What is biodiesel?

Biofuels Northern Ireland (UK)

www.biofuels.fsnet.co.uk

 

  • Biodiesel is a transport fuel oil made mainly from organic vegetable oils, although animal fats may be included in the "recipe". The production process is called transesterification. (See below for information on alternatives)

  • It is completely biodegradable, non-carcinogenic, non-mutagenic, non-allergenic and less toxic to daphnia than table salt.

  • It may be used in any diesel motor vehicle without adjustment, and mixed In any ratio with petrodiesel as a lubricity and emissions improver. (NB – older engines may need to have any natural rubber components in the fuel supply system changed but, as a general rule, any post-‘93 vehicle designed to use ULSD is compatible.)  Biodiesel will clean the fuel system of waxes and gums left behind by previous petrodiesel use - including unblocking injectors - but these will be deposited in the fuel filter, which may need to be changed after a few hundred miles.  A warning loss of power is experienced.

  • Biodiesel contains almost as much energy as its fossil counterpart but, due to higher burning efficiency (cetane number) and lubricity, no fall-off of performance will be noticed by the user. What will be noticed is a reduction in black smoke tailpipe emissions – much of the carbon particulate matter is burnt by the oxygenated fuel.

  • Biodiesel costs two to three times as much to make as it costs to produce fossil diesel. This is the reason why the British Government has agreed to reduce the fuel duty rate, so that the use of an environmentally friendly fuel may be promoted.

  • Specifically, HMG has set out to promote the production of biodiesel from recycled cooking oil, thereby discouraging its use as an animal feed supplement – the "ethical switch".

Tailpipe Emissions

The tailpipe emissions from biodiesel are far more people-friendly than those from petrodiesel. They are neither carcinogenic nor mutagenic and cause far less bronchial irritation. EPA confirms that -

Carbon monoxide is reduced by 47%.

Because biodiesel is an oxygenated fuel, much of the harmful carbon monoxide is converted to the dioxide.

Carbon dioxide is increased by 2%.

This doesn’t matter – the plants from which the oil came absorbed the carbon dioxide from the atmosphere when growing. This is carbon recycling.

Particulates are reduced by 48%.      Total unburned hydrocarbons by 67%

This figure may be improved even further by the use of particulate traps. A reduction of 41% was achieved in Belfast during trials with a 22 year old Translink passenger bus after less than 50 miles travelled.

NOx emissions may be increased by up to 10%.

This is using 100% biodiesel in a standard diesel engine without a catalytic converter fitted. A reduction of 4% may be achieved when a catalytic converter is fitted and by retarding the fuel injection timing by 2 or 3 degrees. Using a mix of biodiesel and petrodiesel results in proportionately decreased NOx emissions.

SOx emissions are reduced 100%.

Biodiesel does not contain sulphur other than by trace contamination,.

Lifecycle Emissions

The main reason why the UK is so far behind other EU member states is an incorrect report published in 1995 which stated that the use of biodiesel would save only 60% of carbon dioxide greenhouse gas emissions. This was contrary to all other reports published world-wide, but it has taken many years to overcome government resistance.

No two lifecycle studies have produced the same results, due to the fact that there are so many variables in the crop production equation.

The US Environmental Protection Agency conclusion was that a 78% carbon emissions reduction, versus petrodiesel, is achievable.

www.epa.gov/otaq/models/biodsl.htm

Production of biodiesel from used cooking oils reduces carbon emissions by 90% (DTI).  Every tonne of biodiesel used saves over 3 tonnes of carbon dioxide emissions, thereby reducing global warming.

"Cleaner Fuels"

  • The environmental benefits of biodiesel should not be confused with claims made for versions of fossil fuels such as "green diesel" or "city diesel". All fossil fuels – including compressed natural gas (CNG) and liquid petroleum gas (LPG) - liberate vast amounts of carbon dioxide, which is now universally acknowledged as contributing to global climate change. The carbon has been stored for many millions of years - hence the expression "fossil fuels".

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  • The plants from which biofuels are made extract carbon (dioxide) from the atmosphere, sequestrate a considerable proportion of it in plant roots left in the soil and then liberate the rest when the fuel is used. No additional carbon dioxide is produced.  As a useful by-product, oxygen is produced by the plants from which biofuels are made. Which is a bit of luck for us.

Biodiesel is made from plants which grow again on the same plot of land, year after year after year. The fuel is therefore SUSTAINABLE

(for ever and ever, amen)

  • If your interest in biodiesel has been whetted and you would like to find out more - even to the extent of making it yourself! - there is an interesting little book advertised on -

http://myweb.tiscali.co.uk/chris.garnett/biodiesel/biodiesel_manual.htm

Biodiesel Elsewhere

  • Biodiesel has been used in Europe and the USA for many years.

  • There are over 1800 biodiesel pumps at filling stations in Germany and Austria. It sells at a price no greater than ULSD and sometimes a promotional eurocent or two less.

  • In the main, biodiesel is made from fresh oil in Germany and recycled oil in Austria. There is no appreciable difference in the product.

  • Biodiesel is added to all petrodiesel in France as a lubricity replacement in ultra low sulphur diesel. The three main French oil companies add 5%; Shell International adds just 2%.  They don’t even bother to tell you at the pumps.

  • Germany produces over 800,000 tonnes of biodiesel a year; France, 120,000 tonnes and Italy, 125,000 tonnes. In 2002, total EU production was estimated at 1.1m tonnes.

  • In the USA, production is based on soy oil. Following EPA approval, production is set to quadruple within the next two years.

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  • It is also available in Denmark, Norway, Belgium, Italy, Spain, Sweden, Czechia and Hungary. In most of these countries, a zero tax rate is applied.

Biodiesel was approved by the US Congress for general use  on 22 June 2000 following exhaustive Tier 1 & 2 trials being carried out by the Environmental Protection Agency. It is the only fuel to have been subjected to these trials.

The maximum potential in the UK for recycled oil production under the new tax regime will be 100,000 tonnes.

This is only 1.5% of the petrodiesel fuel used in the UK, or 0.3% of the total transport fuels.

Biodiesel is not the answer to all our future transport problems, but it would form part of the Government’s sustainable transport policy – if they had one. As it is, they haven’t, so it isn’t. But we are slowly getting there.

Other biofuels - your engine may be at risk

You may come across alternative organic fuels based on vegetable oils or tallows that are not chemically refined to produce the mono alkyl esters known generically as "biodiesel". Unfortunately, they may be unapproved mixtures of recovered oils, petrol,  paint thinners or other modifiers - like the "golden elixir" poured through a J-cloth that "astonished" Mr Jeremy Clarkson on the BBC programme Top Gear!   According to researchers at the University of Idaho - Results of these studies indicated that potential hazards such as stuck piston rings ("gumming up"), carbon build-up on injectors, fuel system failure and lubricating oil contamination (polymerisation) existed when vegetable oils were used as alternative fuels.  **

Whilst we would support any valid attempt to produce sustainable transport fuels, it must be stressed that such fuels have not undergone the literally hundreds of successful laboratory tests and long-term vehicle trials that biodiesel has.  This is why members of the ABI(UK) make mono alkyl esters and do not try to take short cuts.   Caveat emptor - it is your engine (even if it is a battered old Volvo 740!)

Reports have been received from UK sources that indicate the commercial exploitation of such mixtures and the subsequent failure of a number of engines.  Trading Standards Officers have been alerted that such fuels may not be suitable when sold for use in unmodified modern direct injection diesel engined vehicles. Amended HMR&C policy has confirmed that the producers of such fuels must pay the Substitute Fuels rate of excise duty - the same as for ULSD.

**Footnote - In fact, the use of straight vegetable oil (SVO) is well-proven and animal tallows have also been used successfully. Both of these fuels, however, require specialised vehicle conversion and tailpipe emissions of particulates (smoke) can be twice that of ULSD - four times the emissions of biodiesel .  

One responsible source of UK SVO information is www.vegoilmotoring.com