hydrodynamics of two immiscible liquid flow umpir.ump.edu.my/11020/1/fkksa - joshua kau mun kit...

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HYDRODYNAMICS OF TWO IMMISCIBLE

LIQUID FLOW SYSTEM: BIODIESEL SYNTHESIS

JOSHUA KAU MUN KIT

Thesis submitted in partial fulfilment of the requirements

for the award of the degree of

Bachelor of Chemical Engineering (Pure)

Faculty of Chemical & Natural Resources Engineering

UNIVERSITI MALAYSIA PAHANG

JANUARY 2015

JOSHUA KAU MUN KIT (2015)

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ABSTRACT

The hydrodynamic study of two immiscible liquids-liquid flow system is essential,

especially in the liquid-liquid extraction process during biodiesel synthesis. This work

aims to determine variable hydrodynamic parameter such as the liquid holdup fraction

and dispersibility factor in two immiscible liquid-liquid flow system (namely palm oil

and ethanol employed during biodiesel synthesis). A hindrance, which is the mass

transfer limitation coexisted within the liquid-liquid flow system. The formation of

emulsion layer which occurred when the organic phase expanded and the polar phase

inversion occurs under vigorous stirring, resisted the upwards flow of ethanol to the

decanter top and subsequently, inhibits the formation of FAEE. An agitated column

with 6-bladed impellers was employed under a counter-current flow condition where the

heavier palm oil phase was filled in the bottom decanter whereas the lighter ethanol was

filled from the top decanter. Different feed flow rate and stirring speed were tested to

identify the hydrodynamic variables. The ratio of feed flow (ethanol to palm oil)

includes 1:1, 1:3, 3:1, 1:5 and also 5:1 whereas the stirring speed experimented were

300 and 500 RPM. It was observed that the lighter phase liquid holdup decreased along

the number of stages for palm oil-to-ethanol flow ratio of 1:1, 1:3, 3:1, 1:5 and 5:1 with

stirring speed 300 RPM. Similar trend can be observed with stirring speed 500 RPM.

The distribution of these two phases were identified by determining the dispersibility

value, wherein it was found that the dispersibility decreased along the stages together

with increasing stirring speed. Noted also that the dispersibility decreased as the palm

oil-to-ethanol flow ratio increased.

Keywords: Hydrodynamics, liquid-liquid extraction, liquid holdup fraction,

dispersibility

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ABSTRAK

Kajian hidrodinamik bagi dua cecair-cecair yang tak boleh campur dalam sistem

aliran adalah penting, terutama dalam proses pengekstrakan cecair-cecair dalam

sintesis biodiesel. Kerja ini bertujuan untuk menentukan parameter hidrodinamik

ubah seperti pemegangan pecahan dan penyuraian faktor cecair tak boleh campur

dalam dua sistem aliran cecair-cecair (iaitu minyak sawit dan etanol yang bekerja

dalam sintesis biodiesel). Satu halangan, yang merupakan had pemindahan jisim

wujud bersama dalam sistem aliran cecair-cecair. Pembentukan lapisan emulsi yang

berlaku ketika fasa organik berkembang dan fasa penyongsangan kutub berlaku di

bawah kacau bertenaga, menentang aliran ke atas etanol ke atas penyiring dan

seterusnya menghalang pembentukan FAEE. Satu turus gelisah dengan pendesak 6-

bilah telah bekerja di bawah keadaan aliran balas semasa di mana fasa minyak sawit

yang lebih berat telah diisi penyiring bahagian bawah manakala etanol yang lebih

ringan dipenuhi dari penyiring atas. Kadar aliran makanan yang berbeza dan kelajuan

kacau telah diuji untuk mengenal pasti pembolehubah hidrodinamik. Nisbah aliran

makanan (etanol kepada minyak sawit) termasuk 1: 1, 1: 3, 3: 1, 1: 5 dan juga 5: 1

manakala kelajuan kacau yang bereksperimen 300 dan 500 RPM. Ia adalah

diperhatikan bahawa lebih ringan cecair fasa pemegangan menurun bersama-sama

bilangan peringkat untuk nisbah aliran kelapa sawit ke etanol daripada 1: 1, 1: 3, 3:

1, 1: 5 dan 5: 1 dengan kelajuan kacau 300 RPM. Aliran yang sama boleh

diperhatikan dengan kelajuan kacau 500 RPM. Pengagihan ini dua fasa telah dikenal

pasti dengan menentukan nilai penyuraian, di mana didapati bahawa faktor

penyuraian menurun di sepanjang peringkat bersama-sama dengan peningkatan

kelajuan kacau. Diperhatikan juga bahawa faktor penyuraian menurun sebagai nisbah

aliran kelapa sawit ke etanol meningkat.

Kata Kunci: Hidrodinamik, pengekstrakan cecair-cecair, cecair pecahan pemegangan,

penyuraian

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TABLE OF CONTENTS

SUPERVISORS DECLARATION ............................................................................... IV

STUDENTS DECLARATION ...................................................................................... V

Dedication ....................................................................................................................... VI

ACKNOWLEDGEMENT ............................................................................................. VII

ABSTRACT ................................................................................................................. VIII

ABSTRAK ...................................................................................................................... IX

TABLE OF CONTENTS ................................................................................................. X

LIST OF FIGURES ....................................................................................................... XII

LIST OF TABLES ....................................................................................................... XIII

LIST OF ABBREVIATIONS ...................................................................................... XIV

LIST OF ABBREVIATIONS ....................................................................................... XV

1.0 INTRODUCTION.1

1.1 Background ........................................................................................................ 1

1.2 Motivation .......................................................................................................... 2

1.3 Problem Statements ........................................................................................... 3

1.4 Research Objectives ........................................................................................... 4

1.5 Scope of Study ................................................................................................... 4

1.6 Thesis Organization ........................................................................................... 4

2.0 LITERATURE REVIEW ...................................................................................... 6

2.1 Chapter Overview .............................................................................................. 6

2.2 Biodiesel ............................................................................................................ 6

2.3 Choosing Ethanol Over Methanol for Biodiesel Synthesis ............................... 7

2.4 Liquid-Liquid Extraction ................................................................................... 8

2.5 Extractive reaction ........................................................................................... 10

2.6 Agitated extractive columns ............................................................................ 11

2.7 Phase inversion emulsification......................................................................... 13

2.8 Hydrodynamic Properties in Liquid-Liquid Flow System ............................... 13

3.0 MATERIALS AND METHODS ......................................................................... 16

3.1 Chapter overview ............................................................................................. 16

3.2 Materials .......................................................................................................... 16

3.3 Chemicals ......................................................................................................... 16

3.4 Agitated (impeller) extractive column ............................................................. 17

3.5 Calibration of the flowmeters .......................................................................... 18

3.6 Operation of the agitated column ..................................................................... 19

3.7 Injection syringe technique used to measure the liquid holdup parameter ...... 20

3.8 Determining the viscosity of the palm oil and ethanol .................................... 21

3.9 Determining the density of palm oil and ethanol ............................................. 22

3.10 Testing the emulsion layer for any presence of FFAs ..................................... 22

4.0 RESULTS AND DISCUSSION .......................................................................... 23

4.1 Chapter overview ............................................................................................. 23

4.2 Calibration of flowmeters ................................................................................ 23

4.3 Time taken for liquid layer settlement ............................................................. 25

4.4 Time taken for liquid layer settlement ............................................................. 25

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4.5 The effect of flow ratio on liquid holdup ......................................................... 26

4.6 The effect of stirring speed on dispersibility ......................................