These are fuels that are produced from edible crops. Bioethanol is generally derived from commonly grown food crops such as sugar cane, sugar beet, maize (corn), sorghum and wheat. First-generation processes for bioethanol production, in the case of plants such as corn and wheat, rely on starch from plant kernels or, with respect to sugar cane and sugar beet, on the sucrose contained within parts of the plant (McCormick-Brennan et al. 2007). These starches and sugars are fer­mented and are then distilled, in much the same way as the production of alcohol destined for other purposes. The types of crops employed for first-generation bio­fuel production also have lower energy content than conventional petroleum prod­ucts per volume, something which exacerbates the issues surrounding the use of this technology (McCormick-Brennan et al. 2007). With regard to first-generation biodiesel, crops such as rapeseed, palm oil, Jatropha and soya beans are gener­ally used. The oil from these crops is then converted to biodiesel, together with a co-product called glycerol, which can be used for a variety of non-energy-related purposes. Waste vegetable oil (WVO), if cleaned up sufficiently, can also be used to produce biodiesel (Parida et al. 2011).