CL 351 Homework # 12
No Due date, work out the solutions for end semester exam
1. We have
100 kg/hr of a feed that is 60% methylcyclohexane and 40% n-heptane and 50
kg/hr of a feed that is 20% methylcycloheane and 80% n-heptane. These two feeds are mixed with 200 kg/hr of
pure aniline in a single equilibrium stage or a mixer-settler arrangement. What are extract and raffinate compositions
leaving the stage? What is the flow
rate of extract product? Equilibrium
data is given below.
2. We wish
to remove acetic acid from water using isopropyl ether as solvent. The operation is at 20oC and 1
atm. Equilibrium data is given
below. The feed is 0.45 weight fraction
acetic acid and 0.55 weight fraction water.
Feed flow rate is 2000 kg/hr. A
countercurrent system is used. Pure
solvent is used. We desire an extract
stream that is 0.2 weight fraction acetic acid and a raffinate that is 0.2
weight fraction acetic aicd. How much
solvent is required? How many
equilibrium stages or mixer-settler arrangements are required? Find flow rates of extract and raffinate
streams leaving stage to which solvent is fed.
3. A
pyridine-water solution, 50 wt% pyridine, is to be continuously and
countercurrently extracted at the rate of 2.25 kg/sec with pure chlorobenzene
to reduce the pyridine concentration to 2 wt%. Determine the minimum solvent rate required. If 2.3 kg/sec of solvent is used, calculate
the flow rates of final extract and raffinate streams.
Data for Problem 1:
Hydrocarbon Phase, Methylcyclohexane, xA |
wt% n-heptane, xD |
Aniline-rich phase Methylcyclohexane, yA |
wt% n-heptane, yD |
0 |
92.6 |
0 |
6.2 |
9.2 |
83.1 |
0.8 |
6 |
18.6 |
73.4 |
2.7 |
5.3 |
22 |
69.8 |
3.0 |
5.1 |
33.8 |
57.6 |
4.6 |
4.5 |
4.9 |
50.4 |
6.0 |
4.0 |
46.0 |
45.0 |
7.4 |
3.6 |
59.0 |
30.7 |
9.2 |
2.8 |
67.2 |
22.8 |
11.3 |
2.1 |
71.6 |
18.2 |
12.7 |
1.6 |
73.6 |
16.0 |
13.1 |
1.4 |
83.3 |
5.4 |
15.6 |
0.6 |
88.1 |
0 |
16.9 |
0 |
Data for Problem 2:
Acetic acid xA |
Water layer water xD |
wt% Isopropylether xS |
Acetic acid, yA |
Isopropylether
water, yD |
layer, wt% Isopropylether yS |
0.69 |
98.1 |
1.2 |
0.18 |
0.5 |
99.3 |
1.41 |
97.1 |
1.5 |
0.37 |
0.7 |
98.9 |
2.89 |
95.5 |
1.6 |
0.79 |
0.8 |
98.4 |
6.42 |
91.7 |
1.9 |
1.93 |
1.0 |
97.1 |
13.3 |
84.4 |
2.3 |
4.82 |
1.9 |
93.3 |
25.5 |
71.1 |
3.4 |
11.4 |
3.9 |
84.7 |
36.7 |
58.9 |
4.4 |
21.6 |
6.9 |
71.5 |
44.3 |
45.1 |
10.6 |
31.1 |
10.8 |
58.1 |
46.4 |
37.1 |
16.5 |
36.2 |
15.1 |
48.7 |
Data for Problem 3:
water |
Chlorobenzene chlorobenzene |
Phase, wt% pyridine |
water |
Water
phase, chlorobenzene |
wt% pyridine |
0.05 |
99.95 |
0 |
99.92 |
0.08 |
0 |
0.67 |
88.28 |
11.05 |
94.82 |
0.16 |
5.02 |
1.15 |
79.9 |
18.95 |
88.71 |
0.24 |
11.05 |
1.62 |
74.28 |
24.10 |
80.72 |
0.38 |
18.90 |
2.25 |
69.15 |
28.60 |
73.92 |
0.58 |
25.50 |
2.87 |
65.58 |
31.55 |
62.05 |
1.85 |
36.10 |
3.95 |
61.00 |
35.05 |
50.87 |
4.18 |
44.95 |
3.4 |
53.00 |
40.60 |
37.90 |
8.90 |
53.20 |
13.2 |
37.80 |
49.00 |
13.20 |
37.80 |
49.00 |