Reactor micro fluidic

The concept of an integrated micro-fluidic-based system has now been developed (Zhang et al. 2006), with an example shown in Fig. 7. This particular system is based on conventional chromatographic instrumentation and employs a multi-valving system, located between two syringe pumps, shown in the foreground, to enable the introduction of multiple reagents from an auto-sampler to be loaded onto the micro-reactor. Because of the low diffussional distances obtained in this sys-... 

Balogh J, Kuik A, Urge L et al (2009) Double carbonylation of iodobenzene in a micro-fluidics-based high throughput flow reactor. J Mol Catal A Chem 302(l-2) 76-79... 

M 18] [P 17] The wettable pattern can be used as micro-fluidic chips or micro reactors. Pairs or multiples of different hydrophobic stripes can be filled, e.g., with... 

Flego [1] recommends the use of micro devices for automated measurement and microanalysis of high-throughput in situ characterization of catalyst properties. Murphy et al. [5] stress the importance of the development of new reactor designs. Micro reactors at Dow were described for rapid serial screening of polyolefin catalysts. De Bellefon ete al. used a similar approach in combination with a micro mixer [6], Bergh et al. [7] presented a micro fluidic 256-fold flow reactor manufactured from a silicon wafer for the ethane partial oxidation and propane ammoxidation. 

Internal structures of micro devices (sometimes the micro device itself) are very small compared with conventional chemical equipment. However, micro fluidic devices are large enough that the physical laws established for the macroscopic world can be used to describe the behavior in the device. However, some additional terms must be taken into account, which are neglected in designing conventional reactors. An efficiency analysis of micro heat exchangers [46] is used to explain... 

Figure 4.5 Schematic of two possibilities of monitoring and adjusting temperature in a conventional batch reactor and a micro fluidic device [13] (by courtesy of S. Masebe, Kyoto University).

A 14] Micro fluidic pumps with dimensions small enough to be connected inline with the process flow of a micro structured reactor plant are commercially available [78]. The tooth-ring gear pumps of the mzr-series, for example, convey up to 171 h-1 at pressures up to 80 bar. They can be used either as dosing pumps or as booster pumps inline in a hybrid plant or in a micro structured reactor plant with open architecture. The use of the stepwise pressure increase reduces the average plant pressure as indicated schematically in Figure 4.81. 

Figure 14.9 Schematic of living anionic polymerization using a micro-fluidic reactor. (Reprinted with permission from Ref. [11] 2011, John Wiley Sons, Inc.)...

Following the applications of polymer particles, several functional polymeric particles were later prepared in micro-fluidic reactors, including the use of biological polymers and their incorporation into cells. 

During recent years, several reports have been made describing the up-scaling of processes in micro-reactors, by placing many reactors in parallel. One of the first such successful designs for particle formation was developed by Nisisako and Torii [33], who prepared circular arrays of micro-fluidic cross-junction geometries. 

Song, Y., Kumar, Challa, S. S. R., and Hormes, ]., Fabrication of an SU-8 based micro-fluidic reactor on a PEEK substrate sealed by a flexible semi-solid transfer (FST) process, f. Micromech. Microeng., 14 932-940, 2004. 

The integration of sensing and other functions in a micro-flow system requires either monolithic, on-chip or hybrid, multi-scale approaches. Concerning the latter, Hessel and Lowe discuss the lack of compatibility of today s fluidic interfaces and report on a German project team developing a standard for micro-reactor interconnection [9, 10]. 

Figure 1.27 Standardized fluidic backbone for connecting micro-reactor components from different suppliers, yielding a small, compact micro-plant with multiple functions.

The focus of the examples given in this chapter is clearly on micro reactors for chemical processing in contrast to p-TAS or Lab-Chip systems for bioanalytical applications. In the latter microfluidic systems, the fluidic requirements are somehow different from those in micro reactors. Typically, throughput plays only a minor role in p-TAS systems, in contrast to micro reactors, where often the goal is to achieve a maximum molar flux per unit volume of a specific product. Moreover, flow control plays a much greater role in p-TAS systems than in micro reactors. In... 

One of the most frequently used micro reactor types relies on the use of micro-structured platelets with multiple parallel channels, typically manufactured by methods other than routinely used for chip processing, encased in a housing [3,4, 12, 13, 18, 28-39]. If more than one platelet is used, which is usually done to increase throughput, a stack-like arrangement is preferred for parallel feed. Such stacks are either welded directly from the outside [29, 30], are encompassed by a cover [3,18, 31, 32, 37-39], have end caps with fluidic connectors [12,13, 33] or are inserted into a recess of a housing, which is typically composed of two parts [4, 28, 34-36, 40 1]. 

The reactor can be obtained in many materials such as aluminum alloys, copper, silver, titanium and stainless steel. The number of stacked platelets, the dimensions of the micro channels on the platelets and the fluidic connectors were also varied. Pressure tightness up to 25 bar and He tightness were demonstrated, although this is certainly not the upper limit. 

When scaling a conventional centimetre-sized reactor down to the micron scale, the surface-to-volume ratio significantly increases to the point where the container walls can effectively become an active or influential part of the reaction or process occurring in the fluidic channel. Clearly this attribute of micro-reactors can be viewed in a positive way and leads to the opportunity of exploiting surface-dependent performance including electrokinetic driven flow, surface functionalisation and mass transfer, and heat transfer. 

Micro structured reactors will not only increase reactor compactness and reduce the size of sometimes expensive samples but will also allow a thorough fluidic description of the flow in the reactor. The mechanism, which assists here, is the laminar-flow regime, which develops owing to the small reactor dimensions. 

Continuous flow reactors allow a new way of catalyst preparation. The fluidic pathways can be used for the transport of impregnation liquid or solid particles if means are supplied to localize the catalysts at defined positions inside the reactor. One possibility is the flow impregnation of wash-coated micro structures with catalyst solutions [38],... 

Reactor 3 [R 3] Fluidic Manifold Concept - Micro Structured Reactor-to-micro Structured Reactor... 

The concept presented here in much detail as an example of cooperative project work in micro structured reactor plant development is based on the bus system and simultaneously handles a number of tasks such as mechanical stability, fluidic flow and signal transmission. A key feature of the so-called backbone interface is its open architecture. It does not rely on standardized reactors or devices, thus allowing the combination of devices from various suppliers. A robust interface was developed which withstands high pressures and temperatures. Thermal cross-talk was minimized through the use of different heat-conducting materials. 

During the experiments, the micro structured reactor plant concept was also assessed by measuring properties such as seal reliability and thermal cross-talk between parallel fluidic channels. The performance of the micro structured reactor plant with respect to parameters such as product yield, selectivity and compactness, flexibility and robustness were examined using exemplary chemical reactions. These are advanced multi-step reactions in organometallic boron chemistry (liquid/liquid),... 

R 18] A modular set of devices was developed within the pChemTec project introduced above. It consists of a base plate which is identical for all four devices. This base plate acts as the fluidic interface to the piping and is equipped with a micro structured mixer. The base plate can be combined with a heated tube to deliver a mixer-tube reactor. A combination with a porous tube delivers a degasser unit. A combination with a membrane unit (not shown) or a settler results in an extraction device (Figure 4.58). 

Diffusion as an Efficient Means of Transport in Micro- and Nanoscale Chemical Reactors fesT—Driven Fluidic Devices... 

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