COMPARATIVE STUDY OF AN OPEN LAGOON WITH HIGH EFFICIENT

METHANE FREE TREATMENT PLANT AND CDM PROJECT IN PALM OIL

MILL EFFLUENT

LIM LI QEAT

A thesis submitted in partial fulfillment of the

requirement for the award of the degree of

Bachelor of Civil Engineering

Faculty of Civil Engineering & Earth Resources

Universiti Malaysia Pahang

NOVEMBER 2010

ABSTRACT

Treatment of POME has always be the famous research topic in Malaysia due

to the rapidly grown of palm oil industry as a very important agriculture in Malaysia.

Due to the rapidly grown of palm oil industry in Malaysia, a large volume of POME

has been produced at the same time. Raw POME is extremely rich in organic content

which means it has high biochemical oxygen demand (BOD). Thus it needs to be

treated properly to minimized environmental hazard before discharge into water

body. Ponding process or a conventional ponding process has been widely use in

Malaysia to treat POME. Although it is simple in operation, it generated large

amount of sludge and take up large space areas. Besides that, ponding process is also

produce methane gas which bring adverse health to human being and significant

contribute to the green house gases emission. Anaerobic treatment has been

identified as source of methane gas. Thus many studies had been conducted to

develop alternatives methods to treat POME which are more efficient in treating

POME by reducing the, high BOD content and capture the emitted methane gases

while consuming less land area than ponding process. In this study, a comparison of

the current technologies of POME treatment system is conducted. A study is carried

out at palm oil mill Lepar Hilir to study the methane gas emission and organic

content of POME From the study, it found out that high-efficient methane free

POME treatment plants are unable to separate oil and particular from POME using

micro-bubbles technology which showing a high biochemical oxygen demand at the

result. On the other hands, through Clean Development Mechanism, high

biochemical oxygen demand could be reduced significantly and successfully in

capture methane gas for the use of electricity.

V

ABSTRAK

Kebolehrawatan efluen kilang kelapa sawit (POME) selalu menjadi satu

bahan bangat untuk dibincang disebabkan oleh perkembangan industry kelapa sawit

di Malaysia sebagai sector agikultur. Disebabkan perkembangan industri kelapa

sawit yang amat pesat di Malaysia, isipadu air sisa dari kilang kelapa sawit juga

banyak dihasilkan pada masa yang sama. Bahan kumbahan dari kilang kelapa sawit

mengandungi banyak organic substrat dan menyebabkan keperluan oksigen biokimia

tinggi. Disebabkan keaadaan itu, kumbahan dari kilang kelapa sawit perlu dirawat

sebelum disalurkan ke air untuk mengurangkan pencemaran alam sekitar.

Penggunaan kolam untuk merawat air sisa dari kilang kelapa sawit telah menjadi satu

kebiasaan di Malaysia. Operasi untuk cara kolam adalah mudah tetapi ia

menghasilkan banyak pepejal terampai dan memerlukan keluasan yang banyak.

Selain daripada itu, ia juga menghasilkan gas methane yang membahayakan

kesihatan manusia dan menyumbang kepada kesan rumah hijau. Kebolehrawatan

POME secara anarobik telah membuktikan sabagai punca utama pembebasan gas

methane. Oleh sebab itu, banyak kajian telah dijalankan untuk mencari alternative

yang lebih effectif, menjimatkan tempat dan boleh mncegahkan pembebasan gas

methane untuk merawat POME. Dalam kajian mi, prbandingan technology yang

merawat POME telah dijalankan. Kajian im dijalankan di kilang kelapa sawit Lepar

Hilir untuk mengaji pembebasan gas methane dan juga kandungan di dalam POME.

Dalam kajian itu, teknologi yang barn untuk merawat POME juga dijalankan. Tetapi

melalui kajian itu, teknologi barn itu tidak berupaya untuk memisahkan kandungan

minyak dari POME dan meyebabkan keperluan oksigen biokimia ia tinggi. Di

sebaliknya, CDM projek berjaya menapplikasikan gas methane untuk menjana

vi

elektrik.

TABLE OF CONTENTS

Vii

CHAPTER TITLE PAGE

TITLE PAGES j

STUDENT DECLARATION

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT V

ABSTRAK vi

TABLE OF CONTENTS vii

LIST OF TABLES Xl

LIST OF FIGURES Xli

LIST OF ABBREVIATIONS XV

LIST OF APPENDIXES XV!

1

INTRODUCTION 1

1.1 Research background 1

1.2 Aims of Study 3

1.3 Objectives of Study 3

1.4 Scope of Study 3

1.5 Significant of Study 4

2 LITERATURE REVIEW 5

2.1 Origin of Palm Oil Mill Effluent 5

2.2 Palm Oil Mill Processing 6

2.3 Treatment technologies of POME 8

viii

2.3.1 Pre-Treatment 8

2.3.2 Biological Treatment Technology 8

2.3.3 Land Application System 9

2.3.4 Zero Waste Evaporation Technology 9

2.3.5 Conventional system 9

2.4 Current P0MB Treatment 12

2.4.1 Anaerobic Digester System 12

2.4.2 Bioreactor System 15

2.4.3 Membrane Separation Technology 15

2.5 Methane Gas 16

2.6 Characteristics of P0MB 17

2.7 High Efficient Methane Free Treatment Plant 18

2.7.1 Decanter 20

2.7.2 Boiler 21

2.7.3 Sand Cyclone 22

2.7.4 Fly Ash as Based Flocculants 23

2.8 Advantage of High Efficient Methane Free 24

Treatment Plant

2.8.1 Improvement the Environment Condition 24

2.8.2 COD Reduction. 24

2.8.3 Reduction of Waste Consumption 25

2.8.4 Improvement of Oil Extraction at Mill 25

2.8.5 Social and Technical Benefits 25

2.9 Clean Development Mechanism 26

2.10 Advantages of CDM Project 28

2. 10.1 Environmental Benefit 28

2.10.2 Renewable Energy 28

3 METHODOLOGY 29

3.1 Introduction 29

3.2 Flow Chart of Study 30

3.3 Study Location 32

ix

3.4 POME Parameters 37

3.5 Method Used to Obtain Data 39

3.5.1 Biochemical Oxygen Demand 39

3.5.2 Suspended Solid 40

3.5.3 Chemical Oxygen Demand 40

3.5.4 pH 40

3.5.5 Total Solids 41

3.5.6 Ammonia Nitrogen 41

El RESULTS AND ANALYSIS 42

4.1 Introduction 42

4.2 Result 43

4.2.1 Methane Gas 43

4.2.2 Biochemical Oxygen Demand 47

4.2.3 Chemical Oxygen Demand 49

4.2.4 Total Solids 51

4.2.5 Suspended Solid 52

4.2.6 Oil and Grease 53

4.2.7 Ammonia Nitrogen 56

4.2.8 Total Nitrogen 57

4.2.9 pH 59

4.3 Maintenance 61

4.4 Required Area 63

4.5 Summary of Treatment Methods 64

5 CONCLUSION AND RECOMMENDATIONS 66

5.1 Conclusion 66

5.2 Recommendation 68

REFERENCES 69

APPENDICES A 72

APPENDICES B 77

LIST OF TABLES

Xi

PAGE

17

33

34

TABLE NO TITLE

2.1 Characteristics of POME

3.1 Background of Palm Oil Mill at Lepar Hilir

3.2 Background of Kuala Lumpur Kepong

3.3 Background of Bukit Goh Akademic

3.4 POME Treatment Parameters Treatment and

Equipment

34

38

4.1 Result of Methane Gas Emission 44

4.2 Quantity of Fresh Fruit Bunches Processes

45

4.3 Percentage of Methane Gas Emission 45

4.4 Result of Biochemical Oxygen Demand 48

4.5 Result of Chemical Oxygen Demand 50

XII

4.6 Result of Total Solids 51

47 Result of Suspended Solids 53

4.8 Result of Oil and Grease 54

4•9 Percentage of Oil Extraction Rate 55

4.10 Result of Ammonia Nitrogen 56

4.11 Result of Total Nitrogen 58

4.12 Result of pH

59

4.13 Summary of Treatment Methods 65

LIST OF FIGURES

FIGURE NO TITLE PAGE

2.1 Process Flow of a Typical Palm Oil Milling 7

2.2 Conventional Lagoon System 11,

2.3 Open Lagoon at Lepar Hilir 11

2.4 Flow Diagram at Palm Oil Mill at Lepar Hilir 13

2.5 Flow Chart of POME Discharge at Lepar Hilir 14

2.6 Flow Chart of New Treatment System 19

2.7 Flow Chart of POME Treatment for High Efficient 21 Methane Free Treatment Plant

2.8 Fly Ash as Flocculants 23

2.9 CDM Project to Capture Methane Gas 26

2.10 Practical of CDM project 27

3.1 Flow Chart of Study 30

3.2 Flow Chart of Effectiveness POME Treatment 31

3.3 Palm Oil Mill at Lepar Hilir 35

3.4 Open Lagoon at Lepar Hilir 35

3.5 Sluge Generated at Open Lagoon 36

3.6 Discharge of POME at Line A 36

3.7 Inactive Lagoon 37

4.1 Percentage of Methane Gas Emission 46

4.2 Methane Gas Emission 46

4.3 Biochemical Oxygen Demand Graph 48

xlii

xlv

4•4 Comparison of Efficiency 49

45 Chemical Oxygen Demand Graph 50

4.6 Total Solids Graph 52

4•7 Suspended Solids Graph 53

4.8 Oil and Grease Graph 55

49 Ammonia Nitrogen Graph 57

4.10 Total Nitrogen Graph 58

4.11 pH Graph 60

4.12 Testing pH On Site 60

4.13 Leakage of POME at Discharge Line 62

4.14 Bubbles at Surface of Open Lagoon 62

4.15 Large Area Required for Open Lagoon 63

LIST OF ABBREVIATIONS

BUD Biochemical Oxygen Demand

CDM Clean Development Mechanism

COD Chemical Oxygen Demand

cpU Crude Palm Oil

DO Dissolved Oxygen

DOE Department of Environment

EFB Empty Fruit Bunch

FFB Fresh Fruit Bunch

GHG Green House Gas

GWP Global Warming Potential

KLK Kuala Lumpur Kepong

MCF Methane Conversion Factor

MPOB Malaysia Palm Oil Board

O&G Oil and Grease

POM Palm Oil Mill

POME Palm Oil Mill Effluent

SS Suspended Solids

TN Total Nitrogen

TNB Tenaga Nasional Berhad

TS Total Solids

Units

d days

mg/i Milligrams per liter

Percentage °C Degree Celsius h Hours

xv

LIST OF APPENDICES

APPENDIX TITLE PAGE

A Environment Quality Act 1974

72

B Figure of Site Visit 77

xvi

CHAPTER 1

INTRODUCTION

1.1. Research background

The palm oil industry in Malaysia has been expanding rapidly over the last four

decades. Annual palm oil production has increased steadily and the production for 2002

stood at 11.9 million tonnes in crude palm oil and 1.47 million tonnes in palm Kernel oil

(MPOB, 2003). The POME must be treated to an acceptable level before it is discharged

to the environment or it will cause serious and adverse problems. Oil can kill quickly by

coating marine and fresh life, interfering with gas exchanges for life such as oxygen gas.

An accumulation of oil can cause conditions to become anaerobic. It has been found that

0.1ppm of oil in water can upset the biological cycle in rivers.

Palm oil mill effluent (POW) is a wastewater from which generate palm oil

industry, it is a colloidal suspension which is 95-96% water, 0.6-0.7% oil and 4-5% total

solids including 24% suspended solids originating in mixing of sterilizer condensate,

separator sludge and hydrocyclone wastewater. POMIE contains 4,000 mg dm -3 of oil

and grease, which is relatively high compared to the limit of only 50 mg dm -3 (Whiting,

1978).

About 0.1 tonne of raw Palm Oil Mill Effluent (POME) is generated for every

tonne of fresh fruit bunch (FFB) processed (Wong, Y.S, 2006). POME consists of water

soluble components of palm fruits as well as suspended materials like palm fiber and oil.

1

2

Despite its biodegradability, POME cannot be discharged without first being treated

because POW is acidic and has a very high biochemical oxygen demand (BOD).

POME has generally been treated by anaerobic digestion, which resulting in

methane as release into the air. Methane gas is another potent greenhouse gas, tapping

heat 25 times as effectively as carbon dioxide (OECD, 1989). In high efficient treatment

plant it is a closed system which does not involve anaerobic water treatment and thus the

plant does not give off methane gas into the environment. Hence the new technology

plant would be able to improve the environment condition.

In the palm oil mill effluent (POME), about five to seven tones of water are

required to produce one tone of palm oil. About half of the water used ends up as palm

oil mill effluent (POME). POME is a mixture of sterilizer condensate, separator sludge

and hydrocyclone wastewater (Ahmad, A.L., and Ng, A.H., 2003). However in high

efficient treatment plant water will be reuse or recycles to treated POME several times.

Hence, the mill will consume lesser amount of water than the traditional treatment plant.

The major source of PONE is the usage of steam and water extraction processes

and washing activities in the mill (Agamuthu, 1995). POME is recognized not only

because of the large quantity generated but more significant as a type of wastewater with

the highest organic matters content where BOD and COD levels are at 25,000 mg/I and

50,000 mg/I respectively (MA et al, 1993). On the other hand, the new plant able to

reduce the level of COD. The new plant will treat all POME generated at the mills in a

more efficient manner than the current system by applied treated water to palm oil fields

as fertilizer supplement.

1.2 Aims of study

The aim of the study is to survey an open lagoon POME (palm oil mill effluent)

treatment system with current palm oil mill treatment plants.

1.3 Objectives of the study:

I. To determined the feasibility of high-efficient methane- free POME treatment

plant.

ii. To compare the existing open lagoon POME treatment plant with Clean

Development Mechanism project in capture methane.

iii. Replacement of open lagoon with other treatment plants

1.4 Scope of study

i. Identify the conventional method in treating palm oil mill effluent.

ii. Identify the current treatment system in treating palm oil mill effluent.

iii. Advantages and disadvantages of the system.

iv. Study the capture of methane gas emission for current palm oil mill effluent

treatment plants.

4

1.5 significant of the study

Discharge of palm oil mill effluent that did not follow the standard of discharged

effluent will bring adverse effects to the environment, such as water pollution and air

pollution.

Proper study for the current treatment plants is needed in order to improve the

efficiency of the treatment plant and alleviate some adverse effect to the environment

due to the treatment. Biochemical oxygen demand and methane gas emission is the most

significant in this study because high BOD will result the palm oil mill pay up their

summons and methane gas will endanger health of workers. Beside that methane gas is

also one of the renewable energy that could be used for the generate electricity. This

energy should be applied probably so it can bring benefits to people rather than harmful.

Studies of a palm oil mill effluent treatment plants can bring provide alternatives

treatment methods for the treatment plants. It also enables Malaysian to study the new

technology which would be installs in Malaysia in near future.

CHAPTER 2

LITERATURE REVIEW

2.1 Origin of palm oil mill effluent

Mill plays an important role in extracting crude palm oil (CPO) , apart from

extracting the CPO, it also generates wastes such as palm oil mill effluent (POME),

empty fruit bunch (EFB), palm kernel shell and fiber. Among all these wastes POME is

being produced in large volume and highly polluted.

Palm oil mill effluent (POME) cause a serious environmental hazard due to its

high biochemical (BOD) and chemical oxygen demand (COD) if it is disposed without

treatment. The major source of POME is the usage of steam and water in extraction

processes and washing activities in the mill (AgamuthU, 1995).

5

6

2.2 Palm oil mill processing

Process now for a typical palm oil milling is depicted in Figure 2.1. It is a

conventional process of extracting crude palm oil (CPO) from fresh fruit bunches (FFB).

According to the Department of Environment (DOE) in 1999, approximately 225kg of

crude palm oil could be extracts from 1000 kg of processed FFB. Harvested FFB needs

to processes immediately to prevent poor quality of crude palm oil due to the increase in

fatty acid content. FFB is processes at steam heat treatment in sterilizer process at the

temperature of 140°C around 75 to 90 minutes (Maycock, 1990). After sterilizer process,

FFB is subjected to thresher where the fruits are separated from the spikelet. At the

temperature around 90 °C, fruits are then mashed in digester under high pressure. Screw

press is used to press out the oil from the digested mashed fruit. Two outputs would

generate at screw press process, there are crude oil and press cake. According to DOE in

1990, crude oil produce from the screw press process consist mixture of palm oil (35% -

45%), water (45%-55%) and fibrous material in varying proportions. Crude palm oil is

then channel into clarification tank and temperature would be maintains around 90 °C

for better oil separation. Pure crude palm oil would be storage at oil storage after the

process of purifier and vacuum dried. On the other hand, press cake would channeled to

fiber and nut separation stage where fiber are discharged and nut would be convey to

hydrocyclone and store at kernel storage.

I Fresh FnntBunch(FFB)

I

lizer

Thre

Water

Digester

Wens Cake _J Screw.press

H Clari&anon TáÜt j I ,fiberandn.ut se*zdon

Tz

Pure 09 TZ& Sludge Tank,. I

Purifier .....)4

Jr

Decanter i-'Nut C^2d*

Vacuum Drier H

Water S1udgecooc clone

Oil Stmne Tad-

TreatmentKernel storage

Plant

7

Figure 2.1 Palm oil mill process (Sources: MALPOM industries Sdn Bhd, 2006)

8

2.3 Treatment technologies of POME

Four types of treatment have been introduce to treat palm oil mill effluent, which

are pre-treatment , biological treatment technologies, land application system, and zero

waste evaporation technologies.

2.3.1 Pre- treatment

Generally pre-treatment include the stages of screening, sedimentation, and oil

removal. Coagulation and flocculation process in the POME pre-treatment system help

to reduce organic load before going into the secondary treatment in biological process.

The most common coagulants used in treatment are Aluminium sulphate (alum), an

inorganic salt. Coagulant and flocculants were used to reduce the total fatty acid and

suspended solids. However the used of aluminium based coagulant has become under

surveillance due to its side effect. Large amount of aluminium remained in the treatment

and intake large amount of aluminium is believed to develop disease such as

neurodegenerative and Alzheimer disease (Driscoll and Letterman, 1995).

2.3.2 Biological treatment technologies

The most common practice used to treat POMIE is biological process which

based on anaerobic and aerobic ponding system. The organic substance of POME is

generally biodegradable and hence micro-organism are used to degrade the substances.

Micro organism which used here would gradually breakdown the organic substances

into simple end-product such as methane gas, carbon dioxide, hydrogen sulphide, and

water. However biological treatment systems need proper maintenance and control as

the micro organism are very sensitive to the environment. Thus maintenance budget

would increase.

9

2.3.3 Land application system

Land application system is suitable used in mills where they have plantation

nearby. High concentrations of plant nutrient are contained in anaerobic digested POME.

The application of the effluent would provide essential nutrient for plant growth. The

surrounding plantation receiving it could efficiently absorb all treated nutrient. This has

result in the substantial saving in fertilizer budget.

2.3.4 Zero waste evaporation technology

Evaporation is the process where a certain liquid reaches its boiling point and

evaporated, leaving behind all the materials and substances it was combines with its

liquid phrase. POME is made up of about 95% - 96% water thus by evaporation

technology the water would be recovered and the residual solid can be concentrated for

advance utilization (Ma, 2000). When POME boil only water is evaporating and all

others materials will remain in its liquid state as they boiling point is higher than water.

Almost 80% of water is reclaim but it disadvantage of using this technology is the high

energy is required (MA, 1996).

2.3.5 Conventional system (Ponding system)

In traditional treatment system, palm oil mill effluent (PONE) is treated in a

system of anaerobic holding tanks and ponds, with final treatment provided by aerobic

pond. The treated water is then release into the nearby river or to the palm oil fields as

irrigation water. Ponding system comprises of dc-oiling tank, acidification ponds,

anaerobic ponds and facultative or aerobic ponds (Chan and Chooi, 1984). Number of

ponds varies according to the capacity of the palm oil mill. Facultative or aerobic ponds

are necessary to further reduce BOD concentration.

10

More than 85% of palm oil mills in Malaysia have adopted the ponding system

for POME treatment (Ma et al., 1993). Ponding system Comprises of de-oiling tank,

acidification ponds, anaerobic ponds and facultative or aerobic ponds (Chan and Chooi,

1984). Anaerobic digestion means that the degradation of complex organic matters in the

absence of oxygen. This process has longer retention time as the bacteria consortia

responsible for the degradation process requires time to adapt to the new environment

before they can start to consume on organic matters to grow.

Based from investigation of Chan and Chooi in 1984 the retention time in

ponding system normally is around 20-200 days. In the process of degrading palm oil

mill effluent (POME), several Greenhouse gases will be released and it includes

methane, carbon dioxide and traces of hydrogen sulfide. Investigations by Yacob et al,

2006 showed that anaerobic pond had a higher emission of methane with an average

methane composition of 54.4% compared to open digester tank. Microorganisms are

very sensitive to changes in the environment and thus great care has to be taken to

maintain the temperature so that microorganism can thrive. Conventional ponding

process has been an effective method to reduce the biological and chemical constituents

of POME. This method, even though simple and reliable, generates large amounts of

sludge and takes up large land areas.

In a conventional palm oil mill, the mixed effluent (POME) contains a mixture of

steriliser condensate, separator sludge and hydrocyclone waste. The mixed POME is

treated by anaerobic, aerobic/facultative processes before it is discharged. In a palm oil

mill using a decanter, steriliser condensate is the main liquid effluent generated (MA,

AN and Ong, S.H., 1987). The steriliser condensate was found to be easily treatable by

a simple anaerobic process at ambient temperature.

A BOD removal efficiency of more than 90% could be achieved. The process

seemed to attain optimum operating conditions at a BOD loading of I 8 kg per cubic

metre per day with a hydraulic retention time of 15 to 16 days. Despite the low pH of the steriliser condensate, no pH adjustment was required at steady state. The Volatile Fatty

1].

Acid to alkalinity ratio was found to be a good control index. It was quick and simple to

determine. The ratio was always below 03 for healthy digestion. About 21 cubic metres

of biogas was generated for every cubic metre of steriliser condensate digested. The

kinetic model developed by Lawrence & McCarty (1976) was used to determine various

coefficients. The values of k, Ks, Y, kd and ®m were found to be 209 per day, 13 770

mg Iitre', 0 . 358 mg VSS per mg BOD, 0041 per day and 22 days, respectively.

POMECooltn1 Pond Mixing Pond ICH

Oil RecoveryEmission

Open or Oge5ter

Figure 2.2 Conventional Lagoon System or Open Digester system (CDM, 2000)

Figure 2.3 Open lagoon at Lepar Hilir

cl-I4 Emission

Discharge

Aerobic Pond Anaerobic Pond

(Storage 4- Polishing (- Oxidation 4- Aerated)