Study on Saponification Technology of Waste Edible Oil

With rapid economic development, resource shortage and environment pollution have increasingly became a bottleneck in the ongoing development of society. The concept of "cyclic economy" has been proposed to build a resource-saving and environment-friendly society. Under this concept, "waste" should be treated as "misplaced resources". Given more efficient utilization of waste can promote society development. The precursor of waste edible oil is natural oil with main component of glycerol ester. The saponification of glycerol ester could produce glycerol and detergent such as sodium, potassium soap, etc. Therefore, the saponification of waste edible oil could be used directly to produce soap and washing powder. Practically, there are problems like long period of reaction time of saponification, incomplete saponification or no saponification at all. This paper studied the method and mechanism of saponification of waste edible oil and the factors that influenced the saponification degree by analyzing infrared spectrum of the product. Our experiments showed that the saponification processing reached the optimal configuration with four-hour reaction at the temperature of 100degC, the mass ratio of sodium hydroxide solution to the waste edible oil was 1:2 and the concentration of sodium hydroxide was 30%. The research of this paper is far-reaching in saving resources and reducing environmental pollution.