SYNTHESIS OF FATTY ACID ETHYL ESTER FROM CHICKEN FAT USING ZnO/SiO2 HETEROGENEOUS CATALYST

Abstract

The synthesis of fatty acid ethyl ester from chicken fat waste using ZnO/SiO₂ heterogeneous catalyst was carried out using two-step procedures of acid pretreatment by esterification and transesterification of the pretreated oil. The first step reduces the high free fatty acid in the oil to an acceptable level for transesterification using concentrated sulphuric acid at a temperature of 60 ^oC during 1 h of reaction time. The second step was transesterification of the preheated oil using silica promoted zinc oxide as heterogeneous catalyst. A three level, four factorial box behnken design (BBD) of response surface methodology was used whereby the biodiesel yield obtained in the range of 56?88%and a second order quadratic polynomial regression model that established the relationship between biodiesel yield and the process variables was developed. The quality of the produced biodiesel was determined by investigating its physicochemical properties which results are obtained for specific gravity at 15^oC to be 0.889 g/cm³, Flash point was 175^oC, Cloud Point was -3^oC, Pour point was -8^oC, Cetane number was 57.72 and Kinematic Viscosity at 40^oC was 7.95mm²/s. The results obtained are consistent and in line with ASTM standard for biodiesel; hence, chicken fat as non-edible oil can be a good renewable feedstock for biodiesel production for a sustainable green environment.

http://dx.doi.org/10.4314/njt.v35i1.16