Process Design of Distillation Column
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Transcript of Process Design of Distillation Column
![Page 1: Process Design of Distillation Column](https://reader030.fdocuments.in/reader030/viewer/2022012302/577cca0b1a28aba711a537ce/html5/thumbnails/1.jpg)
Process design of distillation column
![Page 2: Process Design of Distillation Column](https://reader030.fdocuments.in/reader030/viewer/2022012302/577cca0b1a28aba711a537ce/html5/thumbnails/2.jpg)
Diagram
Feed
Distillate
Bottom
Cumene 0.996Phenol 0.004
Xd
Cumene 0.0016Phenol 0.9984
Xb
Cumene 0.17Phenol 0.83
Xf
![Page 3: Process Design of Distillation Column](https://reader030.fdocuments.in/reader030/viewer/2022012302/577cca0b1a28aba711a537ce/html5/thumbnails/3.jpg)
Feed composition
Feed stream composition
Feed Mass(Kg/hr)
Phenol 277.452
Cumene 66.972
AMS 4.381
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Cont…
Since the amount of AMS in feed stream is negligible and its properties resembling close to cumene. Hence it can be merged with cumene for easier calculations.
Feed Mass(Kg/hr) Mass(Kgmol/hr)
Xf
Phenol 277.452 2.948 0.83
Cumene 71.353 0.594 0.17
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Calculation for bottom temperature
Bottom pressure = 1.28 atm = 972.8 mmHg
Using Antoine equation
Antoine equation constants for phenol
A = 16.4279B = 3490.89C = -98.59
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Cont…
Putting the constants in above equation
The top temperature as given in process conditions is
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Taking avg temperature
Now taking the average of these temperatures
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Calculating vapour pressure of cumene Using antoine equation
Here = 171.86
The following are the antoine constants for cumene
A = 13.957B = 3363.3C = 207.78
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Cont…
Putting the values in eq above
![Page 10: Process Design of Distillation Column](https://reader030.fdocuments.in/reader030/viewer/2022012302/577cca0b1a28aba711a537ce/html5/thumbnails/10.jpg)
Calculating vapour pressure of phenol Using antoine equation
Here = 171.86
The following are the antoine constants for phenol
A = 14.4387B = 3507.80C = 175.4
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Cont…
Putting the values in eq above
![Page 12: Process Design of Distillation Column](https://reader030.fdocuments.in/reader030/viewer/2022012302/577cca0b1a28aba711a537ce/html5/thumbnails/12.jpg)
Calculating relative volatility
Putting the corresponding values of pressure in above eq
The following corresponding vapor-liquid relation is obtained
X .002 .02 .10 .20 .30 .40 .50 .60 .70 .80 .90 1.0
Y .004 .043 .19 .35 .49 .60 .69 .77 .84 .90 .95 1.0
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VLE diagram Since the feed is entering at its boiling point hence q-line is vertical
0 0.2 0.4 0.6 0.8 1 1.20
0.2
0.4
0.6
0.8
1
1.2
VLE Diagram
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Calculating minimum reflux ratio
So from graph Φm = 0.165
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Calculating maximum reflux ratio
Taking
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Calculating the number of theoretical and real plates required
Here obtained from the graph
Assuming efficiency = 75%
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Calculating flooding velocityAt top plate
At bottom plate
Density at top
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Cont…Density at bottom
Surface tension Top Cumene = 29.01 mN/m Bottom Phenol = 37.66 mN/m
Top = 0.05880 Bottom = 0.0849 Tray spacing = 0.30m
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Figure
![Page 20: Process Design of Distillation Column](https://reader030.fdocuments.in/reader030/viewer/2022012302/577cca0b1a28aba711a537ce/html5/thumbnails/20.jpg)
Cont…So from the previous figure Top Bottom Surface tension correction Top Bottom Flooding velocity Top Bottom
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Cont… Design for 85% flooding velocity at max flow rate Top Bottom
Max vol.flowrate of vapour Top Bottom Net area required Top Bottom N
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Calculating column area and diameter Downcomer area = 12% of column area
Top Bottom Column diameter Top Bottom