Running your car on biofuel

Last updated Monday 21 July 2008

Fuel from plants is a growing concern

The gold-rush for a fossil fuel alternative has unearthed a major controversy. Once hailed as 'carbon-neutral', biofuels are now accused of emitting more CO2 than fossil fuels and have even been blamed for causing food riots. They may still have a promising future, but is it too early to start using biofuels right now?

Even if your engine is compatible with a biofuel and you find a local supplier, there's no guarantee filling your tank will save CO2 (with the notable exception of waste vegetable oil). This is because the crop that produced the fuel might have been grown on the site of a former rainforest, or using tonnes of greenhouse-gas-emitting fertiliser. Consequently, switching to biofuel before the industry is properly regulated could actually seriously increase your carbon emissions.

So is the biofuel boom completely bust? Future 'second generation' biofuels, sustainably grown to a recognised standard, still promise very low carbon motoring. Just not yet.

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Photo: Running your car on biofuel

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What is it?

Pub Fact

  • Using Government figures, Dr. Paul Upham at the Tyndall Centre, University of Manchester, calculates that in a worst case scenario, it would take 5,500 years to offset all of the CO2 that would be released into the atmosphere by converting Brazilian forest to soya for biodiesel
  • Even at best, global biofuel production in 2050 could only provide about 25% of the world's demands for transport fuels, according to the OECD Roundtable on Sustainable Development
  • "The overambitious 10% biofuel target is an experiment, whose unintended effects are difficult to predict and difficult to control" - The Scientific Committee of the European Environment Agency
  • Rudolf Diesel's first engine ran on peanut oil when it was exhibited at the Paris World's Fair in 1900
  • The amount of grain required to fill a large petrol tank with ethanol could feed a person for a year
  • Research suggests that it would take four centuries for biofuel farming to offset the emissions that result from ploughing up Indonesian peat lands to make way for palm oil plantations
  • In theory some biodiesels could provide two to six times as much energy as they consume during production
  • In theory the fuel energy value provided by 40million hectares of corn can be produced from 200,000 hectares of algae
  • In theory some biodiesels could provide two to six times as much energy as they consume during production
  • In Bangladesh a 2kg bag of rice now consumes almost half of the daily income of a poor family
  • At present, biofuels made from algae are 4-10 times as expensive to produce as petroleum-derived fuels or other biodiesels
  • Brazil's biofuel programme reduces by 10 million the number of cars running on petrol

Biofuel is fuel made from living organisms, or a by-product of the waste they produce. Today's 'first-generation' biofuels come from processing food crops such as corn, sugarcane, rapeseed and soya. Second-generation biofuels may come from sources as diverse as agricultural debris, algae and waste animal fat.

Biofuel currently being produced from waste vegetable oil already boasts the sustainable qualities promised by the next generation of fuels. It combines a waste disposal solution with a low-carbon fuel supply, scoring multiple sustainability points.

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How will it make a difference?

In theory, burning biofuels should add less CO2 to the atmosphere than fossil fuels. Biofuel crops absorb CO2 during the year or two they grow. This is released when they are burned in engines, restoring the CO2 to the atmosphere. Fossil fuels are effectively fossilised biofuels. They store CO2 from thousands of years ago. When burned, this carbon is released causing an increase in atmospheric CO2.

Scientists argue that the production of some biofuels is such an energy-intensive process that they produce more, not less, climate change than fossil fuels. This is partly due to the use of nitrogen-rich fertilisers to grow fuel crops. Even higher emissions can result from the added pressure to convert tropical forests, grasslands and peat bogs into farmland. The CO2 released from these carbon stores could only be overcome by hundreds of years of biofuel production. This process is described as "profoundly stupid" by John Beddington, a chief scientific advisor to the government. Yet increased use of biofuel remains in EU legislation.

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What's the debate?

"Not all biofuels are born equal"

Calculations of CO2 emissions from biofuels vary widely. One of the most widely-used bio-ethanols, sugar cane bio-ethanol, has been cited as one of the few biofuels to reduce emissions (by about 70% according to the Department for Transport) compared to fossil fuel equivalents. Other sources claim it offers no savings. More research is under way to establish which of the current crops are most sustainable.

"Reforest land or grow biofuel?"

Critics of biofuels say that reforesting land is a much more effective way to tackle climate change than planting biofuel crops - a viewpoint generally supported by research. One study published in the journal Science suggests that planting trees on uncultivated land rather than planting biofuel crops can save between two and nine times more carbon over a 30-year period.

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What's stopping me?

"It said on the news that biofuels cause food shortages"

Growing biofuels has been dubbed 'a crime against humanity' because it requires arable land that could otherwise be used for growing staple food crops. Food prices are soaring - over the last year the average price of food has leapt by almost 40% - and biofuel production is partly to blame. According to the UN, a child could live for a year off the amount of grain required to fill a 50-litre tank with bio-ethanol.

The fact is, though, that there's actually no overall shortage of food - it's just that much of it is ending up as livestock feed, especially for meat cattle.

"Don't they cause extinctions too?"

Paradoxically, our 'ethical' lifestyles may make one of the great apes extinct in the wild within five years, according to the UN. Until there is a sustainability standard for biofuels, scientists and conservationists predict that major adoption - particularly of palm oil - will lead to the conversion of the world's few remaining wildernesses and habitats for endangered species into a patchwork of intensively-farmed monocrops. Even with a sustainability standard in place, some critics would say that the displacement of human activities (like food farming) by biofuel production will lead to deforestation elsewhere.

Palm oil is considered to be the leading cause of deforestation in South-East Asian countries like Indonesia - but palm oil biodiesel is readily available in leading forecourts, according to Greenpeace. Read this Times article.

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How do I do it?

You probably do already - from April 2008 onwards, whatever fuel you buy will be 2.5% biofuel by law, rising to 10% by 2020. Many filling stations already blend 5-10% biofuel with petrol or diesel as standard. But if you want to increase that proportion to 50, 85 or 100%, there are different methods for different engines.

Petrol engines: these can be converted to run on bio-ethanol, but it's usually too expensive to be practical. All petrol cars can run on E5, which contains just 5% ethanol. If you're in the market for a new car, purpose-built flexi-fuel cars can run on old-fashioned petrol, or blends of up to 85% ethanol (E85). E85 is not widely available but can be found at some supermarket forecourts, with plans to expand the network.

Drivers of diesel cars have two options: you can either convert your car at a cost of 1,500 to run on neat vegetable oil or buy processed vegetable oil (biodiesel) that is ready to put straight into your tank. Either option can be near-carbon-neutral if recycled cooking oil is used.

  • Biodiesel comes in three blends: B5, B30 and B100. Blends of over 5% are not compatible with all engines, so check your manual or contact the manufacturer to confirm it's suitable for your car
  • Check for warranty invalidation if your car is quite new
  • Biodiesel blends over 5% are not widely available in major forecourts - in fact, you will almost certainly have to fill up at a less conventional biodiesel filling station. Check that the biodiesel is government standard: BS14214
  • Change your fuel filters regularly to avoid corrosion: biodiesel contains more water than 'fossil' diesel

For diesel drivers in the mood for DIY, there are ways of making your own biodiesel:

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Glossary terms used on this page
Biofuel is a general term for fuel, including biodiesel, that is derived from biomass - living or recently dead organic matter. In general it is made from sugar, starch, vegetable oils or animal fats. Examples include bio-ethanol from energy crops such sugar cane, corn, palm oil, and rape seed.
CO2, or carbon dioxide, is made up of the elements carbon and oxygen. It exists quite naturally in our atmosphere, as part of the carbon cycle. Everyday processes in the plant and animal world both add CO2 to the atmosphere and take it out. However, because it is a greenhouse gas - meaning it affects the temperature of the earth - the exact level of CO2 is important. Burning fossil fuels releases CO2 into the atmosphere, hence the anxiety that extensive use of these fuels is causing climate change.
Sustainability - whether applied to energy, technology, industry, agriculture or just consumption of resources in general - refers to the concept of using things at a rate that, while meeting our own needs, does not compromise future generations' ability to meet theirs. In environmental terms, a process or industry is unsustainable when it requires natural resources to be used up faster than they can be replenished. navigation


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