chemistry is dealing with solid-forming re-
actions, which usually lead to irreversible blockage of the microchannels.
Often flow chemists will rethink the reaction conditions to avoid the for-
mation of such solids. However, it should be noted that much effort from the
flow chemistry community has resulted in the development of several so-
lutions to deal with solid-forming reactions.
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