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A CMFR is operating at steady state with a second order decay reaction of rate constant...

A CMFR is operating at steady state with a second order decay reaction of rate constant k2=0.5 L/mg/d. It is exactly meeting its goal of 99.9% removal efficiency and the allowed maximum effluent concentration of 0.05 mg/L. The volumetric flow rate is 450 m3Id.

a. What is the influent concentration in mg/L?

b. What is the reactor volume in m3? What volume would be required if the removal efficiency goal were 99.0%? c(5). If the CMFR is replaced with a PFR, what reactor volume is needed (in m3)?

Solutions

Expert Solution

a) conversion = 99.9%

X = 0.999

C = 0.05 mg/L

Influent concentration C0 = 50 mg/L

For CSTR, performance equation is given by

v0 = 450 m3/d = 450000 L/d

For 2nd order reaction,

-r = kC2

C = C0(1-X)

For X = 0.999

.: V = 1.7982 x 1010 L = 1.7982 x 107 m3

For X = 0.99

.: V = 178200000 L = 178200 m3

For PFR, performance equation is given by

On integrating we get

For X = 0.999

.: V = 1.7982 x 107 L = 1.7982 x 104 m3


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