LLE Tuto
2
LLE IMMMISCIBLE MIXTURES 1. An inlet water solution of 800 kg/h containing 12 wt% acetone is extracted with the solvent tricholoroethane containing 0.5 wt% acetone in a counter current try tower at 25 o C. The solvents water and triricholoroethane are essentially immiscible in each other up to a concentration of acetone in water of 27 wt%. The exit concentration in the water (raffinate) stream is 1.0 wt% acetone. The equilibrium data as Table 1 where X is the weight fraction of acetone in water solution and y in the tricholoroethane solution. X Y 0.012 0.0196 0.0294 0.0476 0.0462 0.0741 0.0571 0.0909 0.0833 0.1304 0.1081 0.1666 0.1316 0.2 a) Determine the minimum solvent rate b) Draw the process block diagram and label accordingly c) Determine the number of stages graphically d) Use Kremser equation to determine the number theoretical steps. e) If the overall efficiency is 60%, calculate actual number of stages required. 2. An inlet water solution of 100 kg/h containing 0.010 wt fraction nicotine (A) in water is stripped with a kerosene stream of 200 kg/h containing 0.0005 wt fraction nicotine in a countercurrent stage tower. The water and kerosene are essentially immiscible in each other. It is desired to reduce the concentration of the exit water to 0.001 wt fraction nicotine. The equilibrium data as Table 2. Table 2 f) Draw the process block diagram and label accordingly g) Determine the number of stages graphically h) Use Kremser equation to to determine the number theoretical steps. i) If the overall efficiency is 70%, calculate actual number of stages required. X Y 0.00101 0.000806 0.00246 0.001959 0.005 0.00454 0.00746 0.00682 0.00988 0.00904 0.0202 0.0185
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liquid liquid extraction
Transcript of LLE Tuto
LLE IMMMISCIBLE MIXTURES
1. An inlet water solution of 800 kg/h containing 12 wt% acetone is extracted with the
solvent tricholoroethane containing 0.5 wt% acetone in a counter current try tower at
25 oC. The solvents water and triricholoroethane are essentially immiscible in each
other up to a concentration of acetone in water of 27 wt%. The exit concentration in
the water (raffinate) stream is 1.0 wt% acetone. The equilibrium data as Table 1 where
X is the weight fraction of acetone in water solution and y in the tricholoroethane
solution.
X Y
0.012 0.0196
0.0294 0.0476
0.0462 0.0741
0.0571 0.0909
0.0833 0.1304
0.1081 0.1666
0.1316 0.2
a) Determine the minimum solvent rate
b) Draw the process block diagram and label accordingly
c) Determine the number of stages graphically
d) Use Kremser equation to determine the number theoretical steps.
e) If the overall efficiency is 60%, calculate actual number of stages required.
2. An inlet water solution of 100 kg/h containing 0.010 wt fraction nicotine (A) in water is
stripped with a kerosene stream of 200 kg/h containing 0.0005 wt fraction nicotine in a
countercurrent stage tower. The water and kerosene are essentially immiscible in
each other. It is desired to reduce the concentration of the exit water to 0.001 wt
fraction nicotine. The equilibrium data as Table 2.
Table 2
f) Draw the process block diagram and label accordingly
g) Determine the number of stages graphically
h) Use Kremser equation to to determine the number theoretical steps.
i) If the overall efficiency is 70%, calculate actual number of stages required.
X Y
0.00101 0.000806
0.00246 0.001959
0.005 0.00454
0.00746 0.00682
0.00988 0.00904
0.0202 0.0185
3. A solution of 1000 kg/h containing 1.5 wt% nicotine (A) in water is stripped with a
kerosene stream of 2000 kg/h containing 0.05 wt% nicotine in a countercurrent stage
tower. The exit water is to contain 10% of the original nicotine, that is, 90% is removed.
The equilibrium data as Table 2. Calculate the number of theoretical stages needed.
Table 2
LLE for partially miscible mixture, do below problems in the text book :
12.5.3
12.5.4
12.7.3
12.7.4
X Y
0.00101 0.000806
0.00246 0.001959
0.005 0.00454
0.00746 0.00682
0.00988 0.00904
0.0202 0.0185
