Biodiesel operates in conventional engines. 

Just like petroleum diesel, biodiesel operates in combustion-ignition engines. Essentially no engine modifications are required, and biodiesel maintains the payload capacity and range of diesel. Pure biodiesel is not compatible with natural rubber, sometimes found in pre-1994 vehicles. Because it is a solvent, it can degrade natural rubber hoses and gaskets. This is not a problem with B20 blends (20 percent biodiesel/80 percent diesel) and below.

Biodiesel does not require special storage. In fact, in its pure form or in blends, biodiesel can be stored wherever petroleum diesel is stored, except in concrete-lined tanks. It handles like diesel and uses the same infrastructure for transport, storage and use. At higher blend levels, biodiesel may deteriorate natural rubber or polyurethane foam materials.

 

Biodiesel exhaust is less offensive. The use of biodiesel and biodiesel blends results in a noticeable, less offensive change in exhaust odor, which can be a real benefit in confined spaces. In fact, equipment operators have compared it to the smell of French fries. Users also report having no eye irritation. Since biodiesel is oxygenated, diesel engines have more complete combustion with biodiesel than with petroleum.

 

Biodiesel is safer to use than petroleum diesel. The flash point (the point at which fuel ignites) for biodiesel in its pure form is a minimum of 260 degrees versus about 125 degrees Fahrenheit for regular No. 2 diesel. This makes biodiesel one of the safest fuels to use, handle and store.

 

Biodiesel reduces emissions significantly. Biodiesel is the first alternative fuel to have fully completed the Health Effects testing requirements of the Clean Air Act. The use of biodiesel in a conventional diesel engine results in substantial reduction of unburned hydrocarbons, carbon monoxide, and particulate matter. Emissions of nitrogen oxides are either slightly reduced or slightly increased depending on the duty cycle and testing methods. The use of biodiesel decreases the solid carbon fraction of particulate matter (since the oxygen in biodiesel enables more complete combustion to CO2), eliminates the sulfate fraction (as there is no sulfur in the fuel), while the soluble, or hydrocarbon, fraction stays the same or is increased. Biodiesel works well with new technologies such as catalysts, particulate traps, and exhaust gas re-circulation. Soy biodiesel reduces carbon dioxide by 78% on a life cycle basis.

 

Biodiesel improves domestic energy security. By using domestically produced, renewable fuels like biodiesel, the United States can reduce dependence on foreign countries for oil. Biodiesel has the highest energy balance of any fuel, further increasing its value in our energy portfolio. Every unit of fossil fuel it takes to make biodiesel results in 3.2 units of energy gain. Since petroleum diesel has a negative energy balance of .88, every gallon of biodiesel used has the potential to extend our petroleum reserves by four gallons.

Successful alternative fuels fulfill environmental and energy security needs without sacrificing operating performance. Operationally, biodiesel blends perform very similar to low sulfur diesel in terms of power, torque, and fuel without major modification of engines or infrastructure.

Biodiesel offers similar power to diesel fuel. One of the major advantages of biodiesel is the fact that it can be used in existing engines and fuel injection equipment with little impact to operating performance. Biodiesel has a higher cetane number than most U.S. diesel fuel. In more than 50 million on-road miles and countless marine and off-road applications, biodiesel shows similar fuel consumption, horsepower, torque, and haulage rates as conventional diesel fuel.

Biodiesel provides significant lubricity improvement over petroleum diesel fuel. Lubricity results of biodiesel and petroleum diesel using industry test methods indicate that there is a marked improvement in lubricity when biodiesel is added to conventional diesel fuel. Even biodiesel levels as low as one percent can provide up to a 65 percent increase in lubricity in distillate fuels.

Compatibility of biodiesel with engine components. The switch to low sulfur diesel fuel has caused most OEMs to switch to components suitable for use with biodiesel, but users should contact their OEM for specific information. In general, pure biodiesel will soften and degrade certain types of elastomers and natural rubber compounds over time. Using high percent blends can impact fuel system components (primarily fuel hoses and fuel pump seals), that contain elastomer compounds incompatible with biodiesel. Manufacturers recommend that natural or butyl rubbers not be allowed to come in contact with pure biodiesel. Blends of B20 or lower have not exhibited elastomer degradation and need no changes. If a fuel system does contain these materials and users wish to fuel with blends over B20, replacement with compatible elastomers is recommended.

Biodiesel in cold weather. Cold weather can cloud and even gel any diesel fuel, including biodiesel. Users of a 20 percent biodiesel blend with #2 diesel will usually experience an increase of the cold flow properties (cold filter plugging point, cloud point, pour point) approximately 2 to 10° Fahrenheit. Precautions employed for petroleum diesel are needed for fueling with 20 percent blends. Neat (100 percent) biodiesel will gel faster than petrodiesel in cold weather operations. Solutions for winter operability with neat biodiesel are much the same as that for low-sulfur #2 diesel (i.e., blending with #1 diesel, utilization of fuel heaters, and storage of the vehicle in or near a building). These same solutions work well with biodiesel blends, as do the use of cold flow improvement additives.