Comparative Analysis of Acid Activated Nteje Clay and Two Commercially Available Adsorbents (Fuller’s Earth and Activated Carbon)

Comparative Analysis of Acid Activated Nteje Clay and Two Commercially Available Adsorbents (Fuller’s Earth and Activated Carbon).

ABSTRACT

The composition and bleaching properties of Nteje clay in comparison with two commercially available adsorbents (activated carbon and fuller’s earth) were investigated to study its competence for use as an alternative to high cost imported adsorbents.

The modification of the raw clay sample was carried out by acid activation to enhance the surface area of the clay by exchange of octahedral cations e.g Al3+, Fe3+ and Mg2+ with H+ ions which led to the modification of the clay crystalline structure.

The raw clay sample was characterized using X-ray Diffraction (XRD) analysis and Fourier Transfer Infrared Spectroscopy. The acid activated sample was used along the two commercially available adsorbents (activated carbon and fuller’s earth) in adsorptive  bleaching of palm oil to study its adsorptive capacity.

The bleaching was done at constant temperatures of 60 oc, 80 oc, 100 oc, 120 oc and 140 oc varying time at 10, 20 30, 40 and 50 minutes at each constant temperature. The kinetics and thermodynamics of the adsorption reaction was investigated at 333 k, 353 k, 373 k, 393 k and 413 k.

To further understand the kinetics, the adsorption data were analyzed by pseudo-second-order, elovich and power function equations. Adsorptive bleaching of palm oil was carried out using optimum operating conditions of temperature, clay dosage and reaction time.

The results revealed that the adsorption followed power function equation for both activated carbon (A.C) and fuller’s earth (F.E) with linear regression coefficient (R2) values of 0.987 and 0.990 respectively and followed elovich equation for activated Nteje clay (A.N.C) with (R2) value of 0.985.

TABLE OF CONTENT

Title page

Certification

Approval page

Dedication

Acknowledgement

Table of content

List of Tables

Abstract

List of Figures

List of Abbreviations and Symbols

CHAPTER ONE: INTRODUCTION

• Research background
• Research objectives and scope
• Significant of study

CHAPTER TWO: LITERATURE REVIEW

• Introduction
• Clays
  • Classification of clays
  • Modification of clays-
  • Methods of modification of clay minerals
    • Thermal activation
    • Acid activation 2.1.3.2.1Mechanism of acid activation
  • Characterization techniques for clay
    • X-ray fluorescence
    • Fourier transform infrared spectroscopy (FTIR)
    • Powdered X-ray diffraction analysis
    • Scanning electron microscope
  • Use of clay in decolourizing and refining oil
    • Types of clays used in decolourizing

• Properties required of decolourizing clays

• Activated carbon
  • Production
  • Physical reactivation
  • chemical reactivation
• Pre-treatment – Degumming, deodorization and bleaching
  • Degumming process
  • Deodorization
  • Bleaching process
• What is degumming?
  • Types of degumming
    • Dry degumming
    • Water degumming
    • Acid degumming
    • Enzymatic degumming
    • EDTA – degumming
    • Membrane degumming
  • Process theory of degumming
• What is bleaching?
  • Types of bleaching
    • Heat bleaching
    • Chemical oxidation
    • Adsorption
  • Process theory of bleaching
  • Palm oil (Elaeis guineensis)
    • Composition of crude palm oil (CPO)
  • Survey of related literature

CHAPTER THREE:   EXPERIMENTAL

• Modification of clay by chemical activation
• Physical and chemical characterization of Nteje clay

• Bulk density
• Specific Gravity
• Oil retention
• pH and acidity measurement
• Cation exchange capacity (CEC)

• Pretreatment – degumming and neutralization
  • Degumming process
  • Neutralization process
• Bleaching process
• Adsorption kinetics
• Adsorption isotherm
• Adsorption thermodynamics

CHAPTER FOUR: RESULTS AND DISCUSSION

• Physico-chemical characterization of Nteje clay
• FTIR characterisation
• XRD analysis
• Effect of activation
• Effect of bleaching time
• Effect of temperature
• Adsorption kinetics
• Adsorption isotherm
• Adsorption thermodynamics

CHAPTER FIVE: CONCLUSIONS AND RECOMMENDATIONS

• Conclusion
• Recommendations
• Contribution to knowledge

REFERENCES

INTRODUCTION

Natural clay minerals are well known and familiar to mankind from the earliest days of civilization. Because of their low cost, abundance in most continents of the world, high sorption properties, high dissolubility in acidic solutions and potential for ion exchange, clay materials are suitable substances as source of metals and adsorbents.

Clay is composed mainly of silica, alumina, water and frequently with appreciable quantities of iron, alkalis as well as alkali earth metals. Two structural units are involved in the atomic lattices of most clay minerals. One unit consists of closely packed oxygen atoms and hydroxyls in which aluminum, iron and magnesium atoms are embedded in an octahedral combination so that they are at equal distant from six oxygen or hydroxyls.

The second unit is built of silica tetrahedrons. The silica tetrahedrons (Si4O6(OH)4) are arranged to form a sheet of composition. Clay deposits are widespread over the regions of Nigeria and are under utilized in the process industries largely because we do not have the technology.

These clay deposits can be mined, purified and processed into useful raw materials for the process industries. Naturally occurring clays are alumino-silicate minerals containing sodium, potassium, and calcium, with traces of magnesium and iron which may be substituted for aluminum.

REFERENCES

Preeti S. N., Singh B. K., (2007) – Instrumental characterization of clay by XRF, XRD, and FTIR. Bull. Mater. Sci., 30(3), 235 – 238.

T. Nwabanne and F. C. Ekwu (2013) – Decolourisation of palm oil by Nigerian local clay: A study of adsorption isotherms and bleaching isotherms. International Journal of multidisciplinary Sciences and Engineering, Vol. 4, No. 1, January 2013

O. Ajemba and Okechukwu D. Onukwuli (2012) – Adsorptive removal of colour pigments from palm oil using acid activated Nteje clay. Kinetics, Equilibrium and Thermodynamics. Physicochem. Probl. Miner. Process 49(1), 2013, 369-381

Sleppy, W. C., (2002) – Aluminum compounds- introduction. Kirk-Othmer Encyclopedia of Chemical Technology (online).

Chambers, G. P. C., (1959) – Some industrial applications of the clay mineral, sepiolite. Silicates Inds. 24, 3 11.

Amira  International   limited,            (2001)  –           Alumina           technology      roadmap. Http://www.amira.com.au/documents/alumina/index.

StudentsandScholarship Team.