Purification of crude glycerol from waste cooking oil for the production of bio-soap

Abstract

High purity of glycerol is widely used in various industries application. However, low purity of glycerol produced from the biodiesel industry as a by-product is an obstacle to convert into a high valued product. This study aims to purify crude glycerol extracted from waste cooking oil using acidification, neutralization, activated carbon adsorption followed by solvent evaporation process. The potential application of purified glycerol extracted from waste cooking oil was then observed in the production of biosoap. The physico-chemical properties of purified glycerol extracted from waste cooking oil show pH of 6.03 and light in yellow. The results showed that the biosoap produced using purified glycerol from waste cooking oil was good in terms of pH and colour. The pH was in the acceptable range which was at pH 10.50±0.055 which considered safe to be used while the colour was acceptable as it was light in yellow. However, the texture of the biosoap was a little soft which the hardness was 59.67±4.041 which its shelf life would be affected. From the results in this study, it was proven that the purification methods were significant to remove impurities from the crude glycerol extracted from waste cooking oil.