ABSTRACT
The recovery of glycerine from spent soap lye has been done using soap lye samples obtained from the hot process of soap production using palm kernel oil (P.K.O). The main advantage of hot process is that exact concentration of the lye solution is not known, but to perform this with adequate success, the lye and fat are boiled together at 80 – 1000C at times above 1000C until saponification occurs. The overall weight of glycerine recovered per 100g of oil used was 9.0g. The quantity of spent soap lye obtained was 250ml, Acid value was 555.39, percentage free acid value was 5.6%, total fatty acid = 7.131, percentage free caustic acid = 0.14%, percentage free fatty acid obtained was 0.07131%, the specific gravity was 1.059, purity of glycerine was 92%. These parameters obtained were measured relatively to international standards with negligible error due to the type of equipment used. From the result, it is evident that the amount of glycerine recovered depends largely on the quantity of spent soap lye. Other processes the spend soap lye and the glycerine undergo as may be seen in other chapters includes, salting out, filtration, splitting and others.
CHAPTER ONE
1.0 INTRODUCTION
1.1 BACKGROUND OF THE STUDY
Glycerine, (otherwise known as propan 1, 2, 3 triol) is found dissolved in the soap lye and also as an impurity in the crude soap during the saponification of fats and oils with caustic soda. Customarily, the process of soap manufacture, from fats and oil yields glycerol to about 10% of the value of the soap formed and due to its varied uses, its recovery is pertinent to the manufacturing cost analysis for any soap making business. Glycerol being an important bye product of soap manufacture, many small scale and medium scale soap manufacturers normally discards the lye as an unwanted product.
Glycerol occurs in nature combined in the form of triglycerides (fats and oil) and is obtained during the saponification of these triglycerides. This process was the only means of producing glycerol commercially, until 1949 when synthetic glycerol was produced as the compound recovered as by-product from the soap manufacture was sufficient for the world consumption. Alternatively, glycerol is synthesized from propene by the alternate chlorination and hydroxylation process. It is also obtained from the fermentation of various sugars. Glycerine is also produced by various routes from propylene. The epichlorohydrin process is the most important; it involves the chlorination of propylene to give ally chloride which is oxidized with a strong base to give epichlorohydrin. This epichlorohydrin is then oxidized to give glycerine.