Chemical Engineering - Mass Transfer - Discussion
Discussion Forum : Mass Transfer - Section 6 (Q.No. 46)
46.
A distillation column separates 10000 kg/hr of a benzene-toluene mixture as shown in the figure below :
In the figure xF, xD and xW represent the weight fraction of benzene in the feed, distillate and residue respectively. The reflux ratio is
In the figure xF, xD and xW represent the weight fraction of benzene in the feed, distillate and residue respectively. The reflux ratio is
Discussion:
5 comments Page 1 of 1.
Reece said:
2 years ago
@Aall.
Basis: 1-hr operation
Overall Material Balance (Entire System):
10,000 kg = D + B ---> Eqn [1]
Benzene Balance (Entire System):
0.50(10,000 kg) = 0.95D + 0.05B----> Eqn[2]
Equations [1] and [2] form a system of equations consisting of two equations and two unknowns. Thus, solving equations [1] and [2] simultaneously gives us:
D = 5,000 kg.
B = 5,000 kg.
Overall Material Balance (At Condenser):
8,000 kg = Lₒ + 5,000 kg---> [3]
Solving for the reflux stream using equation [3]:
Lₒ = 3,000 kg.
Reflux Ratio Equation:
R = Lₒ/D
= 3,000 kg/5,000 kg
= 0.60.
Basis: 1-hr operation
Overall Material Balance (Entire System):
10,000 kg = D + B ---> Eqn [1]
Benzene Balance (Entire System):
0.50(10,000 kg) = 0.95D + 0.05B----> Eqn[2]
Equations [1] and [2] form a system of equations consisting of two equations and two unknowns. Thus, solving equations [1] and [2] simultaneously gives us:
D = 5,000 kg.
B = 5,000 kg.
Overall Material Balance (At Condenser):
8,000 kg = Lₒ + 5,000 kg---> [3]
Solving for the reflux stream using equation [3]:
Lₒ = 3,000 kg.
Reflux Ratio Equation:
R = Lₒ/D
= 3,000 kg/5,000 kg
= 0.60.
(1)
Yash said:
4 years ago
@Garima.
You are absolutely correct. Thanks.
You are absolutely correct. Thanks.
Himanshu Lohiya said:
5 years ago
@Garima,
Here, You didn't count the mole fraction of the bottom product.
Here, You didn't count the mole fraction of the bottom product.
(1)
Shambhu padhiyar said:
7 years ago
Here, L/D = R.
Garima said:
1 decade ago
As applying mass balance
F= D+W
F*xf = D*xd+W*xw
D = 5000
And 8000 = D+L
L = 3000
R = 0.6
F= D+W
F*xf = D*xd+W*xw
D = 5000
And 8000 = D+L
L = 3000
R = 0.6
(3)
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