Chemical Engineering - Chemical Reaction Engineering - Discussion
Discussion Forum : Chemical Reaction Engineering - Section 2 (Q.No. 48)
48.
For the liquid phase zero order irreversible reaction A
B, the conversion of A in a CSTR is found to be 0.3 at a space velocity of 0.1min-1 . What will be the conversion for a PFR with a space velocity of 0.2 min-1? Assume that all the other operating conditions are the same for CSTR and PFR.

Discussion:
7 comments Page 1 of 1.
Macri said:
11 months ago
For CSTR:
r = ((CAo)(Xa))/ τ = k
Substituting the given parameters, assume the initial concentration to be 1;
1(0.3)/10=k; k = 0.03.
For PFR:
r = dCAo/d τ = k.
Integrate both sides and simplify in terms of conversion;
CAo(1-Xa)=-k τ + CAo;
Substitute;
1(1-Xa)=-0.03(20) + 1;
Xa = 0.6.
r = ((CAo)(Xa))/ τ = k
Substituting the given parameters, assume the initial concentration to be 1;
1(0.3)/10=k; k = 0.03.
For PFR:
r = dCAo/d τ = k.
Integrate both sides and simplify in terms of conversion;
CAo(1-Xa)=-k τ + CAo;
Substitute;
1(1-Xa)=-0.03(20) + 1;
Xa = 0.6.
Albaz said:
4 years ago
I think 0.15 is correct.
(2)
Ali shareef nasralla said:
5 years ago
For CSTR:
T = C0 . Xa /-ra.
T = C0 . Xa / k.
0.1 = C0 . 0.3 / k.
C0/k = 1/3 --> (1)
For PFR :
T= C0 . integral ( Xa / -ra).
T= C0 . integral ( dXa/ k).
0.2 = Xa . ( C0 / k) ----------> eq. (2).
0.2 =( 1/3). Xa sub eq.(1) in eq.(2).
xa = 0.6.
So, the correct answer is C.
T = C0 . Xa /-ra.
T = C0 . Xa / k.
0.1 = C0 . 0.3 / k.
C0/k = 1/3 --> (1)
For PFR :
T= C0 . integral ( Xa / -ra).
T= C0 . integral ( dXa/ k).
0.2 = Xa . ( C0 / k) ----------> eq. (2).
0.2 =( 1/3). Xa sub eq.(1) in eq.(2).
xa = 0.6.
So, the correct answer is C.
Khalid Abed said:
8 years ago
For CSTR.
T = C0 . Xa /-ra.
T = C0 . Xa / k.
10 = C0 . 0.3 / k.
C0/k = 10/0.3 ----------> eq(1).
For PFR :
T= C0 . integral ( Xa / -ra).
T= C0 . integral ( Xa / k).
T= C0 . ( Xa / k) ----------> eq. (2).
T=( Co/k) . Xa sub eq.(1) in eq.(2)
=> (10/2)=(10/0.3) . Xa.
Xa = 0.15.
So, the correct answer is A.
T = C0 . Xa /-ra.
T = C0 . Xa / k.
10 = C0 . 0.3 / k.
C0/k = 10/0.3 ----------> eq(1).
For PFR :
T= C0 . integral ( Xa / -ra).
T= C0 . integral ( Xa / k).
T= C0 . ( Xa / k) ----------> eq. (2).
T=( Co/k) . Xa sub eq.(1) in eq.(2)
=> (10/2)=(10/0.3) . Xa.
Xa = 0.15.
So, the correct answer is A.
(3)
Ram bahadur niet greater noida said:
8 years ago
The correct answer is 15.
Option 1.
Option 1.
MKS said:
9 years ago
For zero order pfr and cstr gives same conversion, but there are difference in volume of reactor.
So, x a = 0.3 * 0.2 = 0.6
So, x a = 0.3 * 0.2 = 0.6
Susheel kumar said:
1 decade ago
Can anyone explain the answer:
According to me it should be 0.15.
According to me it should be 0.15.
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