WHAT ARE BIOFUELS?

Biofuels, also known as agrofuels, are produced from biomass (living organisms) and food waste products.

Some organic materials used for biofuel production includes corn, wheat, sugar cane, soya beans, vegetable oils, animal fats, wood and organic waste.



To be considered a biofuel, more than 80% of the fuel must consist of renewable materials!

The two most common types of biofuels are bioethanol and biodiesel.

Bioethanol - Bioethanol is made mostly from sugar and starch crops. With advanced technology being developed, cellulosic biomass (trees and grasses) can also be used.

Biodiesel - Biodiesel is made from vegetable oils, animal fats or recycled greases.


HOW ARE BIOFUELS MADE?

There are various ways of making biofuels, but they generally use chemical reactions, fermentation, and heat to break down the starches, sugars, and other molecules in plants. The leftover products are then refined to produce a car-friendly fuel.


Making bioethanol:


The basic steps for bioethanol production are fermentation, distillation, dehydration, and denaturing. Before fermentation, the cellulose and starch in the crops are converted into sugars through the usage of enzymes.

Fermentation
Ethanol is produced by microbial fermentation of the sugars. Two major components of plants, starch and cellulose, are both made up of sugars, and can be converted to sugars for fermentation.


Distillation
For the ethanol to be usable as a fuel, water must be removed. Most of the water is removed by distillation. The purity is limited to 95-96% due to the formation of a low-boiling water-ethanol azeotrope. The water fraction is removed in further treatment in order to better suit petrol engines.

Dehydration
Currently, the most widely used purification method is a physical absorption process using a molecular sieve. Another method, azeotropic distillation, is achieved by adding the hydrocarbon benzene which also denatures the ethanol to render it undrinkable. A third method involves use of calcium oxide as a desiccant.

Making biodiesel:

Biodiesel is made through a chemical process called transesterfication whereby the glycerin is separated from the fat or vegetable oil, leaving behind two products - biodiesel and glycerin.


In this process the vegetable oil or animal fat reacts with alcohol, like methanol, and a catalyst, like lye. They are mixed thoroughly for about an hour and then left to settle, after which the heavy glycerin settles to the bottom and biodiesel sits on top.



USAGE OF BIOFUELS

Biofuels are mainly used in the transportation sector. Most of the vehicles require fuels which provide high power and are dense so that storage is easier. The fuels must also be clean and in liquid form.

Ethanol can be used in petrol engines as a replacement for gasoline. Biodiesel can be used in any diesel engine when mixed with mineral diesel.


PROS AND CONS


Pros:

• Biofuels are carbon neutral, which means that the amount of carbon dioxide created by the burning of biofuels is equal to the carbon dioxide absorption capacity of the plants. Thus, no extra carbon dioxide remains in the atmosphere.

• Biofuels are much more environment-friendly than any other known form of fuels as they cause much less greenhouse gas emissions in comparison to the conventional types of transport fuels.

• Biofuels are very cheap. They can help to save a lot of money usually spent on other type of fuels. They may be the cheapest types of fuels available in the world.

• Biofuels are a perfect replacement for oil products like petrol and diesel. This is because biofuels are easily renewable and are very inexpensive to produce.

• Using biofuels can help to save some more money apart from the amount saved on its cost. Some of the world governments have started to offer tax incentives to the people who opt to buy greener cars which run on biofuels.

• Using biofuels can also help the economy, especially for countries who aren’t oil-rich, as it reduces the dependency on imported, foreign oils. This means that a large part of the national budget can be saved by relying on biofuels.

Cons:

• Environmentalists say that if the use of biofuels is promoted, more land will be needed to produce crops to make biofuels. This will result in a loss of habitat for various species of animals and plants.

• With the increased use of biofuels, farmers may start to grow crops meant for biofuel production rather than for food. Reduced food production can cause the price of food to increase.
  

• A new research has revealed that the burning of materials to produce biofuels emits enough nitrous oxide to create a greenhouse effect.

• The process of biofuels production is non-sustainable. Also, no method of biofuels production has been discovered that does not cause any environmental problems.