| Copyright (c) 2008 Simon Rosser | | | | traditional fuels in automobiles. |
| This second article from The A-Z of Global | | | | Biofuel uses |
| Warming deals with biofuels, which will undoubtedly | | | | The major benefit however probably comes from |
| be a phrase that will be heard a lot more often in | | | | liquid biofuel, for the creation of Ethanol or |
| the future, but what are they?, where do they | | | | biodiesel. Ethanol, a substitute for fossil fuel based |
| come from?, and what is their significance in | | | | petrol, and biodiesel, which is just diesel made with |
| relation to global warming? | | | | crops in place of oil which is a replacement for |
| Biofuels can be described as any fuel that is | | | | traditional diesel fuel in diesel motor vehicles. Whilst |
| derived from biomass ie living organisms or their | | | | diesel cars are more fuel efficient than their petrol |
| metabolic by-products. For example, crops such | | | | counterparts, biodiesel vehicles produce even less |
| as corn and dung from living animals | | | | carbon dioxide. Neither are as efficient however |
| Although there is still somewhat of a scientific | | | | as vehicles running on mostly ethanol-based fuels. |
| debate going on over the advantages of biofuels, | | | | To run on fuel which has a greater than 10% mix |
| it is thought that the main advantage over fossil | | | | of ethanol however, vehicles need a flexi-fuel |
| fuels (coal,oil and gas), is that the burning of | | | | modified engine. |
| biofuels to release energy does not cause a net | | | | The USA grows mainly corn crop, which can be |
| increase of CO2 levels in the atmosphere. This is | | | | converted to ethanol. In Brazil sugar cane is |
| because the source of the biofuel, crops for | | | | grown, and in the UK rapeseed is used. |
| example, have already taken a corresponding | | | | Brazil is at the forefront of biofuel use, using it as |
| amount of CO2 out from the atmosphere during | | | | a fuel in automobiles which have the flex-fuel |
| their growth cycle when they photosynthesise. | | | | engines needed to be able to run on pure ethanol. |
| When this occurs, plants/crops release oxygen | | | | Environmentally friendly or not? |
| and retain the carbon to use as energy. | | | | Despite the benefits of using biofuels, there is a |
| The carbon is then released when the crop is | | | | drawback however, which is the amount of land |
| eventually burnt in order to release its energy. As | | | | required to grow the crops necessary for the |
| long as new crops are planted in place of the | | | | biofuel in the first place. There are already |
| ones that are burnt, there will be no overall | | | | concerns that vast tracts of tropical rainforest like |
| increase in the amount of CO2 released into the | | | | the Amazon in Brazil, are being cleared to plant |
| atmosphere. So, whilst crop based biofuels don't | | | | sugar cane and other crops for biofuel production. |
| reduce the amount of CO2 in the atmosphere, | | | | Another problem is the cost of corn, an essential |
| they are thought to be more or less carbon | | | | ingredient for basic food is also escalating causing |
| neutral. | | | | further problems as the cost of certain products |
| The difference with fossil fuel deposits such as | | | | become unaffordable to many. It would surely be |
| coal is that the coal deposits have been formed in | | | | counter productive if such a situation were to |
| the earth over millions of years and are therefore | | | | develop where the CO2 absorbing tropical |
| considered to be energy deposits rather than part | | | | rainforests were being destroyed to plant crops |
| of the energy cycle. The burning of fossil fuels on | | | | to turn into environmentally friendly biofuels! |
| a scale required to satisfy mankind's energy | | | | There is also a concern that as a by-product of |
| needs, over a relatively short period of time, | | | | growing the corn or other crop used for biofuel |
| hundreds of years as opposed to the millions of | | | | production environmental damage is caused by |
| years it has taken the deposits to form, means | | | | the fossil fuelled tractors, processes, fertilisers etc |
| that the burning of such fuels, adds considerably | | | | used in the growing process, meaning that they |
| to the levels of CO2 in the atmosphere. This in | | | | are not truly carbon neutral at all. |
| turn adds to the greenhouse gases already | | | | Recent research indicates that prairie grasses |
| present in our atmosphere, and contributes to the | | | | actually take out more carbon dioxide from the |
| warming of the Earth's climate. | | | | atmosphere during their growth than they emit |
| Forms of biofuel | | | | when being converted to biofuel, meaning that |
| Biofuels can either be in solid form or liquid form. | | | | they may well be truly carbon neutral. |
| Solid biofuels such as wood or even manure (dried | | | | It would seem more research is needed into |
| cow dung) can be burnt to heat water which can | | | | biofuel production and use, but if grown |
| then be used to power a turbine, which can | | | | responsibly, i.e not on land cleared of rainforest, a |
| generate electricity. Liquid biofuels, such as ethanol | | | | benefit may well be had for the environment by |
| can be used as a substitute or be mixed with | | | | their use. |