Biodiesel FAQ

What is Biodiesel?

Biodiesel is an alternative fuel that can be made from any fat or vegetable oil. It can be used in any diesel engine with few or no modifications. Although biodiesel does not contain petroleum, it can be blended with diesel at any level or used in its pure form.

Biodiesel in fuel applications can exist in two forms, depending if blended or not:

pure (100%) methyl (or ethyl) ester of fatty acids, commonly denoted as B100
2. fuel which contains bio-component (bio-based additive) being methyl (or ethyl) ester of fatty acids. In this meaning the most widely known types of the Biodiesel fuel are the following:
- B20 (20% of pure Biodiesel (fatty acid methyl/ethyl esters) + 80% fossil-fuel diesel)
- B80 (80% of pure Biodiesel (fatty acid methyl/ethyl esters) + 20% fossil-fuel diesel)
- B5 (5% of pure Biodiesel (fatty acid methyl/ethyl esters) + 95% fossil-fuel diesel)
- Other blends containing fatty acid methyl/ethyl esters with varying proportion of them in the final fuel depending on the specifics of the country, where produced/distributed

The term "Biodiesel" is mostly associated and referred to the first meaning (100% renewable fuel). This is specifically typical of scientific & research literature and marketing activities in such countries as: Germany, Austria, USA, Canada and Australia to name only a few.

This portal follows this nomenclature and thus 'biodiesel' is being presented as 100% renewable fuel, and not only as fuel additive or cetane improver.

How is Biodiesel produced ?

Biodiesel is made by reacting any natural oils or fats with alcohol (usually methanol) to produce a new compound - fatty acid alkyl esters: ( --> biodiesel).

Vegetable oils, animal fats, and recycled cooking greases can be transformed into biodiesel using a variety of esterification or transesterification technologies. Oils and fats are composed principally of triglycerides-chemical compounds of fatty acids and glycerin-and free fatty acids. The free fatty acids are bonded with methanol to produce biodiesel under acidic conditions. The triglycerides are transformed into biodiesel and glycerine under base conditions.

	Properties of Biodiesel Biodiesel fuel burns up to 75% cleaner than conventional diesel fuel made from fossil fuels Biodiesel substantially reduces unburned hydrocarbons, carbon monoxide and particulate matter in exhaust fumes Sulphur dioxide emissions are eliminated (biodiesel contains no sulphur) Biodiesel is plant-based and adds no CO₂ to the atmosphere The ozone-forming potential of biodiesel emissions is nearly 50% less than conventional diesel fuel Nitrous oxide (NOx) emissions may increase or decrease but can be reduced to well below conventional diesel fuel levels by adjusting engine timing Biodiesel exhaust is not offensive and doesn't cause eye irritation (it smells like French fries!) Biodiesel is environmentally friendly: it is renewable, "more biodegradable than sugar and less toxic than table salt" (US National Biodiesel Board) Biodiesel can be used in any diesel engine Fuel economy is the same as conventional diesel fuel Biodiesel is a much better lubricant than conventional diesel fuel and extends engine life - a German truck won an entry in the Guinness Book of Records by travelling more than 1.25 million km (780,000 miles) on biodiesel with its original engine Biodiesel has a high cetane rating, which improves engine performance: 20% biodiesel added to conventional diesel fuel improves the cetane rating 3 points, making it a Premium fuel Biodiesel can be mixed with ordinary diesel fuel in any proportion - even a small amount of biodiesel means cleaner emissions and better engine lubrication: 1% biodiesel will increase lubricity by 65% Biodiesel can be produced from any fat or vegetable oil, including waste cooking oil.

See the National Biodiesel Board's complete evaluation of biodiesel emissions and potential health effects, in accordance with the most stringent emissions testing protocols ever required by the US EPA (Acrobat file, 213 kb): www.biodiesel.org/news/bulletin/1998/0498.pdf

Sources:

http://www.journeytoforever.org

http://www.ott.doe.gov/biofuels/renewable_diesel.html