Hydrodynamic studies on liquid-liquid two phase flow separation in microchannel by computational fluid dynamic modelling
Science & Technology Development Journal – Engineering and Technology, 4(2):920-931
Research article
Open Access Full Text Article
Hydrodynamic studies on liquid-liquid two phase flow separation
in microchannel by computational fluid dynamic modelling
Chue Cui Ting1, Afiq Mohd Laziz1, Khoa Dang Dang Bui2,3, Ngoc Thi Nhu Nguyen2,3, Khoa Ta Dang2,3
Pha Ngoc Bui2,3, An Si Xuan Nguyen2,3, Ngon Trung Hoang2,3, Ku Zilati Ku Shaari1,
Loi Hoang Huy Phuoc Pham2,3,*
,
ABSTRACT
Microfluidic systems undergo rapid expansion of its application in different industries over the
few decades as its surface tension-dominated property provides better mixing and improves mass
transfer between two immiscible liquids. Synthesis of biodiesel via transesterification of vegetable
oil and methanol in microfluidic systems by droplet flow requires separation of the products after
the reaction occurred. The separation technique for multiphase fluid flow in the microfluidic system
is different from the macro-system, as the gravitational force is overtaken by surface force. To un-
derstand these phenomena completely, a study on the hydrodynamic characteristics of two-phase
oil-methanol system in microchannel was carried out. A multiphase Volume of Fluid model was
developed to predict the fluid flow in the microchannel. An inline separator design was proposed
along with its variable to obtain effective separation for the oil-methanol system. The separation
performance was evaluated based on the amount of oil recovered and its purity. The capability
of the developed model has been validated through a comparison of simulation results with pub-
lished experiment. It was predicted that the purity of recovered oil was increased by more than
46% when the design with side openings arranged at both sides of the microchannel. The high-
est percentage recovery of oil from the mixture was simulated at 91.3% by adding the number of
side openings to ensure the maximum recovery. The oil that was separated by the inline separator
was predicted to be at 100% purity, which indicates that no methanol contamination throughout
the separation process. The purity of the separated product can be increased by manipulating the
pressure drop across the side openings. Hence, it can be concluded that the separation in a large
diameter microchannel system is possible and methodology can be tuned to achieve the separa-
tion goal. Finally, the simulation results showed that the present volume of fluid model had a good
agreement with the published experiment.
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1Chemical Engineering Department,
Universiti Teknologi PETRONAS (UTP),
3260 Seri Iskandar, Perak, Malaysia
2Faculty of Chemical Engineering, Ho
Chi Minh City University of Technology
(HCMUT), 268 Ly uong Kiet Street,
District 10, Ho Chi Minh City, Vietnam
Key words: microchannel, immiscible liquids separation, computational fluid dynamic, volume of
fluid model, multiphase
3Vietnam National University Ho Chi
Minh City, Linh Trung Ward, u Duc
District, Ho Chi Minh City, Vietnam
that can perform quick separation in the microchan-
nel field, it is important to study the hydrodynamic
INTRODUCTION
Liquid-liquid two phase separation is an important
Correspondence
Loi Hoang Huy Phuoc Pham, Faculty of
Chemical Engineering, Ho Chi Minh City
University of Technology (HCMUT), 268
Ly Thuong Kiet Street, District 10, Ho
Chi Minh City, Vietnam
characteristic of the fluid flow in the microchannel.
aspect when it comes to the usage of microchannel
In macroscale, separation is done by exploiting the
in performing certain chemical reactions that involve
gravitational effect and the difference in density of
the multiphase. However, in microscale, the ef-
the usage of microreactor technology in chemical pro-
Vietnam National University Ho Chi Minh
City, Linh Trung Ward, Thu Duc District,
Ho Chi Minh City, Vietnam
fect of gravitational force is overtaken by the surface
force, and the density difference of the two phases
cesses in the transesterification of vegetable oil and
transfer are improved significantly via microfluidic
Email: phhloi@hcmut.edu.vn
.
microfluidics have apparatus length scale below the
√
History
Laplace length scale ( γ/(ρg)), which later proved
that the effect of gravitational forces is negligible in
microfluidics, two phase separation is possible to per-
form in a single step.
As the reaction and fluid flow happen in the capillary-
size channel, the mechanism of the fluid flow devi-
ates from the macro-system as the effect of gravity and
e capillary effect and viscous force overcome the
gravity and inertial force, causing the fluid to behave
• Received: 27-02-2021
• Accepted: 26-4-2021
• Published: 09-5-2021
DOI : 10.32508/stdjet.v4i2.810
Capillary pressure, P is a critical parameter in the
cap
differently. In order to design a separation system microscale separation process to induce and maintain
Cite this article : Ting C C, Laziz A M, Bui K D D, Nguyen N T N, Dang K T, Bui P N, Nguyen A S X, Hoang N T,
Shaari K Z K, Pham L H H P. Hydrodynamic studies on liquid-liquid two phase flow separation in mi-
crochannel by computational fluid dynamic modelling. Sci. Tech. Dev. J. – Engineering and Technology;
4(2):920-931.
920
Science & Technology Development Journal – Engineering and Technology, 4(2):920-931
very fine capillaries array (less than 50µm), which can
cause difficulty for production of the very fine capil-
laries microchannel. e aim of this project is to con-
duct a numerical study on the hydrodynamics char-
acteristic of liquid-liquid two phase flow separation
in microchannel. In this present work, the separation
is performed in the microchannel system with large
capillary size (particularly more than 250µm). Sepa-
ration system with large capillary size has lesser pres-
sure drop, and therefore is more difficult to carry out
separation.
Copyright
© VNU-HCM Press. This is an open-
access article distributed under the
terms of the Creative Commons
Attribution 4.0 International license.
2γ coscosθ
(1)
P
cap
=
r
where
γ is the interfacial tension,
θ is the contact angle between the liquid phase and
the solid wall of the microdevice
r is the radius of curvature of the interface.
To achive a perfect separation, the capillary pres-
.
as follow:
RELATED WORK
12µlQ
e separation of chloroform and water system at flow
rate up to 0.4 ml/min has been performed by Castell
of the two liquids are generated and separated into
their component phases through an array of separa-
tion ducts. e outlet pressure drops at various po-
sitions were applied to achieve separation. e sep-
aration efficiency was quantified over a range of ap-
plied pressure differentials and inlet flow rates. It
was demonstrated that the capillary pressure is suf-
ficient to separate the two-phase flow through a nar-
row channel over a range of flow rates by applying ap-
propriate pressure drop of the separator. Besides, it
was also proved that the difference in capillary forces
of the two different wetting property fluids allows the
separation to be achieved by ensuring the passage of
(
)
△P
=
outlet
h
(2)
1−0.63
wh3
w
where
l, h and w is the length, height and width of the chan-
nel respectively
Q is the volumetric flow rate and µ is the dynamic vis-
cosity of the liquid.
ere are two main possible failures in the attempt to
.
First is the retain of continuous phase in dispersed
phase outlet and second is the breakthrough of dis-
persed phase which some of the dispersed phase flow
together with the continuous phase through the con-
tinuous phase outlet. First scenario occurs when the
capillary pressure of the continuous phase is insuffi-
cient to provide the driven force for all the continu- one phase through the separation ducts.
ous phases to flow to the continuous phase outlet. e
capillary pressure of continuous phase is smaller than
continuous outlet pressure in this scenario. Second
failure happens when the capillary pressure of the dis-
persed phase is greater than the continuous pressure
outlet, causing the dispersed phase to overcome the
pressure to flow through the continuous outlet. Hence
it is important to maintain the suitable pressure drop
in the microchannel to induce the perfect separation.
drop must be in the range of:
A comparison study showed that the separation tech-
water on chips. e number of the narrow channels
aration can be achieved by applying the appropriate
pressure drops at the two different outlets.
e liquid-liquid separation in microchannel was
modelled using a Y-shaped flow splitter by Kashid et
grated on each of the branches of the Y-splitter, which
are hydrophobic Teflon and hydrophilic steel to sepa-
rate the organic and aqueous phase liquids. e find-
ings found that the separation efficiency is indepen-
dent with droplet velocity. However, an unequal flow
ratio between the two liquids will affect the separation
efficiency. e liquid with higher flow rate will con-
taminate the outlet, causing incomplete separation.
is phenomenon is caused by the dominant of iner-
△Pdispersed > △P
> △Pcontinuous
(3)
c
outlet
c
e outlet pressure drop can be tuned by modifying
the capillary diameter as well as the capillary length
.
By tuning the pressure drop across the outlet to the
desired range, perfect separation can be achieved.
Currently, there are successful inline separators for
the microfluidics that are proven to carry out fast
and effective separation of the two immiscible liquids tial force over wetting force. Besides, capillary size has
flow. However, the design of the separator requires a no significant effect on the separation efficiency. is
921
Science & Technology Development Journal – Engineering and Technology, 4(2):920-931
modelling work had performed a near-perfect separa-
tion in which the aqueous outlet still contains 5 per-
cent of organic solution.
3. e boundary condition along the solid surface
is non-slip with no penetration.
4. No mass transfer and chemical reaction occur
across the two liquids interface.
Another methodology which is similar to the research
liquids within hydrophobic microchannel by insert-
studies have investigated the effect of the sidestream
angle, sidestream penetration, sidestream internal di-
ameter and the fluid properties. Besides, the main-
stream outlet length have been manipulated as the
outlet pressure drop is a function of length. From
there, it was proved that separation of two-phase flow
can be achieved by simply piercing the microchannel
using a hydrophilic metal sidestream needle.
In one study, the liquid-liquid separation has been
performed by applying porous capillaries to the inline
suitable back pressure at the separator and the two-
phase separation can be achieved over a wide range of
flow rates (100-1000µL/min) by tuning the back pres-
sure. Moreover, this study also reported that the pres-
sure difference is the key to successful separation. To
achieve a perfect separation, the outlet pressure drop
has to be smaller than capillary pressure of solvent
and greater than capillary pressure of the carrier. By
adjusting the separator capillary diameter and length,
the outlet pressure drop can be tuned to achieve a per-
fect separation.
Governing Equations
e computational domain used in this work is two-
dimensional. e interface tracking between the
phases in VOF method is done by solving the conti-
nuity equation for the volume fraction of one phase:
[
]
(
)
1
∂
→−
αpρp +∇·αpρp v
p
ρp ∂t
= S+
(4)
(
)
.
.
n
mqp −mpq
∑
q=1
e momentum equation in VOF model is
∂
∂t
−→
−→→−
→−
(ρ v )+∇·(ρ v v )
(5)
(
)
→−
→−
−→
= −∇p+∇· µ(∇ v +∇ v T ) +ρ g + F
e surface tension model in ANSYS Fluent is the
continuum surface force (CSF) model proposed by
to the VOF model results in the source term in the
momentum equation. e outlet pressure drop highly
depends on the surface tension coefficient, σ, and the
surface curvature as measured by two radii in orthog-
onal directions, R1 and R2:
In another study, the separation of liquid-liquid phase
had been demonstrated by using membrane-based
brane is used to separate organic and aqueous phase
and a pressure differential is applied across the outlet.
By applying a suitable back pressure on the organic
outlet, it is able to provide sufficient pressure to pre-
vent all the aqueous phase from permeating through
the membrane.
(
)
1
1
p2 − p1 = σ
+
(6)
R1 R2
Wall adhesion angle is included to adjust the surface
normal in the cells near the wall. It helps to adjust the
curvature of the surface near the wall. Assuming θw is
the contact angle at the wall, then the surface normal
at the cell next to the wall is
THE METHODOLOGY TO DEVELOP
THE MODEL
b
(7)
nb= nbw coscosθw +tw sinsinθw
A Volume of Fluid (VOF) model was developed to
model and investigate the flow behaviour in mi-
crochannel. ANSYS Fluent was used for the simula-
made in this work to study the flow separation of im-
miscible liquids in microchannel:
Boundary and Solver Setup
was generated, and inflation method was used on the
wall boundary as the simulation requires high accu-
racy at the wall film. Mesh independent study was
carried out to identify the suitable mesh size for this
simulation work. e boundary setup was tabulated
1. e liquids are Newtonian liquids and are in-
compressible with constant surface tension and
viscosity.
2. e flow in the microchannel is laminar.
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Science & Technology Development Journal – Engineering and Technology, 4(2):920-931
Figure 1: Schematic diagram of microchannel separator.
Table 1: Boundary and Solver Setup
Property/ Parameter
Fluid/ Value
Density (kg/m3)
Oil = 909.15
Methanol = 785
Viscosity (Pa.s)
Oil = 0.069
Methanol = 0.0005495
Interfacial Tension (N/m)
Velocity (m/s)
0.00327
Oil = 0.00138
Methanol = 0.00214
Wall Adhesion
Oil/ Methanol = 180º
total amount of oil removed and the purity of oil re-
RESULTS AND DISCUSSION
moved. Design 2 has a large amount of methanol es-
caped through the side openings, lowers the oil purity
to 53.9%. Design 1 was able to separate the oil from
the mixture, retrieving almost 80% of pure oil from
the mixture, while design 2 had recovered 67% of oil
from the system. Based on this observation, design 1
is selected for the next analysis.
Two immiscible liquids, oil and methanol were intro-
duced into the microchannel system by a T-junction
and droplet flow were generated with oil as a pri-
mary phase enclosed the secondary phase, methanol
as droplet. e mixture flows along the microchannel
and eventually reaches the inline separator. e side
openings provide exits for the oil to be separated from
the mixture.
Effect of Number of Side Openings
Number of side openings is important as it deter-
mines the separation performance of an inline sepa-
rator. e higher the number of side openings pro-
vides more exits for the primary phase to be separated
from the system. e amount of oil allowed to sepa-
rate from the system rises when the number of side
formance for the 3 types of separator with different
numbers of side openings pair.
Preliminary Design Selection
Two types of designs were proposed to carry out the
separation of the oil-methanol system. Design 1 (Fig-
at both sides of the microchannel while design 2 (Fig-
at one side of the microchannel. Figures 2 and 3
show the simulated oil volume fraction contour for
separation in the oil-methanol system. Both the de-
signs have 2 side openings with different configura-
tions. e simulated result proved design 1 has bet-
ings increases from 1 to 2 pairs, the percentage of
oil recovery increases from 67.9 % to 91.3%. Fur-
ter separation performance than design 2 in terms of ther increase in the number of side openings will not
923
Science & Technology Development Journal – Engineering and Technology, 4(2):920-931
Figure 2: Oil volume fraction contour of inline separator design 1
Figure 3: Oil volume fraction contour of inline separator design 2
Table 2: Effect of number of side openings on separation performance
Number of Side Opening
Pair
Percentage of oil recov- Contamination of methanol at side Purity of oil recovered
ery (%)
openings
(%)
99.3
90.1
100
1
2
3
67.9
Yes
91.3
Yes
91.3
No
raise the amount of oil recovered as it is the max- phenomenon happens as the number of side open-
imum oil recovery that the inline separator can be ings pair increases the pressure drop of the system, re-
achieved. e remaining 8.7% of the oil retains in the taining the methanol from escaping through the side
system and moves together with methanol as oil is the openings, and hence, resulting in higher purity of the
medium that wets the wall. A thin film of oil is found oil recovered. Based on the results, it is observed that
in between the wall and methanol droplet as a result 3 pairs of side openings are sufficient to carry out an
of its wetting properties.
effective separation given the process parameter.
In terms of the oil recovered purity, separators with 2 e previous design with a low percentage of oil purity
pairs of side openings (Figure 4) provide worse sepa- (inline separator with 2 pairs of side openings) was
ration than the 3 pairs side openings (Figure 5). e chosen for the next step of analysis. e objective of
purity of oil increases from 90% to 100% by increas- this is to enhance and improvise the separation based
ing the number of side openings pair from 2 to 3. is on the selected design. Two methods were proposed
924
Science & Technology Development Journal – Engineering and Technology, 4(2):920-931
Figure 4: Oil volume fraction contour of inline separator with 2 pairs of side openings
Figure 5: Oil volume fraction contour of inline separator with 3 pairs of side openings
to improve the design with fixed number of side open- openings as the methanol droplet has insufficient cap-
ings. e methods are:
illary pressure to overcome the pressure drop across
750µm side openings increase the purity of the recov-
ered oil to 100%. Further increases inside openings
length will maintain the purity of oil recovered at its
maximum and this can be observed at 1000µm side
openings with 100% recovered oil purity.
1. Increase the side opening’s length.
2. Applied an external resistance on the side open-
ings.
Effect of Side Opening’s Length
Increasing the length of side openings will reduce the
percentage of oil recovered, as part of the oil fraction
has insufficient capillary pressure to overcome the in-
crease in the side opening pressure drop. is can
be shown as the side opening length increases from
500µm to 750µm and 1000µm, the percentage of oil
recovered reduces from 91.3 to 82.9 and 82% respec-
tively.
the improvement of the recovered oil purity as the
length of the side openings is increased. e pressure
drop across the outlet is given by (2) and it shows the
proportionality of the pressure drop and the length
of the channel. By increasing the length of the out-
let channel, the pressure drop across the side open-
ings increases. For methanol to pass through the side
openings, it must have sufficient capillary pressure to
overcome the pressure drop across the side openings.
Effect of External Resistance in the Side
Openings
erefore, by increasing the length of the side open- e purity of recovered oil can be enhanced by apply-
ings, it prevents the methanol from flowing into side ing a resistance in the side openings outlet. By do-
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Science & Technology Development Journal – Engineering and Technology, 4(2):920-931
Table 3: Effect of Side Opening’s Length on Separation Performance
Length of side openings
Percentage of oil recovery Contamination
of Purity of oil recovered (%)
(µm)
(%)
methanol at side openings
500
91.3
82.9
82.0
Yes
No
No
90.1
100
100
750
1000
Figure 6: Oil volume fraction contour of inline separator with 1000µm long of side openings
ing this step, the pressure drop across the side open- be prevented.
ings increases, adding the difficulty for the methanol However, the effect of the external resistance on the
to pass through the side openings. e external re- percentage of oil recovery is similar with cases of in-
creased inside openings length. As the pressure drop
across the side openings increases, portion of the oil
will have insufficient capillary pressure to overcome
the increment in pressure drop. Hence some of the oil
will not be able to flow into the side opening, resulting
in the reduction of the oil recovery percentage.
sistance is represented by the reduction in the width
of the side openings in the simulation. e first pair
of the side openings width is reduced from 250µm
to 150µm. e comparison of the two separators is
From the simulation results (Fig. 7), it proves that
by applying external resistance (reduction in the side
openings’ width) on the side openings, the purity of
the recovered oil increases from 90% to 100%. Pure
product can be obtained through this methodology
and the problem of methanol flowing into the side
openings can be overcome. When external resis-
tance (usually a thin rod) is applied, and inserted into
the side openings, the cross-sectional area of the side
openings decreases. According to (8), the pressure
drop of across the outlet channel is inversely propor-
tional to the width and height of the channel. e
pressure drop of the side openings with applied resis-
tance is larger than the one without. Since the cross-
sectional area of the side openings decreases, the pres-
sure drop across the side openings increases. e
Relationship between the Pressure Drop
and Separation Performance
e pressure drop across the side openings are ob-
tained based on the simulated results of 2 pairs of side
openings inline separator. A graph of separation per-
formance versus the pressure drop of side openings is
plotted (Fig. 8).
Based on the graph plotted it is clearly seen that the
purity of the separation product is proportional to the
pressure drop of the outlet. As the pressure drop of the
side openings increases, the difficulty of the methanol
to enter side opening increases. Hence the methanol
will be separated from the oil phase. e other curve
shows the relationship between the percentage of oil
methanol will need to have higher capillary pressure recovery and the pressure drop of side openings. As
to overcome the large pressure drop. As a result of the pressure drop of the side openings increases, the
this, the flow of methanol into the side openings can lesser the oil being separated as some of the oil has
926
Science & Technology Development Journal – Engineering and Technology, 4(2):920-931
Table 4: Effect of External Resistance on Separation Performance
Width of first pair of side open-
Percentage of oil re- Contamination
of Purity of oil recovered (%)
ings (µm)
covery (%)
methanol at side openings
250
150
91.3
Yes
No
90.1
100
79.4
Figure 7: Oil volume fraction contour of inline separator with resistance
Figure 8: Graph of separation performance vs pressure drop
927
Science & Technology Development Journal – Engineering and Technology, 4(2):920-931
not sufficient pressure to enter the side openings. Less will be evaluated based on the recovered oil product.
oil is being recovered from the system as it retains in
the main outlet and to be discharged together with
methanol. e finding shows the significance of the
pressure drop across the side openings in achieving
microchannel inline separation.
Preliminary study is conducted to identify the suit-
able design for the inline separator. It is proven that
the design with side openings arranged at both sides
of the microchannel gives better separation perfor-
mance than the design with side openings arranged
at one side of the microchannel. e purity of recov-
ered oil is increased by more than 46%. Based on this
observation, the project is continued with selected de-
sign.
Further analysis is carried out on the selected geom-
etry to investigate the effect of number of side open-
ings, effect of side openings’ length and effect of exter-
nal resistance on the separation performance of the
inline separator. It is observed that the highest per-
centage recovery of oil from the mixture that can be
achieved is 91.3%. is method can be achieved by
adding the number of side openings to ensure the
maximum recovery. e oil that is separated by the
inline separator is found to be at 100% purity, which
indicates that no methanol contamination through-
out the separation process.
For the cases where the contamination of methanol
occurred, whereby the methanol is escaping into the
side openings together with the oil phase, this prob-
lem can be overcome by applying larger pressure drop
across the side openings. is methodology can be
achieved by increasing the length of the side openings,
or by applying external resistance in the side open-
ings. e purity of the recovered oil is proved to be
increased up to 100%, whereby all the methanol will
flow through the main outlet.
e project has demonstrated that the separation of
oil-methanol system in microchannel can be achieved
using a higher number of side openings, which is
3 pairs of side openings for the selected oil and
methanol flow rate. e purity of the separated prod-
uct can be increased by manipulating the pressure
drop across the side openings. Hence, it can be con-
cluded that the separation in a large diameter mi-
crochannel system is possible and methodology can
be tuned to achieve the separation goal.
Model Validation Study
In this study, the experimental result from Garstecki
VOF model. e geometry of the microchannel used
in Garstecki et al.’s experiment is a T-junction as
shown in Fig. 9. e diameter of microchannel is 100
mm and the inlet has a width of 50 mm. Oil is used as
the continuous phase and water as dispersed phase.
is to produce different droplet sizes by injecting var-
ious volumetric flow rate ratio between oil and water
into T-junction microchannel. ree different droplet
sizes have been observed in range of the ratio between
the droplet length, Ld, to the channel width, wc. Ta-
all droplet size scenarios.
Fig. 10 shows the simulation results of the droplet
predicted from the VOF model at different volumet-
the Fig. 10 that increasing the oil-to-water ratio leads
to the increase of the droplet size. is finding is in
.
e droplet lengths predicted from the VOF model
viations between the simulation and experimental re-
sults are around 5%. is finding revealed that good
agreement was observed between the simulation re-
sults and the published experimental data.
CONCLUSION
e flow behaviour of two immiscible liquids in mi-
crochannel is studied using the VOF model that is
available in ANSYS Fluent soꢀware. Separation of
two immiscible liquids in the microchannel by us-
ing a large diameter inline separator system is pro-
posed at the earlier stage of the project. By conducting
this study, this project proves that inline separation by
large diameter separator is possible.
e project is done by using the squeezing regime at
the inlet flow, with the velocity of oil phase at 0.00138
m/s and velocity of methanol phase at 0.00214 m/s,
which bring difficulties for the separation as the two
fluids are flowing at a very slow velocity. e main in-
terest of this project is to recover the oil from the mix-
ture, as the oil phase is the main product of the trans-
Finally, the developed VOF model was validated
against a recently published experimental data. e
validation study shows that the present VOF model
had a good agreement with the published experiment.
ACKNOWLEDGEMENTS
We acknowledge the support of time and facili-
ties from Ho Chi Minh City University of Technol-
ogy (HCMUT), VNU-HCM and Universiti Teknologi
esterification. erefore, the separation performance PETRONAS (UTP) for this study.
928
Science & Technology Development Journal – Engineering and Technology, 4(2):920-931
Figure 9: Computational domain of the microchannel is reproduced from Garstecki et al.17 for the model valida-
tion
Droplet name
Droplet size range
Inlet volume flow rate (µL/s)
Water-oil flow rate ratio, Qo/Qw
Qoil
Qwater
0.010
0.025
0.111
Short
Middle
Long
Ld ≤ 2wc
0.028
0.028
0.28
0.36
0.89
0.396
2wc < Ld≤ 6wc
Ld > 6wc
Figure 10: Predictions of droplet at different sizes: (a) short droplet, b) middle droplet and c) long drop
Table 6: Droplet length comparison between simulation and experiment
Droplet name
Droplet length (mm)
VOF model
154
Deviation (%)
Short
Middle
Long
161
4.3
2.4
3.2
214
209
1024
1058
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Science & Technology Development Journal – Engineering and Technology, 4(2):920-931
6. Kashid MN, Renken A, Kiwi-Minsker L.
CFD modelling
LIST OF ABBREVIATION
CSF Continuum surface force
PTFE Polytetrafluoroethylene
VOF Volume of Fluid
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COMPETING INTERESTS
e authors declare that they have no conflicts of in-
terests.
AUTHORS’ CONTRIBUTIONS
e research methodology was conceptually pro-
posed by Chue Cui Ting and Afiq Mohd Laziz. Orig-
inal draꢀ was prepared by Chue Cui Ting. e re-
search was supervised by Khoa Dang Dang Bui, Ngoc
i Nhu Nguyen, Khoa Ta Dang Pha, Ngoc Bui, An
Si Xuan Nguyen, Ngon Trung Hoang, Ku Zilati Ku
Shaari and Loi Hoang Huy Phuoc Pham. All authors
have read and agreed to the published version of the
manuscript.
11. Adamo A, Heider PL, et al.
Membrane-Based, Liquid-
LiquidSeparatorwithIntegratedPressureControl. Industrial&
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Tạp chí Phát triển Khoa học và Công nghệ – Kĩ thuật và Công nghệ, 4(2): 920-931
Bài nghiên cứu
Open Access Full Text Article
Nghiên cứu về thủy động lực học của sự phân tách dòng chảy giữa
hai pha lỏng-lỏng trong vi kênh bằng mô hình tính toán động lực
học chất lưu
Chue Cui Ting1, Afiq Mohd Laziz1, Bùi Đặng Đăng Khoa2,3, Nguyễn Thị Như Ngọc2,3, Tạ Đăng Khoa2,3
Bùi Ngọc Pha2,3, Nguyễn Sĩ Xuân Ân2,3, Hoàng Trung Ngôn2,3, Ku Zilati Ku Shaari1,
Phạm Hoàng Huy Phước Lợi2,3,*
,
TÓM TẮT
Trong những thập niên gần đây, hệ thống vi lưu được dùng nhiều trong các ngành công nghiệp
khác nhau, vì nhờ đặc tính sức căng bề mặt của nó đã giúp cho sự hòa trộn tốt hơn và tăng sự
truyền khối giữa hai chất lỏng không hòa tan. Quá trình tổng hợp diesel sinh học thông qua phản
ứng tổng hợp este của dầu thực vật và methanol trong hệ thống vi lưu nhỏ giọt yêu cầu tách các
sản phẩm sau khi phản ứng xảy ra. Kỹ thuật tách dòng chất lỏng nhiều pha trong hệ thống vi lưu
khác với hệ vĩ mô, do lực hấp dẫn bị lực bề mặt chi phối. Để hiểu rõ hiện tượng này, nghiên cứu về
đặc điểm thủy động lực học của hệ thống dầu-methanol trong vi kênh đã được thực hiện. Mô hình
thể tích chất lỏng nhiều pha đã được phát triển để dự đoán dòng chất lỏng trong vi kênh. Một bộ
tách nội tuyến đã được thiết kế cùng với biến số của nó để có được sự phân tách hiệu quả cho hệ
thống dầu-methanol. Hiệu suất của quá trình phân tách đã được đánh giá dựa trên lượng dầu thu
hồi và độ tinh khiết của nó. Độ chính xác của mô hình đã phát triển đã được xác nhận thông qua
việc so sánh kết quả mô phỏng với số liệu thực nghiệm đã công bố. Độ tinh khiết của dầu thu hồi
đã được dự đoán tăng hơn 46% khi thiết kế với các lỗ ra được bố trí ở cả hai bên của vi kênh. Tỷ
lệ phần trăm thu hồi cao nhất của dầu từ hỗn hợp được mô phỏng ở mức 91,3% bằng cách tăng
số lượng lỗ ra ở hai bên để đảm bảo thu hồi tối đa. Dầu được tách bằng thiết bị tách nội tuyến
được dự đoán là có độ tinh khiết 100%, điều này cho thấy rằng không có nhiễm methanol trong
suốt quá trình tách. Độ tinh khiết của sản phẩm tách có thể được tăng lên bằng cách điều chỉnh
độ giảm áp suất trên các lỗ ra. Do đó, có thể kết luận rằng việc phân tách trong một hệ thống vi
kênh có đường kính lớn là có thể thực hiện được và phương pháp này có thể được điều chỉnh để
đạt được mục tiêu phân tách. Cuối cùng, kết quả mô phỏng cho thấy mô hình thể tích chất lỏng
này phù hợp với thí nghiệm đã công bố.
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1Khoa Kỹ thuật Hóa học, Trường Đại
học Kỹ thuật Petronas, 3260 Seri
Iskandar, Perak, Malaixia
2Khoa Kỹ thuật Hóa học, Trường Đại
học Bách Khoa TP. Hồ Chí Minh, 268 Lý
ường Kiệt, Quận 10, ành phố Hồ
Chí Minh, Việt Nam
3Đại học Quốc gia ành phố Hồ Chi
Minh, Phường Linh Trung, Quận ủ
Đức, ành phố Hồ Chi Minh, Việt Nam
Từ khoá: vi kênh, tách chất lỏng không hòa tan nhau, tính toán động lực học chất lưu, mô hình
thể tích chất lỏng, nhiều pha
Liên hệ
Phạm Hoàng Huy Phước Lợi, Khoa Kỹ
thuật Hóa học, Trường Đại học Bách Khoa TP.
Hồ Chí Minh, 268 Lý Thường Kiệt, Quận 10,
Thành phố Hồ Chí Minh, Việt Nam
Đại học Quốc gia Thành phố Hồ Chi Minh,
Phường Linh Trung, Quận Thủ Đức, Thành
phố Hồ Chi Minh, Việt Nam
Email: phhloi@hcmut.edu.vn
Lịch sử
• Ngày nhận: 27-02-2021
• Ngày chấp nhận: 26-4-2021
• Ngày đăng: 09-5-2021
DOI : 10.32508/stdjet.v4i2.810
Trích dẫn bài báo này: Ting C C, Laziz A M, Khoa B D D, Ngọc N T N, Khoa T D, Pha B N, Ân N S X, Ngôn H
T, Shaari K Z K, Lợi P H H P. Nghiên cứu về thủy động lực học của sự phân tách dòng chảy giữa hai pha
lỏng-lỏng trong vi kênh bằng mô hình tính toán động lực học chất lưu. Sci. Tech. Dev. J. - Eng. Tech.;
4(2): 920-931.
931
12 trang
18/04/2022
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