Configuration, reactor

The search for Turing patterns led to the introduction of several new types of chemical reactor for studying reaction-diffusion events in feedback systems. Coupled with huge advances in imaging and data analysis capabilities, it is now possible to make detailed quantitative measurements on complex spatiotemporal behaviour. A few of the reactor configurations of interest will be mentioned here. 

At still higher temperatures, when sufficient oxygen is present, combustion and "hot" flames are observed the principal products are carbon oxides and water. Key variables that determine the reaction characteristics are fuel-to-oxidant ratio, pressure, reactor configuration and residence time, and the nature of the surface exposed to the reaction 2one. The chemistry of hot flames, which occur in the high temperature region, has been extensively discussed (60-62) (see Col ustion science and technology). 

Reactor Configuration. The horizontal cross-sectional area of a reactor is a critical parameter with respect to oxygen mass-transfer effects in LPO since it influences the degree of interaction of the two types of zones. Reactions with high intrinsic rates, such as aldehyde oxidations, are largely mass-transfer rate-limited under common operating conditions. Such reactions can be conducted effectively in reactors with small horizontal cross sections. Slower reactions, however, may require larger horizontal cross sections for stable operation. 

Many, but not all, reactor configurations are discussed. Process design, catalyst manufacture, thermodynamics, design of experiments (qv), and process economics, as well as separations, the technologies of which often are appHcable to reactor technology, are discussed elsewhere in the Eniyclopedia (see Catalysis Separation Thermodynamics). 

Multiphase Reactors. The overwhelming majority of industrial reactors are multiphase reactors. Some important reactor configurations are illustrated in Figures 3 and 4. The names presented are often employed, but are not the only ones used. The presence of more than one phase, whether or not it is flowing, confounds analyses of reactors and increases the multiplicity of reactor configurations. Gases, Hquids, and soHds each flow in characteristic fashions, either dispersed in other phases or separately. Flow patterns in these reactors are complex and phases rarely exhibit idealized plug-flow or weU-stirred flow behavior. 

Fig. 28. Linear and CSTR reactor configuration used commercially for PS manufacture (see also Fig. 20).

The heat released from the CO—H2 reaction must be removed from the system to prevent excessive temperatures, catalyst deactivation by sintering, and carbon deposition. Several reactor configurations have been developed to achieve this (47). 

With these kinetic data and a knowledge of the reactor configuration, the development of a computer simulation model of the esterification reaction is iavaluable for optimising esterification reaction operation (25—28). However, all esterification reactions do not necessarily permit straightforward mathematical treatment. In a study of the esterification of 2,3-butanediol and acetic acid usiag sulfuric acid catalyst, it was found that the reaction occurs through two pairs of consecutive reversible reactions of approximately equal speeds. These reactions do not conform to any simple first-, second-, or third-order equation, even ia the early stages (29). 

Methods of immobilization have already been discussed, and various reactor configurations are possible. An enzyme immobilized on... 

Analysis of thermal runaway reactions is reviewed in Chapter 12. Table 4-6 gives various guidelines for the design of reactors and Figure 4-26 illustrates various reactor configurations. 

Select a reactor configuration with a high cooling area/holdup ratio, so that the heat of reaction can be quickly dissipated to the cooling medium. 

There are four main sulfonation reactor configurations applied worldwide to produce all kinds of top quality anionic surfactants from sulfur-based S03/air as the sulfonating agent. All these systems have proven and documented experience ... 

Only the Ballestra MTFFR will be described as an example of a modern sulfonation reactor configuration. The process consists of the following units ... 

Hamielec and coworkers (, 42, 43) have conducted extensive experimental and theoretical studies with styrene polymerization in CSTR s. Theirs represent probably the first published work in this area at commercially interesting temperatures and conversions relating theory to experiment, and determining the effects of reactor configuration and conditions on conversion, molecular weight and MWD. 

The difference between the calculated and experimentally determined critical Reynolds number can be explained from the reactor configuration, which consisted of four coils connected by straight tubing section. The straight sections would lower the rela-... 

A study of this kind can be further extended to develop optimum reactor configurations which are needed to produce given products at the highest possible conversion. 

Two impellers are included in the reactor configuration shown in Figure 2. A three-bladed turbine with 45° pitch and blades 1/8 in X 5/8 in is mounted on the impeller shaft at the top of the reactor. A three-bladed propeller with 45° pitch is mounted at the bottom of the impeller shaft at approximately two-thirds of the reactor depth. 

There is an extensive amount of data in the literature on the effect of many factors (e.g. temperature, monomer and surfactant concentration and types, ionic strength, reactor configuration) on the time evolution of quantities such as conversions, particle number and size, molecular weight, composition. In this section, EPM predictions are compared with the following limited but useful cross section of isothermal experimental data ... 

Figure 1 Illustrates two general MOCVD reactor configurations, the horizontal reactor and the axlsymmetrlc vertical reactor. The reactant gas (ASH3, Ga(CH3)3 and Al( 013)3) enters cold and heats up as It fiows toward the substrate where a solid film of AlGaAs Is being deposited. The chemical transformations Involved In the deposition process may occur both In the gas phase and on the surface of the growing film.

Figure 1. Two typical MOCVD reactor configurations (a) horizontal reactor (b) vertical reactor.

Shear Sensitivity Studies in Stirred Tank Reactor Configurations. . 163... 

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