[Article 69 by kmyhr, 2001-08-13 | 3 Reviews | Review this article]
What is biodiesel fuel?
Biodiesel is a fuel that is made from soy beans, or waste vegetable oil(cooking oil). It can be used in place of petroleum diesel fuel for vehicles or heating oil for buildings. Unlike petroleum diesel, biodiesel is a renewable resource, and it creates less pollution than petroleum diesel. It can be used alone or in combination with petroleum diesel, or with heating oil. Generally, no expensive modifications to the engines are required. This makes it easier to integrate biodiesel into current systems than other alternative energy sources, which often require new equipment.
How is biodiesel made?
Biodiesel fuel is made from oils or fats, which are both hydrocarbons, most commonly soybean oil. These hydrocarbons are filtered, then mixed with an alcohol, which is usually methanol, and a catalyst (sodium or potassium hydroxide). The major products of this reaction are the biodiesel fuel, which is an ester, and glycerol, which has commercial uses, such as in cosmetics.
How is biodiesel labeled?
Biodiesel is designated by the letter B and a number representing the percent of the fuel that is biodiesel. The rest of the fuel is petroleum diesel. For example, a mixture of 20% biodiesel and 80% petroleum diesel would be labeled B20. This ratio of biodiesel to petroleum diesel is commonly used.
What are the advantages of biodiesel fuel?
- Biodiesel fuel is a renewable energy source that can be made from soy beans grown for fuel, or from cooking oils recycled from restaurants. This means it is a renewable resource unlike petroleum-based diesel.
- There is an excess production of soybeans in the United States, therefore biodiesel is an economic way to utilize this surplus.
- Biodiesel is less polluting than petroleum diesel. Compared to petroleum diesel, biodiesel produces less soot (particulate matter), carbon monoxide, unburned hydrocarbons, and sulfur dioxide.
- The absence of sulfur in 100% biodiesel should extend the life of catalytic converters.
- Biodiesel fuel can also be used in combination with heating oil to heat residential and industrial buildings. This can reduce dependence on non-renewable and increasingly expensive heating oil.
- Biodiesel fuel can generally be used in existing oil heating systems and diesel engines without modification, and it can be distributed through existing diesel fuel pumps. This is an advantage over other alternative fuels, which can be expensive to use initially due to high cost of equipment modifications or new purchases. Biodiesel provides almost the same energy per gallon as petroleum diesel.
- The lubricating effects of the biodiesel may extend the lifetime of engines.
What are the disadvantages of biodiesel fuel?
- Biodiesel is currently about one and a half times more expensive than petroleum diesel fuel. Part of this cost is because the most common source of oil is the soybean, which only is only 20% oil. However, the costs of biodiesel can be reduced by making biodiesel from recycled cooking oils rather than from new soy beans, or by making it from plant matter with higher oil content.
- It takes energy to produce biodiesel fuel from soy crops, including the energy of sowing, fertilizing and harvesting.
- Biodiesel fuel can damage rubber hoses in some engines, particularly in cars built before 1994. You should check with the manufacturer before using biodiesel to see if you need to replace any hoses or rubber seals.
- Biodiesel cleans the dirt from the engine. This dirt then collects in the fuel filter, which can clog it. Clogging occurs most often when biodiesel is first used after a period of operation with petroleum diesel, so filters should be changed after the first several hours of biodiesel use.
- Biodiesel is not distributed as widely as traditional, petroleum diesel, but distribution infrastructure is improving.
Where is biodiesel fuel being used now?
- Many municipal fleets, including many in California and city buses in St. Louis, Missouri, run at least partially on biodiesel fuel.
- In California biodiesel fuel is being used by some organic farmers.
- There are public fueling stations for biodiesel in San Francisco, California and one in Sparks, Nevada.
- The Agricultural Research Center of the United States Department of Agriculture uses a biodiesel and heating oil mixture to heat its buildings, and uses biodiesel mixed with petroleum diesel in its farm fleet and tour bus.
- Biodiesel powers some of the marine fleets in Hawaii.
Where can you find out more about biodiesel?
- The alternative fuels data center website is written by the Office of Transportation Technologies (OTT) of the United States' Department of Energy (DOE). This website includes information about what biodiesel is, how it is made, the market for biodiesel, and biodiesel research.
- The website of the National Biodiesel Board (NBB) provides information about biodiesel fuel. The NBB is an organization set up to create a market for biodiesel.
- Biodiesel industries is a group promoting the public distribution and use of biodiesel fuel. Their website has basic information about biodiesel fuel, as well as current information about advances in distribution.
- Pacific Biodiesel, Inc. was formed to find an alternative method of disposing of used cooking oil on Maui. They now also recycle cooking oil in Nagano, Japan.
- The European Union has published information about biodiesel.
- The United States' Department of Energy website has a section on alternative fuels in buses, including a summary of experiments comparing the performance of bus fleets on biodiesel and petroleum diesel.
- The United States' Department of Energy web site has a section on biomass, including biodiesel, as sources of energy.
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