Problem $2(40/100)$: The irreversible fist$-$order gas$-$phase reaction $AB$ is carried out

isothermally in a fluidized bed reactor containing $50kg$ of catalyst. This reactor can be modeled

as a CSTR$.50\%$ conversion is achieved for pure A entering the reactor at a pressure of $20$atm.

There is no pressure drop in the CSTR$.$

It is proposed to put a packed bed reactor $($PBR$)$ containing the same catalyst weight in series with

the CSTR$.$ The pressure drop parameter for the PBR is $=0\mathrm{.}018k{g}^{-1}.$ The particle size is

$0\mathrm{.}2mm,$ the bed porosity is $40\%,$ and the viscosity is the same as that of air at $200C.$

Should the PBR be placed upstream or downstream of the CSTR to achieve the highest

conversion? Explain qualitatively using Levenspiel plots $($Lecture $5).$

What is the conversion exiting the second reactor if the PBR is placed after CSTR$?$