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Biofuels – A Future Blessing or a Curse?

Découvrir les sciences de la vie

Is “bio” the magic formula? Biofuels appear to be a sustainable solution for ensuring energy supplies. However, despite numerous benefits, their increasing use also raises critical questions.

Global crude oil resources shrink and the world’s climate goes haywire due to the global warming - however, our society is built upon progress, economy and trade. Global growth and development involves the transportation of goods, raw materials and people back and forth across the planet. It means mobility within cities and countries, throughout continents and around the whole world. All this mobility requires an increasing amount of fuel. Natural resources, however, are limited.

Biofuels are on advance

A few weeks ago Africa celebrated its first commercial flight using biofuel aviation technology. Around 300 passengers flew from Johannesburg to Cape Town using biofuel produced from tobacco plants. Africa has been the last continent to make use of this technology. With this flight, however, biofuel has now become a global phenomenon.

Although this sounds great in principle, in reality it’s just a drop in the ocean. Airplanes cannot use 100 % biofuel; they usually fly with 10 – 30 % biofuel mixed with traditional kerosene. This is due to three reasons: price, availability and the technology required.

With today’s know how it is not possible to produce the large amounts of biofuel required. Moreover, the elaborate production processes still make them an expensive alternative compared to crude oil based aviation fuel. Engines need to be adapted to work with new kinds of fuel. The same factors also explain the small quantity of biofuels used for private cars, road haulage and agriculture. The challenge of the future will be to find a balance between economics and eco-friendliness that allows for the routine use of sustainable biofuels.

Multiple methods and different generations

What exactly are biofuels? What makes them sustainable and why is there still a need for further research? Let’s start from scratch: since the development of internal combustion engines, fuel has mainly been produced from crude oil, however global oil resources are likely to be used up in the foreseeable future. Moreover, carbon, fixed millions of years ago, is now being released into the atmosphere. This high CO2 emission from fossil fuels is harmful to the environment.

Biofuels in contrast are produced through the transformation of renewable raw materials such as oil palm, grain or wood. They have been in use for approximately ten years now. In general, two types of processes can be distinguished. The sugar of carbohydrate rich plants can be used to produce bio-ethanol, a fuel that can provide a substitute for gasoline. Biodiesel and bio-kerosene on the other hand are made from plant oils.First generation biofuels are made from crops like corn, wheat, sugar cane or rapeseed. This is problematic because fuel and food production are effectively in competition. In order to circumvent this issue, methods have been developed to produce second generation biofuels from non-food plants, residual plant material or from fast growing woody plants. Third generation biofuels represent a quite different approach. Their basic material comprises biomass, including oil-rich algae or bacteria which is produced in glass tanks or bioreactors. They don’t compete for land, are not food sources and they grow extremely quickly.

Saving the planet?

Biofuels are a big step towards developing sustainability. Traditional fuels have a large carbon footprint and are partly responsible for climate change. Using biofuels for energy is much eco-friendlier for reducing CO2 emissions. The other side of the coin, however, is that many different factors influence their environmental impact. Any benefits in terms of absorbing atmospheric CO2, for instance, are lost when tropical rainforests are cleared for the cultivation of energy crops. Increasing monocultures will also result in the loss of ecosystem services including biodiversity, soil and water conservation, the regulation of microclimates and cultural benefits to local people.

Saving the planet is the challenge for the century. Simply changing energy sources will only be part of the solution. Be proactive and save energy whenever possible.