Annular reactor

Carbon Disulfide Chlorination. The chlorination of carbon disulfide [75-15-0] is a very old method of producing carbon tetrachloride that is still practiced commercially in the United States. In this process CS2 reacts continuously with chlorine in an annular reactor at 105—130°C. Product CCl is separated by distillation to a CS2 content of 0—5 ppm. By-product S2CI2 is reduced in a reactor at 450°C with hydrogen without a catalyst to give sulfur of 99.985% purity (32). Other processes use ferric chloride as a catalyst (33,34). 

Annular flow reactors, such as that illustrated in Figure 3.2, are sometimes used for reversible, adiabatic, solid-catalyzed reactions where pressure near the end of the reactor must be minimized to achieve a favorable equilibrium. Ethylbenzene dehydrogenation fits this situation. Repeat Problem 3.7 but substitute an annular reactor for the tube. The inside (inlet) radius of the annulus is 0.1m and the outside (outlet) radius is 1.1m. 

Besides improvements in catalyst characteristics [28], the low productivity of a photocatalytic process can also be improved by reactor design. In photocatalytic research on a laboratory scale, the most widely applied reactors are the top illumination or annular reactors containing a suspended catalyst [29]. This type of... 

Concentration standards, 75 750-751 Concentrators, sulfuric acid, 23 787 Concentric annular reactors, 23 544 Concentric cylinder viscometer, 27 733 Concentric hemispherical analyzer (CHA), 24 103-104, 105 energy resolution of, 24 106 Conching, milk chocolate, 6 363-364 Concomitant polymorphism, 8 69 CONCORD program, 6 10 76 752 Concrete(s)... 

Figure 12.8 TPC test in the annular reactor at high CHSV. Feed composition 0.5% CH4, 2% O2, 1% HjO, balance He.

Figure 12.10 Examples of structured catalytic reactors for kinetic measurements (a) annular reactor [47, 61] (b) plate cell reactor [75].

The extended light source may also be placed at the axis of a reactor composed of two coaxial cylindrical tubes (Figure 12). The emitted radiant power is absorbed by the reaction system contained in the annular reactor volume. Irradiance diminishes in a filled reactor with increasing radius (Eq. 36), this geometry is called the negative geometry of irradiation [2,3]. 

In applying this configuration to problems of preparative photochemistry and large-scale photolysis, we discovered that direct contact between the outer electrode and the reaction mixture can be avoided by taking the latter as part of the dielectric [12]. The outer electrode may then be placed outside an annular reactor of limited thickness (Eq. 36) depending on the chemical properties of the reaction system (Figure 14) [12, 58, 59]. 

Figure 14. Cross section along the plane perpendicular to the axis of an annular reactor with a cylindrical excimer lamp mounted in its axis [12, 58, 59],...

In sensitized or photocatalyzed reactions, conditions of total or constant absorbance can easily be controlled by the concentration of the sensitizer or photocatalyst added. In addition, experience has shown that the concept of spatial separation between the light source and the reaction mixture is in general not required. Dragoco uses immersion-type annular reactor geometries [2, 3, 69, 70] for the production of ( —)-rose oxide by rose bengal sensitized oxidation of (— )-citronellol (Eqs. 45-48, Figure 23). 

Experimental testing of the LSPP and LSSE models (Eqs. 77 and 78, respectively) was performed by Jacob and Dranoff [116] by using an annular reactor filled with either air or water, and the corresponding results showed that the predictions of the LSPP model are not satisfactory for the reasons already mentioned. Good agreement was found between experimental and calculated data by using the LSSE model after optimization of the empirical... 

Equations (79) and (80) describe the radiant exitance at any point in space and originating from the total volume of the light source. By using geometrical concepts to describe a radiation field in an empty annular reactor (Figure 30), integration limits for the spherical coordinates (p, , fi) are given by Eqs. (81)-(84). 

Both batch reactors and continuous-flow reactors have been used. Because Ti02 photocatalysis is generally considered of interest in purifying air or water with low concentrations of pollutants, the absorption of the incident photons by the pollutants is most often insignificant. If it is not the case, a falling film annular reactor (49) can be used as in photochemistry. 

Bolton )R (2000 a) Calculation of Ultraviolet Fluence Rate Distributions in an Annular Reactor Significance of Refraction and Reflection, Wat. Res. 34, No. 13 3315-3324. 

Coated wall annular reactors (Figure 12) are characterized by a thin film of photocatalyst located either on the outer side of inner tube or on the inner side of the outer tube. There are many reasons for preferring the inner side of the outer tube for the coating. The first reason has to do with the flux if is known that at high flux of lighf (>l-2 mW cm ) fhe quantum efficiency is proportional to 1 divided by the square root of fhe intensity. Hence, it is... 

Flat plate reactors, being very simple for construction and analysis, are often used as a tool to obtain kinetic data, later to be used in the modeling of more complex system, for example, that of an annular reactor (Mohseni and Taghipour, 2004). 

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