Biodiesel is one of them. It is equivalent to diesel, which is derived from biological sources. It is a non-toxic, eco-friendly processed fuel, and can be used in vehicles having diesel-driven engine. It is useful as it has less emission than petroleum and diesel. It can also possibly be used in the place of fossil fuels.

Biodiesel looks like a dark yellow colored fluid and is light. It easily gets immersed in water and thus has low density than water, and possess high boiling point with low vapor pressure. It is also non-flammable.

Several countries in the world now prefer biodiesel in their cars than other fuels and thus are also producing them. Australia. Canada Germany, India Spain, United Kingdom, United States, Brazil are some of the countries that produce biodiesel.

Biodiesel has many environmental benefits that make it very resourceful.

1. It produces less emission of carbon monoxide (CO) and Carbon dioxide (CO2).

2. It contains less aromatic hydrocarbons like benzofluoranthene.

3. It reduces the emission of small particles of solid combustion products.

4. It can produce more nitrogen oxide (NO).

5. Sulphur content in biodiesel is low than that of others.

6. It ignites more quickly than other fuels, when added to the engine.

Biodiesel is prepared from hydrocarbon oil or fats. The most common ingredient used in its making is fresh soybean oil. Other things that are used for its production are mustered seed oil and waste vegetable oil.

These oils are mixed, mainly with methanol and sodium hydroxide or potassium hydroxide, which acts as a catalyst and then filtered. The product produce is biodiesel and glycerol. It can be used in two ways- directly that is in pure form or with petroleum.

Biodiesel is gradually becoming the favorite all over the world for its eco-friendly nature as today's world is facing the problem of pollution.

Moreover, it is also free from those additional problems that are common in case of fuels like petroleum diesel, and thus can be said that in the coming years it can be the world's primary energy source for transports. For this reason many companies are becoming interested in commercial level production of biodiesel for its good business prospect

Apart from this biodiesel is still a subject of research. Different researchers are working on it to discover other positive aspects of such a valuable product.