Diesel emissions, especially diesel particulate matter, can cause serious health effects—from worsening asthma to an increased risk of cancer. Fortunately, there are several techniques and technologies, ranging in cost, that reduce diesel emissions. Using biodiesel, either as a 100% replacement for diesel, or as a blend of biodiesel and petroleum diesel is a good first step to reduce diesel emissions.
Alternative fuels can either replace diesel fuel entirely or be blended with diesel fuel, like biodiesel. Some fuels must be used in particular vehicles. Ethanol, for instance, requires a flex fuel vehicle that is specially designed to run on gasoline or any blend up to 85% ethanol (E85); natural gas must be burned in specific vehicles.
There are benefits and disadvantages to all fuels. Some fuels, such as compressed natural gas, may provide tremendous environmental benefit; however, current limitations include power, vehicle range and lack of infrastructure. Some biofuels may be available nationally but are in relatively short supply locally. Using alternative fuels as a sole strategy is not likely to be sufficient to meet transport fuel demands, or to address air quality needs. As an air quality strategy, cleaner fuels need to be part of a mix of strategies including combining cleaner fuels with advanced exhaust controls.
What is biodiesel?
Biodiesel is made from a variety of crops such as canola, soybean and palmseed, and can be made from recycled grease. When burned, each of these result in slightly different environmental benefits. Biodiesel can replace diesel fuel entirely (100% biodiesel, “B99 or B100”) or it can be blended with diesel fuel in varying percentages. Biodiesel 5 (5% biodiesel/95% diesel fuel) and Biodiesel 20 (20% biodiesel/80% diesel fuel) are the two most commonly used blends. In terms of environmental benefit, the higher the percentage of biodiesel, the better.
Biodiesel can be directly substituted for diesel as a stand-alone fuel (called B100 for 100% biodiesel), or can be used as an additive in different proportions or blends. This is referred to as B5 (5% biodiesel blended with conventional diesel), B20 (20% biodiesel), etc. It is often used in blends of 2% (partly for lubrication—it is a very good sulfur-free lubricant) or 20%.
Is biodiesel the same as vegetable oil?
No. Fuel-grade biodiesel must be made to strict industry standards in order to insure proper performance. Biodiesel that meets industry standards (ASTM D6751) and is legally registered with the Environmental Protection Agency (EPA) is a legal motor fuel for sale and distribution.
How is biodiesel used?
Biodiesel can be used in diesel vehicles (newer cars, usually 1994 or newer are required for B100—100% biodiesel) and some equipment. It is currently used in many parts of the country in transit buses, school buses, to haul refuse and is also used for on-site electricity generation and heating applications.
Many homes, especially in the Northeastern U.S. use oil to heat their homes. A B20 blend (20% biodiesel) of heating oil is gaining momentum and many distributors are delivering the product to homes.
Where to buy biodiesel
Biodiesel is available nationwide. There are several ways to purchase the fuel. It can be purchased directly from biodiesel producers and marketers, petroleum distributors, or at a handful of public pumps. For a list of registered biodiesel suppliers, see the National Biodiesel Board