Chapter 3: Fractionation Rules of Thumb for Chemical Engineers, 5th Edition by Stephen Hall This Excel workbook includes Visual Basic for Application function subroutines. Macros must be enabled for them to work.
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Chapter 3: FractionationRules of Thumb for Chemical Engineers, 5th Edition
by Stephen Hall
This Excel workbook includes Visual Basic for Application function subroutines.Macros must be enabled for them to work.
Antoine ConstantsA B C
Methyl Alcohol 8.1 1,582.3 239.7 Ethyl Alcohol 8.1 1,592.9 226.2 System Pressure 760 mm Hg
Mole Fraction Methyl Alcohol VP, mm Hg Partial Pressure
X Y Temp, deg C Difference0.00 0.00 78.298191854 1,275.42 760.00 0.00 760.00 (0.00)0.10 0.16 76.62501972 1,200.44 711.06 120.04 639.96 (0.00)0.20 0.30 75.030439013 1,132.40 666.90 226.48 533.52 (0.00)0.30 0.42 73.509200873 1,070.50 626.93 321.15 438.85 (0.00)0.40 0.53 72.056463845 1,014.03 590.65 405.61 354.39 0.00 0.50 0.63 70.667734183 962.38 557.63 481.19 278.81 0.00 0.60 0.72 69.338764978 915.01 527.49 549.00 211.00 (0.00)0.70 0.80 68.065743233 871.47 499.91 610.03 149.97 (0.00)0.80 0.88 66.845061452 831.35 474.62 665.08 94.92 (0.00)0.90 0.94 65.673400907 794.29 451.36 714.86 45.14 (0.00)1.00 1.00 64.547732539 760.00 429.92 760.00 0.00 (0.00)
Methyl Alcohol
Ethyl Alcohol
Methyl Alcohol
Ethyl Alcohol
Problem Statement:Construct a table of vapor-liquid equilibrium values for a system of methanol-ethanol at 1 atmosphere pressure, assuming ideal behavior.
Problem Statement:Construct a table of vapor-liquid equilibrium values for a system of methanol-ethanol at 1 atmosphere pressure, assuming ideal behavior.
Antoine Constants
A B CEthyl Alcohol 8.1 1,592.9 226.2 Water 8.0 1,701.8 231.5
Mole Fraction Ethyl Alcohol VP, mm Hg Margules
X Y Temp, deg C Ethyl Alcohol Water0.00 0.00 100.09 1,699.09 760.00 4.964 1.000 0.03 0.23 93.65 1,355.04 601.42 4.314 1.002 0.06 0.35 89.78 1,177.22 520.02 3.781 1.008 0.10 0.44 86.60 1,046.49 460.47 3.212 1.023 0.15 0.51 84.30 959.27 420.88 2.671 1.050 0.20 0.54 82.94 910.83 398.94 2.268 1.087 0.30 0.59 81.49 861.00 376.42 1.729 1.189 0.40 0.62 80.65 833.48 364.01 1.411 1.326 0.50 0.65 79.99 812.34 354.48 1.220 1.493 0.60 0.69 79.41 794.18 346.30 1.107 1.680 0.70 0.75 78.94 779.45 339.67 1.043 1.872 0.80 0.82 78.60 769.13 335.03 1.012 2.045 0.90 0.91 78.40 763.19 332.36 1.001 2.170 1.00 1.00 78.30 760.00 330.93 1.000 2.214
Solution Model VLE Ethanol-Water Reference LineNone 1Margules 2 X Y X Yvan Laar 3 0 0 0 0
0.056 0.366 1 10.091 0.4480.189 0.5390.286 0.5820.323 0.60.331 0.6050.419 0.6270.512 0.666
0.62 0.7120.704 0.7590.715 0.7640.798 0.8180.843 0.8510.847 0.8540.849 0.8560.884 0.8860.908 0.9070.922 0.92
γ1 γ2
Problem Statement:Construct a table of vapor-liquid equilibrium values for a system of ethanol-water at 1 atmosphere pressure, using Activity coefficients from the Margules model.
Source:Kurihara, K., Nakamichi, M., Kojima, K., "Isobaric Vapor-Liquid Equilibria for Methanol + Ethanol + Water and the Three Constituent Binary Systems," J. Chem Eng. Data 1993, Vol 38, p 446-449.
Margules Parameters van Laar Parameters
1.6022 0.7947 1.6798 0.9227
Margules Model van Laar ModelPartial Pressure
Water Difference0.00 760.00 (0.00) 4.964 1.000 5.364 1.000
175.38 584.62 (0.00) 4.314 1.002 4.506 1.003 267.09 492.91 (0.00) 3.781 1.008 3.851 1.010 336.16 423.84 0.00 3.212 1.023 3.197 1.026 384.38 375.62 0.00 2.671 1.050 2.618 1.056 413.06 346.94 0.00 2.268 1.087 2.211 1.094 446.66 313.34 0.00 1.729 1.189 1.699 1.194 470.39 289.61 0.00 1.411 1.326 1.409 1.320 495.44 264.56 (0.00) 1.220 1.493 1.235 1.469 527.32 232.68 (0.00) 1.107 1.680 1.128 1.639 569.28 190.72 (0.00) 1.043 1.872 1.063 1.830 622.98 137.02 (0.00) 1.012 2.045 1.025 2.041 687.89 72.11 (0.00) 1.001 2.170 1.006 2.270 760.00 0.00 0.00 1.000 2.214 1.000 2.516
(0.00)
A12 A21 A12 A21
Ethyl Alcohol γ1 γ2 γ1 γ2
Problem Statement:Construct a table of vapor-liquid equilibrium values for a system of ethanol-water at 1 atmosphere pressure, using Activity coefficients from the Margules model.
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Vapor-Liquid Equilibrium
Reference Line
Predicted
Experimental
Mole Fraction, Liquid Phase
Mo
le F
rac
tio
n,
Va
po
r P
ha
se
Kurihara, K., Nakamichi, M., Kojima, K., "Isobaric Vapor-Liquid Equilibria for Methanol + Ethanol + Water and the Three Constituent Binary Systems," J. Chem Eng. Data 1993, Vol 38, p 446-449.
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Vapor-Liquid Equilibrium
Reference Line
Predicted
Experimental
Mole Fraction, Liquid Phase
Mo
le F
rac
tio
n,
Va
po
r P
ha
se
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Vapor-Liquid Equilibrium
Reference Line
Predicted
Experimental
Mole Fraction, Liquid Phase
Mo
le F
rac
tio
n,
Va
po
r P
ha
se
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Vapor-Liquid Equilibrium
Reference Line
Predicted
Experimental
Mole Fraction, Liquid Phase
Mo
le F
rac
tio
n,
Va
po
r P
ha
se
Antoine ConstantsA B C
Methyl Alcohol 8.1 1,582.3 239.7 Ethyl Alcohol 8.1 1,592.9 226.2
Molar Composition Bottoms Feed DistillateMethyl Alcohol 0.40 0.98 Ethyl Alcohol 0.60 0.02
Mole Fraction Methyl Alcohol VP, mm Hg Partial Pressure
X Y Temp, deg C Difference0.40 0.53 72.06 1,014.03 590.65 405.61 354.39 0.00
Minimum Reflux Ratioalpha 1.716808
3.34
Methyl Alcohol
Ethyl Alcohol
Methyl Alcohol
Ethyl Alcohol
Rm
Problem Statement:Estimate the minimum reflux ratio for a binary feed consisting of 40 mole% methanol and 60 mole% ethanol at its bubble point. The desired distillate composition is 98 mole % methanol.
Answer
Problem Statement:Estimate the minimum reflux ratio for a binary feed consisting of 40 mole% methanol and 60 mole% ethanol at its bubble point. The desired distillate composition is 98 mole % methanol.
Antoine ConstantsA B C
n-hexane 6.8 1,112.6 218.0 n-heptane 6.8 1,224.4 212.9 n-octane 6.9 1,317.0 205.5
System Pressure 760 mm Hg Temperature 102 deg C
Molar Composition Feed VP, mm Hg PPn-hexane 0.10 1,915.450 191.545 5.12 n-heptane 0.50 837.854 418.927 2.24 n-octane 0.40 373.820 149.528 1.00
760.000 Difference 0.000
Feed Condition, q 1.00 (1 = feed at the Bubble Point) Theta 1.30
Molar Composition Feed Distillaten-hexane 0.10 5.12 0.13 0.173 0.23 n-heptane 0.50 2.24 1.19 0.820 1.96 n-octane 0.40 1.00 (1.33) 0.007 (0.02)
0.00 2.17 = Rm + 1 Difference (0.00)
Calculation of the distillate and bottoms compositionsMoles
Molar Composition Feed Light Key Heavy Key Bottoms Distillaten-hexane 0.10 0.00 10.00 n-heptane 0.50 x 95% 2.50 47.50 n-octane 0.40 x 99% 39.60 0.40
42.10 57.90
αi
αi xi αi / (αi - θ) xiD αi / (αi - θ)
Recovery of Keys
Problem Statement:Estimate the minimum reflux ratio for the tertiary system n-hexane, n-heptane, n-octane, with the feed at the bubble point and molar composition 0.1, 0.5, 0.4 respectively. 95% of the n-heptane should be contained in the distillate and 99% of the n-octane in the bottoms.
Mole Fraction
Bottoms Distillate0.00 0.173 Feed 100 moles0.06 0.820 0.94 0.007
Problem Statement:Estimate the minimum reflux ratio for the tertiary system n-hexane, n-heptane, n-octane, with the feed at the bubble point and molar composition 0.1, 0.5, 0.4 respectively. 95% of the n-heptane should be contained in the distillate and 99% of the n-octane in the bottoms.
Answer
Antoine ConstantsA B C
Methyl Alcohol 8.1 1,582.3 239.7 Ethyl Alcohol 8.1 1,592.9 226.2
Molar Composition Bottoms Feed Distillate BottomsMethyl Alcohol 0.40 0.98 0.01Ethyl Alcohol 0.60 0.02 0.99System Pressure 760
Mole Fraction Methyl Alcohol VP, mm Hg Partial Pressure
X Y Temp, deg C Methanol Ethanol Methanol Ethanol Difference0.01 0.02 78.13 1,267.58 754.87 12.68 747.32 (0.00)0.40 0.53 72.06 1,014.03 590.65 405.61 354.39 0.00 0.98 0.99 64.77 766.65 434.07 751.32 8.68 (0.00)
0.00 Minimum Reflux Ratioalpha 1.679202
3.52
Minimum Number of Stages at Infinite Reflux
Fenske Equation
14.64
Molkanov Equation
For R = 5.0 X = 0.25
N = 26.09 Y = 0.42
RHS = 0.42 Difference (0.00)
Rm
Nm
Y = 1 – exp[(1 + 54.4X)(X – 1) / ((11 + 117.2X)(X0.5)]
Y = (N – Nmin) / (N + 1)
X = (R – Rmin) / (R + 1)
Problem Statement:Find the number of stages for a methanol-ethanol column, with 40 mole% methanol in the feed, 98 mole% methanol in the distillate, an 1% methanol in the bottoms, given a reflux ratio of 5.0
Answer
1.679 1.717 1.766
αi
Problem Statement:Find the number of stages for a methanol-ethanol column, with 40 mole% methanol in the feed, 98 mole% methanol in the distillate, an 1% methanol in the bottoms, given a reflux ratio of 5.0
Antoine Constants
A B CEthyl Alcohol 8.1 1,592.9 226.2 Water 8.0 1,701.8 231.5
Mole Fraction Ethyl Alcohol VP, mm Hg Margules
X Y Temp, deg C Ethyl Alcohol Water0.00 0.00 100.09 1,699.09 760.00 4.964 1.000 0.03 0.23 93.65 1,355.04 601.42 4.314 1.002 0.06 0.35 89.78 1,177.22 520.02 3.781 1.008 0.10 0.44 86.60 1,046.49 460.47 3.212 1.023 0.15 0.51 84.30 959.27 420.88 2.671 1.050 0.20 0.54 82.94 910.83 398.94 2.268 1.087 0.28 0.58 81.72 869.00 380.04 1.824 1.164 0.40 0.62 80.65 833.48 364.01 1.411 1.326 0.50 0.65 79.99 812.34 354.48 1.220 1.493 0.60 0.69 79.41 794.18 346.30 1.107 1.680 0.70 0.75 78.94 779.45 339.67 1.043 1.872 0.80 0.82 78.60 769.13 335.03 1.012 2.045 0.90 0.91 78.40 763.19 332.36 1.001 2.170 1.00 1.00 78.30 760.00 330.93 1.000 2.214
Molar Composition Bottoms Feed DistillateEthyl Alcohol 0.02 0.40 0.88 Water 0.98 0.60 0.12
Reflux Ratio 6Feed, q 0.999
Reference Line Stripping Feed RectificationSlope 1.00 Slope 1.18 Slope 999.00 SlopeIntercept 0.00 Intercept (0.00) Intercept (399.20) Intercept
X Y X Y X Y X0.00 0.00 0.02 0.02 0.40 0.40 0.88 1.00 1.00 0.40 0.47 0.40 0.47 0.40
Step DataX Y
0.02 0.02 0.02 0.17 0.15 0.17 0.15 0.50 0.44 0.50 0.44 0.63
γ1 γ2
Problem Statement:Construct a McCabe-Thiele Diagram for a system of ethanol-water at 1 atmosphere pressure, using Activity coefficients from the Margules model.
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
McCabe-Thiele Diagram
Mole Fraction, Liquid Phase
Mo
le F
rac
tio
n,
Va
po
r P
ha
se
0.59 0.63 0.59 0.69 0.66 0.69 0.66 0.72 0.70 0.72 0.70 0.75 0.73 0.75 0.73 0.77 0.75 0.77 0.75 0.78 0.76 0.78 0.76 0.79 0.78 0.79 0.78 0.80 0.79 0.80 0.79 0.81 0.80 0.81 0.80 0.82 0.81 0.82 0.81 0.83 0.82 0.83 0.82 0.83 0.83 0.83 0.83 0.84 0.84 0.84 0.84 0.85 0.84 0.85 0.84 0.85 0.85 0.85 0.85 0.86 0.86 0.86 0.86 0.87 0.87 0.87 0.87 0.87 0.87 0.87 0.87 0.88 0.88 0.88 0.88 0.89 0.89 0.89 0.89 0.90 0.90 0.90 0.90 0.90 0.91 0.90 0.91 0.91 0.92 0.91 0.92 0.92 0.93 0.92 0.93 0.93 0.94 0.93 0.94 0.94
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
McCabe-Thiele Diagram
Mole Fraction, Liquid Phase
Mo
le F
rac
tio
n,
Va
po
r P
ha
se
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
McCabe-Thiele Diagram
Reference Line
VLE Curve
Stripping
Feed
Rectification
Tray Steps
Murphree VLE
Mole Fraction, Liquid Phase
Mo
le F
ract
ion
, Vap
or
Ph
ase
0.95 0.94 0.95 0.95 0.97 0.95 0.97 0.97 0.98 0.97 0.98 0.98 1.00 0.98 1.00 1.00 1.02 1.00 1.02 1.02 1.04 1.02 1.04 1.04 1.07 1.04 1.07 1.06 1.09 1.06 1.09 1.09 1.12 1.09 1.12 1.11 1.15 1.11 1.15 1.14 1.18 1.14 1.18 1.16
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
McCabe-Thiele Diagram
Reference Line
VLE Curve
Stripping
Feed
Rectification
Tray Steps
Murphree VLE
Mole Fraction, Liquid Phase
Mo
le F
ract
ion
, Vap
or
Ph
ase
Margules Parameters van Laar Parameters
1.6022 0.7947 1.6798 0.9227
Margules Model van Laar ModelPartial Pressure
Water Difference0.00 760.00 (0.00) 4.964 1.000 5.364 1.000
175.38 584.62 (0.00) 4.314 1.002 4.506 1.003 267.09 492.91 (0.00) 3.781 1.008 3.851 1.010 336.16 423.84 0.00 3.212 1.023 3.197 1.026 384.38 375.62 0.00 2.671 1.050 2.618 1.056 413.06 346.94 0.00 2.268 1.087 2.211 1.094 440.72 319.28 (0.00) 1.824 1.164 1.787 1.170 470.39 289.61 0.00 1.411 1.326 1.409 1.320 495.44 264.56 (0.00) 1.220 1.493 1.235 1.469 527.32 232.68 (0.00) 1.107 1.680 1.128 1.639 569.28 190.72 (0.00) 1.043 1.872 1.063 1.830 622.98 137.02 (0.00) 1.012 2.045 1.025 2.041 687.89 72.11 (0.00) 1.001 2.170 1.006 2.270 760.00 0.00 0.00 1.000 2.214 1.000 2.516
(0.00)
Murphree Tray Efficiency: 1
Segment 1 Origin Segment 2 Origin
Rectification Step X Y X0.86 Reboiler 0.02 0.02 0.02 0.17 0.13 1 0.15 0.17 0.15 0.50
Y 2 0.44 0.50 0.44 0.63 0.88 3 0.59 0.63 0.59 0.69 0.47 4 0.66 0.69 0.66 0.72
5 0.70 0.72 0.70 0.75 6 0.73 0.75 0.73 0.77 7 0.75 0.77 0.75 0.78 8 0.76 0.78 0.76 0.79 9 0.78 0.79 0.78 0.80
10 0.79 0.80 0.79 0.81 11 0.80 0.81 0.80 0.82 12 0.81 0.82 0.81 0.83 13 0.82 0.83 0.82 0.83 14 0.83 0.83 0.83 0.84
A12 A21 A12 A21
Ethyl Alcohol γ1 γ2 γ1 γ2
MurphreeY
Problem Statement:Construct a McCabe-Thiele Diagram for a system of ethanol-water at 1 atmosphere pressure, using Activity coefficients from the Margules model.
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
McCabe-Thiele Diagram
Mole Fraction, Liquid Phase
Mo
le F
rac
tio
n,
Va
po
r P
ha
se
15 0.84 0.84 0.84 0.85 16 0.84 0.85 0.84 0.85 17 0.85 0.85 0.85 0.86 18 0.86 0.86 0.86 0.87 19 0.87 0.87 0.87 0.87 20 0.87 0.87 0.87 0.88 21 0.88 0.88 0.88 0.89 22 0.89 0.89 0.89 0.90 23 0.90 0.90 0.90 0.90 24 0.91 0.90 0.91 0.91 25 0.92 0.91 0.92 0.92 26 0.93 0.92 0.93 0.93 27 0.94 0.93 0.94 0.94 28 0.95 0.94 0.95 0.95 29 0.97 0.95 0.97 0.97 30 0.98 0.97 0.98 0.98 31 1.00 0.98 1.00 1.00 32 1.02 1.00 1.02 1.02 33 1.04 1.02 1.04 1.04 34 1.07 1.04 1.07 1.06 35 1.09 1.06 1.09 1.09 36 1.12 1.09 1.12 1.11 37 1.15 1.11 1.15 1.14 38 1.18 1.14 1.18 1.16
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
McCabe-Thiele Diagram
Mole Fraction, Liquid Phase
Mo
le F
rac
tio
n,
Va
po
r P
ha
se
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
McCabe-Thiele Diagram
Reference Line
VLE Curve
Stripping
Feed
Rectification
Tray Steps
Murphree VLE
Mole Fraction, Liquid Phase
Mo
le F
ract
ion
, Vap
or
Ph
ase
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
McCabe-Thiele Diagram
Reference Line
VLE Curve
Stripping
Feed
Rectification
Tray Steps
Murphree VLE
Mole Fraction, Liquid Phase
Mo
le F
ract
ion
, Vap
or
Ph
ase
Solution ModelNone 1Margules 2van Laar 3
VP, mm Hg Margules Partial Pressure
VLE Y Water Water Difference0.17 95.42 1,443.10 641.88 4.516 1.001 130.35 629.65 (0.00)0.50 84.36 961.35 421.82 2.687 1.049 383.19 376.81 0.00 0.63 80.36 824.27 359.85 1.320 1.392 480.25 279.75 0.00 0.69 79.47 795.77 347.02 1.115 1.662 523.92 236.08 0.00 0.72 79.13 785.21 342.26 1.065 1.791 550.11 209.89 0.00 0.75 78.95 779.73 339.80 1.044 1.868 568.23 191.77 0.00 0.77 78.84 776.36 338.28 1.033 1.919 581.89 178.11 0.00 0.78 78.76 774.06 337.25 1.026 1.956 592.81 167.19 0.00 0.79 78.71 772.37 336.49 1.021 1.985 601.91 158.09 0.00 0.80 78.66 771.06 335.90 1.017 2.009 609.75 150.25 0.00 0.81 78.63 770.00 335.42 1.015 2.028 616.70 143.30 0.00 0.82 78.60 769.12 335.03 1.012 2.045 623.00 137.00 0.00 0.83 78.58 768.37 334.69 1.011 2.060 628.82 131.18 0.00 0.83 78.55 767.71 334.39 1.009 2.073 634.29 125.71 0.00 0.84 78.53 767.13 334.13 1.008 2.085 639.51 120.49 0.00
Temp, deg C
Ethyl Alcohol γ1 γ2
Ethyl Alcohol
0.85 78.52 766.60 333.89 1.007 2.096 644.57 115.43 0.00 0.85 78.50 766.11 333.67 1.006 2.106 649.53 110.47 0.00 0.86 78.49 765.65 333.46 1.005 2.116 654.47 105.53 0.00 0.87 78.47 765.22 333.27 1.004 2.125 659.43 100.58 0.00 0.87 78.46 764.80 333.08 1.004 2.134 664.47 95.53 0.00 0.88 78.44 764.41 332.91 1.003 2.143 669.65 90.35 0.00 0.89 78.43 764.02 332.73 1.003 2.151 675.03 84.97 0.00 0.90 78.42 763.64 332.56 1.002 2.160 680.68 79.32 0.00 0.90 78.41 763.26 332.39 1.002 2.168 686.67 73.33 0.00 0.91 78.39 762.89 332.22 1.001 2.176 693.08 66.92 0.00 0.92 78.38 762.51 332.06 1.001 2.184 700.01 59.99 0.00 0.93 78.37 762.13 331.88 1.001 2.191 707.57 52.43 0.00 0.94 78.36 761.75 331.71 1.000 2.198 715.90 44.10 0.00 0.95 78.34 761.35 331.53 1.000 2.205 725.14 34.86 0.00 0.97 78.33 760.93 331.34 1.000 2.210 735.46 24.54 0.00 0.98 78.31 760.48 331.14 1.000 2.213 747.05 12.95 0.00 1.00 78.30 760.00 330.92 1.000 2.214 760.09 (0.09) 0.00 1.02 78.28 759.44 330.67 1.000 2.210 774.72 (14.72) 0.00 1.04 78.26 758.78 330.38 1.000 2.201 790.98 (30.98) 0.00 1.06 78.23 757.95 330.00 0.999 2.184 808.70 (48.70) 0.00 1.09 78.19 756.89 329.53 0.999 2.158 827.37 (67.37) 0.00 1.11 78.15 755.55 328.93 0.997 2.120 846.07 (86.07) 0.00 1.14 78.10 753.96 328.21 0.994 2.073 863.48 (103.48) 0.00 1.16 78.04 752.26 327.45 0.990 2.020 878.28 (118.28) 0.00
3,916.90 Difference
Total
Antoine ConstantsA B C
Light n-Pentane 6.8 1,059.0 231.4 Heavy n-Octane 6.9 1,317.0 205.5
Water 8.0 1,701.8 231.5
Pressure, mm Hg Pressure Temperature Maximum Minimum
LP Steam Pressure 1 bar (gauge) 121 C 652.3 MP Steam Pressure 5 bar (gauge) 159 C 1,703.8 HP Steam Pressure 15 bar (gauge) 202 C 4,020.2 Tower Water Temp. 30 C 370.5 Chilled Water Temp. 5 C 108.4 Reboiler approach 15 C Condenser approach 10 C
Mole Fraction n-Pentane VP, mm Hg Partial Pressure
X Y n-Pentane n-Octane n-Pentane n-Octane DifferenceBottoms 0.05 0.38 105.7 652.3 4,993.14 423.78 249.66 402.59 0.00
0.05 0.31 144.3 1,703.8 10,493.08 1,241.17 524.65 1,179.12 0.00 0.05 0.25 186.7 4,020.2 20,252.38 3,165.84 1,012.62 3,007.55 0.00
Mole Fraction n-Pentane VP, mm Hg y/P*
X Y n-Pentane n-Octane n-Pentane n-Octane DifferenceDistillate 0.95 40.0 370.5 866.33 31.20 0.00109658 0.00 0.00
0.95 15.0 108.4 348.28 7.69 0.00272770 0.01 0.00
Therefore, to operate this column at close to atmospheric pressure (760 mm Hg), choose MP or HP steam for the reboiler, and tower water for the condenser.
Bubble Point Temp, deg C
Maximum Pressure
Dew Point Temp, deg C
Minimum Pressure
Problem Statement:Determine a column pressure that fits within available steam and cooling water temperatures
Results
Therefore, to operate this column at close to atmospheric pressure (760 mm Hg), choose MP or HP steam for the reboiler, and tower water for the condenser.
Antoine Coefficients Mol WtA B C MW
Methyl Alcohol 8.08097 1582.271 239.726 32.042Water 8.01352769 1701.78587 231.466749 18.015Methane 6.61182948 389.926958 265.99 16.043Ethane 6.80265848 656.401366 255.99 30.07Propane 6.95916997 857.736201 252.414186 44.097Toluene 7.05282866 1397.197 224.2974 92.141Acetic Acid 7.49044999 1604.16592 229.902701 60.052Isobutane 6.74811109 882.803422 240 58.124n-Butane 6.96820966 1000.63935 245.310958 58.124Isopentane 6.78967307 1020.01442 233.1 72.151n-Pentane 6.83902998 1059.01668 231.448959 72.151n-Hexane 6.76098367 1112.56081 218.029908 86.178n-Heptane 6.81342209 1224.41518 212.94937 100.21n-Octane 6.85804739 1316.95574 205.523542 114.232Ethyl Alcohol 8.1122 1592.864 226.184 46.069