A Study of Biodiesel (Ethyl Ester) Production from Grease/Oil Rich Sludge through Acid-Catalytic Ethanol Transesterification and It’s Fuel Specifications

Abstract

The objective of this study is to produce biodiesel from grease/oil rich sludge which was trapped from the canteen of Mahidol University’s Salaya campus. The biodiesel was produced through the process of transesterification reaction in the presence of an acidic catalyst of concentrated sulfuric acid. 100% excess ethanol was used to accomplish the reaction at the molecular ratio of 30:1 (ethanol to grease) at 90C for 90 minutes. The finished product contained 95.17% biodiesel by volume with an API gravity value of 0.90 g/cm3 at 15C, a viscosity value of 8.69 mm2/s at 40C, a flash point value of 184C, and a heat value of 9,685.35 cal/g. The blending with petroleum based diesel or baseline diesel (commercial diesel) at the proportions of 5, 10, 15, and 20 percent showed no statistical significant difference at the 0.05 level. In addition, the engine performance of the blends had slightly higher engine torque and engine power than baseline diesel. In conclusion, this study found that the conversion of the canteen’s trap grease into ethyl ester had the potential to be a diesel substitute, particularly at the blending ration of 15%.