Tubular exchanger reactor

An effective base-level regulatory control system has been developed and tested using a rigorous, nonlinear dynamic simulation of the entire system tubular reactor, heat exchangers, and three distillation columns. 

The products from the primary reactor are cooled in a tubular exchanger and are sent to the main absorber where the major proportion of chlorinated methanes is absorbed in a refrigerated mixture of chloroform and carbon tetrachloride. The stripped gas is scrubbed with dilute muriatic acid to produce a 30-32 per cent HCl solution, thus removing most of the hydrogen chloride. It is then dried. After that it is recycled to the primary reactor. 

Very strong stirring equipment is needed for mixing because of the high viscosity, and long tubular reactors with low cross-sectional area are needed for heat exchange. 

Medium Pressure Synthesis. Pressures of 500—2000 kPa (5—20 atm) were typical for the medium pressure Fischer-Tropsch process. Cobalt catalysts similar to those used for the normal pressure synthesis were typically used at temperatures ranging from 170 to 200°C ia tubular "heat exchanger" type reactors. 

Reactors may be operated batchwise or continuously, e.g. in tubular, tubes in shell (with or without internal catalyst beds), continuous stirred tank or fluidized bed reactors. Continuous reactors generally offer the advantage of low materials inventory and reduced variation of operating parameters. Recycle of reactants, products or of diluent is often used with continuous reactors, possibly in conjunction with an external heat exchanger. 

Figure 6-10. An autothermal multi-tubular reactor with an internal heat exchanger.

The resistance of titanium in nitric acid is good at most concentrations and at temperatures up to boiling . Thus tubular heat exchangers are used in ammonium nitrate production for preheating the acid prior to its introduction into the reactor via titanium sparge pipes. In explosives manufacture, concentrated nitric acid is cooled in titanium coils and titanium tanks are... 

Example 8.9 Find the temperature distribution in a laminar flow, tubular heat exchanger having a uniform inlet temperature and constant wall temperature Twall- Ignore the temperature dependence of viscosity so that the velocity profile is parabolic everywhere in the reactor. Use art/P = 0.4 and report your results in terms of the dimensionless temperature... 

It is possible to calculate U through Eq. (12.3), the global heat-exchange co-eflicient. Table 12.7 presents the experimental results. U varies from 3900 to 5000 W m and has a mean value of 4500 W m These values are in the same order of magnitude of the coeffleients obtained in plate exchangers and are higher than the ones obtained in tubular reactors, and far away from values measured in batch reactors. 

Chapter 4 eoncerns differential applications, which take place with respect to both time and position and which are normally formulated as partial differential equations. Applications include diffusion and conduction, tubular chemical reactors, differential mass transfer and shell and tube heat exchange. It is shown that such problems can be solved with relative ease, by utilising a finite-differencing solution technique in the simulation approach. 

ILLUSTRATION 10.5 DETERMINATION OF THE VOLUME REQUIREMENTS FOR OPERATION OF A TUBULAR REACTOR UNDER NONISOTHERMAL CONDITIONS WITH HEAT EXCHANGE... 

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