Refining of crude palm kernel oil

Description

ABSTRACT

This work studied the refining of crude palm kernel oil derived from the kernels within the nut of a palm fruit.

This research project was aimed at reducing the nonglycerides present in oil in their crude form using an alkali method of refining.

The crude palm kernel oil was first washed with distilled water by heating the mixture in an electric heater for about 2 hours to reduce the impurities present in the oil in their crude form, degummed with phosphoric acid and neutralized with NaOH caustic soda. The saponification value, iodine value and acid value was analyzed and their values are: for crude palm kernel oil, 33.1, 695.45 and 746.13 respectively, for neutralized palm kernel oil, 11.22, 725.6 and 687.24 respectively.

CHAPTER ONE

1.1 INTRODUCTION

Palm kernel oil, the second most consumed lauric acid group oil is derived from the dried kernels of the oil palm, ElaeisGuinensis.

Palm kernel oil co-product of palm oil and coconut oil comprises less than 5 percent of the total natural fats and oils, but they are important feed stocks of the oleochemical industry. Coconut oil is commercially a major source of lauric acid, together with palm kernel oil and to small extent babassu oil. It belongs to the so called lauric oils, which are characterized by their high lauric oil content of approximately 50 percent.

The lauric oils are highly desirable materials in the oleochemical industry worldwide because of the important of the lauric fraction especially in the manufacture of soap and detergents.

1.2 BACKGROUND OF THE STUDY

Two distinctly different types of oils are produced from the fruit of the south East Asia and African oil palm, ElaeisGuinensis Central American palm ElaeisOleifera.

Palm oil is obtained from the fleshy part of the fruit which resembles an over sized olive about the size of a small chicken egg. Palm kernel oil is derived from that kernel within the nut. Well over 98 percent of the fatty acids in palm oil belong to the C: 16 and C: 18 group where as approximately 64 percent of the fatty acids in palm kernel oil consist of C: 12 and C: 14 lauric group.

A palm tree produces 1015 fresh fruit bunches throughout the year weighing 523kg 1050lb each. The bunches are cut from the tree with knives attached to long poles and are transported to the oil mill. There they are sterilized by steam at about 40psig for 5675 minutes to deactivate lipase enzymes and loosen the fruits from the stalk.

The fruits are knocked loose from the stalk in thresher drums and passed through a digester to convert the fleshy pulp to mash. Then the mash is pressed by twin screw expellers or hydraulically to yield red crude oil. The shells of the nuts cracked and the kernels are separated, dried and bagged for later solvent extraction or mechanically pressed in a fashion similar to the processing of raw crop oil seeds.

1.3 STATEMENT OF PROBLEM

Palm kernel oils consist mainly of glycerides, and like other oils in their crude form, may consist of small and variable portions of nonglyceride components as well. In order to render the oils to an edible form, some of these non glycerides need to be either removed or reduced to an acceptable level so as to meet the request of the buyers.

Therefore, this project aims at reducing the nonglycerides present in oil in their crude form using the chemical alkali method of refining.

1.4 AIMS/OBJECTIVE OF THE STUDY

1. Reduction of the free fatty acids from 5.0 to 0.03 percent or less.

2. Production of a fully deodourized product.

3. Operation without substantially greater utilities consumption than a standard deodourizer.

4. Recovery of the fatty acids from the sparge stream.

5. Obtaining a mixture of traicylglycerols with the desired solid content profiles over the range of product used;

6. Preparation and storage of semisolid products with desire textures.

1.5 SCOPE OF THE STUDY

The refining of crude palm kernel oil is converting it to quality edible oil renewing objectionable impurities to the desired levels in the most efficient manner where possible, losses in the desirable components are kept minimal.

After refining of crude palm kernel oil, a good quality has low free fatty acid FFA content, does not contaminate with water or other impurities and has a good bleacheability.