Florida Institute of Technology

College of Engineering

Department of Chemical Engineering

CHE – 4115ChE Process Laboratory II

Formal Report # 1

Experiment # 4Batch Distillation

Performed by: Abdullah Kurdi

For: Dr. Maria Pozo de Fernandez

Experiment performed on: April 12, 2016

Date: April 29, 2016

Team D Grade:Partners: H. Baatiyyah

N. Almakhmari K. Almansoori F. Alkhaldi

I. Introduction

Distillation is a separations method that is commonly use industry to separate

components or component groups from liquid mixtures by using their volatility as the mean of

separation. Distillation is used in oil refineries to separate crude oil into its derivatives like fuel

gas, light oils, gasoline and kerosene; it is also used in food processing and perfumery and

medicinal of herbs “herbal distillate”. Distillation comes in many forms some examples are

simple distillation, batch distillation, and vacuum distillation. The operation of distillation could

be designed as batch, of continues, with or without reflux.

In this experiment a batch distillation with total reflux was studied. The purpose of the

experiment was to evaluate the efficiency of the plate column.

II. Equipment and Procedure

The apparatus includes a glass distillation column that is flexible and can be used in

several ways to obtain useful data. The column has multiple plates, operates under vacuum and

has a jacket for insulation. The plates have disc bubble caps and liquid down-comers. There are

two fixed pots, each with a corresponding size electric mantle heater. Finally there is a condenser

on the top with a flow splitter to the distillate collection flask.

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Figure 1: Experimental Apparatus Setup

The procedure start by obtaining 500 ml of water and 1000 ml of acetic acid, then

calculating the mole fraction for the initial mixture. The two are mixed together carefully via

adding acid to water. The glass joints are then slipped together such that they align and seal. The

distillate stopcock is then closed. The condenser cooling water is turned on at a moderate

flowrate; the heater for the reboiler is turned on as well at low heat, gradually increasing until a

slow boil occurs. The heat upward is gradually adjusted until water vapor is seen rising into the

condenser. When steady state is established, samples of approximately 50 ml each of liquid and

vapor in still pot, and distillate product. When taking a vapor sample, the flask should be

submerged in an ice bath. The volume and weight of the samples are measured, as well as the

temperature at both the still pot and at the top of the column. The temperature and flowrate of

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both the inlet and outlet cooling water are also recorded. Another sample collection is then

repeated after a few minutes. Refer to the Batch Distillation Experiment handout for more

information regarding Safety precautions, pH meter procedure, Gas Chromatography operating

instructions, and choosing the proper Gas Chromatography settings(1).

III. Experimental Results

Table1: Experimental Data – Sample Measurements

Sample Volume of Sample (mL) Weight of Sample (g)Distillate 1 17.3 17.49

Still pot Liquid 1 18.0 18.81Still pot Vapor 1 10.8 11.25

Distillate 2 14.0 14.17Distillate 3 9.2 9.32

Still pot Liquid 3 N/a N/aStill pot Vapor 3 N/a N/a

Table 2: Experimental Data – Values from Gas Chromatograph

Sample Area H2O (Water) Area CH3COOH (Acetic Acid) Total AreaDistillate 1 48383 5918 54301

Still pot Liquid 1 18563 22725 41288Still pot Vapor 1 29048 17353 46401

Distillate 2 49873 6185 56058Distillate 3 49019 6744 55763

Still pot Liquid 3 17692 22801 40493Still pot Vapor 3 26378 17800 44178

Table 3: Experimental Data – Percentage Area

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Sample Area % of H2O Area % of CH3COOHDistillate 1 89.1% 10.9%

Still pot Liquid 1 45.0% 55.0%Still pot Vapor 1 62.6% 37.4%

Distillate 2 89.0% 11.0%Distillate 3 87.9% 12.1%

Still pot Liquid 3 43.7% 56.3%Still pot Vapor 3 59.7% 40.3%

Table 4: Experimental Data – Flowrate of Cooling Water

Measurement Number Volume (mL) Time (s) Flow Rate (mL/s)1 275 4.28 64.252 280 4.81 58.21

Average 61.23

Table 5: Experimental Data – Location and Temperature

Location Temperature at Trial 1 (oC) Temperature at Trial 2 (oC)Still Pot 106 106Distillate 102 102

Table 6: Volume Percentage, Mole Percent Acetic Acid, and Mole Percentage Water

Volume Percentage Mole Percentage AA

Mole Percentage Water

15.5 5.0 95.064.9 37.1 62.946.9 20.8 79.215.7 5.1 94.917.1 5.5 94.566.1 38.4 61.650.0 23.2 76.8

Table 7: McCabe-Thiele Results

Number of Real Stages 27Number of Ideal Trays 5.53% Efficiency 20.5

Table 8: Theoretical Number of Stages at Total Reflux Using Eq. 11.51(1)

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Mole Percentage of Acetic Acid Mole Percentage of Water

5.0 95.037.1 62.9

α 1.8997Number of Theoretical Stages 2.76

Efficiency 10.2 %

Table 9: Water Mole Fraction, Total Moles in the Initial Still pot Mixture, Ratio of Final to Initial Moles, Flowrate of Cooling Water, and Heat Removed in the Condenser

Water Mole Fraction (xs1) 0.6Total Moles in initial Still pot Mixture

(S1)45.2

xdav 0.95

xsav 0.62

xs1 0.629xs2 0.616

S2/S1 (From xdav Equation) 0.96

S2/S1 (From Integral) 0.98S2 (From xd

av Equation) 43.39S2 (From Integral) 44.22

Db (From xdav Equation) 1.83

Db (From Integral) 1.01q (J/s) 256.0

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Figure 2: y-x Equilibrium Curve

Figure 3: Temperature versus x, y Curve

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Figure 4: 1/y versus 1/x plot to find the Relative Volatility

Figure 5: McCabe Thiele on the y-x Equilibrium Curve IV. Discussion

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From the equilibrium data provided by Dr. Pozo(1), the y-x equilibrium curve in Figure 2,

and the T-x-y plot in Figure 3 were constructed. From the y-x equilibrium values and using

equation 11.8(1): y A=α x A

1+(α−1)x A; a 1/yA versus 1/xA plot was constructed in Figure 4 to find the

relative volatility (α). The using the slope, the value was found to be 1.8997.

Using the McCabe Thiele graphical method and the y-x plot, Figure 5 was constructed to

determine the number of theoretical stages and the overall column efficiency, Table 7 displays

the results obtained. The ideal number of stags was found to be 5.53 ideal stages, the efficiency

was found to be 20.5%.

Equation 11.51(1) was used to calculate the number of theoretical stags; Table 8 displays

the results. The number of theoretical stages was found to be 2.76 stags which gave an efficiency

of 10.2. Table 9 shows the water mole fraction (xs1), the total moles in the initial still pot mixture

(S1), the average Distillate and Still pot mole fractions (xdav and xs

av), initial and final still pot

mole fractions (xs1 and xs2), the ratio of S2 to S1 using the both the xdav and the integral

equations(1), and the estimated heat removed in the condenser. The water mole fraction (xs1) was

found to be 0.6; the total moles in the initial still pot mixture (S1) was found to be 45.2 moles; the

average Distillate and Still pot mole fractions (xdav and xs

av) were found to be 0.95 and 0.62,

respectively. The final to initial number of moles in the still pot was calculated in two ways, the

first method used the average distillate mole fraction and gave a ratio of 0.96; the second method

was using an integral equation(1), the ratio was found to be 0.98; the two values are very close to

each other with a 0.02 difference. The heat removed in the condenser was estimated to be 256

J/s.

V. Conclusion

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In conclusion, the results obtained indicate accurate findings with respect to the theory.

The column efficiency was found to be very low and that can be related to the improper

insolation that resulted in a large heat loss. The lab helped in applying the concepts learned in

Separations class, which gave a good insight of the operations.

VI. Recommendations

In recommendation, the lab should have been conducted early in the semester to allow

more time for the students to participate in the data collection process. The insulation on the

column should be improved to increase the possibility of having better results. An external plate

should be obtained to provide the student with a sense feeling of how the plate operates.

VII. Reference

1. Chemical Engineering Process Lab II/Batch Distillation. 2016

VIII. Appendix A: Sample Calculations

Percentage Area of Acetic Acid:

%A AA=A AA

AH 2 O+A AA= 5918

48383+5918=10.9 %

Percentage Volume of Acetic Acid:%V AA=1.0831+1.3664 X AA−3.7666 ×10−3 X AA

2=1.0831+1.3664∗10.9−3.7666 ×10−3¿10.92=15.5% Percentage Mole of Acetic Acid:%Mole AA=1.5197+0.24127 X AA+7.3534 × 10−3 X AA

2=1.5197+0.24127∗10.9+7.3534 ×10−3 ¿10.92=5.0 % Still pot mole fraction of water:

X H 2 O=molesof water

totalnumber of moles=

500 mL∗1 g/ml18g /mol

500 mL∗1 g/ml18 g/mol

+ 1000mL∗1g /mL∗1.04960.05

=0.61

Relative volatility of Acetic Acid in Water (From Slope of Figure 4):

α= 10.5264

=1.8997

Theoretical Number of Trays:

n=

log [( x A

xB )d ( xB

x A )s]logα av

−1=log [( 0.9498

0.0502 )d( 0.3708

0.6292 )s]

log (1.8997 )−1=2.76 Trays

Column Efficiency:

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Efficiency=ntheoretical

nactual∗100 %=2.76

27∗100 %=10.2 %

S2/S1 (from xdav):

ln ( S1

S2 )=∫x s2

x s1 dxs

xd−xs=

S1

S2=

xd−xs1

xd−xs2

= .95−.63.95−.62

=0.96

S2/S1 (from integral):S1

S2=

kx s−xs2

kx s−xs1

=(0.0403)(0.6225)−.62(0.0403)(0.6225)−.63

=0.98

Difference and Percentage Difference:Difference=0.98−0.96=0.02

% Difference=0.020.96

∗100 %=2.1 %

S2 Calculation:S2=S1−Db=45.22−1.006=44.22

S2 Calculation using S2/S1 (from integral):S2=0.9777∗S1=0.9777∗45.22=44.22

S2 Calculation using S2/S1 (from xdav):

S2=0.9597∗S1=0.9597∗45.22=43.39 Heat Removed from Condenser:

q=m c p ΔT=Qtρ c p ΔT =61.23 mLs

∗1 gmL

∗4.1814 JgK

∗(26−25 )=256 J /s

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IX. Appendix B: Experimental Data

Table 10: Distillation Experiment

Sample measurements Values from Gas Chromatograph Area %

Sample Volume of Sample (mL)

Weight of Sample (g)

Area H2O (Water)

Area CH3COOH

(Acetic Acid)

Total Area

Area % of H2O

Area % of CH3COOH

Distillate 1 17.3 17.49 48383 5918 5430189.1% 10.9%

Still pot Liquid 1 18.0 18.81 18563 22725 4128845.0% 55.0%

Still pot Vapor 1 10.8 11.25 29048 17353 4640162.6% 37.4%

Distillate 2 14.0 14.17 49873 6185 5605889.0% 11.0%

Distillate 3 9.2 9.32 49019 6744 5576387.9% 12.1%

Still pot Liquid 3 N/a N/a 17692 22801 4049343.7% 56.3%

Still pot Vapor 3 N/a N/a 26378 17800 4417859.7% 40.3%

Flowrate of Cooling Water

Measurement number Volume (mL) Time (s) Flow Rate (mL/s)1 275 4.28 64.25

2 280 4.81 58.21

Average 61.23

Location Temperature at Trial 1 (C)

Temperature at Trial 2

(C)Still Pot 106 106Distillate 102 102

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