PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY
OFFICE FOR INTERNATIONAL STUDY PROGRAMS
DISTILLATION
No.
1
2
3
Name
Lai Minh Nhật Ánh
Lê Tấn Phong
Nguyễn Duy Minh Triết
Student ID
2152015
2153684
2152321
Department: Processes and Equipment
Instructor: Phạm Hoàng Huy Phước Lợi
Class: CC07
Group 3A
30 April 2024
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
1. ABSTRACT
1.1. Experimental purpose
The objective of the experiment is to understand and apply basic concepts in distillation of binary
mixtures. Continuous distillation of ethanol water mixture will be investigated:
- Determine the overall efficiency of the column
- Investigate effect of reflux ratio on the product composition
- Investigate effect of location of feed flow on the product composition
1.2. Experimental methods
This lab is mainly designed to separate binary components including ethanol and water using
distillation with 5 stages batch column,
1.3. Raw results
Table 1
No
1
2
3
4
5
Locat
ion of
feed Feed (F)
4
4
4
2
5
150
150
150
150
150
Flow rate
Distillate
(D)
(ml/ph)
64
82
64
60
72
Temperature
Concentration
Reflu
x (Lo)
Feed
(xF)
Distilla
te (xD)
Feed
(tF)
28.2
56.4
84.6
56.4
56.4
0.026
0.026
0.026
0.026
0.026
0.174
0.222
0.42
0.307
0.26
59
57
56
51
63
Distilla
Reflux
te (tD
(tLo)
liquid)
31
73
33
75
32
71
32
72
32
72
2. EXPERIMENTAL THEORY
The separation dynamics are most heavily dependent on the vapor pressure of the species in the
column. The more volatile component is also known as the light key, the less volatile component
is also known as the heavy key. For a two-component separation:
All symbols are defined in the nomenclature section at the end of the text. By Raoult’s law, this
means that relative volatility can be described in terms of mole fractions in the liquid and vapor
phases.
This can be rearranged to give
1
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
The tradition approach to modeling distillation processes is known as the McCabe-Thiele
approach. This model requires making the following assumptions:
- That the relative volatility is constant over the temperature range in the column
- That the components have equal and constant molar enthalpy
- That enthalpy changes and heat of mixing are negligible
- That the pressure is uniform within the column
These assumption allow equations to be derived relating flow rates to molar compositions in each
stage of the column. The column is divided into the vapor phase, and the rectification section, in
which the less volatile component is selectively condensed. In each section, the liquid and vapor
compositions can be related to flow rates.
Rectification section:
Vn+1yn+1=Lnxn + DxD (6)
yn+1=(Ln/ Vn+1) + (D/ Vn+1)xD (7)
where the stages are numbered consecutively, beginning with the top stage
L/V=R/(R+1) (8)
yn = (R/(R+1))xn + (1/R+1)xD (9)
Stripping section:
yn = (Ln/Vn)xn – (Bn/Vn)xB (10)
VB=V/B (11)
L/V=(V+B)/V = (VB+1)/VB (12)
yn = ((VB+1)/VB)xn – (1/VB)xB (13)
Given equilibrium data for the components of the distillation, these equations can be used to
model the stages graphically, as shown in Figure 1.
2
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
Figure 1 : Sample McCabe-Thiele diagram. Each step indicates a theoretical stage
going to complete equilibrium. The calculations are shown for the rectification section only.
Reprinted from Seader (1998)
Because true vapor-liquid equilibrium is unlikely to be achieved on each stage, this method must
be adapted in order to properly model the distillation system. A widely used method for this is
known as Murphree Efficiency
yn - yn+1
EM = y* - y
(14)
n n+1
Where y* used in this equation is derived from experimentally measured liquid-phase
composition values. The Murphree Efficiency can be used to alter the equilibrium line in the
McCabe – Thiele graph. This adapted graph can be used to more accurately predict the separation
under different conditions of feed composition and reflux retios.
3. EXPERIMENTAL RESULTS
Table 1 : Raw results
No
Locat
ion of
feed Feed (F)
1
2
3
4
5
4
4
4
2
5
150
150
150
150
150
Flow rate
Distillat
e (D)
(ml/ph)
64
82
64
60
72
Temperature
Concentration
Reflux
(Lo)
28.2
56.4
84.6
56.4
56.4
Feed
Distilla
te
Feed
(tF)
0.026
0.026
0.026
0.026
0.026
0.174
0.222
0.42
0.307
0.26
59
57
56
51
63
Distill
ate (tD
liquid)
31
33
32
32
32
Reflux
(tLo)
Table 4 : Raw results processing
Flow rate (ml/min)=dd*5.64
Ratio mol(mol C2H5OH/total
mo;l)
Distillate
Feed (F)
(D)
(ml/ph)
Reflux
(Lo)
Feed
(xF)
Distillate
(xD)
Bottom
(xW)
No
Location
of feed
1
4
150
64
28.2
0.026
0.174
0.005
2
4
150
82
56.4
0.026
0.222
0.005
3
4
150
64
84.6
0.026
0.42
0.004
4
2
150
60
56.4
0.026
0.307
0.004
5
5
150
72
56.4
0.026
0.26
0.005
3
73
75
71
72
72
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
Table 5 : Calculation Results
Location
No of feed
Reflux
ratio (
R)
1
4
2
HF(Kcal/Kmol)
HGF
(Kcal/Kmol)
HLF
(Kcal/Kmol)
q
q/(q-1)
25362.5955
54898.7625
28074.5598
1.1011
10.8912
57
25209.8088
54898.7625
28074.5598
1.1068
10.3633
1.3219
56
25133.4154
54898.7625
28074.5598
1.1096
10.1241
2
0.94
51
24751.4486
54898.7625
28074.5598
1.1239
9.071
5
0.7833
63
25668.169
54898.7625
28074.5598
1.0897
12.1483
0.4406
tF
59
4
0.6878
3
4
4
5
Table 6 : Input line equation and Linear equation
No
Input line equation (Feed line or q-line)
Linear equation (Rectifying line)
1
y=10.8912x-0.2572
y=0.3058x+0.1208
2
y=10.3633x-0.2434
y=0.4075x+0.1315
3
y=10.1241x-0.2372
y=0.5693x+0.1809
4
y=9.071x-0.2098
y=0.4845x+0.1582
5
y=12.1483x-0.2899
y=0.4392x+0.1458
Table 7 : Experimental Results
No
Location of
feed
Reflux ratio
(R)
Theory
plate
xD
General tray
efficiency
E0
1
4
0.4406
2.5
0.174
0.5
2
4
0.6878
3.5
0.222
0.7
3
4
1.3219
4.5
0.42
0.9
4
2
0.94
3.8
0.307
0.76
5
5
0.7833
3.6
0.26
0.72
4. GRAPH
Schematic calculation of theoretical trays
Each graph corresponds to an experiment
Graph of theoretical specimens with Lo=5
4
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
Feed tray 4, L = 5
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Input line equation
Linear equation
y=10.8912x-0.2572
Theory plates : nLT = 2.5
y=0.3058x+0.1208
Graph of theoretical specimens with Lo=10
5
1
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
Feed tray 4, L = 10
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Input line equation
Linear equation
y=10.3633x-0.2434
Theory plates: nLT = 3.5
y=0.4075x+0.1315
Graph of theoretical specimens with Lo=15
6
0.9
1
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
Feed tray 4, L = 15
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0.2
0.4
0.6
0.8
Input line equation
Linear equation
y=10.1241x-0.2372
Theory plates: nLT = 4.5
y=0.5693x+0.1809
Graph of theoretical specimens number 2
7
1
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
Feed tray 2, L = 10
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Input line equation
Linear equation
y=9.071x-0.2098
Theory plates: nLT = 3.8
y=0.4845x+0.1582
Graph of theoretical specimens with number 5
8
0.9
1
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
Feed tray 5, L = 10
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Input line equation
Linear equation
y=12.1483x-0.2899
Theory plates: nLT = 3.6
y=0.4392x+0.1458
1
5. EXPERIMENTAL THEORY
5.1.
The effect of the flow on the product's purity, on the performance of the
wheel and the overall performance of the column
5.1.1. The effect of the flow on the product's purity
It is clear from the experiments 1,2,3 that as the flow of circulation increases, the purity
of the product increases
This can be explained on the basis of heat. With a constant supply of heat, the molar
mass of the Go is constant
We have Go = Lo + D. As the flow of circulation increases, this also means decreasing
the flow of product. For the whole tower powder, the amount of heat entering the boiler has the
function of separating the mixed phase. Individual dosing rates will be calculated according to the
amount of heat supplied separately - calculated on 1 molar peak.
Thus, when D decreases, ie the heat supplied separately increases the separation, ie
increasing the purity of the product (including top and bottom products).
5.1.2
The effect of the flow on the performance of the wheel
9
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
By experiment, it is clear that as the flow increases, the process efficiency increases.
Increased productivity means that the system works as close to the theory
However, it must be noted that general performance does not allow for an assessment of
the economic viability of the equipment. Our goal is to produce the desired purity product. As the
flow increases, the efficiency of the tray increases, which means that the number of trays needed
will be reduced, thus reducing the initial cost of manufacturing the device. However, as the flow
increases, as noted above, the individual supply will increase. Want to get the desired amount of
product to spend more heat. This cost sometimes accounts for a huge percentage of the total cost
of the
5.1.3 The effect of the flow on the product's purity, and the overall performance of the
column
During the distillation, the liquid stream as well as the vapor stream will change the
concentration as it passes through each tray (change in concentration). However, the change of
concentration when passing through each tray but also depends on the ability to exchange in the
tray. It is clear that when inputting the trays near the bottom, the number of exchange rate
increases, resulting in peak product purity increase; when the input tray near the top, the result
will be the opposite. However, when the input position is not the same as the theoretical position,
the exchange capacity of the trays will decrease (although the number of theoretical tray is
increased then), so the achievement of purity Higher is not sure.
Through experiment, we find that the input tray does not affect the efficiency of the tray. The
effect of the input trays on the performance of the trays cannot be concluded based on its high or
low position, but based on its deviation from the theoretical position as close to this position as
the efficiency the higher the tray
5.2.
The phenomena and processes taking place in the tower when operating
stable
On each tray there is the boiling of the mixture of boiling temperature of the mixture in each
tray is different and gradually reduced to the final tray.
- stable operating system is proper operation of the heat exchanger in order to
ensure the heat supply to the currents
- The flow meters should be stable
Thermometer on the trays of different values, the higher the temperature the lower the
temperature
5.3.
The causes of the error and how to overcome
 During the experiment
 The valves are not fully opened so the flow is unstable
 Marbles are always drop so always monitor the flow
 Measurement of alcohol by incorrect design by the reader
 error due to flow measurement (press incorrect clock, unstable flow)
 Do not read the measured values at the same time
 In the calculation process: data rounding, table lookup, unit conversion, plotting
inaccurate
10
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
 Restricted and corrected
 Experiment must be careful, the operation of the members must coordinate rhythm
 Always adjust the flow of input and flow at the correct value
 measure the values at the same time
6. DISCUSSION
6.1 The effect of the flow on the product's purity, on the performance of the wheel
and the overall performance of the column
+The effect of flow on the product's purity:
Experiments 1, 2, and 3 demonstrate that as the flow of circulation rises, so does the purity of the
product. This may be explained in terms of heat. With a steady source of heat, the molar mass of
the Go remains constant. We have Go = Lo + D. As circulation rises, the flow of product
decreases. The quantity of heat that enters the boiler for the entire tower powder serves to
separate the mixed phase. Individual dosage rates will be computed based on the quantity of heat
provided separately, using a 1 molar peak. Thus, when D lowers, the heat given separately
enhances separation, resulting in increased product purity (including top and bottom products).
+The effect of the flow on the performance of the wheel:
Experiments show that as the flow increases, so does the process efficiency. Increased
productivity indicates that the system operates as closely as possible to the theory. However, it
should be emphasized that overall performance does not allow for an evaluation of the
equipment's economic feasibility. Our purpose is to manufacture the required pure product. As
the flow grows, the tray's efficiency increases, reducing the number of trays required and thereby
lowering the device's original production cost. when previously stated, when the flow grows, so
does the individual supply. Want to acquire the right amount of merchandise to spend more heat.
This expense can account for a significant portion of the overall cost.
+The effect of the flow on the product's purity, and the overall performance of the column:
During distillation, both the liquid and vapor streams change concentration as they travel through
each tray. However, the change in concentration as one passes through each tray is also
determined by the tray's capacity to interchange. It is obvious that inserting the trays at the
bottom increases the number of exchange rates, resulting in an increase in peak product purity;
inputting the trays near the top has the reverse effect. However, when the input position differs
from the theoretical position, the exchange capacity of the trays decreases (even if the number of
theoretical trays increases), making the accomplishment of purity higher uncertain.
6.2 The phenomena and processes taking place in the tower when operating stable
The boiling temperature of the mixture varies from tray to tray and progressively decreases until
the last tray.
• A stable operating system ensures appropriate heat exchanger functioning to give heat to the
currents.
• The flow meters should be steady.
•Thermometers on trays should have varied values, with greater temperatures indicating lower
temperatures.
6.3 The causes of the error and how to overcome
During the experiment:
The flow is unsteady due to partially opened valves.
11
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
Marbles drop often, therefore check the flow.
Incorrect alcohol measurement by the reader.
Error owing to flow measurement (incorrect clock, unsteady flow).
Avoid reading the measured values simultaneously. Inaccuracies in calculations, such as data
rounding, table lookups, unit conversions, and graphing, must be restricted and addressed.
Experiments should be conducted with caution and coordination among team members.
Adjust input flow to get the desired value.
Measure values simultaneously.
7. APPENDIX
The calculation of the data for all 5 experiments was similar.
Data table:
Ethanol:
 Specific weight: r = 0.772 g/ml
 Molecular weight: Mr = 46 g/mol
 Specific heat (40 – 80 oC) : Cr = 119.6 J/mol.K
 Latent heat of vaporization at 86,5oC rr = 39741 j/mol
Water:
 Specific weight (40 – 80 oC) : n = 0.992 g/ml
 Molecular weight: Mn = 18 g/mol
 Specific heat (trong khoaûng 40 – 80 oC) : Cn = 75.24 J/mol.K
 Latent heat of vaporization at 86,5oC rn = 41200 j/mol
We need to calculate the following parameters in turn:

It changes from the contraceptive to molar xD , xF
do ruou   r
Mr
x
do ruou   r (100 - do ruou)   n

Mr
Mn
 Varies from flow to mol / min
Q(ml / phut ) do ruou   r (100 - do ruou)   n
Q(mol / phut ) 
(

)
100
Mr
Mn

Distillate concentration.
xW 

x F .F  x D .D
F D
Average specific heat of the mixture C2H5OH - H2O (Chh)
Chh  x.CR  (1  x)CN
CN : specific heat of water. (Kcal/Kmol.oC)
CR : specific heat of alcohol. (Kcal/Kmol.oC)

Average latent heat of mixture C2H5OH - H2O (Kcal/Kmol)
12
(12)
(13)
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
rhh  x.rR  (1  x)rN
rhh, rR, rN : heat of vaporization of the mixture, pure alcohol, water at the temperature
under consideration
 Calculate CF, CLF, CGF , HF, HLF, HGF
C F  C LF  Cr  xF  Cn  (1  xF )
(14)
CGF  Cr  y F  Cn  (1  y F )
(15)
(16)
(17)
H F  CF  t F
H LF  C F  t sF
tsF : boiling point of the mixture
(18)
H GF  CF  t sF  rr  y F  rn (1  xF )
 Calculate the reflux ratio R , q
 Find out the slope = R /(R +1) , and free radical in its equation = xD / (R +1)
 Find the input slope by q/(q-1) and free radical in its equation =
xF/(q-1)
 Draw a graph to calculate the number of theoretical points, thus deducting the
overall efficiency of the distillation tower : E0 = nLT / nT
 The checklist
DISTILATE
ρr (kg/m3)
ρn (kg/m3)
Temperature
100
100
100
716.20
716.20
716.20
960.60
960.60
960.60
100
716.20
960.60
100
716.20
960.60
ρr (kg/m )
DISTILATE
ρn (kg/m3)
ρtb (kg/m3)
44
44
42
769.23
769.23
771.01
990.06
990.06
990.76
901.73
890.69
856.71
42.5
770.57
990.59
889.38
42.5
770.57
990.59
887.18
3
ρtb (kg/m3)
947.49
Temperature
3
Temperature
ρr (kg/m )
FEED
ρn (kg/m3)
50
763.85
987.80
13
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
51.5
762.49
987.20
946.75
50
48
48
763.85
765.65
765.65
987.80
988.58
988.58
947.49
948.45
948.45
ρtb (kg/m3)
Temperature
ρr (kg/m )
REFLUX
ρn (kg/m3)
38
774.542
992.096
905.33
38
774.542
992.096
894.46
41
38
38
771.896
774.542
774.542
991.103
992.096
992.096
857.43
892.22
890.04
tF sôi tb = 89
look xFtb = 0.0623
tFtb = 49.5
tF sôi tb = 89
Cetylic J/kg.K
2823.997
3333.60
CWater J/kg.K
4186
4227.86
CF
3995.320
4102.664
3
SPECIFIC HEAT
Determine the boiling point of the input stream
LATENT HEAT
retylic J/kg.K
874135.62
tF sôi tb = 89
rw J/kg.K
2390408.04
tF sôi tb = 89
rF J/kg.K
2178129.90
14
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
KLR cuû
a Etylic theo nhieä
t ñoä
p
850
800
750
700
650
-50
0
50
100
y = -0.0012x2 - 0.803x + 806.51
150
t
KLR cuû
a nöôù
c theo nhieä
t ñoä
p
1010
1000
990
980
970
960
950
940
930
0
50
100
2
y = -0.0032x - 0.0946x + 1000.5
15
150
t
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
Nhieät hoù
a hôi theo nhieät ñoä
cuû
a röôïu etylic kcal/kg
r
225
205
185
165
145
0
50
100
150
y = -0.000000001x 5 + 0.0000006x 4 - 0.0001x 3 + 0.0051x 2 - 0.1711x + 221.1
T
Nhieä
t hoù
a hôi cuû
a nöôù
c kcal/kg
r
600
580
560
540
520
500
0
50
100
150
t
y = -0.0012x2 - 0.4217x + 594.89
16
PROCESS & EQUIPMENT EXPERIMENT
DISTILLATION
ETYLI
C -Water
NÖÔÙ
C
Ethylen-
T ÑOÄ( C) o
NHIEÄ
Temperature C
100
90
80
70
0
10
20
30
40
50
60
70
80
90
100
% ETYLI C
8. REFERENCES
[1]. Voõ Vaên Bang ,Vuõ Baù Minh - Quaù trình vaø Thieát bò – Taäp 3 – Truyeàn
khoái, ÑHQG TP HCM, 2004.
[2]. Trònh Vaên Duõng - Toùm taét baøi giaûng Caùc quaù trình vaø thieát bò truyeàn
khoái, ÑH Baùn coâng Toân Ñöùc Thaéng, 2003.
[3]. Soå tay quaù trình vaø thieát bò, ÑH QG TP HCM, 2004
17