Segmented reactor

Open tubular reactor ( ) Segmented reactor Hi) Packed bed reactor... 

Segmented reactor (a) triglycerides solution tallow 20, water 1.5, acetone 15, MTBE 63.5 (% p/p) (b) adjustment of water content. 

The segmented reactor is not an ideal reactor for intrinsic kinetic measurements. because gas-liquid and the interparticle resistances in this reactor are difficult to eliminate. However, the laboratory-scale reactor can duplicate the... 

Lang et al. reported the use of a post-column air-segmented reactor to enable fluorimetric detection of reserpine. As oxidizing reagent sulfuric acid - sodium nitrite was used, which converted reserpine into 3,4-dehydroreserpine. The reaction product was detected by measuring emission above 470 nm after excitation at a wavelength of 395 nm. 

Ten untreated oil shale samples were simultaneously pyrolyzed in a segmented reactor constructed of stainless steel (Figure 2). Approximately 12 g of shale was weighed into each 6-inch high individual sample vessel with stainless steel frit bottom. The vessels were placed into the 10 compartments of the reactor resting on a wire mesh so as to be positioned near the center of the furnace. The lid with 3 thermocouples and a gas inlet was bolted into place with a Viton 0-ring seal (the top... 

For slow reactions (reaction times > 5 min) an air or liquid segmented reactor is typically used. Segmented systems are also required for reactions that require separation of the reagent from the reaction product by solvent extraction, for example when ion-pair reagents are used to form the product for detection. The reaction products are usually of different polarity to the reagent, permitting their separation by extraetion... 

The desired form in homopolymers is the isotactic arrangement (at least 93% is required to give the desired properties). Copolymers have a random arrangement. In block copolymers a secondary reactor is used where active polymer chains can further polymerize to produce segments that use ethylene monomer. 

Scale-Up Principles. Key factors affecting scale-up of reactor performance are nature of reaction zones, specific reaction rates, and mass- and heat-transport rates to and from reaction sites. Where considerable uncertainties exist or large quantities of products are needed for market evaluations, intermediate-sized demonstration units between pilot and industrial plants are usehil. Matching overall fluid flow characteristics within the reactor might determine the operative criteria. Ideally, the smaller reactor acts as a volume segment of the larger one. Elow distributions are not markedly influenced by... 

Titanium disulfide can also be made by pyrolysis of titanium trisulfide at 550°C. A continuous process based on the reaction between titanium tetrachloride vapor and dry, oxygen-free hydrogen sulfide has been developed at pilot scale (173). The preheated reactants ate fed iato a tubular reactor at approximately 500°C. The product particles comprise orthogonally intersecting hexagonal plates or plate segments and have a relatively high surface area (>4 /g), quite different from the flat platelets produced from the reaction between titanium metal and sulfur vapor. The powder, reported to be stable to... 

Figure 8.34 Segmented flow tubular reactor (SFTR). (After Lemaitre etal., 1996, 1997)...

Doiiiiet, M., Joiigeii, N., Lemaitre, J. and Bowen, P., 2000. New morphology of calcium oxalate triliydrate precipitated in a segmented flow tubular reactor. Journal of Materials Science Letters, 19, 749-750. 

Donnet, M., Jongen, N., Lemaitre, J., Bowen, P. and Hofmann, H., 1999. Better control of nucleation and phase purity using a new segmented flow tubular reactor Model system Precipitation of calcium oxalate. In 14th International Symposium on Industrial Crystallization. Cambridge, U.K., September 12-16, Institution of Chemical Engineers, CD ROM, pp. 1-13. 

Schreiner, A., Jones, A.G., Donnet, M. and Jongen, N., 2001. Precipitation of CaC03 in the Segmented Flow Tubular Reactor (SFTR). In BIWIC-H International Workshop on Industrial Crystallization, Delft 19-20 September 2001. 

The purpose of this analysis was to assess the risk of operating Limerick Station, specifically with regard to its location near a high population density area. These risks were evaluated to determine whether they represent a disproportionately high segment of the total societal risk from postulated nuclear reactor incidents. 

In the design of optimal catalytic gas-Hquid reactors, hydrodynamics deserves special attention. Different flow regimes have been observed in co- and countercurrent operation. Segmented flow (often referred to as Taylor flow) with the gas bubbles having a diameter close to the tube diameter appeared to be the most advantageous as far as mass transfer and residence time distribution (RTD) is concerned. Many reviews on three-phase monolithic processes have been pubhshed [37-40]. 

Kreutzer, M.T. et al. (2005) Multiphase monolith reactors chemical reaction engineering of segmented flow in microchannels. 7th International Conference on Gas-Liquid and Gas-Liquid-Solid, 2005,... 

We first explain the setting of reactors for all CFD simulations. We used Fluent 6.2 as a CFD code. Each reactant fluid is split into laminated fluid segments at the reactor inlet. The flow in reactors was assumed to be laminar flow. Thus, the reactants mix only by molecular diffusion, and reactions take place fi om the interface between each reactant fluid. The reaction formulas and the rate equations of multiple reactions proceeding in reactors were as follows A + B R, ri = A iCaCb B + R S, t2 = CbCr, where R was the desired product and S was the by-product. The other assumptions were as follows the diffusion coefficient of every component was 10" m /s the reactants reacted isothermally, that is, k was fixed at... 

Sulfuric acid, formaldehyde, and hydrogen cyanide are pumped into a glass-lined mixer (mixer 1, Ml, of Fig. 13). Particular care is exercised so that the three charge operations are carried out in the order indicated above, to ensure the stability of the mixture at all times. In a separate segment of the plant, ethylenediamine (EDA) and dilute sodium hydroxide are charged and mixed in mixer 3 (M3 in Fig. 13). The solutions from mixer 1 and mixer 3 are pumped to the reactor (REACTOR, Rl, in Fig. 13). When the reaction is complete, the reaction mixture is tested for traces of hydrogen cyanide. Dilute solution of formaldehyde is prepared in mixture 2 and is added to the reaction mbrture, if there is any HCN present. 

Testing, A., Heeguijuela, J. R., Development of a continuous segmented tubular flow reactor and the scale-out concept -in search of perfect powders, Chem. Eng. Technol. 26, 3 (2003) 303-305. 

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