THE CHARACTERIZATION OF BIODIESEL PRODUCED FROM USED COOKING OIL USING WATERLESS PROCESSES

Abstract

Biodiesel is a fuel produced from plant oils or animal fats that can be substituted for petroleum diesel in many internal combustion engines. Biodiesel is biodegradable, cleaner burning alternative. Used cooking oil has significant potential as the raw material for biodiesel production. After glycerol separation, the obtained biodiesel contains impurities which may cause reduction in engine life time. Impurities which exist in raw biodiesel include: methanol, soap, glycerol and catalyst. Traditionally, all of these impurities are removed from the biodiesel by water washing. Water washing has several disadvantages, such as producing large amounts of waste water that requires treatment and causing plant operational problems such as emulsion formation. The objective of this study was to investigate the use of ion exchange resins, silicagel and sawdust to purify raw biodiesel without using water. It was found that complete soap removal was attained at each test point in biodiesel after dry washing with ion exchange resins and sawdust A. Silicagel can reduce soap levels from 629 ppm to below 50 ppm at a flow rate of 2 BV/h. Purification with the ion exchange resin caused the acid value of the purified biodiesel to increase. The analysis of biofuel properties was also conducted. Results indicate that the values of viscosity, acid value, phosphorus content and sulfur content were met the national technical regulation on biofuels.
Keywords: Used cooking oil, biodiesel, biofuel, ion exchange resin, dry wash