CHAPTER ONE
1.0 INTRODUCTION
1.1 Research Background
Currently there is an urgent need to develop alternative energy resources, such as biodiesel fuel due to the gradual reduction of world petroleum reserves, its economic and social concerns and the environmental pollution of increasing exhaust emissions of harmful gases like SOx, NOx, and Cox, coupled with the steady increase in energy consumption have spurred research interest in alternative and renewable energy sources. A successful substitute for diesel fuel, used mainly in the transportation sector, was found to be the mixture of the ester derivatives from the vegetable oils and animal fats. This new feedstock is environmental friendly, renewable, and totally in- dependent from petroleum
Biodiesel is a renewable, biodegradable fuel that can be manufactured domestically from vegetable oils, animal fats, or recycled restaurant grease. It is a cleaner-burning replacement for petroleum diesel fuel. Biodiesel is defined as the mono-alkyl esters of vegetable oils or animal fats, obtained by transesterification of oils or fats with an alcohol, usually methanol or ethanol. The major component of vegetable oil is triglycerides. When the triglycerides react with alcohol in the presence of base catalyst, this is called “transesterification.” In this reaction, triglycerides are converted to diglyceride, monoglyceride, and finally converted to glycerol. The reaction occurs in three steps. In the first step, a triglyceride reacts with an alcohol molecule producing a diglyceride
–ester and then the diglyceride reacts with another alcohol molecule producing a mono-glyceride and another mono-ester, and finally, the mono- glyceride reacts with another alcohol molecule giving glycerin and another mono-ester. (Vonortas and Pappayanakos, 2014)