What is Biofuel?

What is biofuel?

Biofuels are transport fuels made from plant material and recycled elements of the food chain, and as such are considered renewable and sustainable in contrast to the majority of liquid and gas fuels we use today, which are fossil based with limited world reserves. Biofuels can be used in either pure form or blended with fossil fuels, in diesel powered vehicles and boats. There are two classes of biofuel: biodiesel and bioethanol.

Biodiesel

Biodiesel is produced through a process in which organically derived oils are combined with alcohol (ethanol or methanol) in the presence of a catalyst to form ethyl or methyl ester. The biomass-derived ethyl or methyl esters can be blended with conventional diesel fuel or used as a neat fuel (100% biodiesel). Biodiesel is derived from vegetable oils, for example rapeseed. It can replace diesel entirely or it can be mixed with it in different proportions for running diesel engines which require little or no modification. Biodiesel sold on UK forecourts is a blend of 5% biodiesel and 95% mineral diesel, and requires no engine modification. Biodiesel is better for the environment than petrol diesel since it is made from renewable resources and has lower emissions.

Bioethanol

Bioethanol and its derivative, ETBE, are oxygenated products, produced from a range of agricultural feedstocks, e.g. starch and sugar crops. It can be used in existing, slightly modified, petrol engines, although cold starting requires the addition of a small amount of a volatile fuel component - usually petrol. Vegetable ETBE is used as an additive to enhance the octane rating, as a replacement for the fossil oxygenate MTBE. (sharifah Norazira)