Chip Micro Reactors

Better chemistry through confinement economy of scale limits and expenditure of scale-up micro reactors origin from microfabrication expert opinions general advantages of micro flow hybrid construction industry s efforts chip micro reactors numbering-up vision of computer-like chemical workstation [205]. 

Accordingly, chip micro reaction systems are frequently described in the literature. Most of them are made of silicon (see, e.g., [19, 56-62]) Glass can be manufactured by similar routes as for silicon and could hence constitute gas-phase micro reactors however, the glass chip micro reactors described so far were made for liquid-phase applications (see, e.g., [63-70]). 

Reactor 10 [R 10] Catalyst Membrane Si-chip Micro Reactor with Sensing and Heating Functions... 

Reactor 14 [R 14] Self-heating Chip Micro Reactor... 

Investigations with the modular multi-channel [28,98] and silicon chip [19, 56-62] micro reactors demonstrate that by exact temperature control the oxidation of ammonia can be run with increased and deliberately steered selectivity. A major application is provided by carrying out former high-temperature reactions in the low-temperature regime. In the case of ammonia oxidation in the chip micro reactor, the yield of the value product NO was actually lower in that regime. In the case of the multi-plate-stack micro reactor, higher yields of the value product NO2 were achieved. 

Reactor type Chip micro reactor with one micro-channel mixing tee Channel width depth 200 pm (at top) x 100 pm... 

Reactor type Chip micro reactor Micro reactor Borosilicate glass... 

Reactor 5 [R 5] Chip Micro Reactor with Multiple Vertical Injections in a Main Channel... 

The chip micro reactor [R 5] comprises a long micro channel connected to two vertically positioned shorter channels at each end which lead to two reservoirs [17]. These shorter channels are oriented in opposite directions so that a Z-type flow configuration results. In the downstream section of the long channel, two other vertically oriented shorter channels are also attached. These channels are each connected to a liquid reservoir. A total of five reservoirs are made in this way (Figure 4.6). 

Reactor type Chip micro reactor with multiple vertical injections in a main channel Micro-channels etch 146 pm 38 pm mask width etch depth... 

Reactor 6 [R 6] Chip Micro Reactor with Multiple Micro Channel-Mixing Tees... 

Figure 4.8 Schematic of the commercial 110 Caliper chip micro reactor for performing organic...

Reactor 7 [R 7] Chip Micro Reactor with Z-type Flow Configuration... 

Reactor [R S] Chip Micro Reactor with Extended Serpentine Path and Ports for Two-step Processing... 

Reactor type Chip micro reactor with extended serpentine path and ports for two-step processing Serpentine micro channel width depth 100 pm 25 pm... 

Reactor type Single-channel chip micro reactor Zeolite catalyst layer thickness 3 pm... 

This class of hybrid components comprises chip micro-reactor devices, as described in Section 4.1.3, connected to conventional tubing. This may be H PLC tubing which sometimes has as small internals as micro channels themselves. The main function of the tubing is to provide longer residence times. Sometimes, flow through the tube produces characteristic flow patterns such as in slug-flow tube reactors. Chip-tube micro reactors are typical examples of multi-scale architecture (assembly of components of hybrid origin). 

D devices have complex requirements on assembly and, in particular, sealing. Integration of sensing is not as facile as for chip micro reactors. In turn, 3-D devices are robust and comprise the classical materials for chemical engineering apparatus. 

This chip micro reactor was designed to have transparent reaction sections, to provide a large specific surface area of the flowing liquid, and to minimize fouling by crystallization of insoluble photoproducts [72-74]. 

Table4.9 Benchmarking of mixing-tee chip micro-reactor operation to macro batch-scaie synthesis for a series of 2-aminothiazoies [10],...

The Knorr synthesis was chosen as an example to demonstrate that with an automated micro-reactor system a further step was made over existing parallel micro flow processing techniques, providing a 2 x 2 library in a chip micro reactor [20]. The new approach was designed for much higher diversity, aiming at a 7 x 32 library. 

P 53] Before operation, a start-up time of about 10 min was applied to stabilize pressure in the chip micro reactor ([R 6]) [20]. As a result, a stable flow pattern was achieved. The reactant solutions were filled into vials. Slugs from the reactant solutions were introduced sequentially into the micro chip reactor with the autosampler and propelled through the chip with methanol as driving solvent. The flow rates were set to 1 pi min The slug volume was reduced to 2.5 pi. 

The chip micro reactor ([R 6]) was only one part of a complex serial-screening apparatus [20]. This automated system consists of an autosampler (CTC-HTS Pal system) which introduces the reactant solutions in the chip via capillaries. A pumping system (p-HPLC-CEC System) serves for fluid motion by hydro dynamic-driven flow. A dilution system [Jasco PU-15(5)] is used for slug dilution on-chip. The detection system was a Jasco UV-1575 and analysis was carried out by LC/MS (Agilent 1100 series capLC-Waters Micromass ZQ). All components were on-line and self-configured. 

P 55] Before synthesis, a micro-mixing tee chip micro reactor (Figure 4.85) (with two mixing tees and four reservoirs) was primed with anhydrous tetrahydrofuran (THF). A 40 gl volume of a 0.1 M solution of tetrabutylammonium fluoride trihydrate in anhydrous THF is filled into one reservoir of a micro-mixing tee chip reactor [15], 40 gl of a 0.1 M solution of 4-bromobenzaldehyde in anhydrous THF is added to a second reservoir, 40 gl of a 0.1 M solution of the silyl enol ether (masking the enolate of a carbonyl compound such as cyclohexanone) in anhydrous THF is added to a third reservoir and anhydrous TH F is filled into the fourth collection reservoir. Electrical fields of417,455,476 and 0 V cm are applied to transport the reaction species from the respective reservoirs. The reaction is carried out at room temperature. 

Figure 4.85 Flow configuration for the aldol reaction of silyl enol ethers in a mixing-tee chip micro reactor [15],...

Figure 4.87 Flow configuration for a Wittig synthesis in a chip micro reactor with three vertical injections [13].

P 75/The protocol relies on sequential filling of selected charmels or parts of them in a chip micro reactor [17]. Thus, a short description of the micro reactor flow configuration is needed to understand details of the protocol. 

Figure 5.11 Schematic of the single-channel chip micro reactor. Divergent inlet channels (A) secondary inlet channel (B) serpentine irradiation channel (center) outlet channel (Q [21. ...

Using a single-channel chip micro reactor, singlet oxygen is generated by photochemical means in presence of catalytic amounts of Rose Bengal [21]. By [4 -i- 2] cycloaddition of this oxygen species to a-terpinene, the product ascaridole is obtained. 

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