Production and characterization of biofuel from waste cooking

Abstract

At present, the use of other sources of energy other than energy source from crude oil has accelerated. This is due to limited resources of fossil fuel, increasing prices of crude oil and environmental concerns. Alternative fuels such as biofuel are becoming more important because it can serve as a replacement for petroleum diesel due to its comparable fuel properties and cleaner emission. For use in a standard diesel engine, biodiesel can be blended (mixed) with petroleum diesel at any concentration. In this study, transesterification of waste cooking oil with methanol was catalyzed by heterogeneous catalyst TiO2-supported-MgO and the biodiesel produced was characterised. Waste cooking oil (WCO) was used because it is regarded as one of the cheapest feedstock for biodiesel production in that most oils from oil crops are used as food. Waste cooking oil is available in vast amounts each day in every restaurants and fast food outlets worldwide. The waste cooking oil used in this study was laboratory prepared by the addition of 5 wt. % of oleic acid into 95 wt. % of soybeans oil.10 wt. % of titanium-supported-magnesium oxide catalyst (MgO/TiO2) used was prepared by incipient wetness impregnation and characterized using XRF, BET and XRD. These materials were tested with the catalyst for the conversion of waste vegetable oil to biodiesel in presence of methanol and hexane co-solvent. Methanol to oil mole ratio of 18:1 was employed in the transesterification process. When hexane was used as cosolvent, methanol to oil mole ratio of 18:1 and methanol to hexane mole ratio of 1:1 was used. The effects of reaction time, reaction temperature and hexane co-solvent on the waste vegetable oil conversion has been established. The 1HNMR analysis was used to estimate the structure of FAME produced. It was observed that the oil conversion increases with the increased reaction time, reaction temperature and use of hexane as co-solvent.