Flow Reactor Systems

Cross-flow reactors are fed continuously with streams of components of the reaction mixture whereby some components are introduced at the inlet, while others are introduced at other locations. The reaction mixture flows out continuously from the end of the reaction zone. A cascade of CSTRs with additional feeds to individual reactors represents a cross-flow reactor system. Cross-flow reactors are also operated at steady-state conditions ... 

For example, a microwave discharge on H2 in an inert diluent, such as argon gas, is an efficient method for producing H atoms as reactants. Subsequent reaction of these H atoms with NO2 will yield OH and NO, and can serve as a useful source of hydroxyl radicals. These methods of reactant formation are well suited for experiments involving either static or flow reactor systems. 

The Csajagi research group used a commercial X-Cube continuous flow reactor system [32] to perform similar reactions. The reactor is made of stainless steel, capable of reaching pressures of up to 150 bar, and equipped with preloaded catalyst cartridges. Monoamides of aryldicarboxylic acids are obtained in a reaction over a tetrakis(triphenylphosphine)palladium catalyst using A-methylpyrrolidone as base [33]. Terephtalic acid was reported as the byproduct, but not the oc-ketoamide. 

Figure 6.3 Concentration profile through an iV-stage mixed flow reactor system compared with single flow reactors.

For the mixed flow reactor system of Example 9.5, we wish to get 70% conversion in the smallest size of reactor. Sketch your recommended system and on it indicate the temperature of the flowing stream entering and leaving the reactor as well as r, the space time needed. 

Scheme Q D, and E, From Fig. 12.1 the exit age distribution function for the two equal-size plug-mixed flow reactor system is...

Bypass - A bypass is a parallel path taken by a portion of the fluid that skips the reactor altogether without any residence time. As with dead zones, a bypass is not very useful unless a plug flow or mixed tank reactor is placed into the bypass, resulting in a parallel-flow reactor system. 

To define the effectiveness of the UV/H202 process on a wide range of priority pollutants in water, Sundstrom et al. (1989) conducted experiments in a recirculating flow reactor system with low-pressure UV lamps at 254 nm. The temperature of the solution was maintained at 25°C, and pH was maintained at 6.8 by a phosphate buffer. Molar ratio of peroxide to pollutant was varied during the experiments. As the molar ratio of peroxide to pollutant increased, the reaction rates increased. Three monosubstituted benzenes were selected to examine the effect of a single substituent group on the rate of reaction of benzene. The rates of reaction were of similar magnitude for benzene and monosubstituted benzenes (toluene, chlorobenzene, and phenol) at the ratio of 7 for peroxide to pollutant. 

Figure 8 A continuous flow reactor system for subcritical and supercritical studies. (From SRI International.)...

A system for the Heck reaction between methyl acrylate and iodobenzene has been developed comprising an imidazolium-functionalized polystyrene monolith, initially for use in batch. This system could be reused six times before any reduction in yield was observed. Accordingly, a continuous-flow reactor system was developed using DMF at 200 °C with a residence time of 3-4 min to achieve full conversion. This system was characterized by very low palladium loadings (0.02 mol%), and ICP-MS of the solution aliquots showed leaching of less than 1 ppm. Attempts at using EtOH as solvent to provide a more environmentally and procedurally benign protocol resulted in maximum yields of 85% [144]. 

Studies have been made using both continuous flow reactor system and a pulse flow microreactor system with purified helium as the carrier gas similar to that described elsewhere... 

Bruckner (2001) combined UV-vis with EPR spectroscopy, using online gas chromatography for product analysis. For many transition metal ions, EPR and optical spectra are complementary, in that some states are detectable or distinguishable with only one of the methods. The UV-vis facility was added to a previously described flow reactor system for EPR spectroscopy (Bruckner et al., 1996). A fiber optical probe (Avantes, AVS-PC-2000 plug-in spectrometer) was inserted directly into the reactor via a Teflon -sealed feedthrough and placed in the catalyst bed. UV-vis spectra were reported for temperatures up to 810 K. The design was later expanded to include a third method, Raman spectroscopy (Bruckner, 2005 Bruckner and Kondratenko, 2006). A hole in the... 

Over HBEA zeolites, acetylation of 2-methoxynaphthalene with acetic anhydride leads mainly to l-acetyl-2-methoxynaphthalene. However, the desired product, i.e. 2-acetyl-6-methoxynaphthalene, precursor of Naproxen is obtained at long reaction time by an intermolecular irreversible isomerization process. A very selective production of II (83%) can be obtained by acetylation of 2-methoxynaphthalene over a commercial HBEA zeolite (Si/Al = 15) at 170°C, with nitrobenzene as a solvent. With dealuminated HBEA samples (framework Si/Al ratio between 20 and 40), better results could be expected. Furthermore, preliminary experiments showed that this selective synthesis of 2-methoxynaphthalene can be carried out in a flow reactor system. 

Fujiyama et alid have proposed reconfiguring FCC operations to increase propylene yield. The group have demonstrated a down-flow reactor system operating at high catalyst to oil ratios (>15), high reaction temperature (> 550°C) and short residence time (< 0.5 sec) and obtained propylene yields over 15%. 

HDS activities were measured in a flow reactor system using thiophene as the model compound. Reaction rates for the HDS of thiophene to butene were determined at 325°C and atmospheric pressure. HDS testing used -60 mesh catalyst. 

Pt/Alumina. A sample (0.5g) of 0.3% Pt/alumina EUROPT-3 was used to promote hexane to benzene conversion in a Micromeritics 2900 flow reactor system which permitted in-situ TPR, TPD, TPO and pulse hydrogen chemisorption etc. The exit stream from the reactor was analysed via a residual gas analyser and an FID gas... 

Y. Ishihara, H. Nanbu, T. Ikemura, and T. Takesue, Catalytic Decomposition of Polyethylene using a Tubular Flow Reactor System, Fuel, 69, 978-984 (1990). 

K. Takuma et al. [36] LDPE A fixed-bed mbular flow reactor system was used in helium atmosphere 10 H-gaUosiUcate HZSM-5... 

Figure 32.18 Si 2p photoelectron spectra from the top surface of TMS plasma coatings produced in (a) closed reactor system and (b) flow reactor system with and without second surface treatment by O2 or Ar plasmas.

Figure 32.21 summarizes results of Rp measurement of TMS plasma-coated Alclad 7075-T6 panels under IVD conditions in both closed and flow reactor systems, with and without subsequent Ar plasma treatments. TMS plasma coatings produced in a closed reactor system showed higher Rp values than those obtained in a flow reactor system. The second Ar discharge treatment of the flow system TMS coating remarkably increased the Rp value to nearly comparable to that for the closed system TMS. The second Ar plasma treatment of the closed system TMS coating, on the other hand, reduced the value of Rp slightly from that for the closed system TMS. 

Figure 1 Possible cross-flow reactor systems consisting of tubular reactors. (From Ref. 1.)...

We shall focus on one specialty, Cajun seafood gumbo. Develop a continuous-flow reactor system that would produce 5 gal/h of a gommet-quality seafood gumbo. Prepare a flow sheet of the entire operation. Outline certain experiments and areas of research that would be needed to ensme the success of your project. Discuss how you would begin to research these problems. Make a plan for any experiments to be carried out (see Section 5.7.2). 

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