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Jun 13

Biofuels – The Benefits and Drawbacks

Biofuels have long been seen as a renewable alternative to fossil fuels. With petroleum and diesel in limited supply, and some analysts predicting their depletion by the middle of this century, research and development has been placed in biofuels in order to reduce our dependence on conventional sources of energy.

Biofuels are typically synthesised from food sources, like corn crop or sugar cane, to create the energy used to power vehicles like passenger cars and aeroplanes. For example, bio-diesel fuel, produced most widely in Europe, successfully converts crops with large amounts of natural oil into a viable fuel source. Bio-petrol, widely produced in Brazil and the United States, synthesises corn or sugar-cane crop to form ethanol. Our fuel industry is now set up with storage tanks and fuel dispensing pumps to supply a range of different fuels including ethanol and biodiesel.

Renewable source of energy

Biofuels offer an attractive alternative to conventional fuels because they are wholly renewable: while fossil fuels would take many thousands of years to regenerate once depleted, biofuels can be redeveloped quickly, providing a source of energy which can be manufactured, at least partially, on demand. However, there is scepticism as to whether biofuels would be able to provide a long-term source of fuel without having severe environmental implications.

Fewer CO2 emissions but long term environmental concerns

Many biofuels are proven to produce lower carbon emissions than petroleum fuels, which is somewhat beneficial from the outset. However, by utilising food crops this poses many difficulties for the world economy. In order to generate additional food crops for the fuel industry, in addition to supplying the food industry, large-scale land use changes would need to be made. This would inevitably involve the destruction of natural habitats, leading to land-use changes we have seen in South America, from cattle farming and timber production. In this respect we would be depleting the supply of fossil fuels with one hand and then destroying our worldwide natural landscapes with the other.

The crops conundrum

Using corn or sugar cane crops for fuel would also put pressure on worldwide food prices, which could lead to famine in particularly poor nations. Food crops also have high-level water requirements, which could also put pressure on worldwide water prices and supplies. There is also scepticism about whether food crops could realistically support the worldwide economy with enough fuel to continue current rates of usage. For corn ethanol to displace gasoline consumption in the United States, around 120 per cent of all cropland would need to be appropriated for corn-ethanol production.

In this respect, the current range of commercially viable biofuels is a short-term solution at best. However, research and development has been continuing into the creation of other forms of biofuels, which could potentially negate the environmental impact of these “first-generation” fuels. Second-generation biofuels, derived from non-food sources such as crop waste or fast-growing grasses, would potentially have little impact on worldwide food prices. Although these fuels are at an early stage of development, and are currently expensive, research has shown that the average cost of production is beginning to fall. However, second-generation fuels would still create land-use changes and would potentially require equally high-level water requirements for synthesis.

Need for technological development

One of the difficulties with biofuels is the volume of useable fuel created compared to the amount of crop harvested, otherwise known as the ‘net energy yield per hectare of land’. If technology developed to allow producers to create large volumes of fuel from a relatively small amount of crop, there could yet be a viable future for biofuels.

Third-generation fuels, which hope to source fuel from algae and bacteria, could yet provide an opportunity for success. These fuels will potentially use genetic modification to produce high yields of long-chain fatty acids. This technology would not require the use of food crops and potentially negate the other disadvantages of conventional biofuels. However, these fuels are still in very early stages of development and will require further investment before they can offer a viable solution.

There is no doubt that biofuels, in principle, are an excellent idea for renewable fuel production; however, technology needs to develop further if they are to become a viable long-term source of energy.

1 comment

  1. easterbrookgibson

    If we could focus less on corn and more on waste from timber, switch grass or cotton fabric clothing production waste. A student science fair project I judged demonstrated how cotton teeshirt production waste could be used to produce biofuel.

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