ABSTRACT
The adsorptive removal of the colour pigment (due to high content of carotenoids) from palm oil using ortho-phosphoric acid activated kaolin clay was investigated in this research. The clay was activated at different acid concentrations to improve its adsorptive capacity. In order to study the effect of process variables on the bleaching efficiency of the raw and activated clay samples, adsorbent dosages (1.0 – 3.0 g); reaction temperatures (30 - 120°C); and reaction time (5 - 60 minutes.) was varied for the adsorption experiment. The results show that bleaching efficiency increases with acid concentrations, contact time, temperature and clay dosage. Freundlich and Langmuir adsorption isotherms were used to analyze the experimental results. The data conformed to Freundlich Isotherm model with a regression coefficient of 0.9673.The experimental data were also analyzed using the established kinetic models of Pseudo-first order, Pseudo-second order, and intra-particle diffusion. The experimental data fitted well to the Pseudo-second order kinetic model with regression coefficient of 0.9982. The value of ∆H obtained was -11.108kJ/mol which suggests that the adsorption process is exothermic and physisorption in nature since the magnitude is less than 20kJ/mol.
TABLE OF CONTENTS
LETTER OF TRANSMITTAL ................................................................................................ ii
CERTIFICATION ................................................................................................................... iii
DEDICATION ........................................................................................................................ iv
ACKNOWLEDGMENT .......................................................................................................... v
ABSTRACT ............................................................................................................................ vi
TABLE OF CONTENTS ....................................................................................................... vii
LIST OF FIGURES .................................................................................................................. x
LIST OF TABLES .................................................................................................................. xi
CHAPTER ONE.......................................................................................................................1
INTRODUCTION ....................................................................................................................1
1.1 Background Study .....................................................................................................1
1.2 Research Aim and Objective .....................................................................................4
1.3 Justification of the Research ......................................................................................4
CHAPTER TWO ......................................................................................................................6
LITERATURE REVIEW .........................................................................................................6
2.1 Palm Oil (Elaeis guineensis)......................................................................................6
2.1.1 Chemical composition of palm oil .....................................................................9
2.1.2 Applications and advantages of palm oil..........................................................14
2.2 Refining of Palm Oil................................................................................................14
2.2.1 Chemical (Alkaline) Refining ..........................................................................15
2.2.3 Physical Refining..............................................................................................16
2.3 Bleaching by adsorption ..........................................................................................18
2.3.1 Adsorption ........................................................................................................18
2.3.2 Adsorption Isotherms .......................................................................................22
2.3.3 Adsorption Thermodynamics ...........................................................................26
2.3.4 Adsorption kinetics...........................................................................................28
CHAPTER THREE ................................................................................................................30
PROJECT METHODOLOGY ...............................................................................................30
3.1 Materials ..................................................................................................................30
3.2 Clay preparation and activation ...............................................................................30
3.3 Physical characterization of the kaolin clay ............................................................31
3.3.1 Bulk density ......................................................................................................31
3.3.2 Clay moisture content. ......................................................................................31
3.3.3 pH measurement ...............................................................................................32
3.3.4 Porosity .............................................................................................................32
3.3.5 Specific Gravity ................................................................................................32
3.4 Degumming .............................................................................................................32
3.5 Neutralization ..........................................................................................................33
3.6 Adsorption Experiment............................................................................................33
CHAPTER FOUR ..................................................................................................................35
RESULTS AND DISCUSSION.............................................................................................35
4.1 Physical Characterization of the clay ......................................................................35
4.2 Effect of Acid Concentration on Bleaching Efficiency ...........................................35
4.3 Effect of Contact Time on Bleaching Efficiency ....................................................38
4.4 Effect of Clay Dosage on Bleaching Efficiency ......................................................38
4.5. Effect of Temperature on the Bleaching Efficiency ................................................44
4.6 Effect of the use of Industrial Adsorbent in place of activated Kaolin Clay ...........44
4.7 Adsorption Isotherms...............................................................................................49
4.8 Adsorption Thermodynamics ..................................................................................53
CHAPTER FIVE ....................................................................................................................64
CONCLUSIONS AND RECOMMENDATION ...................................................................64
5.1 CONCLUSION........................................................................................................64
5.2 RECOMMENDATIONS.........................................................................................65
REFERENCES .......................................................................................................................66
