Problem 1: A 100 kg/hr stream containing a mixture of 50% acetone and 50% water
ID: 1073166 • Letter: P
Question
Problem 1: A 100 kg/hr stream containing a mixture of 50% acetone and 50% water by weight is to be separated into its components. The separation process consists of extraction of the acetone from water into a solvent that dissolves acetone but it is nearly immiscible with water. The solvent to be used is methyl isobutyl ketone (MIBK). In a pilot plant study, for every 100 kg of acetone- water fed to the first extractor, 100 kg of MIBK are fed to the first extractor and 75 kg are fed to the second extractor. The extract from the first stage is found to contain 27.5% acetone (A) and the rest MIBK (M) and water (W). The second stage raffinate has a mass of 43.1 kg and consists of 5.3 acetone, 1.6% MIBK and the rest water. The second-stage extract contains 9.0% acetone, 88% MIBK and the rest water. Calculate 1. Mass and composition of stage 1 raffinate and extract. 2. Mass of stage 2 extract. 3. Fill out the table. NOTE: Component percentage by mass 100 kg M 75 kg M 100 kg Stage 1 Stage 2 43.1 Kg 0.5 A 0.5 W 0.053 A 0.016 M W 0.275 A 0.09 A 0.88 M W A acetone (1) M methyl isobutyl ketone (2) W water (3)Explanation / Answer
STREAM
m1(Kg/hr)
XA
XM
XW
1
100
0.5
-
0.5
2
100
-
100
-
3
m 3
0.275
XM3
XW3
4
m 4
XA4
XW4
XW4
5
75
-
1.00
-
6
m 6
0.09
0.8
0.03
7
43.1
0.053
0.016
0.931
A = acetone
M = methyl isobutyl ketone
W = water
Data and results
STREAM
m1(Kg/hr)
XA
XM
XW
1
100
0.5
-
0.5
2
100
-
100
-
3
145.15
0.275
0.0675
0.05
4
54.15
0.184
0.0375
0.779
5
75
-
1.00
-
6
86.75
0.09
0.88
0.03
7
43.1
0.053
0.016
0.931
STREAM
m1(Kg/hr)
XA
XM
XW
1
100
0.5
-
0.5
2
100
-
100
-
3
m 3
0.275
XM3
XW3
4
m 4
XA4
XW4
XW4
5
75
-
1.00
-
6
m 6
0.09
0.8
0.03
7
43.1
0.053
0.016
0.931