|New ASTM Standard for Pure Biodiesel Helps Clear the Air
Legislation and incentives are driving increased development of environmentally-friendly products. The U.S. Energy Policy Act of 1992 and the Clean Air Act of 1990 have accelerated the development of alternative fuels. Presidential Order 13149, Greening the Government Through Federal Fleet and Transportation Efficiency (2000), requires federal agencies to reduce petroleum consumption and increase the fuel efficiency of their fleets by introducing alternative-fuel powered vehicles. Agencies operating 20 or more vehicles in the United States must reduce their entire motor vehicle fleets annual petroleum consumption by at least 20 percent by the end of fiscal year 2005, compared with FY 1999 petroleum consumption levels.
The Order says the displacement of petroleum by alternative fuels will:
Ensure a healthier environment through the reduction of greenhouse gases and other pollutants in the atmosphere;
Promote markets for more alternative fuel and fuel-efficient vehicles;
Encourage new technologies; and
Enhance the United States energy self-sufficiency and security.
An alternative fuel worth its weight in bacon grease is biodiesel, a biodegradable fuel produced from vegetable oils or recycled restaurant greases, according to the U.S. Department of Energy. Biodiesel reduces serious air pollutants such as particulates, carbon monoxide, hydrocarbons, and air toxins, the DOE explains on its Web site. Blends of 20 percent biodiesel with 80 percent petroleum diesel (B20) can be used in unmodified diesel engines, or biodiesel can be used in its pure form (B100), but may require certain engine modifications to avoid maintenance and performance problems.
ASTM International has developed a new standard to define pure biodiesel: D 6751, Standard Specification for Biodiesel Fuel (B100), Blend Stock for Distillate Fuels. Formerly Provisional Standard PS 121, the new specification wont require existing biodiesel manufacturers to change the way they make biodiesel, says Steve Howell, a chemical engineer who led the standards development since 1994.
Biodiesel fuel can power any type of equipment that runs on diesel fuel, such as trucks, buses, tractors, and snow plows, he says. The purpose of the specification is to provide a quality standard for pure biodiesel (B100) before it is blended with diesel fuel in volumes up to 20 percent, says Howell, the president of MARC-IV Consulting, Inc., which develops industrial products from agriculture.
It defines what biodiesel is (i.e., a mono-alkyl ester of long chain fatty acid of vegetable oils and animal fats) and identifies the physical and chemical properties that it must meet to provide trouble-free operation in conventional diesel applications, Howell explains. While biodiesel can be used in its pure form, most U.S. engine manufacturers did not have sufficient information on levels higher than B20 to approve an ASTM standard for the fuel.
When fuel suppliers register their fuel with EPA, they have to indicate what specification they will use, he says. For diesel fuel, it is D 975 [ASTM D 975, Standard Specification for Diesel Fuel Oils (2002)]. For biodiesel, it will now be D 6751.
According to Howell, a veritable microcosm of the fuel industry either developed or reviewed the standard as members of ASTM Committee D02 on Petroleum Products and Lubricants. They include: chemical and mechanical engineers; chemists; quality specialists; customers; state and federal regulators and agencies; engineers; engine, fuel-injection equipment and petroleum-pipeline companies; third-party consultants; petroleum refiners and distributors; biodiesel producers; and purchasing personnel.
Users can reference D 6751 as an industry consensus standard for the sale or purchase of biodiesel, Howell adds: Without an ASTM standard, each production company and each purchasing company must develop their own set of specifications and negotiate them on every sale. This takes time and money. With an ASTM specification, they can just use it and not have to go through that effort every time they put out a new bid spec or change suppliers.
Similar to the ASTM petrodiesel standard D 975, ASTM D 6751 does not distinguish between the starting raw material or the process used to produce the fueljust the finished quality of the fuel, Howell concludes.
Technical questions may be directed to Steve Howell at MARC-IV, Kearney, Mo. (phone: 816/635-5772). Committee D02 meets June 16-21 in Montreal and Dec. 8-13 in Anaheim, Calif. For meeting or membership details, contact Dave Bradley, manager, ASTM Technical Committee Operations (phone: 610/832-8681). //
Copyright 2002, ASTM