Biodiesel refers to a vegetable oil- or animal fat-based diesel fuel consisting of long-chain alkyl (methyl, propyl or ethyl) esters. Biodiesel is typically made by chemically reacting lipids (e.g., vegetable oil, animal fat (tallow)) with an alcohol.
Biodiesel is meant to be used in standard diesel engines and is thus distinct from the vegetable and waste oils used to fuel converted diesel engines. Biodiesel can be used alone, or blended with petrodiesel.
The National Biodiesel Board (USA) also has a technical definition of "biodiesel" as a mono-alkyl ester.[1]
Blends
Biodiesel sampleBlends of biodiesel and conventional hydrocarbon-based diesel are products most commonly distributed for use in the retail diesel fuel marketplace. Much of the world uses a system known as the "B" factor to state the amount of biodiesel in any fuel mix:
- 100% biodiesel is referred to as B100, while
- 20% biodiesel is labeled B20
- 5% biodiesel is labeled B5
- 2% biodiesel is labeled B2
[2] Obviously, the higher the percentage of biodiesel, the more ecology-friendly the fuel is.[3] It is common in the USA to see B99.9 because a federal tax credit is awarded to the first entity which blends petroleum diesel with pure biodiesel. Blends of 20 percent biodiesel with 80 percent petroleum diesel (B20)[citation needed] can generally be used in unmodified diesel engines. Biodiesel can also be used in its pure form (B100), but may require certain engine modifications[citation needed] to avoid maintenance and performance problems[citation needed]. Blending B100 with petroleum diesel may be accomplished by:
- Mixing in tanks at manufacturing point prior to delivery to tanker truck
- Splash mixing in the tanker truck (adding specific percentages of Biodiesel and petroleum diesel)
- In-line mixing, two components arrive at tanker truck simultaneously.
- Metered pump mixing, petroleum diesel and Biodiesel meters are set to X total volume, transfer pump pulls from two points and mix is complete on leaving pump.
Applications
Biodiesel can be used in pure form (B100) or may be blended with petroleum diesel at any concentration in most injection pump diesel engines. New extreme high pressure (29,000 psi) common rail engines have strict factory limits of B5 or B20 depending on manufacturer.[citation needed] Biodiesel has different solvent properties than petrodiesel, and will degrade natural rubber gaskets and hoses in vehicles (mostly vehicles manufactured before 1992), although these tend to wear out naturally and most likely will have already been replaced with FKM, which is nonreactive to biodiesel. Biodiesel has been known to break down deposits of residue in the fuel lines where petrodiesel has been used.[4] As a result, fuel filters may become clogged with particulates if a quick transition to pure biodiesel is made. Therefore, it is recommended to change the fuel filters on engines and heaters shortly after first switching to a biodiesel blend.[5]
Distribution
Since the passage of the Energy Policy Act of 2005 biodiesel use has been increasing in the United States.[6] In the UK, the Renewable Transport Fuel Obligation obliges suppliers to include 5% renewable fuel in all transport fuel sold in the UK by 2010. For road diesel, this effectively means 5% biodiesel.
Vehicular use and manufacturer acceptance
In 2005, Chrysler (then part of DaimlerChrysler) released the Jeep Liberty CRD diesels from the factory into the American market with 5% biodiesel blends, indicating at least partial acceptance of biodiesel as an acceptable diesel fuel additive.[7] In 2007, DaimlerChrysler indicated intention to increase warranty coverage to 20% biodiesel blends if biofuel quality in the United States can be standardized.[8]
Starting in 2004, the city of Halifax, Nova Scotia decided to update its bus system to allow the fleet of city buses to run entirely on a fish-oil based biodiesel. This caused the city some initial mechanical issues but after several years of refining, the entire fleet had successfully been converted.[9][10]
In 2007, McDonalds of UK announced that it would start producing biodiesel from the wasteoil byproduct of its restaurants. This fuel would be used to run its fleet.[11]
Railway usage
British Train Operating Company Virgin Trains claimed to have run the world's first "biodiesel train", which was converted to run on 80% petrodiesel and only 20% biodiesel, and it is claimed it will save 14% on direct emissions.[12]
The Royal Train on 15 September 2007 completed its first ever journey run on 100% biodiesel fuel supplied by Green Fuels Ltd. His Royal Highness, The Prince of Wales, and Green Fuels managing director, James Hygate, were the first passengers on a train fueled entirely by biodiesel fuel. Since 2007 the Royal Train has operated successfully on B100 (100% biodiesel).[13]
Similarly, a state-owned short-line railroad in Eastern Washington ran a test of a 25% biodiesel / 75% petrodiesel blend during the summer of 2008, purchasing fuel from a biodiesel producer seated along the railroad tracks.[14] The train will be powered by biodiesel made in part from canola grown in agricultural regions through which the short line runs.
Also in 2007 Disneyland began running the park trains on B98 biodiesel blends (98% biodiesel). The program was discontinued in 2008 due to storage issues, but in January 2009 it was announced that the park would then be running all trains on biodiesel manufactured from its own used cooking oils. This is a change from running the trains on soy-based biodiesel.[15]
Aircraft use
A test flight has been performed by a Czech jet aircraft completely powered on biodiesel.[16] Other recent jet flights using biofuel, however, have been using other types of renewable fuels.
As a heating oil
Biodiesel can also be used as a heating fuel in domestic and commercial boilers, a mix of heating oil and biofuel which is standardized and taxed slightly differently than diesel fuel used for transportation. It is sometimes known as "bioheat" (which is a registered trademark of the National Biodiesel Board [NBB] and the National Oilheat Research Alliance [NORA] in the U.S., and Columbia Fuels in Canada). Heating biodiesel is available in various blends; up to 20% biofuel is considered acceptable for use in existing furnaces without modification.
Older furnaces may contain rubber parts that would be affected by biodiesel's solvent properties, but can otherwise burn biodiesel without any conversion required. Care must be taken at first, however, given that varnishes left behind by petrodiesel will be released and can clog pipes- fuel filtering and prompt filter replacement is required. Another approach is to start using biodiesel as blend, and decreasing the petroleum proportion over time can allow the varnishes to come off more gradually and be less likely to clog. Thanks to its strong solvent properties, however, the furnace is cleaned out and generally becomes more efficient.[citation needed] A technical research paper[17] describes laboratory research and field trials project using pure biodiesel and biodiesel blends as a heating fuel in oil fired boilers. During the Biodiesel Expo 2006 in the UK, Andrew J. Robertson presented his biodiesel heating oil research from his technical paper and suggested that B20 biodiesel could reduce UK household CO2 emissions by 1.5 million tons per year.
A law passed under Massachusetts Governor Deval Patrick requires all home heating diesel in that state to be 2% biofuel by July 1, 2010, and 5% biofuel by 2013.[18]
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Thu, 12 Aug 2010 21:16:59 GMT+00:00
Reduces CO2 Emissions at Cisco Ottawa Bluesfest MarketWatch (press release) By relying on Rothsay Biodiesel , the 12-day event was able to reduce its lifecycle CO2 emissions by approximately 26000 kg. ...
