Environmental guidance for your business in Northern Ireland & Scotland

What are biofuels?

Biodiesel, bioethanol and biogas

Transport biofuels are a renewable alternative to limited resources of fossil fuels. They can be liquid or gas and can help to reduce your business transport emissions. The impact that biofuels have on reducing CO2 emissions will depend on where they come from and the way they are produced.

What is biodiesel?

Biodiesel is a substitute fuel produced for diesel engines. It is a renewable fuel made from vegetable oil crops, for example rapeseed or soybean. You can also make biodiesel from waste cooking oils. It doesn't contain petroleum and is biodegradable.

Biodiesel can be mixed with normal diesel to make a blended biodiesel. This is available in a variety of blends including:

  • B5 - 5 per cent biodiesel with 95 per cent ultra-low sulphur diesel, most commonly available
  • B30 - 30 per cent biodiesel blend, only available from a limited number of outlets
  • up to 100 per cent or pure biodiesel (B100), available from specialist suppliers.

You can use the 5 per cent blend with no engine modification and it will not affect your vehicle warranty. You should contact your vehicle manufacturer before using a higher blend as it could affect engine performance and warranty if your engine is not modified.

Energy Saving Trust: Buying a fuel efficient vehicle tool

What is bioethanol?

Bioethanol is a renewable fuel used as a petrol substitute for vehicles. It is made from starches or sugar, for example corn or sugar cane. It is biodegradable and less toxic and explosive than petrol.

You can use bioethanol in different blends to fuel vehicles:

  • E5 - 5 per cent bioethanol with 95 per cent unleaded petrol, most commonly available
  • E85 - 85 per cent blend, from a limited number of outlets.

You won't need to modify your engine to use a 5 per cent blend of bioethanol. Some car manufacturers are starting to sell vehicles that can run on all blends of bioethanol up to 85 per cent. Bioethanol is also becoming more available at filling stations in the UK.

Energy Saving Trust: Buying a fuel efficient vehicle tool

What is biogas?

Biogas is a renewable fuel made from biodegradable materials including maize crops and wastes, such as municipal or food wastes. The main component of biogas is methane. Biogas can be purified to produce liquid biomethane (LBM), which can be used as a vehicle fuel. You can also purify landfill gas to produce biomethane.

Using biomethane can greatly reduce CO2 emissions compared to diesel. It also reduces nitrous oxide emissions and has no particulate (dust) emissions.

Biomethane can be stored as a compressed gas for road vehicles. Any vehicle that can operate on compressed natural gas (CNG) or liquefied natural gas (LNG) can run on LBM.

Some commercial vehicles operate on biomethane, for example heavy goods vehicles, vans and buses. However, a number of new models are due to come onto the market in the next few years.

Energy Saving Trust: Buying a fuel efficient vehicle tool

Other alternative fuels

For details about other alternative transport fuels, see the page on how to use alternatively powered vehicles in our guideline: Reducing your vehicle emissions

Further information

Energy Saving Trust: Buying a fuel efficient vehicle tool

Renewable Energy Association: Renewable transport fuels

Renewable Energy Centre: Biodiesel and bioethanol fuel suppliers

Biodiesel filling stations: Biodiesel outlets

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