Annular chemical reactor

SUPERPOSITION PRINCIPLE RADIAL TEMPERATURE GRADIENTS IN AN ANNULAR CHEMICAL REACTOR... 

Tam, W. Y. (1987). Sustained chemical waves in an annular gel reactor a chemical pinwheel. Nature, 329, 619-20. 

Swinney and coworkers developed the continuously fed unstirred reactor (CFUR) in 1987 (Tam et al., 1988a). It consists of a gel that is in diffusive contact with an input from the CSTR, as shown in Figure 3.9. The gel prevents convection, and the CSTR keeps the system away from equilibrium. With this device, transitions between well-defined patterns can be studied. The CFUR does for the study of pattern formation and chemical waves what the CSTR did for oscillating reactions. If the gel is in the shape of a ring (an annular gel reactor), then, with special initiation conditions, pinwheels of wavefronts chasing each other can be created (Noszticzius et al., 1987). As we will see in Chapter 14, gel reactors proved essential for the discovery of Turing patterns. 

Pareek, V.K., S.J. Cox, M.P. Brungs, B. Young, and A.A. Adesina, Computational fluid dynamic (CFD) Simulation of a Pilot-Scale Annular Bubble Column Photocatalytic Reactor. Chemical Engineering Science, 2003. 58(3-6) p. 859-865. 

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]. 

The feasibility of combining chemical reaction and adsorption separation in a single unit has been discussed in this chapter. In particular, two units allowing continuous operation have been considered, namely annular reactive chromatography and simulated moving-bed reactors. 

Thus, there are at least two important chemical differences between these reactions in (a) the radiofrequency discharge in an annular ozon-izer-type reactor at pressures near 200 torr, and (b) the microwave discharge in a cylindrical reactor at pressures of 12 or 50 torr. Under the microwave conditions, C2H2 is always produced (together with CH4) from H2 + CO and H2 + C02 (without cooling) form CO but no hydrocarbons. Obviously, it would be extremely useful to understand these phenomena. We have explored this situation a bit further, in the following manner. 

Reactant A is converted irreversibly and exothermically to products in a 2-in.-inner-diameter tubular reactor via first-order chemical kinetics. The reactive mixture in the inner pipe is cooled using a concentric double-pipe heat exchanger. The nonreactive cooling fluid in the annular region flows countercurrently with respect to the reactive fluid. The radius ratio of the double-pipe configuration is If = Rinside/ outside = 0.5, the inlet temperature of the reactive fluid is 340 K,... 

Consider a liquid-phase plug-flow tubular reactor with irreversible nth-order endothermic chemical reaction. The reactive mixture is heated with a fluid that flows cocurrently in the annular region of a double-pipe configuration. The mass and heat transfer Peclet numbers are large for both fluids. All physical properties of both fluids are independent of temperature and conversion, and the inlet conditions at z = 0 are specified. What equations are required to investigate the phenomenon of parametric sensitivity in this system ... 

Groppi G, Ibashi W, Valentini M, Forzatti P. High-temperature combustion of CH4 over Pd0/Al203 Kinetic measurements in a structured annular reactor. Chemical Engineering Science 2001 56 831-839. 

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