iv
A STUDY ON THE EFFECTIVENESS OF IN-SITU HIGH INTENSITY
ULTRASONIC (HIU) IN INCREASING THE RATE OF FILTRATION
IN PALM OIL REFINING INDUSTRIES
AHMAD ZIAD BIN SULAIMAN
A thesis submitted in fulfilment of the
requirements for the award of the degree of
Master of Engineering (Chemical)
Faculty of Chemical and Natural Resources Engineering
Universiti Teknologi Malaysia
MARCH 2005
vi
“Dengan nama Allah yang Maha Pemurah lagi Maha Penyayang. Selawat dan Salam
ke atas junjungan besar Nabi Muhammad S.A.W.”
“Specially dedicated to my wife and mum, sister, brothers and all of my friends.”
vii
ACKNOWLEDGMENT
I would like to express my sincere appreciation and thanks to my main thesis
supervisor Associate Professor Dr. Rosli Mohd Yunus and co-supervisor,
Associate Professor Dr. Radzuan Junin for their guidance, precious advices,
critics, friendship and continuous support throughout this study.
I am grateful to all staff and researchers at Faculty of Chemical & Natural
Resources Engineering, Research Management Center (RMC), Felda Oil Product
(FOP) Pasir Gudang, Mr Ng Beng Hooi from Crest Ultrasonic for supplying the
ultrasonic systems and providing the technical advices, Professor Dr Hathaichanok
Duriyabunleng from University of Chulalangkorn Bangkok , Mr Choo Chee Wei
from PINTAS IP, Puan Sharifah Bt Hashim and my friends who cheered up my life.
I am owing a special debt of gratitude for the financial support by Ministry of
Science, Technology and Innovation Malaysia (MOSTI) under the scholarship of
National Science Fellowship Scheme (NSF) and IRPA grant project.
Lastly, I wish to express my unlimited appreciation to my beloved wife and
my family for their irreplaceable encouragement, undying love and prayers. To my
mum for her infinite patience, sacrifice and understanding during the years of this
study.
Above all, I thank God the almighty for his grace, mercy and guidance which
enable the successful completion of this study.
viii
ABSTRACT
Application of ultrasound wave fields in the filtration and separation
technology is a new and clean technology and offers an attractive alternative to the
classical cleaning processes. Fouling phenomenon is a major bottleneck in this
separation technology, as expected in the industrial application of such finely porous
media. As the filtration process continues, the concentration of solute keeps building
up on the filter surface to form a filter cake. This results in a continuous decline of
the flux. In this study, the effect of intermittent application of ultrasound wave fields
on the filtration of bentonite in Refined Bleached Deodorized (RBD) oil suspension
is presented. In general, the intermittent application of ultrasound fields increased the
overall flux of the filtration. The main mechanism responsible in reducing the
thickness of the filter cake, and hence increasing the rate of filtration, is the
cavitation phenomenon. Four parameters affecting the ultrasound assisted filtration
were investigated. The parameters include the filtration cycle time, sonication cycle
time, applied pressure, and ultrasound intensity. The highest percentage of
improvement achieved in the study was 88.47%, conducted at 5 minutes filtration
cycle time and 12 minutes sonication cycle time. The result also showed that the
degree of flux improvement was initially increased with the increase in the applied
pressure. However, as the pressure was further increased, compaction of cake layer
took place which constricted the filtrate path, and hence, reduced the degree of flux
improvement. On the other hand, the degree of flux improvement was linearly
related to the ultrasound intensity. In this study, the highest flux was obtained when
the ultrasound intensity was set at 1.2109 W/cm2. An Ultrasonic Clean-in-Place
(UCIP) method of cleaning the filtration system was also developed in this study.
The UCIP method showed an effective method of cleaning, with 71.5% flux
recovery achieved after only 15 minutes of UCIP cleaning processes. Empirical
models were developed in this study to represent the profile of the filtration process.
The developed model showed good fits with the experimental data, with error not
more than 5%.
ix
ABSTRAK
Penggunaan medan gelombang ultrabunyi di dalam teknologi penurasan dan
pemisahan adalah baru dan teknologi pembersihan menawarkan alternatif kepada
pembersihan secara klasik. Fenomena Penyumbatan adalah gangguan terbesar di
dalam teknologi pemisahan ini. Semasa proses penapisan berterusan, kepekatan
daripada suspensi akan membentuk lapisan kek di atas permukaan penapis dan ini
menyebabkan penurunan kepada fluks secara berterusan. Di dalam kajian ini, kesan
sela pengaplikasian gelombang ultrabunyi ke atas penapisan lumpur teraktif di dalam
penapisan, pelunturan dan penyahbauan (RBD) suspensi minyak adalah diterangkan.
Secara umum, pengaplikasian gelombang daya ultrabunyi bersela meningkatkan
keseluruhan fluks di dalam penapisan. Mekanisma utama yang bertanggungjawab di
dalam mengurangkan ketebalan kek dan seterusnya meningkatkan kadar penapisan
adalah fenomena peronggaan. Empat parameter yang memberi kesan kepada
penapisan berbantukan ultrabunyi telah dikaji. Parameter itu termasuk kitaran masa
penapisan, kitaran masa sonikasi, kesan tekanan dan keamatan ultrabunyi. Peratus
tertinggi peningkatan kadar penurasan yang dicapai di dalam kajian ini adalah
88.47% yang dijalankan pada 5 minit kitaran masa penapisan dan 12 minit kitaran
masa sonikasi. Keputusan juga menunjukkan bahawa darjah pembaikan fluks telah
pada awalnya meningkat dengan peningkatan di dalam kesan tekanan. Oleh sebab
itu, apabila tekanan ditingkatkan kek akan menjadi padat. Seterusnya, darjah
pembaikan fluks akan berkurang. Sebaliknya, darjah pembaikan fluks dihubungkan
secara linear terhadap keamatan ultrabunyi. Di dalam kajian ini, fluks tertinggi yang
dicapai apabila keamatan ultrabunyi telah disetkan pada 1.2109 W/cm2. Kaedah
sistem penapisan Pembersihan Setempat Ultrabunyi (UCIP) juga telah dibangunkan
di dalam kajian ini. Kaedah UCIP menunjukkan keberkesan kaedah pembersihan
dengan 71.5% mendapat kembali fluks yang dicapai selepas hanya 15 minit proses
pembersihan UCIP. Model empirik telah dibangunkan di dalam kajian ini untuk
mewakili profil proses penapisan. Model yang dibangunkan menunjukkan
kesesuaian yang baik dengan data eksperimen dengan ralat tidak melebihi 5%.
x
TABLE OF CONTENTS
CHAPTER TITLE PAGE
1 INTRODUCTION 1
1.1 Objective of Study 5
1.2 Scopes of Study 5
1.3 Contribution of Study 6
2 LITERATURE REVIEW
2.1 Basic Theory of Filtration 7
2.1.1 Cake Accumulated on the Filter Surface 9
2.1.2 Constant-Pressure Filtration 12
2.2 History of Palm Oil 14
2.3 Overview of the Malaysian Palm Oil Industry 15
2.4 Palm Oil Refinery Processing 16
2.4.1 Palm Oil Degumming 17
2.4.2 Palm Oil Bleaching (Adsorption Clay) 17
2.4.3 Filtration 21
2.5 Pressure Leaf Filter 21
2.5.1 Working Principle of Pressure Leaf Filter 22
2.5.2 Designation of Pressure Leaf Filter 22
2.5.3 Application and Importance 25
2.6 Filter Characterization 26
2.7 Causes of Flux Decline 28
2.7.1 Definition of Flux 29
2.8 Methods of Solving Flux Decline Phenomena 30
xi
2.8.1 Sample Pretreatment 30
2.8.2 Cake Treatment 30
2.8.3 Filtration Aid 31
2.8.4 Ultrasonic Field Assisted 31
2.9 Conventional Cleaning Method for Leaf Filter
in RBD Palm Oil 33
2.10 Clean-In-Place (CIP) 34
2.10.1 Historical Background 35
2.10.2 Types of CIP System 36
2.11 Theory of Sound Waves 36
2.12 Classification of Sound Waves 39
2.13 Parameters of Sound 41
2.14 Ultrasound 41
2.15 Piezoelectric Transducer (PZT) 42
2.15.1 Physical Effects of Power Ultrasound 43
2.15.2 Cavitation 43
RESEARCH METHODOLOGY
3 METHODOLOGY 45
3.1 Introduction 45
3.2 The Sound Generating Equipment 46
3.2.1 The Power Generator 48
3.2.2 The Genesis Piezoelectric (PZT)
Transducers 49
3.3 Feed Sample Preparation 49
3.4 Experimental set-up and Equipment 50
3.5 The Filters and Ultrasonic Filtration Vessel 52
3.6 Design of Research Work 54
3.6.1 Experimental procedure for
Baseline determination 54
3.6.2 Experimental method to determine
xii
the effectiveness of in-situ ultrasonic
assisted system in increasing the rate
of filtration. 57
3.6.3 Experimental Procedure to determine
the effectiveness of Ultrasonic Clean In
Place (CIP) in comparison to conventional
cleaning method. 58
3.6.3.1 Filtration Experiment Using
Clean Oil 60
3.6.3.2 Cleaning Experiment by UCIP 60
3.6.4 Development of an empirical model of
in-situ ultrasonic assisted filtration system 61
4 MODELLING & SIMULATION 62
4.1 Introduction 62
4.2 Analysis on Total Volume of Filtration 63
4.2.1 Step of Analysis in Microsoft Excel 2000 63
4.3 Analysis on the Difference Between Initial and
Final Filtrate Flow Rate 65
4.3.1 Step of Analysis in Microsoft Excel 2000 65
4.4 Analysis on Comparative Error Between the Data 66
4.4.1 Step of Analysis in Microsoft Excell 2000 67
5 RESULTS & DISCUSSION 68
5.1 Experimental Data for Baseline Determination 69
5.2 The Effectiveness of In-Situ Ultrasonication in
increasing the Rate of Filtration 70
5.2.1 Effect of Sonication Cycle Time 70
5.2.2 Effect of Filtration Cycle Time 82
5.2.3 Effect of Applied Pressure 88
5.2.4 Effect of Ultrasound Intensity 92
xiii
5.2.5 Effect of Ultrasonic Application on the
Spesific Cake Resistance ( 95
5.3 Ultrasonic-Clean-In-Place (UCIP) of Stainless
Steel Pressure Leaf Filter Fouled by palm Oil
Suspension 98
5.4 Modelling of Filtration Process 100
5.4.1 Analysis on the Error between the
Tabulation of Data between Empirical
Model and Experimental Result 101
5.4.2 Analysis on the Effect of Sonication in
Terms of Varying Pressure 102
5.4.3 Results on Data Retrofitting Approach 103
6 CONCLUSION AND RECOMMENDATIONS 108
REFERENCES 111
PUBLICATIONS 116
PATENT 117
PROJECT FUNDING 118
APPENDICES 119
xiv
LIST OF TABLES
TABLE TITLE PAGE
2.1 Typical properties of adsorption clays 18
2.2 Categories of filter characterization 27
3.1 A summary of the operating conditions of the experiments 54
3.2 Combinations of sonicated and un-sonicated filtration
intervals
57
5.1 Percentage of flux increment as a function of sonication cycle
time at 5 minutes filtration cycle time. 75
5.2 Percentage of flux increment as a function of sonication
cycle time at 8 minutes filtration cycle time. 77
5.3 Percentage of flux increment as a function of sonication cycle
time at 10 minutes filtration cycle time. 78
5.4 Percentage of flux increment as a function of sonication
cycle time at 12 minutes filtration cycle time. 79
5.5 Least square regression data points of all the sets of filtration
cycle time 81
5.6 The percent increment (%) of Sonication at 40 kHz in filtration
of activated clay in oil suspension (Comparison between
5 minutes F , 8 minutes F , 10 minutes F and 12 minutes F in
4 minutes sonication cycle) 83
5.7 The percent increment (%) of Sonication at 40 kHz in filtration
of activated clay in oil suspension (Comparison between
xv
5 minutes F , 8 minutes F , 10 minutes F and 12 minutes F in
8 minutes sonication cycle) 84
5.8 The percent increment (%) of Sonication at 40 kHz in filtration
of activated clay in oil suspension (Comparison between
5 minutes F , 8 minutes F , 10 minutes F and 12 minutes F in
12 minutes sonication cycle) 85
5.9 Least square regression data points of all the sets of
sonication cycle time 87
5.10 The summary of percentage of flux improvement for all the
investigated applied pressures 92
5.11 The summary of percentage of flux improvement for all the
investigated ultrasound intensities 94
5.12 Value for for each condition 97
5.13 The summary of the cleaning performance 100
5.14 Results on the Analysis on the percentage of error between
the tabulation of data between empirical model and
experimental results. 102
5.15 Results on the analysis on the effect of sonication in terms of
varying pressure. 103
xvi
LIST OF FIGURES
FIGURE TITLE PAGE
2.1 Schematic Diagram of Porous Media 8
2.2 Proportional relation between pressure drop and flow rates
of clean liquid flowing through fixed porous media
9
2.3 Section through a filter cake 10
2.4 Determination of constants in a constant-pressure filtration
run
14
2.5 The Typical Flow Chart for the Palm Oil Process 20
2.6 Typical pressure leaf filter used in the vegetable oil
industry
22
2.7 Filtration elements used in an automatic Niagara Leaf
Filter
23
2.8 The design of stainless steel filtration mesh 24
2.9 Rings for Metafilter 24
2.10 Vertical arrangement of pressure leaf filter 25
2.11 Horizontal arrangement of pressure leaf filter 26
2.12 A Schematic presentation of the three stages in flux
decline: (1) Initial rapid drop from the flux of pure water
filtration: (II) long-term gradual flux decline: and (III)
time independent steady-state flux 28
2.13 Steps of conventional cleaning for leaf filter in Palm Oil
Process (Cleaning By Rinsing and Recirculation) 34
2.14 The coils of a spring to represent individual molecules of a
sound conducting medium 37
2.15 Wave and particle movement 38
xvii
2.16 An acoustic spectrum illustrating the range of frequencies
of mechanical waves and some of their common sources
of generation of application 40
2.17 Mechanism of bubble growth followed by its collapse
during cavitation induced by ultrasound 44
3.1 Schematic diagram of the ultrasonic generating system 47
3.2 Genesis ultrasonic generator (front & rear) with adjustable
output power intensity control. 48
3.3 The flow process for the preparation of the feed sample
Schematic 50
3.4 Diagram and of the experimental setup for Niagara Leaf
Filter.
51
3.5 The Lab Scale Design of Niagara Leaf Filter 52
3.6 Cross-sectional of Ultrasonic Filtration Vessel view (top
view, front view, side view) and method of bonding the
transducers on to the system.
53
3.7 Flow Chart of the Filtration Experimental 55
3.8 The flow chart of the filter leaf cleaning method 56
3.9 Flow process of Conventional and In-situ Cleaning
Method
59
4.1 Flowchart of the modeling methodology on the total
volume of filtrate. 64
4.2 Flowchart of the modeling methodology of analysis on the
difference of initial and final filtrate flow rate 65
4.3 Flowchart of the modeling methodology of analysis on
comparative error between the data 67
5.1 Typical curve of filtrate flux versus filtration time in the
filtration of Activated Clay from RBD Oil. 69
5.2 Intermittent application of ultrasound field in filtration
process 71
5.3 a) Scanning electron micrograph (x400) of cake structure
after 10 minutes filtration (before ultrasonication) 72
5.3 b) Scanning electron micrograph (x400) of cake structure
xviii
after Ultrasonication 72
5.4 Effect of varying the sonication cycle time. 73
5.5 The effect of varying the sonication cycle time on the
filtration of activated clay in oil suspension (at filtration
cycle time of 5 min). 75
5.6 The effect of varying the sonication cycle time on the
filtration of activated clay in oil suspension (at filtration
cycle time of 8 min) 77
5.7 The effect of varying the sonication cycle time on the
filtration of activated clay in oil suspension (at filtration
cycle time of 10 min). 78
5.8 The effect of varying the sonication cycle time on the
filtration of activated clay in oil suspension (at filtration
cycle time of 12 min). 79
5.9 Summary of equilibrium flux increment as a function of
Sonication Cycle Time for various Filtration Cycle Time. 81
5.10 Sonication at 40 kHz in filtration of activated clay in oil
suspension (Comparison between 5 minutes F , 8 minutes
F , 10 minutes F and 12 minutes F in 4 minutes sonication
cycle)
83
5.11 Sonication at 40 kHz in filtration of activated clay in oil
suspension (Comparison between 5 minutes F , 8 minutes
F , 10 minutes F and 12 minutes F in 8 minutes sonication
cycle)
84
5.12 Sonication at 40 kHz in filtration of activated clay in oil
suspension (Comparison between 5 minutes F , 8 minutes
F , 10 minutes F and 12 minutes F in 12 minutes
sonication cycle)
85
5.13 Summary of equilibrium flux increment as a function of
Filtration Cycle Time for various Sonication Cycle Time. 87
5.14 Graph of Flux vs Filtration Time For the Pressure Range
between 3 – 6 bars (without sonication) 89
5.15 Graph of Flux vs. Filtration Time with Pressure at 3 bars 89
xix
5.16 Graph of Flux vs. Filtration Time with Pressure at 4 bars 90
5.17 Graph of Flux vs. Filtration Time with Pressure at 5 bars 90
5.18 Graph of Flux vs. Filtration Time with Pressure at 6 bars 91
5.19 Graph of Flux vs Filtration Time For the Intensity Range
between 0.2422 W/cm2 - 1.2109 W/cm2 93
5.20 The percentage of flux improvement as function of
ultrasoundintensity 94
5.21 Graphical determination of constants in a constant-
pressure filtration run without the application of ultrasonic
wave
95
5.22 Graphical determination of constants in a constant-
pressure filtration run with the application of ultrasonic
wave at optimum condition (5f:12s) 96
5.23 Graphical determination of constants in a constant-
pressure filtration run with the application of ultrasonic
wave at lowest condition (12f:4s) 96
5.24 Influence of sonication exposure time on flux recovery in
the cleaning-in-place of fouled filter (10 minutes
sonication exposure time) 99
5.25 Influence of sonication exposure time on flux recovery in
the
cleaning-in-place of fouled filter (15 minutes sonication
exposure time)
99
5.26 The combination of the influence of sonication exposure
time on flux recovery in the cleaning-in-place of fouled
filter (x) clean filter level; ( ) 15 minutes sonication; ( )
10 minutes sonication; (X) cleaning without ultrasound 100
5.27 Sample graphical result of comparison between empirical
model an experiment results. 104
5.28 Sample graphical result of comparison between the effect
of sonication. 104
5.29 Kp vs influencing factor of pressure(bar) 105
xx
5.30 Ki vs influencing factor of intensity of ultrasonic
wave(W/cm2) 106
5.31 Ks vs influencing factor of sonication time(minute) 106
xxi
LIST OF SYMBOLS
˚C - Degree Celsius
P - Pressure Drop
A - Cross-sectional area
CPO - Crude Palm Oil
F - Frequency
G - gram
HIU - High Intensity Ultrasonic
I - Intensity (W/m2)
In - inches
Kg - Kilogram
KHz - Kilohertz
L - Bed Depth
MPOB - Malaysian Palm Oil Board
Pa - Pressure in Pascal
PZT - Piezoelectric Ceramic Transducer
RBD - Refined, Bleached and Deodorized
S - time in second
So - Specific surface area
UCIP - Ultrasonic Clean In Place
Uo - Superficial velocity
V - Filtrate volume
W - Watt
- Specific cake resistance (m/kg)
- Porosity
µ - Liquid viscosity
µm - Micrometer
- Density (kg/m3)
xxii
LIST OF APPENDICES
APPENDIX TITLE PAGE
A Technical Specifications 119
B Experimental Data (Sonication & Filtration Cycle) 125
C Experimental Data (Pressure & Power Intensity) 152
D Saw Teeth Graph Of Sonication & Filtration Cycle Time 166
E Data of Empirical Model 173
1
CHAPTER 1
INTRODUCTION
Palm oil industry has been the bread and butter of Malaysian industry ever since
palm tree was brought into the country in the 1960’s. The fast growth of this industry
has made Malaysia to be the largest producer of palm oil for many years. Palm tree is
easily grown in tropical climate countries. Hence, the profitable industry has been
adopted by neighboring countries such as Thailand, Indonesia, Vietnam, Cambodia, as
well as Philippines. Realizing the competitiveness of the industry and the advantages of
neighboring countries with large cultivating land, much research has been focused on
improving the overall operation of the industry so as to increase its productivity.
In any chemical and oleochemical industry, separation processes are of key
importance, whether it is a minor or the main part of operation. Choosing the best
separation method for the job is crucial to ensure economic operation. Filtration, for
instance, is a typical solid-liquid separation technique commonly used in the industry. It
is preferred from other solid-liquid separation techniques because it offers low
investment costs, easy to scale up, long lifespan of the filters because of mild operation
conditions, compact construction and fast, easy to make installation, low energy, and
low chemical consumption.
2
In the edible/vegetable oil industry, filtration is an important unit operation for
the separation of bleaching earth from the treated oil. In this process, pressure leaf filters
are most commonly used for this purpose.
During operation, the rate of filtration decreases progressively as a result of
filter cake build-up on the surface of the filter medium. The process comes to an end
when the whole chamber is filled with solids, normally about 2 ½ hours (for standard
size filter) after separating 500 kg of solids from the treated oil. The separating system
requires a regeneration process, which normally takes about 1½ hours. The sequence of
filtration and regeneration process is repeated for approximately two to three weeks,
depending on the condition of the filter medium, before a thorough cleaning method is
conducted. The conventional cleaning of the filter leafs include disassembling of the
filter unit, immersing the filter leafs in caustic solution, followed by high pressure water
cleaning (60- 90 bar) and steam cleaning. The total downtime from disassembling,
cleaning, up till assembling of the filter system averages about 2 days. The implication
of long downtime period in the plant operation is its higher operation and capital cost in
which the plant has to invest on the standby filter unit and on the cleaning operation.
Presently, there has not been much work focusing on developing methods to
improve the filtration process. Improvement in the rate of filtration, for instance, will
reduce the operation time, and hence, increase the productivity. The present method of
knocking or vibrating the filter leaf is only applicable after the filtration process is
completed, i.e. during the regeneration of the filter medium. Vibrating or knocking the
filter leaf during the filtration is not adopted because it may disrupt the whole formation
of the filter cake. This is not acceptable since in filtration processes, filter cake is the
true medium performing the solid-liquid separation.
Upon close examination of the filtration process, the main problem which
dominates in reducing the flux during the filtration process is the fouling phenomenon.
Fouling refers to a combination of flux reducing factors which include the blinding of
3
filter medium as a result of particles retained on the filter surface as liquid passes
through the filter medium, cake formation, and the formation of concentrated layer near
the filter surface. Many methods have been proposed to reduce fouling. In general, the
methods include sample pretreatment, filter pretreatment, abrasives, filtration aids, back
flushing, baffling and oscillatory flow techniques, electric field assisted and ultrasonic
field assisted.
The common method used to secure high filtration rate is by pretreating the feed
solution before entering the filtration system. The method employs flocculating agent,
causing particles to agglomerate into larger entities, thereby preventing them from
penetrating inside the pores. Hence, a greater filtrate flux can be achieved during
filtration. Another method of reducing the fouling phenomenon is by modification of the
filter surface properties. Surface characteristics and filter morphology have a
considerable effect on the adsorption of solution and, as a result on the separation. The
addition of filtration aid to the feed stream prior to filtration of a suspension increases
the filtration rate by modifying the porosity of the filter cake and the particle size
distribution which increases its permeability. A common type of filtration aid is
diatomaceous earth but the fact that the filtration aid should be retrieved in the blow-
down of the stream to be recycled makes this technique rather difficult to apply. This
technique is more suitable for dead-end filtration operation, particularly the conventional
filtration such as plate and frame filter press, leaf filter, vacuum belt filter etc.
There are reports of the use of abrasive materials, added to the mixture in order
to disrupt the layer on the surface of the filter. Another method of reducing the fouling
phenomenon is baffling and oscillatory flow techniques. These techniques are to
promote and/or increase turbulent condition near the filter surface. These techniques also
have been used by several workers in order to improve the filtration flux. The presence
of the baffle resulted in a radial flow inside the filter, and hence, the path length was
increased. However, these methods are more suitable in membrane filtration rather than
in the conventional filtration since they require crossflow mode of filtration to cause the
sweeping action on the filtering surface. Back-flushing technique is an effective method
4
to remove fouling layer from the filtering surface. In this method, the filtrate is
negatively pressured to force the liquid to flow back into the system through the filter
medium. The back flushing will cause the cake to break/disrupt and forces the particles
to reenter the bulk suspension. However, the total disruption of the cake during the
filtration operation is not wanted in the conventional filtration since in this kind of
filtration, the cake layer is the true medium which performs the separation.
The application of ultrasound wave fields in filtration operation, particularly
membrane filtration, has been identified as a new and clean technology and as an
alternative to the classical cleaning. The use of ultrasound fields in the control of filter
fouling and filter cake formation, especially in the membrane filtration, has been studied
and proven by a number of researchers. The application of ultrasound wave field in
membrane filtration processes was found to improve the rate of filtration and reduce the
rate of filter fouling. Nevertheless, the technique has not been applied in the
conventional filtration operation, especially in leaf filtration processes, to increase
productivity.
The suitability of each method used in solving the flux decline phenomenon
depends on the qualities of the foulants as well as the nature of the filter. The economic
and production demands must also be considered in choosing the appropriate method of
solution. Another important consideration is the fact that in pressure leaf filter operation
a minimal layer of filter cake is required to achieve good separation of solid-liquid
suspension. Thus, the acquired technique must be able to reduce the fouling
phenomenon without losing the efficacy of the filtration.
Realizing the capability of ultrasound wave fields in cleaning processes, the
technique was studied in this research to increase the rate of filtration of leaf filter. The
application of high intensity ultrasound in the solid-liquid suspension would cause the
occurrence of cavitation microbubbles in the liquid medium which is responsible in
5
removing particles especially at the interface between the liquid and solids in the
suspension.
1.1 Objectives of Study
The objective of the research is to investigate:
i) The possibility of intensifying the filtration operation,
ii) Increasing the rate of filtration,
iii) Reducing the downtime, by means of Ultrasound Wave Fields.
1.2 Scopes of Study
To achieve the objectives, four scopes have been identified in this research. The scopes
of this research are listed as below:
1.2.1 To study the effectiveness of In-Situ ultrasonic cleaning system in increasing the
rate of filtration of bleaching earth suspension. Several experimental works were
carried out to examine the behavior of the filtration in the presence of ultrasound
field.
1.2.2 To identify the optimum combination of filtration cycle time and sonication
cycle time which give the highest flux increment. The rate of filtration was
influenced by the filtration time and by the duration of ultrasound exposure.
Thus, research was carried out to determine the optimum condition of the two
parameters.
6
1.2.3 To study the effect of ultrasound intensity on the degree of flux increment.
The degree of flux increment was also influenced by the intensity of the
ultrasound field. This study established the optimum ultrasound intensity to be
used for the system which results in the best flux improvement.
1.2.4 To study the effectiveness of ultrasonic Clean-In-Place (CIP) method in
comparison to Conventional method. A Clean-In-Place method was developed in
the research study to clean the filter leaf and the filtering chamber without
having to disassemble the filtration system. This scope of study compares the
effectiveness of the developed method, with the conventional method of
cleaning.
1.2.5 Development of an empirical model. From the results gathered in this study,
analysis of transport processes taking place in the separation of spent bleaching
earth from oil suspension was undertaken. An empirical model was developed
which enable the prediction of filtration rate as a function of various parameters.
1.3 Contribution of the study
A positive outcome from the research would bring a new dimension to related
industries in improving the rate of production due to an effective and efficient high
intensity ultrasonic cleaning and process design for the purpose of In-situ cleaning
method, a demonstration process plant, application of advance technology in high
intensity ultrasonic cleaning and at the same time offering potential savings in the
operational costs.
112
REFERENCES
Anton Puskar. (1982). “ The Use of High Intensity Ultrasonics”. New York U.S.A:
Elsevier Scientific Publishing Company, Inc. 30 – 55
Bernardini, E. (1983). “ Oil Seeds, Oils and Fats: Oils and Fats Processing Volume II”.
Rome, Italy: Publishing House Via Failla 63.
Christopher Dickenson. (1992). “Filters and filtration handbook”. 3rd ed. Oxford :
Elsevier Advanced Technology.
Coulson, J.M. and Richardson, J.F.(1991) “Chemical Engineering, Vol. 2. Fourth Ed.,
“Particle Technology and Separation Processes”, Pergamon Press. 282-335
Dahnke S., Swamy .K.M., Keil F.J. (1999). “ A comparative study on the modeling of
sound pressure field distributions in a sonoreactor with experimental investigation”
Journal of Ultrasonics Sonochemistry. Vol. 6. 221-226.
Dahnke S., Swamy K.M., Keil F.J. (1999). “ Modelling of three-dimensional pressure
fields in sonochemical reactors with an inhomogeneous density distribution of
cavitation bubbles. Comparison of theoretical and experimental results” Journal of
Ultrasonics Sonochemistry. Vol. 6. 221-226.
113
Dale Ensminger . (1973). “Ultrasonics-The Low and High Intensity Applications”.
Marcel Dekker,Inc. New York. 423-427.
Dezhkunov N.V. (2002). “ Multibubble sonoluminescence intensity dependence on
liquid temperature at different ultrasound intensities”. Journal of Ultrasonics
Sonochemistry. Vol. 9 103-106
Elliot Goldberg. (1997). “Handbook of Downstream Processing”, Lockwood Green
Engineers, Inc., New York. 318-334
Farmer A.D., A.F. Collings, G.J. Jameson (2000). “Effect of ultrasound on surface
cleaning of silica particles” International Journal of Mineral Processing. Vol.60.101-
113
Geankoplis, C.J. (1995). “Transport Processes and Unit Operations”. 3rd ed. Singapore:
Prentice Hall Simon & Schuster (Asia) Pte. Ltd. 800 – 840
John Fuchs. F.. (2002). “Ultrasonic Cleaning: Fundamental Theory & Application”.
http://www.variclean.nl / theory.html. Jamestown, NY 14701.
Karleskind, A. (1996). “ Oils and Fats Manual: A Comprehensive Treatise (Properties-
Production-Applications) Volume 2”. New Jersey U.S.A : Intercept Ltd. 807 – 893
Mason, T.J. (1990). “ Sonochemistry: The Uses of Ultrasound in Chemistry”. Royal
Society of Chemistry, Germany
114
Mason, T.J. (1995). “Ultrasonic Intensification of Chemical Processing and Related
Operations”. Proceeding of The First International Conference on Science,
Engineering and Technology of Intensive Processing, 18-20th September 1995,
Nottingham, UK.
Ramlan A. Aziz, Hamdani Saidi et al. (1989). “ Initial Study on Crude Palm Oil
Filtration”. One day Seminar on The Latest Development in Filtration Technology,
Filtech ’89.
Riera E. -Franco de Sarabia, et. Al. (2000). “ Application of high-power ultrasound to
enhance fluid/solid particle separation processes”. Journal of Ultrasonics. Vol. 38.
642-646.
Rushton A., A.S. Ward, R.G. Holdich. (1996). “Solid-Liquid Filtration and Separation
Technology”. 1st ed. VCH Publishers, Inc., New York, NY (USA). 33-77
Rushton A., A.S. Ward, R.G. Holdich. (1996). “Solid-Liquid Filtration and Separation
Technology”. 1st ed. VCH Publishers, Inc., New York, NY (USA). 397 – 478
Sa’ari Mustapha, Yahya Sukirman. (1996). “ Mathematical Modelling of Coupling Flow
and Cake Formation in Filtration Process”. Proceedings Volume 1: 7th World
Filtration Congress Budapest, Hungary. Hungarian Chemical Society.
Sukti Majumdar, P. Senthil Kumar, A.B. Pandit. (1998). “ Effect of liquid-phase
properties on ultrasound intensity and cavitational activity” Journal of Ultrasonics
Sonochemistry. Vol. 5. 113-118.
115
Sulaiman A.Z., Yunus, R.M. (2001) “Intensified Niagara Leaf Filtration Via In-Situ
Ultrasonic wave Fields.” Symposium of Malaysian Chemical Engineers (SomChe)
Johor Bahru, Malaysia.
Sulaiman A.Z,Yunus, R.M.Radzuan Junin.(2001) “Development of High Intensity
Ultrasonic (HIU) for Stainless Steel Filter Leaf Cleaning.” Regional Symposium on
Chemical Engineering (RSCE), Institute Technology Bandung, Indonesia
Sulaiman A.Z,Yunus, R.M., H. Abdullah (2002), “ Modelling of Ultrasonic in
Increasing The Rate of Filtration in Palm Oil Industry. World Engineering Congress
(WEC) Kuching Sarawak
Tsochatzidis N.A., Guiraud. P., Wilhelm. A.M., Delmas .H.. (2001). “ Determination of
velocity, size and concentration of ultrasonic cavitation bubbles by the phase-
Doppler Technique” Journal of Chemical Engineering Science. Vol. 56. 1831-1840.
Veldkamp F.G. (1987). “Paper On The Various Filtration Steps In Edible/Vegetable Oil
Processing”, Symposium Of Oil Processing, Curacao/Na
Wakeman, R.J (1982), “Effect of Solids Concentration and pH on Electrofiltration.”
Filtration and separation, pp 316-319
Wakeman, R.J and Tarleton, E.s (1987), “Membrane Fouling Prevention in Crossflow
Microfiltration by the Use of Electric Fields.” Chem. Eng.Sci.,Vol 42,No4, pp 829-
842.
Wakeman, R.J and Tarleton,E.S (1986), “Membrane Filtration”, Filtration and
Separation, pp 174-176
116
William, A.R (1983), “Ultrasound : Biological Effects and Potential Hazards” Medical
Physics Series, Academic Press.
Yunus, R.M. (1996). “Ultrasound Fields In Crossflow Microfiltration”, Ph. D Thesis,
University of Wales Swansea
117
PUBLICATIONS
Sulaiman A.Z., Yunus, R.M. Intensified Niagara Leaf Filtration Via In-Situ Ultrasonic
wave Fields. Symposium of Malaysian Chemical Engineers (SomChe) 2001 ,
September 2001, Johor Bahru, Malaysia.
Sulaiman A.Z,Yunus, R.M.Radzuan Junin. Development of High Intensity Ultrasonic
(HIU) for Stainless Steel Filter Leaf Cleaning. Regional Symposium on Chemical
Engineering (RSCE) 2001 , October 2001, Institute Technology Bandung, Indonesia
Sulaiman A.Z,Yunus, R.M., H. Abdullah “ Modelling of Ultrasonic in Increasing The
Rate of Filtration in Palm Oil Industry. World Engineering Congress (WEC) 2002,
July 2002, Kuching Sarawak
Sulaiman A.Z,Yunus R.M, Effect of Sonication For In-Situ Stainless Steel Leaf
Filtration. Asian Pacific of Chemical Engineering Conference (APPCHE 2004) 17 to
21 October 2004 at Kitakyushu, JAPAN
Sulaiman A.Z,Yunus R.M, A Study on the Effectiveness of In-Situ High Intensity
Ultrasonic (HIU) in Increasing the Rate of Filtration in Palm Oil Refining Industries.
4th Seminar National Science Fellowship (NSF), Ministry of Science, Technology &
Innovation Malaysia, 20 to 21 Disember 2004 at Vistana Hotel, Penang (Silver
Medal Award Presenter)
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PATENT
Sulaiman A.Z, Rosli M.Y. In-Situ High Intensity Ultrasonic (HIU) Asissted for
Stainless Steel Leaf Filtration. Malaysian Patent Identification Number :
PI 20032885