PLEASE NOTE: These bulletins, published since 1997, are historical. The content is not updated.
Natural, renewable resources such as vegetable oils and recycled restaurant greases can be chemically transformed into clean-burning biodiesel fuels. As its name implies, biodiesel is like diesel fuel except that it’s organically produced. It’s also safe for the environment, biodegradable, domestically produced, and produces significantly less air pollution than diesel fuel. It even smells better than diesel fuel-it smells like french fries, donuts, or barbecue.
Biodiesel is one of several alternative fuels, such as ethanol, compressed natural gas, propane, methanol, etc, that are being developed to reduce our reliance on non-renewable petroleum fuels.
Biodiesel is a diesel fuel substitute produced from renewable sources such as vegetable oils, animal fats, and recycled cooking oils. It can be used in unmodified diesel engines. It is safe, biodegradable, and reduces air pollutants such as soot, particulates, carbon monoxide, hydrocarbons and other air toxics. Performance, storage requirements, and maintenance are similar for biodiesel blend fuels and petroleum diesel (petrodiesel).
Biodiesel is usually blended with petroleum diesel for use in diesel engines. A blend called B20, for example, refers to 20% biodiesel, 80% petroleum diesel. Purchasers can benefit from ensuring that biodiesel specified meets the ASTM specification for pure biodiesel (B100) before blending with petrodiesel.
A study by EPA found that biodiesel, B20 (20% biodiesel blended with 80% conventional diesel fuel) reduced total hydrocarbons by up to 30%, Carbon Monoxide up to 20%, and total particulate matter up to 15%. Typically, emissions of nitrogen oxides (NOx) are either slightly reduced or slightly increased depending on the duty cycle of the engine and testing methods used. Increases in NOx can be effectively eliminated with the use of normal mechanical remediation techniques (e.g. catalysts or timing changes). Research also documents the fact that the ozone forming potential of the hydrocarbon emissions of pure biodiesel is nearly 50% less than that of petroleum fuel. Pure biodiesel does not contain sulfur and therefore reduces sulfur dioxide exhaust from diesel engines to virtually zero.
Currently, there are over 50 users of biodiesel in the United States, including transit bus fleets, heavy-duty truck fleets, national parks and military operations, according to the National Biodiesel Board. The use of biodiesel is researched and encouraged by the US Department of Energy and the US Department of Agriculture/Agricultural Research Service. Following is a list of some public agencies that are using biodiesel:
City of Cincinnati: using in 150 buses
A short list of users is available at: http://www.biodiesel.org/resources/users/
John Deere Promotes Use of Biodiesel in Engines -
New warranty statements makes company a leader among engine manufacturers
Greener fuel grabs Northwest attention (biodiesel)
Environmental Purchasing Program
The King County Environmental Purchasing Program assists County agencies in implementation of King County Executive Policy CON-7-1-2, which requires agencies to use recycled and other environmentally preferable products wherever practicable.
The program assembles information about these products and makes it available to specific agency users who can evaluate them and develop applications in County projects.
These environmental purchasing bulletins contain information about the results of product evaluations and other accomplishments of County agencies. We hope this information will help you find ways to use recycled materials in the work of your agency and that you will contact us if we can help you with further information or if you have suggestions.
Environmental Purchasing Program King County Procurement Services Division
Published: February 5, 2002
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Bulletin List
Updated: February 5, 2002
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