Ideal reactors segregated CSTRs

The ideal flow reactors are the CSTR and the PFR. (This chapter later introduces a third kind of ideal reactor, the segregated CSTR, but it has the same distribution of residence times as the regular, perfectly mixed CSTR.) Real reactors sometimes resemble these ideal types or they can be assembled from combinations of the ideal types. 

Fig. 7.2 Tank batch reactor with a segregated zone (a) modeled as two ideal suitably connected CSTRs (b)...

We will now determine the mean conversion predicted by the segregation model for an ideal PFR, a CSTR, and a laminar flow reactor,... 

Ideal PFR Ideal CSTR Ideal laminar Row reactor Segregation Maximum mixedness Dispersion Tanks in series... 

We next study the effect of particle size. Figure 8.22 shows ca(6) for particle sizes ranging from 0.1 pm to 1.0 cm. We see that if the stirrer is able to produce A particles of 1.0 pm or less, then the reactor is essentially in the state of maximum mixedness, or, equivalently, operates as an ideally mixed CSTR. At the other extreme, if the A particles are larger than about 1.0 mm, then the reactor operates essentially as a segregated-flow reactor. Segregated flow essentially reduces the reaction rate to zero because the A and B species cannot come into contact. 

The ideal cases are the piston flow reactor (PFR), also known as a plug flow reactor, and the continuous flow stirred tank reactor (CSTR). A third kind of ideal reactor, the completely segregated CSTR, has the same distribution of residence times as a normal, perfectly mixed CSTR. The washout function for a CSTR has the simple exponential form... 

A CSTR is a deliberately backmixed reactor and, in principle, its effluent temperature and composition are the same as the reactor contents. With an ideal CSTR, the feed blends instantaneously with the uniform reactor contents. In actual practice, of course, we find that feed blending time may be protracted, and varying degrees of segregation, short circuiting and stagnation exist in the reactor contents. 

The reactor is believed equivalent to a PFR in series with a CSTR. A second order reaction with kC0 =2.5 is to be processed there. Find (a) the residence time in each element (b) conversion in segregated flow (c) ideal conversion with the PFR first in series (d) ideal conversion with the CSTR first in series. 

Derive the equation of a Srsi-order reaction using the segregation model when the RTD is equivalent to fa) an ideal PFR, (b) an idea CSTR, and (c) a laminar flow reactor. Compare these conversions with those obtained from the design equation. 

Given the RTD of two equal-sized CSTRs in series for a single, second-order, Irreversible reaction, compute the reactor effluent concentration for the following cases . segregated how, maximum mixedness. and. two ideal CSTR.s,... 

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