Testing microreactors

Kinetic analysis—The model of the test microreactor was based on the following equations, whose symbols are defined in the Notation. They represent the adaptation of the general Eqs. (33) and (34) in Section IV to the specific reacting system herein considered. 

The experiment in Fig. 36 has been analyzed according to the usual plug-flow model of the test microreactor. In this case, the ammonia mass balance equations were modified in order to include the oxidation reaction R5 in Table V, which was considered to proceed via adsorbed ammonia NH3. Moreover, the mass balance for gaseous nitrogen was introduced... 

The kinetic analysis of the whole set of transient data collected over the powdered SCR catalyst has been addressed using the dynamic ID isothermal heterogeneous plug-flow model of the test microreactor (Chatterjee et al., 2005 Ciardelli et al., 2004a) described in Section IV. 

Hessel, V., Hofmann, C., Lowe, H., Worz, O., Zapf, R., A novel catalyst testing microreactor for heterogeneous gas phase reactions, in Proceedings of the 6th International Conference on Microreaction Technology, IMRET 6 (11-14 March 2002), AIChE Pub. 

The Chemical Development Drug Evaluation branch of Johnson Johnson Pharmaceutical Research Development LLC in Raritan, USA, tested microreactors for processes at elevated temperatures above the limit of most multipurpose conventional reactors, which is above 140°C [34], Operation above this limit is only possible by means of special reactors equipped with heat transfer units. 

IMM provides two reactors for catalyst screening. The catalyst testing microreactor contains 10 microstructured plates made out of stainless steel, whicii can be coated on demand with various catalysts. Every plate is fed simultaneously by a sub-stream and the reactor can be operated serially or in parallel. The pressure stability of this reactor is 20 bar (100 bar at 400 °C) and a maximum temperature of 800 °C is possible. MicroChannel plates with different channel geometries with specific surface areas around 7300 m m are offered by IMM. 

Reaction conditions 0.1 g of the zeolite Y modified catalyst, tested in a conventional glass microreactor with racemic butan-2-ol (7.35 x 10" mol h-1), prevaporized in a nitrogen diluent (6.2 -6.7 x 10" mol h-1). Products were analyzed using on-line GC with a 40m capillary y- cyclodextrin colimm with trifluoroacetyl stationary phase, temperature programmed from 25-70 "C with a split ratio of 120 1. 

The catalysts were tested for their CO oxidation activity in an automated microreactor apparatus. The catalysts were tested at space velocities of 7,000 -60,000 hr . A small quantity of catalyst (typically 0.1 - 0.5 g.) was supported on a frit in a quartz microreactor. The composition of the gases to the inlet of the reactor was controlled by mass flow controllers and was CO = 50 ppm, CO2 = 0, or 7,000 ppm, HjO = 40% relative humidity (at 25°C), balance air. These conditions are typical of conditions found in spacecraft cabin atmospheres. The temperature of the catalyst bed was measured with a thermocouple placed half way into the catalyst bed, and controlled using a temperature controller. The inlet and outlet CO/CO2 concentrations were measured by non-dispersive infrared (NDIR) monitors. 

Catalytic activity tests have been performed in a quartz microreactor (I.D.=0.8 cm) filled with 0.45 g of fine catalyst powders (dp=0 1 micron). The reactor has been fed with lean fiiel/air mixtures (1.3% of CO, 1.3% of H2 and 1% of CH4 in air resp ively) and has been operated at atmospheric pressure and with GHSV= 54000 Ncc/gcath The inlet and outlet gas compositions were determined by on-line Gas Chromatography. A 4 m column (I D. =5mm) filled with Porapak QS was used to separate CH4, CO2 and H2O with He as carrier gas. Two molecular sieves (5 A) columns (I D.=5 mm) 3m length, with He and Ar as carrier gases, were used for the separation and analysis of CO, N2, O2, CH4, and H2, N2, O2 respectively... 

Figure 4.43 Benchmarking of untreated and pre-treated Y-piece micro reactors to a commercial micro test-tube for the hydrolysis of p-nitrophenyl-/ -D-galactopyranoside. Y-piece micro reactor ( ) commercial micro test-tube ( ) pre-treated Y-piece microreactor (A) [26],...

Senkan, S., Krantz, K., Ozturk, S. et al. (1999) High-throughput testing of heterogeneous catalyst libraries using array microreactors and mass spectrometry. Angew. Chem. Int. Ed., 38, 2794. 

Catalytic tests were conducted in a pulse microreactor coupled to a quadrupole mass spectrometer. Samples were dried in situ in flowing helium at 773 K for four hours and, thereafter, sequential propane pulses were injected at 703 K with mass-spectrometric analysis of the products.The main text can start here. 

The redispersion microreactor is applied for the liquid-liquid polycondensation to yield an OLED material by multiple Suzuki coupling. As the initial test reaction, the following single Suzuki coupling is currently being explored in the liquid-liquid system made from water/ dioxane/toluene. 

Microreactors with the thin film catalyst deposited as described were repetitively tested across a wide temperature range. The feed was composed of 1.7% CO, 68% H2, and 21% CO2 with N2 as the balance. The flow rate was maintained at 5 Ncm3/min ( 0.6 Wt) which the researchers believed would be enough for a 0.5 Wg fuel cell. However, using the DOE assumptions (45% for reformer systems), this would translate into approximately 0.27 W.7 After each... 

Isomerization processes have been used as test reactions in developing microreactors for dynamic, high throughput screening of fluid/liquid molecular catalysis [45]. 

WUes and Watts [48,53] have reported the use of a rather successful heterogenic catalytic system to carry out these reactions. They have tested a borosilicate glass microreactor (dimensions 3.0 x 3.0 x 0.6 cm) consisting of two etched layers with two inlets, mixing channels, a larger etched region and the outlet. A solid-supported catalyst was dry-packed in this structure (Fig. 4). 

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