alternative fuels fulfill environmental and energy security
needs without sacrificing operating performance. Operationally,
biodiesel performs very similar to low sulfur diesel in terms
of power, torque, and fuel without major modification of engines
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 U.S.
diesel fuel. In over 15 million miles of in-field demonstrations
biodiesel showed similar fuel consumption, horsepower, torque,
and haulage rates as conventional diesel fuel.
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 below 1 percent can provide
up to a 65 percent increase in lubricity in distillate fuels.
of biodiesel with engine components . The recent 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, 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. Biodiesel will
lead to degradation of these materials over time, although the
effect is lessened with biodiesel blends. If a fuel system does
contain these materials and users wish to fuel with pure biodiesel,
replacement with compatible elastomers is recommended.
in cold weather . Cold weather can cloud and even gel
any diesel fuel, including biodiesel. Users of a 20 percent
biodiesel blend will experience an increase of the cold flow
properties (cold filter plugging point, cloud point, pour point)
of approximately 3 to 5° 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).
solutions work well with biodiesel blends, as do the use of
cold flow improvement additives.
Source : National Biodiesel Board, USA