Biodiesel is a renewable energy source produced from natural oils and fats, used as a substitute for petroleum diesel without the need for diesel engine modification. Biodegradable and non-toxic, biodiesel produces lower exhaust emissions. This eBook describes the production and characterisation of biodiesel, along with current experimental research work in the field. The book will be of great interest to advanced undergraduates, postgraduates and researchers in renewable energy, as well as to fuel engineers.