ABSTRACT

This project work is on the bleaching of palm oil using heat (activated charcoal).

The charcoal used for this work was made from pieces of animal bone by carbonization method.  It was then activated into two different samples.  Firstly, the basic sample was activated using anaphoric acid (H2 s04) while the other was activated by just heating as a control for the experiment; both at a constant temperature of 5000c and approximate time of 2hours.

They were both size reduced into fines and sieved into particle 3ye of 150um portion of the crude palm oil was degummed and neutralized for bleaching.  Each interval of bleaching with both the acid activated and the ordinary activated charcoal was 8mins and temperature of 1500c over a hot plate, and subsequent filtration of the solution.

A spectrophotometer was used to measure the absorbance of the oils (crude and bleached) at selected wave length of 480Um.  This was converted as the degree of colour reduction expressed in percentages.

Results obtained showed that optimum quantity of the charcoal for bleaching is 5% by weight, of the oil, which gives a percentage colour reduction as 97. 14% for the acid activated and 93.57% for the calcinated sample.

Also, the characterization of both the original  oil and the bleaching oil showed that the later has appreciable properties.  Hence colour reduction was observable by naked eyes.

CHAPTER ONE

INTRODUCTION

1.1              PREAMBLE

Palm oil is one of the various types of vegetable oils, belonging to the group called liquids, because of its fatty acids content.

The majority of the fats contains some colouring matter either as a natural constituent or discoloration produced during the processing.  Natural pigments present in vegetable oils are mainly the carotenoid, giving yellow and red colours, and the chlorophylls which give green colours.  Colour deterioration can also take place during the extraction process, especially in the local method of extraction used in the most parts of the Eastern region in Nigeria.

Removal or reduction of colours and other components, otherwise called ‘Bleaching” is necessary not only because a pale-coloured fat has an appeal of ‘purity’ but also because the colours of the fat can influence the appearance of prepared food and even more importantly, the pigment present may affect the flavour and stability of the fats and food made from it.

The decolouration (bleaching) could be achieved by chemical treatment, heat treatment and adsorption methods.  The most effective and widely used being the later.  Thus, in this research project, bleaching by adsorption is carred out using an “Activated charcoal” (an adsorbent), a kind of active carbon, to substitute the use of local clays and the imported ‘Fuller’s Earth – in Palm Oil bleaching, which are rather expensive.

The charcoal can be produced from different sources as from, coal, wood, bone, coconut shell, etc.  It would be verified the most suitable form and type of charcoal for effective bleaching and the most favourable condition at which  the “activated charcoal could be used, which in them affects the bleach ability’ of the Palm oil itself.

1.2              OBJECTIVE

The objective / aim of this research project is to verify the effectiveness of ‘Activated charcoal’ in the bleaching of palm oil.  It will also expose the improvement in the use of local raw material (charcoal) in a chemical process (bleaching), in lien of the imported fuller’s Earth or other adsorbents which more expensive.

1.3              SCOPE OF THE STUDY

Basically, this, study dwells on the colours reduction of Palm oil, using an Activated charcoal as an adsorbent (bleaching agent).  The major raw materials, Palm oil and charcoal were locally sourced, and information as regards the process were obtained form the literary and other resourceful materials (texts) that treats ‘Adsorption’ as a chemical process.

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