The irreversible endothermic vapor-phase reaction follows an elementary rate lawand is car...

The irreversible endothermic vapor-phase reaction follows an elementary rate law

and is carried out adiabatically in a 500-dm3 PFR. Species A is fed to the reactor at a rate of 10 mol/min and a pressure of 2 atm. An inert stream is also fed to the reactor at 2 atm, as shown in Figure 1. The entrance temperature of both streams is 1100 K.

Figure 1 Adiabatic PFR with inerts.

(a) First derive an expression for CA01 as a function of CA0 and ΘI.

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(b) Sketch the conversion and temperature profiles for the case when no inerts are present. Using a dashed line, sketch the profiles when a moderate amount of inerts are added. Using a dotted line, sketch the profiles when a large amount of inerts are added. Sketch or plot the exit conversion as a function of ΘI. Qualitative sketches are fine.

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(c) Is there a ratio of inerts to the entering molar flow rate of A (i.e., ΘI = FI0/FA0) at which the conversion is at a maximum? Explain why there “is„ or “is not„ a maximum.

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(d) Repeat parts (b) and (c) for an exothermic reaction .

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(e) Repeat parts (b) and (c) for a second-order endothermic reaction.

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(f) Repeat parts (b) and (c) for an exothermic reversible reaction (KC = 2 dm3 /mol at 1100 K).

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(g) Repeat (b) through (f) when the total volumetric flow rate υ0 is held constant and the mole fractions are varied.

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(h) Sketch or plot FB for parts (d) through (g).