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THE CONTINUOUS BIODIESEL PRODUCTION ON HOMOGENEOUS AND HETEROGENEOUS CATALYST

BY

MR. TINNABHOP SANTADKHA

A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF

MASTER OF ENGINEERING IN CHEMICAL ENGINEERING DEPARTMENT OF CHEMICAL ENGINEERING

FACULTY OF ENGINEERING THAMMASAT UNIVERSITY

ACADEMIC YEAR 2016 COPYRIGHT OF THAMMASAT UNIVERSITY

Ref. code: 25595810030527KRQ

THE CONTINUOUS BIODIESEL PRODUCTION ON HOMOGENUOUSAND HETEROGENUOUS CATALYST

BY

MR. TINNABHOP SANTADKHA

A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER

OF ENGINEERING IN CHEMICAL ENGINEERING DEPARTMENT OF CHEMICAL ENGINEERING

FACULTY OF ENGINEERING THAMMASAT UNIVERSITY

ACADEMIC YEAR 2016 COPYRIGHT OF THAMMASAT UNIVERSITY

Ref. code: 25595810030527KRQ

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Thesis Title THE CONTINUOUS OF BIODIESEL PRODUCTION ON HOMOGENEOUS AND HETEROGENEOUS CATALYST

Author Mr.Tinnabhop Santadkha Degree Master of Engineering Department/Faculty/University Chemical Engineering

Faculty of Engineering Thammasat University

Thesis Advisor Assistant Professor Malee Santikunaporn, Ph.D. Academic Years 2016

ABSTRACT

This research aims to study the production of biodiesel from waste

cooking palm oil, which is generated from a number of sectors. Since waste cooking palm oil contained a large amount of free fatty acids, which inhibit the trans-esterification reaction and forms some soap. Therefore, the oil must be treated in an esterification process first so that the free fatty acid content is lower than 1 % wt. of oil. Esterification of waste cooking palm oil operated at 65oC, alcohol-to-oil molar ratio of 24:1, catalyst concentration of 6 % wt. of free fatty acid, volumetric flow rate of 50 ml/min and was able to reduce the amount of free fatty acids from 1.83 % wt. to 0.31 % wt. of oil. This research aims to study the continuous flow system using homogeneous, heterogeneous catalyst and study the production of biodiesel by tubular membrane reactor, which can minimize the limitations of chemical equilibrium in trans-esterification reaction. The optimal condition of the continuous flow using a homogeneous catalyst process obtained the % FAMEs of 97.79 % wt., which less than the process inserted a membrane reactor that has the purity of 99.8 % wt. of FAMEs. In the final part of the experiment, this research had studied the production of biodiesel by membrane reactor used heterogeneous catalyst and heated by microwave, The study was found that the process installed membrane

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reactor used heterogeneous catalyst has more % FAMEs than non-membrane reactor process significantly. Keywords: Biodoesel, Waste cooking palm oil, Trans-esterification, Membrane reactor

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หัวข้อวิทยานิพนธ์ การผลิตไบโอดีเซลแบบต่อเนื่องโดยใช้ตัวเร่งปฏิกิริยาแบบเอกพันธ์และวิวิธพันธ์

ชื่อผู้เขียน นายติณณภพ สันทัดค้า ชื่อปริญญา วิศวกรรมศาสตรมหาบัณฑิต สาขาวิชา/คณะ/มหาวิทยาลัย วิศวกรรมเคมี

คณะวิศวกรรมศาสตร์ มหาวิทยาลัยธรรมศาสตร์

อาจารย์ที่ปรึกษาวิทยานิพนธ์ ผู้ช่วยศาสตราจารย์ ดร. มาลี สันติคุณาภรณ์ ปีการศึกษา 2559

บทคดัยอ่

งานวิจัยนี้มุ่งผลิตไบโอดีเซลจากน้้ามันปาล์มที่ผ่านการใช้งานแล้วซึ่งเป็นของเสียที่เกิดข้ึนจากหลายหน่วยการผลิต เนื่องจากน้้ามันที่ผ่านการใช้งานแล้วประกอบไปด้วยกรดไขมันอิสระจ้านวนมากซึ่งก่อให้เกิดสบู่ขึ้นดังนั้นน้้ามันดังกล่าวจะต้องผ่านกระบวนการบ้าบัดโดยกระบวนการเอสเตอริฟิเคชันให้เหลือปริมาณกรดไขมันอิสระต่้ากว่า 1 % โดยมวล กระบวนการเอสเตอริฟิเคชันด้าเนินการที่สภาวะ อุณหภูมิ 65 องศาเซลเซียส อัตราส่วนโดยโมลของแอลกอฮอล์ต่อน้้ามัน 24: 1 ความเข้มข้นของตัวเร่งปฏิกิริยา 6 % โดยมวล และอัตราการไหลที่ 50 มิลลิลิตรต่อนาที ซึ่งสามารถลดปริมาณกรดไขมันอิสระจาก 1.83 % โดยมวล เหลือ 0.31 % โดยมวล ของน้้ามัน งานวิจัยนี้มุ่งผลิตไบโอดีเซลโดยระบบการไหลแบบต่อเนื่องโดยใช้ตัวเร่งปฏิกิริยาแบบเอกพันธ์และวิวิธพันธ์ และศึกษาการผลิตไบโอดีเซลโดยใช้เครื่องปฏิกรณ์แบบเยื่อเลือกผ่านซึ่งสามารถลดข้อจ้ากัดของสมดุลในปฏิกิริยารานส์เอสเตอริฟิเคชันลงได้ โดยสภาวะที่เหมาะสมที่สุดของการด้าเนินงานจะให้ความบริสุทธิ์ของไบโอดีเซลอยู่ที่ 97.79 % โดยมวล ซึ่งมีความบริสุทธิ์ต่้ากว่าระบบที่ใช้เครื่องปฏิกรณ์แบบเยื่อเลือกผ่าน ซึ่งให้ความบริสุทธิ์สูงสุดที่ 99.8 % โดยมวล อีกทั้งยังได้ศึกษาเปรียบเทียบการผลิตไบโอดีเซลจากน้้ามันปาล์มใช้แล้วโดยเครื่องปฏิกรณ์แบบเยื่อเลือกผ่านกับระบบที่ไม่ได้มีการติดตั้งเครื่องปฏิกรณ์แบบเยื่อเลือกผ่าน โดยใช้ตัวเร่งปฏิกิริยาแบบวิวิธพันธ์ซึ่งพบว่ากระบวนการที่ใช้เครื่องปฏิกรณ์แบบเยื่อเลือกผ่านให้ความบริสุทธิ์ของไบโอดีเซลสูงสุดที่ 96.6 % โดยมวล และมีความบริสุทธิ์สูงกว่าระบบธรรมดาอย่างมีนัยส้าคัญ คา้สา้คญั: ไบโอดีเซล, น้้ามันปาล์มใช้แล้ว, ทรานส์เอสเตอริฟิเคชัน, เครือ่งปฏิกรณ์แบบเยื่อเลือกผ่าน

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ACKNOWLEDGEMENTS

I would like to express my sincere thanks to my thesis advisor, Assistant Professor Dr. Malee Santikunaporn for her invaluable assistance and constant encouragement throughout the course of this research. I am most grateful for her teaching and advice, not only the research methodologies but also many other methodologies in life. This thesis would not have been completed without all the support that I have always received from her kindness.

In addition, I would like to thank Mr. Damrongsak Burirat, an English expert and a former exchange student of the AFS program in the United States, who devotes the valuable time to correct English language in this thesis.

In addition, I am most grateful to the faculty of Engineering of Thammasat University for granting me this prestigious full scholarship through my graduate study

Finally, I most grateful to my parents and my friends for all their support throughout the period of this research.

Mr.Tinnabhop Santadkha

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TABLE OF CONTENTS Page ABSTRACT (1) ACKNOWLEDGEMENTS (4) LIST OF TABLES (9) LIST OF FIGURES (10) LIST OF ABBREVIATIONS (12) CHAPTER 1 INTRODUCTION

1.1 Background and importance of the issue 1 1.2 Objectives 2 1.3 Scope of study 3

1.4 Research Methodology 3 1.5 Anticipated Benefit Gain 4

CHAPTER 2 REVIEW OF LITERATURE

2.1 Biodiesel 5 2.2 The raw materials used in production 5 2.3 Features of biodiesel 6 2.4 The advantages and disadvantages of using biodiesel 6 2.5 Technology to produce biodiesel 7

2.5.1 Technology trans-esterification 7 2.5.2 Technology esterification 8

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5.2.3 Two-steps process 8 2.6 The heating of the dielectric 9 2.7 Microwave Heating 10 2.8 Membrane reactor 11 2.9 Chemical Equilibrium 11 2.10 Le Chatelier's principle 12 2.11 Semi-permeable 12 2.12 The structure of permeation membrane 12 2.13 Separation principle of the membrane selectively 13 2.14 Inorganic membrane 14 2.15 Membrane reactor characteristic divided following the function 15 2.16 Membrane reactor characteristics classified by catalyst restriction 16 2.17 literatures review 16

CHAPTER 3 RESEARCH METHODOLOGY

3.1 Raw material and chemical substance 26 3.1.1 Substance 26 3.1.2 Chemical substance 26

3.2 Equipment 27 3.2.1 Equipment for biodiesel production using microwave 27

heating 3.2.2 Analyst equipment the property of biodiesel 30

3.3 Research methodology 32 3.3.1 Continuous biodiesel production under microwave 32 heating

CHAPTER 4 RESULTS AND DISCUSSION

4.1 Acid-catalyzed esterification process 34

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4.1.1 The design of esterification process 34 4.1.2 Result of esterification process 34

4.2 The production of biodiesel using homogeneous 35 catalyst heated by microwave 4.2.1 The design of trans-esterification using 35

homogeneous catalyst heated by microwave process 4.2.2 Effect of molar ratio of alcohol-to-oil 35 4.2.3 The effect of concentration of catalyst 36 4.2.4 Effect of the volumetric flow rate 37 4.2.5 Effect of reaction temperature 38 4.2.6 The optimized operating conditions 39

4.3 The production of biodiesel by membrane reactor 40 using homogeneous catalyst heated by microwave 4.3.1 The design of production of biodiesel by 40

membrane reactor using homogeneous catalyst heated by microwave system

4.3.2 The effect of retention time 40 4.3.3 The effect of alcohol to oil molar ratio 41

4.3.4 Effect of catalyst concentration 42 4.4 The production of biodiesel by membrane reactor 43

using heterogeneous catalyst heated by microwave 4.4.1 The design of the production of biodiesel 43

by membrane reactor using heterogeneous catalyst heated by microwave system

4.3.2 The production of biodiesel by membrane reactor 44 using heterogeneous catalyst heated by microwave compare with the non-used membrane reactor

4.5 Catalyst analysis 46

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CHAPTER 5 CONCLUSIONS AND RECOMMENDATIONS 5.1 Esterification process 50 5.2 The continuous flow biodiesel production under 50

microwave heating used homogeneous catalyst 5.3 The production of biodiesel by membrane reactor under 51

microwave heating used homogeneous catalyst and heterogeneous REFERENCES 54 APPENDICES

APPENDIX A The calulation of biodiesel 58 APPENDIX B Biodiesel quality requirement 60 APPENDIX C The calculation and design of continuous 62

flow biodiesel production BIOGRAPHY 65

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Tables Page 3.1 Multi-mode microwave specification 28 3.2 Pump specification 29 3.3 Membrane reactor specification 29 3.4 Agitated stirrer specification 30 3.5 Gas chromatography specification 31 3.6 Compact titration specification 32 5.1 The comparison of biodiesel production using homogeneous 52

catalyst applied membrane reactor and Biodiesel production using heterogeneous catalyst applied membrane reactor

B.1 The characteristic of biodiesel : methyl ester of fatty acid type in 2011 59 C.1 Property of fluid 61 C.2 The property of tube 61 C.3 The sample calculation of the system 62 C.4 The calculation of head and power of pump 62

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LIST OF FIGURES Figures Page 1.1 Trans-esterification reaction 1 2.1 Reaction mechanism tranesterification 7 2.2 Mechanism of esterification reaction 8 2.3 The characteristics of the dielectric particles 9 2.4 Membrane reactor 11 2.5 Semi-permeable 12 2.6 Characteristics of membrane 13 2.7 Crossectional layer of membrane by SEM 13 2.8 The structure of semi-permeable layer 15 2.9 Membrane reactor characteristic divided following the function 15 2.10 Microwave flow system 16 2.11 Effect of retention time of microwave heating system 17 2.12 Microwave heating system installed cooling water 18 2.13 Catalyst preparation from rice husk 19 2.14 The catalyst model and a plausible reaction mechanism 21

for trans-esterification 2.15 Schematic diagram of packed bed membrane reactor 22

to produce biodiesel 2.16 Schematic diagram of membrane reactor for biodiesel production 23 2.17 Schematic diagram of membrane reactor for biodiesel production 23 2.18 Configuration of the trans-esterification reaction tank coupled to 23

a membrane module used for CBR-MS and SBMR strategies 3.1 Research procedure 25 3.2 Waste cooking palm oil from Thanachok limited company 26 3.3 Potassium hydroxide pellets 26

3.4 ᵞ-Al2O3 27

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3.5 Multi-mode microwave 27 3.6 Peristaltic pump 28 3.7 Membrane reactor 29 3.8 Agitated stirrer 30 A.1 The standard chromatogram of methyl ester 57 A.2 Chromatogram of biodiesel production that consist of methyl ester 58

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LIST OF ABBREVIATIONS Symbols/Abbreviations Terms

Permeation flux J Phenomenological coefficient L Driving force in term of X dX/dx Diffusion coefficient DAM

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CHAPTER 1 INTRODUCTION

1.1 Background and importance of the issue

Energy is an important factor that influences the growth of economies around the world. Currently, energy is derived from fossil fuels, which are non-renewable, expensive and fluctuate unexpectedly due to the market at that time. According to the report from the Department of Mineral Fuels, oil will be used up in 47 years [1]. Thailand is one of the countries that depend on imported fossil fuels as the main source of energy, especially in the transportation sector. It was estimated that the demand for diesel oil will expand by 3-4 percent per year. In order to obtain more fuel and compile with the current awareness of global warming, researchers are motivated to study and develop sustainable alternative energy and cleaner energy to replace conventional petroleum-based fuel and responded to Thailand’s policy which will increase biodiesel fuels production from 6.5 million liters per day in 2070 to 14 million liters per day in 2036 according to the Department of Energy's Alternative Energy Strategy[2].

Biodiesel is produced from the trans - esterification reaction using alcohol and a basic catalyst such as potassium hydroxide for homogeneous system and calcium oxide for heterogeneous system, under high intensity agitation and heat.

Figure 1.1 Trans-esterification reaction

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Biodiesel has lower viscosity compared to the vegetable oil feedstock, but has the same great features as diesel fuel. Additional, biodiesel combustion emission profile demonstrated lower emission of carbon monoxide, particulate matter and unburned hydrocarbon compared to diesel fuel[3], [4].

As the heating process used in the conventional heating method depend on thermal conductivity convection and radiation, which is considered as an inefficient heat transfer method, so the reaction time to relatively long. However, microwave irradiation delivers energy directly to the reagent. Therefore, by using microwave radiation it is often possible to reduce reaction time and energy consumption, as well as improve product yields[5], [6]. This is possible because the vegetable oil, methanol, and potassium hydroxide contain both polar and ionic components, rapid heating is observed upon microwave radiation that is capable of induce the generation of energy on a molecular level[7]. So far not a lot of work has been done to evaluate the transformation of waste cooking palm oil to biodiesel in a continuous type flow and with microwave heating.

Waste cooking palm oil is currently generated from local restaurants for food-process industries. This research aims to produce biodiesel from waste cooking palm oil in a continuous flow system assisted by microwave irradiation to produce large quantities of biodiesel in very short reaction time[8]. The waste cooking palm oil has a high amount of free fatty acid, so it has to be treated by esterification reaction first to reduce the amount of free fatty acids to less than 1 wt. % in order to prevent formation of soap. Parameters investigated in this experiment are the reaction temperature, alcohol-to-methanol molar ratio, the amount of catalyst, and volumetric flow rate of the feedstock. 1.2 Objectives

1. To study the continuous flow biodiesel production systems from waste

cooking palm oil using heterogeneous catalysts of the systems that installed membrane reactor and normal system heated by microwave

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2. To study biodiesel production system by membrane reactor using heterogeneous catalyst 1.3 Scope of study

1. Study the process of producing biodiesel using a 2,000 watt microwave

heat source. 2. Study the process of producing biodiesel using palm oil, waste cooking

palm oil and methanol as a substrate. 3. Study the continuous biodiesel production with the use of a

homogeneous catalyst. The glass coil has a diameter of 3 cm and 140 cm in length using potassium hydroxide as a catalyst.

4. Study the continuous biodiesel production with the use of a heterogeneous catalyst. The glass pipe has a diameter of 3 cm and a length of 140 cm and use KOH / Al2O3 as catalyst.

5. Study the working of the tubular ceramic membrane reactor (TiO2 / Al2O3) that has a pore size of 0.05 micrometers and the length of 250 mm.

6. Study and optimization of each variable which is the concentration of the catalyst, volumetric flow rate, temperature, alcohol to oil molar ratio.

1.4 Research Methodology

1. Workplace Research Faculty of Engineering, Thammasat University

2. Procedures and research. 2.1 studies and research documents related to the production of

biodiesel in batch and continuous process both of homogeneous and heterogeneous catalysts.

2.2 Scope of variables involved in the research. The following factors: 1. The molar ratio of alcohol to oil is 6: 1, 7.5: 1, 9: 1, and 12: 1

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2. The temperature values are 50 ๐C, 55 ๐C, 60 ๐C and 65 ๐C 3. The concentration of catalyst is 0.5 % wt., 1 % wt., 1.5 % wt.

and 2.0 % wt. 4. The flow rate value is 220 ml / min, 520 ml / min, 820 ml /

min and 1120 ml/min

1.5 Anticipated Benefit Gain

1. Be able to know how to produce biodiesel by the system that heated by microwave, using heterogeneous catalyst.

2. Be able to know the production process of biodiesel by the system that heated by microwave, using a heterogeneous catalyst that applied the tubular membrane reactor.

3. Be able to know the influence of the variables that affect the production of biodiesel and determine the optimum conditions of operation.

4. Be able to introduce information about biodiesel gained from this research to the public as an alternative fuel in Thailand.

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CHAPTER 2 REVIEW OF LITERATURE

2.1 Biodiesel [9]

Biodiesel is a renewable diesel fuel, a substance classified to ester made from vegetable oil through a chemical process called Trans-esterification by reacting vegetable oil with an alcohol such as methanol or ethanol using an alkaline catalyst. It is an ester of a fatty acid called Fatty Acid Methyl Ester, nomenclature of biodiesel depends on the type of alcohol used in the reaction such as methyl esters is the esters obtained from the use of methanol as a chemical reaction or ethyl ester is the esters obtained from the use of ethanol. A substance in the reaction, the biodiesel can be divided into three types.

1. Biodiesel made from vegetable oils or animal fats that can be applied to any diesel engine.

2. Biodiesel blends bringing a vegetable oil or animal oil mixed with kerosene or diesel before being used, such as diesel Coco and palm diesel.

3. Biodiesel ester from a chemical reaction called Trans-esterification process which alcohol mixes with oils of vegetable or animal using acid or alkaline catalyst

2.2 The raw materials used in production

The common raw materials used to produce biodiesel are as follows: 1. CPO 2. Coconut oil 3. Nut oil 4. Sunflower oil 5. Rapeseed oil 6. Soybean oil

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7. Peanut Oil 8. Castor Oil 9. Sesame oil 10. Used Vegetable Oil.

2.3 Features of biodiesel [4]

Biodiesel has physical properties similar to diesel, but burns cleaner than diesel because the amount of oxygen in biodiesel molecule able to make biodiesel having complete combustion and normally has less carbon monoxide. Because of there is no sulfur in biodiesel and has no problem with sulfates. In addition, biodiesel has less soot. It does not cause a blockage of the exhaust system. Another important feature is the lubricants which can help extend the useful life of the engine.

2.4 The advantages and disadvantages of using biodiesel

The advantages of using biodiesel include the following. 1. Cetane number is higher than diesel, making it the perfect fire

ignition and can be improved the explosion. 2. Has complete combustion and has less of carbon monoxide

gases. 3. Has no black smoke and sulfur dioxide. 4. Helps reduce pollution from the exhaust. 5. Reduces the environmental impact. 6. Do not waste money on tuning the engine. 7. Can improve engine lubrication. 8. Can reduce lubricant imports, some from abroad.

The disadvantage of biodiesel is as follows. 1. The cost of production is relatively high.

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2. Power of the engine is lower than diesel 2.5 Technology to produce biodiesel [4]

2.5.1 Technology trans-esterification Technology trans-esterification is very popular technology used in

the production of esters. A triglyceride changed to ester at atmospheric pressure and a temperature of about 50-70๐C by reaction with excess alcohol and alkaline catalyst. Methyl alcohol or methanol is commonly used as an inexpensive and sensitive to a chemical reaction. In general, use potassium hydroxide is also used as an easier and cheaper catalyst. The yield varies according to temperature, time and free fatty acid. Figure 2.1 reaction mechanism trans-esterification (from http://goo.gl/8iVe0J)

Technology of trans-esterification reaction is divided into four sub-technologies.

1. Trans-esterification by CD process (continuous deglyceralization process).

2. Trans-esterification using lipase. Production of methyl esters from the reaction is usually catalyzed by based, which requires a high-temperature operation. Currently has developed into a lipase, which can cause reactions at room temperature interactions with high specificity and easy separation of glycerol.

3. Trans-esterification under the conditions of supercritical methanol. This technology doesn't use a catalyst, but use carbon dioxide as a

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8 reaction to reduce the reaction time. The pressure and the ratio between methanol and crude oil, the ratio of carbon dioxide to methanol and methanol to soybean oil by weight, 0.1 and 24 respectively, with the experimental conditions are as follows. The temperature of the reactor and the pressure used was 280๐C and 14.3 MPa.

4. Technology Trans-esterification by using microwaves. Using a microwave to heat by keeping up with changing electric field causes the molecules rotate rapidly and the heat from the friction of movement and increases the speed of the reaction and make it less time.

2.5.2 Technology esterification

Technology esterification is the reaction of free fatty acids reacted with alcohols with an acid catalyst under a temperature of 65-95๐C. The reaction produces ester and water.

Figure 2.2 Mechanism of esterification reaction (source http://goo.gl/8iVe0J).

The study of biodiesel production from palm oil by esterification process found that three kinds of variables that influence the reaction are methanol per mole of water, the amount of the catalyst and the temperature in the reaction. For this experiment, the best conditions are suitable. The molar ratio of methanol to oil at 40: 1, the amount of catalyst 5% by volume compared to the volume of oil and temperature in the reaction of 95๐C for 9 hours to yield the methyl ester of 97 %.

2.5.3 Two-steps process

In the case of oil, raw materials has higher fatty acids. It is necessary steps to reduce free fatty acid from the oil by esterification process. The

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9 acid is used as a catalyst for changing the fatty acid to ester. Then begin the second stage by trans-esterification. It uses base as a catalyst. The production of biodiesel using a two-step would have been on the rise of yield.

The study of production ethyl ester from palm oil with 7.5% free fatty acid in a two-step procedure by using microwaves as a heat source can reduce fatty acids in the oil to below 2% by esterification reaction. The appropriate condition of probation is the molar ratio between the amounts of free fatty acids 1:24. The catalyst was 4% by weight relative to the fatty acid. Molar ratio of ethanol per CPO equal to 4: 1 potassium hydroxide equal to 1.5% by weight of the CPO. Microwave wattages of 70 watts, and the reaction time is 5 minutes, which produce ethyl ester with a purity of 97.4%.

2.6 The heating of the dielectric [10]

The dielectric heating works on the radio or microwave frequency electromagnetic waves going through the material. The electromagnetic field will cause the dipolar molecules, which has positive and negative electrodes are aligned to the direction of the waves that pass through the material causing friction between the molecules. The heat is distributed throughout the material or the transfer of energy from the waves in the material itself.

Figure 2.3 The characteristics of the dielectric particles (Source: Department of Alternative Energy Development and Energy Conservation).

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Materials that can be used for dielectric heating must be materials that respond to electromagnetic wave. It must be a material with a polar molecular structure or consisting of polar molecules as well. Materials with non-polar molecules such as air, Teflon or glass can’t absorb the wave energy. The wave passes through the material without heat or any change and metal is reflective material and can’t heat up. Suitable for stove structure and reflector. 2.7 Microwave Heating [11]

The microwave-heated instrument works using magnetron to generate high-power microwave through the wave guide to the material to be heated. The value of the radio power used for heating in the industry will range from 200 watts to 60 kilowatts in the 915 MHz, 2.45 GHz and 5.8 GHz bands. It works in the same way as radio waves. But with higher frequencies, the voltage levels used to generate waves compared to radio waves with equal wavelengths are optimized. Microwave are suitable for heating materials smaller than radio waves because the waves are able to pass into the material at a shallow level. In the microwave, heat is generated by the transformation of electromagnetic energy. Electromagnetic energy is the kinetic energy of a molecule within a material that passes through the process. So heat is produced in the material first. In general, materials that interact with microwave are available in four types.

1. Conductors are materials with free electrons such as metal material. Typically, these rubbing materials are designed as wave retention areas to control the direction of wave propagation, such as the microwave wall.

2. Insulator material is a material that does not have electrical conductivity properties, such as glass, ceramic, air, etc. This insulation can be transmitted by electromagnetic waves without interaction, so it is used as a material to wrap the material to heat. These materials are considered to be dielectric materials without electromagnetic interference.

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3. The dielectric is a material between conductors and electrical insulation classified as dielectric material with electromagnetic losses. It can absorb electromagnetic waves and convert them into heat energy from friction.

4. Materials with magnetic elements This material such as iron, which has the interaction with microwave. It can absorb the electromagnetic to heat suddenly such as silicon carbide, so it was brought to make electromagnetic absorption material.

2.8 Membrane reactor[12]

It consists of two units, which are a selective membrane functioning to separate the mixture by the size of the particle as the separator and the reactor unit as the reaction unit. Separation of substances occurs while reaction occurring and focus on eliminating the limitation of the chemical equilibrium reaction. Figure 2.4 membrane reactor (from http://goo.gl/96Dws0) 2.9 Chemical Equilibrium [13]

When the reactant reacts until the product occurring, some reaction occurs until the reactant is used up. For incomplete chemical reactions, it is found that when the substrate reacted until the product formed, no matter how long the reaction take place, it was found that there was a constant amount of reactant and

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12 product remaining because the system is in chemical equilibrium reaction. Chemical equilibrium must be take palace under two conditions: 1. it is a reversible reaction. 2. The reaction occurs in the closed system. 2.10 Le Chatelier's principle [13]

When the system is in equilibrium, it is disturbed by changes in factors that affect the equilibrium. The system will change in the direction that reduces the effect of the interference in order for the system to regain its equilibrium. 2.11 Semi-permeable [14]

It is a filter between two phases of substrate that allows certain types of substances to pass through, so it is called Semi-permeate and using pore size as separator.

Figure 2.5 semi-permeable (from goo. gl/eEnGZA)

2.12 The structure of permeation membrane [15]

It’s divided in two main parts.

1. Symmetric membrane has same physical property in all direction which has both porosity and non-porosity. For the membrane having special

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13 characteristic filled with immobilized membrane is symmetric membrane as shown in figure 2 (a,b,c)

2. Asymmetric membrane has differential physical property in each direction consisting of top layer and supporter which has porosity. If the membrane made from different material, it called composite membrane

Figure 2.6 Characteristics of membrane (from Tan et.al, 2015) Figure 2.7 Crossectional layer of membrane by SEM (from tan et.al, 2015) 2.13 Separation principle of the membrane selectively

Figure 2.4 shows the mechanism of membrane which split the feed in two lines. One of those that pass through membrane called permeate line and the other that doesn’t pass through the membrane is retaintate line.

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The performance of membrane layer can be determined in three values: permeation flux (molm-2s-1), permeance (molm-2s-1Pa-1) and permeability (molmm-2s-

1Pa-1 ) Permeation flux

(1)

J= permeation flux L= phenomenological coefficient dX/dx = driving force in term of X

If describe the concentration in term of driving force, it should describe by using of Fick’s law.

(2)

DAM = Diffusion coefficient

If describe pressure-driven convective in term of driving force, it should be described by using Darcy’s law

(3)

2.14 Inorganic membrane

Inorganic membrane made from inorganic material such as glass, metal, Zeolite etc. normally always use asymmetric because it provides top layer that has thin layer which is very appropriate for separating the substance But there are often problems in the production process because the thin layer is penetrated through the porous part of the hole or fracture, but solve the problem by adding an intermediate layer in the membrane.

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Figure 2.8 The structure of semi-permeable layer (From tan et al., 2015)

2.15 Membrane reactor characteristic divided following the function Figure 2.9 Membrane reactor characteristic divided following the function (from tan et. al, 2015)

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1. Pull out the product to increase conversion and selectivity 2. Increase the quantity of reactance 3. Increase the substance and pull out the product in the same time

2.16 Membrane reactor characteristics classified by catalyst restriction

1. Membrane reactor act as pulling the product or adding the reactant in to the reaction The membrane affect a little to the reaction. Therefore, it’s called inert membrane and the catalyst used in the packed or fluidized form by catalysts is usually placed on the separation layer.

2. Catalyst coat on the surface of the separation layer. Caution: The catalyst must not react with the membrane.

3. The catalyst is in the porous layer In the old membrane reactor, there is often a problem of disruption of the reaction due to the diffusion problem of the substrate. The precipitate passes through the porous layer. This type of membrane is the catalyst to penetrate into the porous. 2.17 Literatures review Figure 2.10 Microwave flow system (From Encinar et. al, 2011 )

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Encinar et. al [8] this study investigated the production of methyl ester or biodiesel from soybean oil by using continuous microwave heating which adapted from home microwave. The variables are determined to see the effect of each variable that affected on the process included temperature (50-110๐C), alcohol-to-oil molar ratio (3: 1, 6: 1, 9: 1, 12: 1), concentration of the catalyst (0.5% wt., 1.0 % wt., 1.5% wt.). At a temperature of 70๐C, the catalyst concentration of 1% wt. and the molar ratio of alcohol to oil is 12: 1 obtained the yield of the reaction of 99 % wt. From this research show that using microwave can reduce the time of the reaction from 150 minutes to 2 minutes.

Figure 2.11 Effect of retention time of microwave heating system (From Refaat et. al, 2008)

Refaat et. al, 2008 [16] investigated the optimal reaction time of trans-esterification heated by microwave and compared with the conventional heating system. Moreover, they try to compare the engine efficiency and the amount of biodiesel gas produced with conventional diesel. The results show that microwave heating system gives a maximum Yield of 99.63% in just 2 minutes of biodiesel production. It is slightly lower than diesel and has the amount of CO is lower, but NOx is higher.

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18 Figure 2.12 Microwave heating system installed cooling water (From Refaat et. al, 2010)

Teo et. al, 2010 [17] This research produces biodiesel from algal oil which were Nannochloropsis sp. and Tetraselmis sp. under microwave heating with cooling system and conventional heating. Both algae well known for their high content of oil. This research compares the yield of conventional heating methods and microwave heating method. The results showed that the yield of Nannochloropsis sp. had 83.33% and Tetraselmis sp. had 77.14%. The results showed that the highest yield was the working condition of 50๐C, the electrical power was 800W, the molar ratio of oil to methanol at 1:12 and the analysis showed that the carbon content was not very dense (less than C19).

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Figure 2.12 Catalyst preparation from rice husk (from Roschat et. al, 2016)

Roschat et. al, 2016 [18] This research prepares sodium silicate for use as a catalyst for biodiesel production by boiling some husk with 1 molar dichloric acid for 3 hours at 100๐C and then calcined. Bring to boil with sodium hydroxide for 1 hour and then bring the solution to dry to get the sodium silicate. The condition of this process were alcohol to oil molar ratio of 12:1, the amount of accelerator is 2.5% wt, the temperature is 65๐C, it takes 30 minutes, the percentage of FAME is 94%

Zabeti et. al, 2009 [19] This research aims to study the optimum conditions for biodiesel production by trans-esterification reaction from palm oil using a central composition disassembly (CCD) analysis and RSM (respond surface methodology). This research uses CaO / Al2O3 as catalyst and the procedure of preparing include that prepare a solution of calcium acetate 40 g per 50 ml of water, then mixed with Al2O3 40 g for 3 hours. Bring the liquid to the oven and heat at 100 ๐

C overnight and then calcined at 718๐C for 5 hours. This study found that the optimum condition was at 65๐C, alcohol-to-oil molar ratio of 12: 1, 6% wt of catalyst and obtained conversion of 98.64%

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Figure 2.13 The catalyst model and a plausible reaction mechanism for transesterification ( from Li et. al, 2012)

Li et. al, 2012 [20] Cis-3-hexene-1-yl acetate was used as a primary

ingredient, especially in the food and cosmetics industry. In this work, the substance is synthesized by the substrate: Cis-3-hexene-1-yl and ethyl acetate using KOH / Al2O3 as a catalyst in the process. The optimum condition obtained % yield of 59.3% with a catalyst concentration of 30% wt at 88๐C for 2 hours.

KOH / Al2O3 catalysts were prepared by using a 50 ml KOH solution per

weight of ᵞ-Al2O3 20 g, heated at 40๐C for 3 hours, then dehumidified at 90๐ overnight. Calcine at 500๐C for 3 hours to get K2OCO2 on the catalyst surface, which can react. Incidentally, this research found that when the catalyst was burnt and then washed with water, Al-O-K is released on the catalyst surface and does not cause a trans-esterification reaction.

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Figure 2.14 Schematic diagram of packed bed membrane reactor to produce biodiesel (From Barotian et. al, 2011)

Barotian et. al, 2011 [21] Fatty acid methyl ester (FAME) known as biodiesel derived from animal or plant oil by trans-esterification process. Typically, the reaction takes place in a stirred vessel reactor with homogeneous strong base catalyst. In consequence, there is problem of separation catalyst from the product. Membrane can solve this problem. In addition, it is very useful for the process because when the reaction proceeds into an equilibrium reaction, even if the substance remains in the system, but the product can’t take place continuously and The system will seemly stationary. By using a membrane through the reactor can pull the product out of the system or add the reactant to the system. As a result, the equilibrium shifted to the product site.

This research used a membrane of 40 cm in diameter and 2.54 cm in external diameter. The material used is Ti / Al2O3 using KOH as a catalyst. By studying the various conditions, it was found that if using the catalyst at 157.04 g/unit volume, the temperature at 70๐C, cross flow rate of 0.21 cm / s would have the highest conversion

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Figure 2.15 Schematic diagram of membrane reactor for biodiesel production (from Xu et al, 2015)

Xu et al, 2015 [22] In this study, KF was used. Ca-Mg-Al hydrotalcite was embedded in an inert ceramic membrane for biodiesel production through trans-esterification between soybean oil and methanol. From that, the experimental design was based on the principle of the Central Composite Design (CCD) and the principle of response Surface methodology to find the best working conditions, such as temperature, the amount of catalyst. Then, the data was processed through the ANOVA program to obtain quadratic equation for predicting the maximum state. This research utilized a honey comb membrane with a length of 200 mm and a volume of 4.9 ml. The experiment was carried out at optimum conditions at 67๐C, volumetric flow rate of 4.8 milliliters per minute and obtained the yield of reaction for 94%.

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Figure 2.16 Schematic diagram of membrane reactor for biodiesel production (From Atadashi et. al, 2012 )

Figure 2.17 Configuration of the trans-esterification reaction tank coupled to a membrane module used for CBR-MS and SBMR strategies ( From Reyes et. al, 2012 )

Atadashi et. al, 2012 [23] This study aims to maximize the purity of biodiesel by using 0.02 μm porosity size of tubular membrane reactor and compared to standard ASTM, D6751, EN14241. The experimental design was performed using the CCD (central composition design). The data were processed through the ANOVA program to obtain a quadratic equation. Then, the optimum condition was obtained by RSM (response surface methodology) and were transmembrane pressure, 2 bar, temperature 40 ๐C and flow rate 150 L/min with corresponding permeate flux of 9.08

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24 (kg/m2 h). At these optimum conditions, the values of free glycerol (0.007wt%) and potassium (0.297 mg/L). From these conditions, obtained maximum %yield of 94.53 % which were below ASTM standard specifications for biodiesel fuel.

Reyes et. al, 2012 [24] This research deals with the production of fatty acid methyl with the purity and the lowest methanol to oil molar ratio. This research used tubular membrane reactor to separate monoglycerides (MGs), diglycerides (DGs) and glycerol from chemical products. The research also aims to improve the efficiency of batch reactor by installing a membrane tube. It is divided into two types: batch reactor membrane system (CBR-MS) and sequential batch membrane reactor (SBMR). SBMR has good yield of 87 wt. %. Both processes are suitable for very viscous substances to increase the permeation flux, which is related to the reduction of MG and DG SBMR. The efficiency of FAME production is better than CBR 34% and better than CBR-MS 13%, which also makes MG decreased to 79% compared to CBR and 20% compared to CBR-MS and this research aims to achieve the highest purity product.

Xu et al, 2015 [25] This study investigates the production of biodiesel through tranesterification using soybean and methanol as feedstock and use membrane reactor, in which ceramic membrane was packed with MCM-41 supported p-toluenesulfonic acid (PTSA). The experimental design was performed using the CCD (central composition design). The data were processed through the ANOVA program to obtain a quadratic equation. Then, the optimum condition was obtained by RSM (response surface methodology). The optimum condition was at 80๐C, the catalyst concentration was 0.27g / cm3, the circulation speed was 4.15 ml / min. Obtained yield of 80 % from prediction and 79.1 % from experiment.

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CHAPTER 3 RESEARCH METHODOLOGY

This chapter is about the research procedure of producing biodiesel

through trans-esterification by focusing on two different systems which are the system that inserted membrane reactor and without membrane reactor system. Moreover, this research study about the effect of variables that affect to the reaction including catalyst concentration, temperature, alcohol to oil molar ratio.

Figure 3.1 Research procedure

Research Procedure

Literature review

Produce biodiesel using

homogeneous catalyst under

microwave heating

Design the production of

biodiesel by membrane reactor

under microwave heating

system

Produce biodiesel by

membrane reactor using

homogeneous catalyst

Produce biodiesel by

membrane reactor using

heterogeneous catalyst

Analyze the property

of biodiesel

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26 3.1 Raw material and chemical substance

3.1.1 Substance Used palm oil was the substance used in this experiment. It

consisted of 1.83% of fatty acid weight. The substance has been contributed by Thanachok Company Limited. Figure 3.2 Waste cooking palm oil from Thanachok limited company

3.1.2 Chemical substance 1. Catalyst

1.1 Potassium hydroxide ( purity of 85 % wt. ) from Cairo erbar

Figure 3.3 Potassium hydroxide pellets

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Figure 3.4 ᵞ-Al2O3

1.2 ᵞ-Al2O3 ( Alumina ) 1 mm size, 0.77 g/ml density 2. Methanol ( CH3OH with purity of 98 % wt.)

3.2 Equipment

3.2.1 Equipment for biodiesel production using microwave heating 1. Microwave

A prototype microwave with special design and invention from Research Center of Microwave Utilization in Engineering (R.C.M.E) was applied for the experiment of this process. It can be able to control temperature and power supply

Figure 3.5 Multi-mode microwave

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28 to use with magnetron during the reaction is operating. This prototype microwave is different from home microwave which cannot control temperature. Table 3.1 Multi-mode microwave specification

2. Pump The peristaltic pump was used to pump oil and alcohol into the

microwave for heating and continuous production system.

Figure 3.6 Peristaltic pump

Multi-mode microwave Volume 100 L

Electrical Power 0 – 2000 W

Controlling temperature PID Controller Setting the time 0.00 – 99.59 hr

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Table 3.2 Pump specification

Pump

Brand model Watson Marlow, 603s Flow rate Max. 11 L/min

Pressure 2 bar

Speed round 0- 165 rpm

3. Tubular membrane reactor Figure 3.7 Membrane reactor Table 3.2 Membrane reactor specification

Pump

Brand Pall, USA Length 20 cm

Porosity 0.05 µm

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4. Agitated stirrer Figure 3.8 Agitated stirrer Table 3.3 Agitated stirrer specification

Agitated stirrer Brand KA Stirrer Eurostar digital, Euro-St D.

Speed 50- 2000 rpm Torque 30Ncm

3.2.2 Analyst equipment the property of biodiesel

1. Gas chromatography Used for analyzing the quantity of fatty acid methyl ester

(FAMEs) or the purity of biodiesel and has the characteristics and features as shown in the table.

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31 Figure 3.9 Gas chromatography-FID Table 3.4 Gas chromatography specification

Gas chromatography Brand model Hewlett Packard, GC-HP6890

Column Stabile wax

Detector FID

2. Compact titration Compact titration can measure acid-base value and fatty acid

quantity of biodiesel by finding the equivalence point automatically and has the characteristics and features as shown in the table.

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32 Figure 3.10 Compact titration

Table 3.5 Compact titration specification

Compact titration

Brand model Mettler Toledo, G-20 Electrode DGi116 - SC PH 0 - 14

3.3 Research methodology

3.3.1 Continuous biodiesel production under microwave heating 1. Prepare used palm oil. 2. Measure the amount of free fatty acid by titration 3. If the waste cooking oil had an initial free fatty acid (FFA) content

more than 1 % wt. of oil, which is more than the limitation of a satisfactory trans-esterification reaction using an alkaline catalyst, FFAs was first converted to esters in a pre-treatment process with methanol-to-oil ratio of 24:1 using H2SO4 as catalyst (6 wt. % of FFA). The reaction occurred in the 350 ml reactor volume, flow rate of 50 ml/min and heated by microwave at 65๐C.

4. Trans-esterification process was heated by the microwave irradiation. This experiment had investigation many sets of parameters as shown in

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33 Table 1 for finding the optimized conditions. The variables include the temperature range from 50 to 65oC, the concentration of catalyst from 1.5 to 2.5 % wt. of oil. The molar ratio of alcohol-to-oil is from 7.5:1 to 12:1 and flow rates ranging from 220 to 820 ml/min catalyzed by potassium hydroxide.

5. Separating biodiesel by separating funnel and wash by water. 6. The methyl esters were analyzed by using a Gas chromatograph

(HP 6890) equipped with a Flame Ionization Detector (FID) and a wax column (Stabilwax; 30 m × 0.25 µm × 0.25 µm). Analysis parameters were used as the carrier gas had a flow rate of 1 ml/min, linear velocity of 30 cm/s and a sample injection split ratio of 50:1. The temperature gradient maintained in the oven was 60๐C (2 min), 10๐C/min to 200๐C, 5๐C to 240๐C and hold 240๐C for 7 minutes were adopted throughout the runs.

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CHAPTER 4 RESULTS AND DISCUSSION

4.1 Acid-catalyzed esterification process

4.1.1 The design of esterification process This system is composed of the main substrates which were high

free fatty acid oil, alcohol and an acid catalyst. The substance is sent to the mixture by a pump that can adjust the maximum flow rate of 11 L / min and produce a maximum pressure of 2 atmospheres. Then, sent to heat in multi-mode microwave designed for proper reaction because the temperature can be adjusted as desired. After heating, the processed material is then separated by separating funnel and analyzed by auto-titration.

Figure 4.1 Esterification process

4.1.2 Result of esterification process

The waste cooking oil had an initial free fatty acid (FFA) content of 1.83 % wt. of oil, which is above more than 1 % wt., the limit for a satisfactory trans-esterification reaction using an alkaline catalyst. Therefore FFAs was first converted to esters in a pre-treatment process with methanol-to-oil ratio of 24:1 using H2SO4 as catalyst (6 % wt. of FFA). The reaction occurred in the 350 ml reactor volume, flow

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rate of 50 ml/min heated by microwave at 65๐C and can reduce %FFA from 1.83 wt. % to 0.31 % wt.

4.2 The production of biodiesel using homogeneous catalyst heated by microwave

4.2.1 The design of trans-esterification using homogeneous catalyst heated by microwave process

This system is composed of the main substrates which were waste cooking oil, alcohol and base catalyst. The substance is sent to the mixture by pump. Then, sent to heat in multi-mode microwave. After heating, the processed material is then separated by separating funnel and analyzed by gas chromatography.

Figure 4.2 tranesterification using homogeneous catalyst heated by microwave process

4.2.2 Effect of molar ratio of alcohol-to-oil

One of the main factors affecting the yield of biodiesel is the molar ratio alcohol-to-oil. Theoretically, the ratio of trans-esterification reaction requires 3 mole of alcohol to 1 mole of triglyceride. An excess of alcohol is used in biodiesel production to ensure that the oils or fat will be completely converted to ester and a

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higher alcohol triglyceride ratio results in a great ester conversion in a shorter time [26], [27].

In order to investigate the effect of molar ratios on biodiesel yield, an experiment was conducted with various molar ratio ranging from 6:1 to 12:1 with a constant catalyst concentration of 1.5 wt. % catalyst, volumetric flow rate of 520 ml / min and the temperature of 50๐C. As shown, the maximum FAMEs was 90.5% and obtained by using 12:1 molar ratio of alcohol-to- oil. The amount of FAMEs has increased with alcohol quantity used because a methanol-to-oil molar ratio larger than the stoichiometric molar ratio can shift the equilibrium conversion of the reaction. Figure 4.3 Effect of alcohol to oil molar ratio on FAMEs and yields (%).

4.2.3 The effect of concentration of catalyst

Catalyst concentration can affect the yield of the biodiesel product as well. In this part, the reaction temperature of 50๐C, volumetric flow rate of 520 ml / min, and alcohol to oil molar ratio of 7.5:1 were maintained constant with four concentrations of catalyst (1 % wt. – 2.5 % wt.). The result is given in Fig.3.

82.00

87.03 87.67 90.51 81.73

86.73

96.88 96.67

50

55

60

65

70

75

80

85

90

95

100

6:1 7.5:1 9:1 12:1

FAM

E (w

t.%

), Y

ied

ls (

%)

Alcohol-to-oil molar ratio

%FAME

%yields

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Figure 4.4 The effect of catalyst concentration

As shown, the maximum FAMEs was 89.9 % wt. and obtained by using 2.5 % wt. of catalyst. However, biodiesel conversion efficiency was observed to decrease dramatically at high amount of catalyst, because excessive alkaline catalyst can cause more triglycerides to react with the alkali catalyst to form undesirable soap[26], [28].

4.2.4 Effect of the volumetric flow rate

Figure 4.5 The effect of volumetric flow rate on FAMEs (% wt.) and yield (%).

88.49 87.41 90.27 89.03

90.17 92.41 93.43

96.30

50

60

70

80

90

100

220 520 820 1120

FAM

E (%

wt.

), Y

ield

(%

)

Volumetirc flow rate (ml/min)

% FAME

%Yields

86.05 87.41 87.10 89.82

86.32

92.41

96.74

91.55

50

60

70

80

90

100

1 1.5 2 2.5

FA

ME

(%

wt.),

Yie

ld (

%)

Catalyst concentration (% wt.)

%FAME

% Yields

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In this part, to the effect of reaction time on formation of methyl ester is varied at four volumetric flow rates, various flow rate from 220 – 1120 ml/min at catalyst concentration of 1.5 %wt., temperature of 50๐C, alcohol-to-oil molar ratio of 12:1.

As shown in figure 4.5, biodiesel increase with flow rate at the beginning. The maximum FAMEs was 90.26 %wt. However, when flow rate was reduced lower than 820 ml/min and biodiesel yield started to decrease with increasing flow rate because excess reaction time cause the trans-esterification reaction to be reversed [28], [29].

4.2.5 Effect of reaction temperature

Figure 4.6 shows the results of experiments to find the optimum temperature. The synthetic of biodiesel fuel from the reactor by the substrate mole ratio of 7.5: 1 and the catalyst concentration of 1.5% wt. and flow rate of 520 ml/min, As shown in Figure 4.6, the maximum of FAMEs was 90.32 % wt. and obtained at a temperature of 60๐C. Figure 4.6 The effect of catalyst concentration

FAMEs increased with the increasing of reaction temperature, because the trans - esterification reaction is an endothermic reaction. However, if the temperature increased beyond the appropriate temperature, the yield of biodiesel product decreases because at higher reaction temperature will promote the saponification reaction of triglycerides [28], [30].

87.03

89.38

90.32 89.95

86.73

90.00

91.55 91.40

86

87

88

89

90

91

92

40 45 50 55 60 65 70

FA

ME

s (

% w

t.),

Yie

ld (

%)

Temperature (oC)

% FAME

% Yields

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97.79

92.17 96.98

89.01

76.78

99.10 99.44 95.48

98.08 95.02

50

60

70

80

90

100

520 670 820 970 1120

FA

ME

(%

wt.),

Yie

ld (

%)

Volumetric flow rate (ml/min)

% FAME

% yield

4.2.6 The optimized operating conditions The optimized conditions for trans-esterification can be operated at

60๐C, alcohol-to-oil molar ratio of 12:1, the concentration of catalyst 2.5 % wt., and flow rate of 820 ml/min. Biodiesel produced from these conditions was found to contain 96.98 % wt. FAMEs.

Eevera et al.[28] the retention time can affect to each concentration of catalyst. The research was conducted by adjusting the different four flow rate in the values found on the flow rate of 520 ml / min with retention time 31 seconds to give the amount of FAMEs as high as 97.79 % wt., as shown in Figure 4.7.

Figure 4.7 The effect of flow rate to 2.5 % wt. catalyst

The production of biodiesel from waste cooking palm oil with a continuous microwave reactor can be summarized as follows. The alcohol-to-oil molar ratio was found to have a significant effect on biodiesel yield and the amount of FAMEs. The amount of catalyst was found to have a positive influence on biodiesel initially, but biodiesel yield will start to decrease if the amount of catalyst was increased to higher than 2.5 % wt. Volumetric flow rate below 820 mL/min was found to cause trans-esterification reaction to be reversed. The high reaction temperature was found to increase the activity of saponification, which caused biodiesel yield and FAMEs content to decrease. The experiment showed that the optimum conditions for the production process is at alcohol-to-oil ratio of 12: 1, catalyst concentration of 2.5 % wt., a flow rate of 520 ml/ min and reacted to a

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temperature of 60oC.

4.3 The production of biodiesel by membrane reactor using homogeneous catalyst heated by microwave

4.3.1 The design of production of biodiesel by membrane reactor using

homogeneous catalyst heated by microwave system This system is composed of the main substrates which were waste

cooking oil, alcohol and base catalyst. The substance is sent to the mixture by pump. Then, sends to heat in multi-mode microwave that was inserted with membrane reactor that can pull the product and affect to the reaction yield. After heating, the processed material is then separated by separating funnel and analyzed by gas chromatography.

Figure 4.8 production of biodiesel by membrane reactor using homogeneous catalyst heated by microwave system

4.3.2 The effect of retention time

Initially, researcher tried to use the same condition as the best condition of the previous experiment, but the results show that the % FAME value was not passing the standard (EN14103) and lower than the previous system. Because of the other variables involved and might affect to the process. Then, the

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retention time must be varied from 40 s to 160 s. The other condition must constant which consist of the temperature of 60๐ C, alcohol to oil molar ratio of 12:1, catalyst concentration of 2.5 % wt. The best results was at 80 s were obtained with %FAMEss of 94.72 which found that there was no difference in %FAMEs at another time significantly. Therefore, we try to vary the parameter of alcohol to oil molar ratio at different value.

As shown in the figure, the %FAMEs increased with the increasing of retention time, but after 120 s %FAMEs decrease dramatically because an excess reaction time causes the trans-esterification reaction to be reversed [28], [29] and affected to the yield of the reaction.

Figure 4.9 The effect of retention time of membrane reactor

4.3.3 The effect of alcohol to oil molar ratio

Alcohol to oil molar ratio is very important to the process as the excess of alcohol makes the reaction proceed to the product side and increase the yield of product. This experiment was to find the appropriate alcohol to oil molar ratio by varying four parameters of alcohol to oil molar ratio from 12:1 to 24:1 and the other condition consisting of as follow the temperature of 60๐C, retention time

94.34 94.72 94.32

86.60

85

87

89

91

93

95

0 50 100 150 200

FAM

Es (

% w

t.)

Retention time (minute)

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Figure 4.10 The effect of alcohol to oil molar ratio

of 80 s, catalyst concentration of 2.5 wt. %. As shown in figure 4.10, the maximum of FAMEs was 98.86 % wt. and obtained at an alcohol to oil molar ratio of 18:1. As shown in the graph, %FAMEs increased with the increasing of alcohol to oil molar ratio and decrease after 18: 1.

% FAME increased with the increasing of alcohol to oil molar ratio. From the previous system that was not applied membrane reactor found that this system used lower alcohol than the membrane reactor system because the membrane reactor withdraw the alcohol, which is substrate from the reaction but obtained higher FAME than normal system.

4.2.4 Effect of catalyst concentration

Biodiesel conversion efficiency was observed to decrease dramatically at high amount of catalyst, because excessive alkaline catalyst can cause more triglycerides to react with the alkali catalyst to form undesirable soap [28].

94.72

95.61

98.86

97.04

93

94

95

96

97

98

99

100

1:12 15:1 18:1 24:1

FAM

Es (

% w

t. )

Alcohol to oil ratio

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Figure 4.11 Effect of catalyst concentration

The effect of catalyst concentration alcohol to oil molar ratio was studied in four parameters consisting of concentration of catalyst from 1 – 3 % wt. For studying the only effect of catalyst concentration, the other parameter was constant as follow the temperature of 60๐C, retention time of 80 s, alcohol to oil molar ratio of 18:1. The result was shown in the figure 4.11 and the best condition was at the catalyst concentration of 3 % wt. obtained the %FAMEs of 99.85 % wt. 4.4 The production of biodiesel by membrane reactor using heterogeneous catalyst heated by microwave

4.4.1 The design of the production of biodiesel by membrane

reactor using heterogeneous cata lyst heated by microwave system Methanol and oil were charged into the mixing vessel and pre-

heated to 50๐C by heating mantle and go to heat at multi-mode microwave up to 60๐C. Subsequently the reactor was filled with palm oil and alcohol. The permeate stream consists of glycerol, methanol and a little of bio-diesel. The methanol will be collected in a round bottom flask no. 5 which is the methanol recovery unit. Methanol is one of the most importance of the trans-esterification reactant and has a lower boiling point that can evaporate and return again to the system to minimize its

90

91

92

93

94

95

96

97

98

99

100

1.50 2.00 2.50 3

FAM

Es (

% w

t. )

Catalyst Concentration ( % wt. )

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consumption. The products were sampled every 4 minutes during the operating time after 60 minute the products were transferred to the separating funnel to separate biodiesel from glycerol. The excess alcohol was removed from the ester layer by evaporation and the biodiesel was analyzed by gas chromatography. The catalysts were taken out and the system was flushed for 30 min with pure ethanol, DI water 30 minutes, 0.01 molar of sodium hydroxide 30 minutes and then drained after each run due to the excellent chemical and physical stability of the ceramic membrane.

Figure 4.12 The production of biodiesel by membrane reactor using heterogeneous catalyst heated by microwave system

4.4.2 The production of biodiesel by membrane reactor using heterogeneous catalyst heated by microwave compare with the non-used membrane reactor

This experiment aimed to compare the effects of membrane reactor and non- used membrane reactor systems with the same experimental conditions using temperature at 60 ๐C, 8 g catalyst and WHSV 2.1 h.-1 collects samples every 4 minutes. The results indicate that the system with a membrane reactor produces a higher percentage of FAME than a system with no membrane reactor and obtained a maximum% FAME of 96.6 wt. % because during the trans-esterification reaction in a membrane reactor, In the membrane reactor, the porosity

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45

size is 0.05 micrometers which smaller than the size of oil droplet. Therefore, the oil cannot pass through the membrane reactor, but biodiesel, methanol and glycerol can pass through the membrane as the size of porosity has larger than all of them. Trans-esterification reaction will be shifted to the product side (according to Le Chatelier’s Principle), so conversion will be increased by overcoming the equilibrium limitation.

Figure 4.13 Comparing of membrane reactor and non-membrane reactor

4.4.3 Effect WHSV effect of biodiesel production by membrane reactor

For systems that produce biodiesel using a membrane reactor and using KOH / Al2O3 catalysts, two systems were investigated: a system with no membrane reactor and a membrane reactor system at WHSV of 4.2 h-1 and installed a recovery of alcohol system. It was found that the system with the membrane reactor installed would make biodiesel significantly higher purity. However, it takes a lot of time to get the high purity biodiesel. Also, the researcher compared the two-state experiments, WHSV 4.2 min-1 and 2.1 min-1, at WHSV = 2.1 has higher percentages of FAMEs.

86.04 86.33

91.21

92.30

90.62

94.67

93.67

96.43

94.63 94.04

96.60

87.80

89.73

88.29 88.83

86.97 87.87

89.43 89.58 90.27

88.72

89.89

84

86

88

90

92

94

96

98

0:14 0:21 0:28 0:36 0:43 0:50 0:57 1:04

FAM

E (

% w

t.)

Time hr:min

membrane reactor

non-membrane reactor

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Figure 4.14 Effect of WHSV

4.5 Catalyst analysis

The SEM analysis of potassium hydroxide catalyst supported on alumina (KOH/Al2O3) showed a good dispersion of potassium hydroxide on the surface of alumina based on these results as shown in figure 4.15, after loading of potassium hydroxide, alumina retained its structure that was important for catalysis and therefore the potassium species were found highly distributed upon the surface of the support.

86.04 86.33

91.21 92.30

90.62

94.67 93.67

96.43 94.63 94.04

96.60

63.79 65.89

70.69 72.75

76.18 76.53 78.67

80.11 80.43 81.23

74.57

60

65

70

75

80

85

90

95

0:00 0:14 0:28 0:43 0:57 1:12

% F

AM

E

Time hr:min

WHSV 2.1

WHSV 4.2

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Figure 4.15 Alumina before loading potassium hydroxide

Figure 4.16 Alumina after loading potassium hydroxide

Figure 4.16 shows the elemental composition of the catalyst used in this study using EDX. An important observation is the high percentage of potassium that existed in the catalyst and there is the average quantity of potassium about 12 % wt. Besides, due to the high weight percentage of oxygen, it can be postulated that potassium may exist for the most part in oxide form.

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Figure 4.17 SEM-EDX result in spectrum 1 area

Figure 4.18 SEM-EDX result in spectrum 2 area

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Figure 4.19 SEM-EDX result in spectrum 3 area

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CHAPTER 5 CONCLUSIONS AND RECOMMENDATIONS

5.1 Esterification process

The free fatty acid content affects to the trans-esterification process. Due to the free fat content more than 1 % wt. can produces soaps and affects to the purity of biodiesel. Therefore, the oil must undergo esterification, which is the process of reducing free fatty acids. The reaction consists of alcohol and oils containing more than 1% wt. of free fatty acids. This type of acid reaction used was sulfuric acid, can reduce the amount of free fatty acids from 1.83% to 0.31%, which is a very efficient process and used the retention time only 7 minutes under 65 ° C, 6% wt. of catalyst. 5.2 The continuous flow biodiesel production under microwave heating used homogeneous catalyst

The continuous flow biodiesel production heated by microwave which invented for the experiment and modified the 2000 watt-microwave to adjust and can control the temperature in the reaction used with polyethylene tube which has the diameter of 8 mm and the length of 7.50 m for sending the substance to heat in microwave. From the experiment found that the microwave reactor that invented can produce biodiesel in the rate of 520-820 ml/min and the product from the process achieves the EN14103 standard.

The production of biodiesel from waste cooking palm oil with a continuous microwave reactor can be summarized as follows. The alcohol-to-oil molar ratio was found to have a significant effect on biodiesel yield and the amount of FAMEs. The amount of catalyst was found to have a positive influence on biodiesel initially, but biodiesel yield will start to decrease if the amount of catalyst was increased to higher than 2.5 % wt. Volumetric flow rate below 820 ml/min was

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51 found to cause the trans-esterification reaction to be reversed. The high reaction temperature was found to increase the activity of saponification, which caused the biodiesel yield and FAMEs content to decrease. The experiment showed that the optimum conditions for the production process is at alcohol-to-oil ratio of 12: 1, catalyst concentration of 2.5 % wt., a flow rate of 520 ml/ min and reacted to a temperature of 60oC

5.3 The production of biodiesel by membrane reactor under microwave heating used homogeneous catalyst and heterogeneous

Membrane Reactor is a device that pulls the product out of the system, resulting in a trans-esterification reaction shift to the product site and improves the purity of the biodiesel. For this experiment, a membrane has a porosity of 0.05 μm, a length of 20 cm and a KOH catalyst was used as the catalyst. This experiment tries to find the best conditions and study in 3 variables which were the catalyst concentration, the molar ratio of alcohol to oil, the retention time.

At first, this series of experiments used the same conditions as those of the previous series. However, the results showed that the amount of FAMEs was much lower and did not achieve the standards. Thus, all four retention time modifications were performed: 40, 80, 120, 160 seconds, respectively, at 60๐C, 12: 1 molar ratio of alcohol to oil of, catalyst concentration of 2.5% wt. It was found that at 80 seconds, the %FAMEs were highest at 94.72% wt. However, the% FAMEs did not significantly differ. Then, researcher studied the effect of alcohol to oil molar ratio.

The alcohol to oil molar ratio was adjusted to 12: 1, 15: 1, 18: 1, 24: 1. The best conditions were 18: 1 obtained FAMEs at 98.86 and % FAMEs of each variable are clearly different compared to the previous system. Higher alcohol content was required to get a high% FAME due to the membrane reactor pulls alcohol out of the system. The researchers also studied the effects of catalyst concentrations.

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The amount of FAMEs increased with the amount of catalyst used. At 3% wt, the% FAMEs were 99.85% wt. and found that biodiesel production using a membrane reactor was required alcohol more than normal but gives higher biodiesel purity.

For the systems produced biodiesel using a membrane reactor and using KOH / Al2O3 catalysts, two systems were investigated: a system with no membrane reactor and a membrane reactor system at WHSV of 4.2 h-1 and installed a recovery of alcohol system. It was found that the system with the membrane reactor installed would make biodiesel significantly higher purity. However, it takes a lot of time to get the high purity biodiesel. Also, the researcher compared the two-state experiments, WHSV 4.2 and 2.1 h-1, at WHSV = 2.1 to higher percentages of FAMEs. However, this system also required further study and development. Table 5.1 the comparison of biodiesel production using homogeneous catalyst applied membrane reactor and Biodiesel production using heterogeneous catalyst applied membrane reactor

Biodiesel production using homogeneous catalyst applied membrane reactor

Biodiesel production using homogeneous catalyst

Has higher yield and purity of the product. Has lower yield and purity of the product.

Require more quantity of alcohol. Require lower quantity of alcohol.

Take longer retention time. Take shorter retention time. Use lower quantity of catalyst to achieve the standard of EN14103.

Use higher quantity of catalyst to achieve the standard of EN14103.

Biodiesel production using homogeneous catalyst applied membrane reactor

Biodiesel production using heterogeneous catalyst applied

membrane reactor Take shorter retention time. Take longer retention time.

Has lower cost of operation. Has higher cost of operation. Require lower quantity of alcohol. Require higher quantity of alcohol.

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Need water washing process. No need water washing process.

Cannot reuse the catalyst. Can reuse the catalyst.

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REFERENCES 1 The Department of mineral fuel [internet]. Bangkok: Department; 2016[cited 3 november 2016]. Petroleum reserves. 2016. Available from: http://goo.gl/PxxbMw. 2 Ministry of energy [internet]. Bangkok: Ministry; 2015[cited 3 november 2016]. Alternative energy development plan. Available from: http://www.dede.go.th/ download/files/AEDP2015_ Final_ version.pdf. 3 Hoekman SK, Broch A, Robbins C, Ceniceros E, Natarajan M. Review of biodiesel composition, properties, and specifications. Renewable and Sustainable Energy Reviews. 2011;16:143-69. 4 Sumalee N. In order to get PSU biodiesel. Songkla: Research and Development Office, Prince songkla publisher; 2014. 5 Bowman M, Holcomb J, Kormos C, Leadbeater N, William V. Approach for scale- up of microwave-promoted reaction. Org Process Res Dev. 2007; 12: 41-57. 6 Leadbeater N, Stencil L. Fast, easy preparation of biodiesel using microwave heating, Energy Fuel. 2006;20: 2281-83. 7 Koopmans C, Iannelli M, Kerep P, Klink M, Schmitz S, Sinnwell S. Microwave -assisted polymer chemistry: heck-reaction, transesterification, Baeyer-villager oxidation, oxazoline polymerization, acrylamide and porous materials, Tetrahedron 2006;62: 4709-14. 8 Encinar JM, Gonzalez JF, Martinez G, Sanchez N, Pardal A. Soybean oil transesterification by the use of a microwave flow system. Fuel. 2011; 95: 386-93. 9 Wikipedia [Internet]. The united state: 2016 [cited 2016 febuary 25]. Biodiesel. Availablefrom:https://th.wikipedia.org/wiki/%E0%B9%84%E0%B8%9A%E0%B9%82%E0%B8%AD%E0%B8%94%E0%B8%B5%E0%B9%80%E0%B8%8B%E0%B8%A5. 10 Department of alternative energy development and efficiency [internet]. Bangkok: Department; 2016 [cited 2016 febbuary 20]. Dielectric heating. Available from: goo.gl/8IEwSt. 11 Rattanadecho P. Basic knowledge of microwave heating. Pathumtani: Thammasat publisher; 2008.

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55 12 Fogler S. Elements of chemical reaction engineering. Boston: Prentice hall; 2016. 13 Russell JB. General chemistry. 1st ed. Singapore: McGraw-Hill; 1981. 14 Synthesis [internet]. London: 2016 [cited 2016 febuary 25]. Semi-Permeable. Available from: http://www.synthesisips.net/blog/people-are-not-billiard-balls/. 15 Tan X. Inorganic membrane reactor. Singapore: C.O.S. printer Pte Ltd; 2015. 16 Refaat AA, Sibak HA, El Sheltawy ST, Eidiwani GI. Production optimization and quality assessment of biodiesel from waste vegetable oil. international Journal of Environmental Science & Technology. 2008;5:75-82. 17 Teo CL, Idris A. Rapid alkali catalyzed trans-esterification of microalgae lipids to biodiesel using simultaneous cooling and microwave heating and its optimization. Bioresource Technology. 2010;174:311-15. 18 Roschat W, Siritanon T, Yoosuk B, Promarak V. Rice husk-derived sodium silicate as highly efficient and low-cost basic heterogeneous catalyst for biodiesel production. Elsevier 2016;119:453-62. 19 Zabeti M, Daud WMAW, Aroua MK. Biodiesel Production using alumina-supported calcium oxide: An optimization study, Elsevier. 2009;91:243-48. 20 Li X, Yu D, Zhang W. Effect synthesis of cis-3-hexen-1-yl acetate via transesterification over KOH/Al2O3. Applied catalysis. 2012;455:1-7. 21 Baroutian S, Aroua MK, Raman AAA, Sulaiman NMN. A pack bed membrane reactor for production of biodiesel using activated carbon supported catalys, bioresource 2011;102:1095-102. 22 Xu W, Gao L, Xiao G. Biodiesel production optimization using monolithic catalyst. Fuel. 2015;159:484–90. 23 Adashi IM. Purification of crude biodiesel using dry washing and membrane technology. Alexandria Engineering Journal. 2014; 54: 1265-72. 24 Reyes I, Ciudad G, Misra M, Mohanty A, Jeison D, Navia R. Novel sequential batch membrane reactor to increase fatty acid methyl esters. Chemical Engineering Journal. 2012; 197: 459–67.

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56 25 Xu W, Gao L,Wang S, Xiao G. Biodiesel production in a membrane reactor using MCM-41 supported solid acid catalyst. Bioresource Technology. 2015;159:286-91. 26 Leung DYC, Guo Y. Transesterification of neat and used frying oil: optimization for biodiesel production. Fuel Process Technol. 2006;87:883–90. 27 Zhang Y, Dube MA, McLean DD, Kates M. Biodiesel production from waste cooking oil: 2. Economic assessment and sensitivity analysis, Bioresour Technol. 2003; 90:229–40. 28 Eevera T, Rajendran K, Saradha S. Biodiesel production process optimization and characterization to assess the suitability of the product for varied environmental conditions. Renew Energy. 2009; 34: 762–65. 29 Ma F, Clements LD, Hanna MA. The effects of catalyst, free fatty acids, and water on transesterification of beef tallow. Trans Am Soc Agric Eng. 1998;41:1261–64 30 Freedman B, Pryde EH, Mounts TL. Variables affecting the yields of fatty esters from transesterified vegetable oils. J Am Oil Chem Soc. 1984; 61: 1638–43. .

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APPENDICES

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APPENDIX A THE CALULATION OF BIODIESEL

1. The yield of biodiesel The yield of biodiesel is the quantity in percentage of remaining biodiesel after washing process defined at the following equation.

2. The quantity of methyl ester

The quantity of methyl ester is the purity value of biodiesel from production process. Figure A.1 the standard chromatogram of methyl ester

From the picture A.1 is the standard chromatogram of methyl ester for comparing with the biodiesel that produce from the process A.2 is the chromatogram of biodiesel production that consist of methyl ester which are C14:0, C16:0, C18:0, C18:1, C18:2 and C17:0 is internal standard (ISD). FAMEs quantity can be determined from the following equation.

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Figure A.2 chromatogram of biodiesel production that consist of methyl ester

∑

By ∑ is sum of area of C14:0, C16:0, C18:0, C18:1, C18:2 is area of internal standard, ISD is concentration of (M) is volumetric of C17:0 (ml) m is mass of biodiesel used in analytical process

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APPENDIX B BIODIESEL QUALITY REQUIREMENT

According to the announcement of department of Energy Business in

2011, biodiesel in Thailand should meet the standard set by means of its characteristic and quality which included methyl ester of fatty acid shown here in the table below

Table B.1 The characteristic of biodiesel : methyl ester of fatty acid type in 2011

No. Requirement unit Higher-lower Method

1 Methyl ester % wt. not lower than 96.5 EN14103

2 Density at 15๐

C kg/m3 not lower than

and not higher than

860

900 ASTM D 1298

3 Viscosity at 40๐

C centistoke not lower than

and not higher than

3.5

5.0 ASTM D 445

4 Flash point ๐

C not lower than 120 ASTM D 93

5 Sulfur % wt. not higher than 0.001 ASTM D 2622

6 Carbon % wt. not higher than 0.3 ASTM D 4530

7 Cetane number not lower than 51 ASTM D 613

8 Sulfate % wt. not higher than 0.02 ASTM D 874

9 Water % wt. not higher than 0.05 ASTM D 2709

10 All of contaminate % wt. not higher than 0.002

4 ASTM D 5452

11 Corrosion of copper

sheet not higher than no.1 ASTM D 130

12

stability to oxidation

reaction at 110 ๐

C

hour not lower than 6 EN 14112

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13 acid value mg KOH/g not higher than 0.5 ASTM D 664

14 Iodine value g Iodine /100g

not higher than 120 EN 14111

15 linoleic acid methyl

ester % wt. not higher than 12.0 EN 14103

16 methanol % wt. not higher than 0.20 EN 14110

17 monoglyceride % wt. not higher than 0.80 EN 14105

18 diglyceride % wt. not higher than 0.20 EN 14105

19 triglyceride % wt. not higher than 0.20 EN 14105

20 free glyceride % wt. not higher than 0.02 EN 14105

21 all of glyceride % wt. not higher than 0.25 EN 14105

22 metal group 1

(Alkaline) mg/kg not higher than 5.0

EN 14105 and

EN 14109

23 metal group 1 (Alkaline earth)

mg/kg not higher than 5.0 EN 14538

24 phosphorus % wt. not higher than 0.001

0 ASTM D 4951

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APPENDIX C THE CALCULATION AND DESIGN OF CONTINUOUS FLOW BIODIESEL

PRODUCTION

The calculation and design of continuous flow biodiesel production, was to find the size of pump for fluid that can be able to flow. The property of oil and alcohol is shown in the table below.

Table C.1 Property of fluid

property unit palm oil ( 40๐C ) methanol ( 25 ๐C )

density ( ) kg/m3 910 786

dynamic viscosity ( ) Pa.s 0.0234 0.000544

dielectric constant ( ) - 2.1 – 3.4 32.7

Table C.2 The property of tube property unit PE tube

diameter m 0.008

length m 7.50 operating temperature ๐C < 120

dielectric constant - 2.26

Dielectric constant has properties that demonstrate the ability to absorb energy from microwave, the higher value of dielectric constant, the better it can absorb microwave energy better and heat quickly. The material of tube used in the microwave should have low electric constant for protecting heat lost in the process and in this process choose polyethylene tube which has low electric constant value and resist to chemical corrosion. Palm oil has low electric constant value. Therefore, it should be mixed with alcohol to help absorption of microwave better. The table C.3 had shown the equation for designing pump in the continuous flow system.

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Table C.3 The sample calculation of the system no. particular unit equation quantity notation

1 surface area (A) m2

5.03 × 10-5 D = 8 mm

2 volumetric flow rate (Q) m3/s - 8.667 ×

10-6 520 ml/min

3 velocity (v) m/s

0.173

4 Reynolds number (Re) -

33.016

5 Major loss (hl) m

2.755

Laminar flow

6 Minor loss (hm) m 25 % of major loss 0.689

7

head pump (hp) m 4.590

P1 = P2 v1 = 0

z2 – z1 =1

Table C.4 The calculation of head and power of pump

The calculated Reynolds number is between only 31 and 71 which can predict the flow characteristic in the pipe being laminar flow and Reynolds number

Molar ratio

( kg/m3)

( Pa.s)

Q ( ml/min)

Q (m3/s)

v ( m/s )

Re hp

In case of different alcohol to oil molar ratio

6 : 1 884.222 0.019 520 8.667 × 10-6 0.173 31.817 4.725 7.5 : 1 879.370 0.018 520 8.667 × 10-6 0.173 33.061 4.590

9 : 1 874.974 0.018 520 8.667 × 10-6 0.173 34.303 4.465 12 :1 867.317 0.016 520 8.667 × 10-6 0.173 36.783 4.242

In case of different flow rate 7.5 : 1 879.370 0.018 220.000 3.667 × 10-6 0.073 13.987 2.483

7.5 : 1 879.370 0.018 520.000 8.667 × 10-6 0.173 33.061 4.590 7.5 : 1 879.370 0.018 820.000 1.3667 × 10-5 0.272 52.134 6.794

7.5 : 1 879.370 0.018 1120.000 1.886 × 10-5 0.372 71.208 9.095 In case of having the most of loss

6:1 884.222 0.019 1120.000 1.867 × 10-5 0.372 68.529 9.385

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shown that the ability to mix is very low. Therefore, it is necessary to help stir the oil mixture with alcohol by installing the agitator in the process.

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BIOGRAPHY Name Mr.Tinnabhop Santadkha Date of Birth December17, 1991 Educational Attainment

Academic year 2014: Bachelor of Engineering (Chemical Engineering), Thammasat University, Thailand

Scholarship Year 2015: Full scholarship from the Faculty of Engineering, Thammasat university

Publications 1. Santadkha T, Santikunaporn M. Continuous biodiesel production from waste cooking oil using homogeneous catalyst with microwave heating. In: Suresh P, Son P, Ghosh N, Hirao H, editors. Proceeding of the IIER international conference. The IIER international conference 105th; 2017 jun 5-6; Bangkok, India. Odisha: IRAJ research forum; 2017. P.137-40.