•Biofuels are fuels made from plant material and recycled elements of the food chain.

•These fuels are generally in the form of alcohols, esters, ethers, and other chemicals produced from biomass.

•The principle fuel used as a petrol substitute for road transport vehicles is bioethanol. Bioethanol fuel is mainly produced by the sugar fermentation process, although it can also be manufactured by the chemical process of reacting ethylene with steam.

•The main sources of sugar required to produce ethanol come from fuel or energy crops. These crops are grown specifically for energy use and include corn, maize and wheat crops.

•Ethanol or ethyl alcohol (C2H5OH) is a clear colourless liquid, it is biodegradable, low in toxicity and causes little environmental pollution if spilt. Ethanol burns to produce carbon dioxide and water.

•Biodiesel is an alternative fuel similar to conventional or ‘fossil’ diesel. Biodiesel can be produced from straight vegetable oil, animal oil/fats, tallow and waste cooking oil. The process used to convert these oils to Biodiesel is called transesterification.

The Advantages

Renewable

Sugar beet

Rape seed

Dramatically reduces emissions

Carbon neutral

Biodegradable

Non-toxic

Fuel and exhaust emissions are less unpleasant

Can be used directly in unmodified diesel engine

High flashpoint- safer to store and transport

Simple to make

Used neat or blended in any ratio with petroleum

diesel

So Its A Good Idea!

Disadvantages

• Poorly made biodiesel can cause Poorly made biodiesel can cause engine problems- gives out more engine problems- gives out more nitrogen oxide emissions nitrogen oxide emissions

Biodiesel produced Biodiesel produced from from

agricultural crops agricultural crops involve involve

additional land useadditional land use

• Transportation & storage requires Transportation & storage requires special management. It can’t be special management. It can’t be transported in pipelines, it has to transported in pipelines, it has to be transported by truck or be transported by truck or rail, which increases the rail, which increases the cost.cost.

Biodiesel is less suitable Biodiesel is less suitable for use in low temperatures,for use in low temperatures,

than petrodiesel than petrodiesel

Another disadvantage of Another disadvantage of biodiesel is that it tends to biodiesel is that it tends to reduce fuel economy reduce fuel economy

• More expensive to produceMore expensive to produce

Poor Poor availability- very few availability- very few

outlets & outlets & manufacturersmanufacturers

Future Problems

• Some countries have limited Some countries have limited water resources water resources

A suitable climate is A suitable climate is needed to grow most cropsneeded to grow most crops

Crops grown for biodiesel use Crops grown for biodiesel use land for food cropsland for food crops

There isn’t enough food waste There isn’t enough food waste to produce large to produce large amounts of amounts of biodieselbiodiesel