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