Bubble reactors

Bubble Reactors In bubble columns the gas is dispersed by nozzles or spargers without mechanical agitation. In order to improve the operation, redispersion at intei vals may be effected by static mixers, such as perforated plates. The liquid may be clear or be a slurry. 

Reactor types Stirred tank or tower, bubbling reactor RPB... 

However with stirring and coalescence and breakup, both effects tend to mix the contents of the bubbles or drops, and this situation should be handled using the CSTR mass balance equation. As you might expect, for a real drop or bubble reactor the residence time distribution might not be given accurately by either of these limits, and it might be necessary to measure the RDT to correctly describe the flow pattern in the discontinuous phase. 

Figure 12-15 Sketch of concentration profiles between a spherical bubble and a solid spherical catalyst particle in a continuous liquid phase (upper) in a gas-liquid sluny reactor or between a bubble and a planar solid wall (lower) in a catalytic w bubble reactor, It is assmned that a reactant A must migrate from the bubble, tirough the drop, md to tiie solid catdyst smface to react. Concentration variations may occur because of mass transfer limitations around both bubble and solid phases.

Shaker flasks Laminaria japonica (kelp) Plasminogen activator protein Gao et al., 2005 56 pg/g dry cell weight Illuminated bubble column bubble reactor... 

Figure 3.27 Flow regimes in slurry bubble reactors...

Film diffusion resistance All bubbling reactors such as Catalytic fixed-bed G/S reactors BFB and three-phase reactors All fast, noncatalytic G/S reactions such as combustion and gasification ... 

Design models for slurry bubble reactors Axial dispersion model... 

Figure 4-14. A two-phase tubular flow reactor (e.g., gas-liquid bubble reactor for oxidation of pollutants in water). (Source J. M. Smith, Chemical Engineering Kinetics, 3rd ed., McGraw-Hill, Inc. 1981.)...

To increase the yield of triethoxysilane, it is necessary to eliminate the hydrogen chloride formed from the reaction zone as soon as possible. It is hardly conceivable in periodical bubble reactors with a small phase contact surface. Because it is difficult to bring large amounts of heat for HCI desorption to the reactive mixture, packed towers do not allow for a continuous process either. The most convenient apparatus for the etherification of trichlorosilane is film-type, which allows for a continuous process. 

Thoroughbred A family of flue-gas desulfurization processes. Commercialized versions have been called Thoroughbred-101, Thoroughbred-102, and Thoroughbred-121. Another name used for the last is CT-121. They are integrated flue-gas desulfurization processes that achieve limestone neutralization, oxidation, and conversion to gypsum, in a complex jet bubbling reactor. Developed... 

Two points should be emphasized First, the previous relationships for pressure drop and holdup are not valid for saddles and Pall rings, but data for these packings in specific situations are found in the literature (R6, D16, W2). Second, as a rough approximation, the equations for downward flow in a packed bubble reactor are still valid for upward flow. [The upflow data for pellets and spheres from Tlirpin and Huntington (T11) and Sato et al. (S8) will be useful for specific cases.]... 

Results of Figs. 27 and 28 are confined to aqueous and/or electrolyte solutions. Many industrially important gas-liquid reactions involve polar or nonpolar organic media. Mass-transfer rates in agitated bubble reactors using viscous and organic solvents are substantially different from those using aqueous media, so data for the latter cannot be extended directly. 

Adsorption flotation involves the removal of dissolved pollutants by activated carbon in a bubble reactor, and subsequent removal of activated carbon as well as other suspended particles by flotation technique (71). This process was found efficient for removing both dissolved organics and suspended solids from an industrial effluent (72), and for removing the emulsifled oil from water (73). The mechanism of removal has been proposed by Wang (72,73). 

Bubble fractionation is similar to foam fractionation except that there is no foam produced in the system thus, it is applied to dilute surface-active solutions that do not foam while foam fractionation is applied to surface-active solutes at high concentration (76,77). Technically speaking, bubble fractionation represents an operation in which gas is bubbled up through a vertical bubble reactor containing the surface-active solute(s)... 

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