What Exactly Are Biofuels
Many of us have heard this word crop up at some point. Often it is touted as a cheaper and greener fuel source for our cars. Yet not many fully understand what biofuels actually are and where they come from.
By definition, a Biofuel is fuel that is created from either living matter or the waste products produced from living matter.
Now, there are two opposing sides to the coin when we talk about the use of biofuel. Supporters advocate switching over biofuels as an alternative to the fossil fuels we currently use so readily. They claim the build up of harmful greenhouse gases can be greatly reduced. Although the combustion of biofuel still produces carbon dioxide, mass growing of the plants to create the fuel could counter balance the overall levels in the air.
Those against a large scale switch over to biofuels highlight potential problems on closer inspection. Mass production and growing of the crops for a fuel source could too have detrimental effects on our current eco-system. Our global food supply systems could become unstable.
Biofuels can be split into four simple generations according to their primary sources.
1st Generation Biofuels come from animal fats, sugars, starches and oils. They are refined and converted into biofuel by specialist filtering equipment. The most common biofuels in this section include ethanol, biogas, bioalcohol and biodiesel.
2nd Generation Biofuels are mainly sourced from agricultural waste and non-crops. By taking the waste products from an existing process a useable biofuel can be produced with some additional processing. The most common source is Ligno-cellulosic biomass which includes wood chips, willow and switch grass.
3rd Generation Biofuels are created by processing the most rapidly growing forms of biomass. For example, Algae is a highly suitable source.
4th Generation Biofuels come from genetically modified plants or biomass. These sources can be cleverly engineered to produce far more energy per yield. Energy requirements for breaking down the source can also be lowered, resulting in a more efficient process. Special strains can be grown in new environments and non-agricultural land space. Bodies of water can even become suitable for growing plants.
The Biofuel’s characteristics will vary between these groups, making them suitable for different applications.
Biodiesel is one of the most well known examples of a 1st generation biofuel. Primarily sourced from seed oils such as sunflower, soybean or canola. Reclaimed animal fats can also used. Biodiesel can be used in our existing diesel engines with light modifications, making it a great renewable alternative. With the current high taxes on fuel it can even prove to be more cost effective too.
Ethanol is another widely used 1st generation biofuel. It is an alcohol produced from corn feed stocks and sugar canes. Ethanol is most commonly found mixed with petrol to use in combustion engines, including our current cars. Varying proportions of ethanol are used depending on an engines capability. However, special engines have been developed that are capable on running on 100% ethanol.
Hard Biofuels come in different forms but all lie within the 2nd generation group. Low-density biomass sources are compressed into compact pellets, making a highly combustible fuel source. Sawdust, wood chippings and even grass are suitable sources. Hard biofuels are most commonly used for heating and electricity production.
published: 21/08/2015 10:03:30