Biodiesel is a renewable fuel composed by fatty acids methyl esters which can guarantee a green-house gas saving of 90% and more compared to its fossil substitute. If the esters that compose the biodiesel are methylic, they are called FAME (Fatty acid methyl ester). It is obtained through the chemical reaction of methanol (or bioethanol) with vegetable oils (rape, sunflower, soy, palm). It does not contain sulfur and, compared to oil-derived diesel, greenhouse gas emissions are reduced (including CO2), as well as carbon monoxide (CO) emissions and emissions of particles and other polluting products.