Ethanol & Biodiesel

There are a number of biofuels which include vegetable oil, biodiesel, bioalcohols, bioethers, biogas and syngas which are produced from biomass. Biofuels are to some extent renewable as their source materials absorb carbon from the atmosphere as they grow and this carbon is recycled into vehicle fuel.

First generation biofuels come from crops such as sugar cane, corn and wheat which are used to produce bioalcohols like ethanol by fermentation. Crops that produce large amounts of vegetable oil like soybean and palm oil can be used to produce biodiesel.

Environmental considerations

Some of the concerns with these two crop types is they have, in some cases, been grown in direct competition for food production and/or the requirement to expand crop producing areas has resulted in loss of other habitats. These problems can be prevented with careful selection of location and crop choice and with developing second generation biofuels. The Jamison Group of scientists, sponsored by NRMA, advocates developing sugar cane plantations for ethanol production in Northern Australia, with due attention to environmental impacts.

Second generation biofuels are based on non-food crops and products such as waste from crop production and other agricultural and forestry activities. Methanol and syngas can also be produced from second generation processes. Secondary methods use enzymes to convert any cellulose material, such as wheat straw, bagasse or trees, to ethanol. This method has not yet been shown to be economically viable but extensive research is continuing. The use of algae to produce biodiesel is attracting attention but this process also has not yet been shown to be economically competitive.

"We're picking the low hanging fruit in biofuel production now," said Dr Mark Diesendorf from the Institute of Environmental Studies at the University of NSW. "We can achieve far more efficient extraction of biofuels with new genetic engineering. We can also incorporate the burning of biofuel residues into renewable electricity production," he said. For more detail on biofuels see the Jamison Group Report page 41.

Ethanol

Biofuels are already available in the form of ethanol - e.g. E10 is now widely available. Biodiesel is available at a limited number of service stations - for example all Caltex diesel in the Newcastle region contains 2 per cent biodiesel.

The NSW Government has mandated that all diesel must contain 2 per cent biodiesel.

By July 2012 the E10 mandate should ensure that 6 per cent of all fuel sold in NSW is ethanol blended E10.

Vehicle suitability

Most cars are suitable for E10 but if you are thinking of using it you should check your vehicle's suitability.

If your vehicle is suitable try a couple of tanks of E10 to see if your vehicle operates normally, without pinging or rattling noises from the engine. Vehicles built before 1986 should not use any ethanol.

Ethanol has a solvent effect, so in older vehicles the first one or two tankfuls of E10 may cause the gums and dirt in the fuel tank and lines to loosen and deposit in the fuel filter. This may cause the vehicle to stop and require the filter to be changed once or twice.

To avoid operational issues, vehicles should be maintained in accordance with manufacturer's servicing procedures using genuine replacement parts. This will ensure that the fuel systems of vehicles listed as suitable to use E10 blended petrol continue to be ethanol tolerant.

E85 (85 per cent ethanol/15 per cent petrol) has recently been introduced to the Australian market. Motorist should not use this fuel unless their vehicle is designed to use it. Using in a vehicle NOT designed for it will mean the vehicle either will not start or will run very roughly.

Research also shows that using pure or blended biodiesel with standard fuel can reduce greenhouse gas emissions from transport though this depends on the source of the feedstock (CSIRO).

The highest greenhouse gas (CO2) savings are obtained by replacing base diesel with biodiesel from used cooking oil. Palm oil can produce up to an 80 per cent saving in emissions provided it is sourced from pre-1990 plantations.

More about the future of fuel

• Alternative Fuels and Technologies
• Biofuels: Ethanol & Biodiesel
• Hybrids
• Electric Vehicles (EVs)
• Hydrogen
• Gaseous fuels