Question

Initial concentration= 1mol/L, velocity of flow=2000L/min, liquid phase reactant enter the reactor. (-rA=kCA^2 , k=5000L/mol*min) We want to achieve a conversion of 90 % of the reactant.

1) Find the volume of the reactor when using the CSTR reactor. And find the volume of the reactor when using the PFR reactor.

2) Find the conversion of A at the exit of the reactor when you make the volume of the PFR reactor equal to that of the CSTR reactor saved in 1).

Answer 1

given :

initial conc .= 1mol/L

velocity of flow =2000L/min

liquid phase reactor enters the reactor

-rA=kCA^2

k=5000L/mol*min

we need to achieve 90% conversion of reactanat

1)

for CSTR required volume for 90% conversion

performance equation for CSTR

where V is volume of reactor

v is flowrate of liquid reactant

as we know

V = 2000*0.90/(5000*1*(1-0.9)²)

V = 36L for CSTR

now to find volume for PFR

where V is volume of reactor

v is flowrate of liquid reactant

as we know

V = 2000/(5000*1)*[1/(1-0.9)-1/(1-0)]

V=3.6L for PFR

2)

if we make volume of PFR equal to CSTR

put V =36 for PFR

1-X =1/91

1-X=0.01098

X=0.9890

98.90%

if we use PFR of volume equal to volume of CSTR REQUIRED FOR 90% CONVERSION THE CONVERSION OF EXIT WILL BE 98.90%