The irreversible end othennic 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...

The irreversible end othennic 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 3 atm. An inert stream is also fed to the reactor at 3 atm, as shown in Figure P 11-5_B. The entrance temperature of both streams is 1100 K.

(a) First derive an expression for C_AOI
as a function of C_Ao
and

₁.

(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. Qualitative sketches are fine. Describe the similarities and differences between the curves.

(c) Sketch or plot and then analyze the exit conversion as a function of

₁. Is there a ratio of the entering molar flow rates of inerts (I) to A (i.e.,

₁
= F₁₀/F_Ao) at which the conversion is at a maximum? Explain, why there "is" or " is not" a maximum.

(d) What would change in parts (b) and (c) if reactions were exothermic and reversible with
H
_Rx
= -80 kJ/mol and K_c
= 2 dm³/mol at 1100 K?

(e) Sketch or plot F8 for parts (c) and (d) and describe what you find.

(f) Plot the heat that must be removed along the reactor [ Q vs. V] to maintain isothermal operation for pure A fed and an exothermic reaction.