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Biodiesel for Transit...
Transit fleets report positive experiences
with biodiesel. City bus fleets that have used biodiesel include
those in Cedar Rapids, Iowa; Cincinnati, Ohio and St. Louis,
Missouri. Bi-State Development Agency in St. Louis conducted
one of the first demonstration
projects using biodiesel blends in Call-a-Ride vans to
evaluate its suitability as a motor fuel. The evaluation revealed
that:
- Biodiesel is a viable motor fuel
- Performance and fuel economy were
unchanged
- Exhaust emissions improved dramatically
- The fuel was fully compatible with
vehicle and fuel dispensing equipment
Based on these positive results, the Agency continued biodiesel
use in the entire paratransit fleet.
Click here to see study
Click here to
see user testimony
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,
so those would need to be changed to more modern material
if B100 is desired. This is not a problem with B20 blends
(20 percent biodiesel/80 percent diesel) and below.
Biodiesel exhaust is less offensive. The use of biodiesel
and biodiesel blends results in a noticeable, less offensive
change in exhaust odor. 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 more than
200 degrees versus about 125 degrees Fahrenheit for regular
No. 2 diesel. This makes biodiesel the safest fuel to use,
handle and store.
Click here
for a sample material safety data sheet
Click
here for environmental and safety information
Biodiesel has a full ASTM fuel
specification. The American Society of Testing and Materials
(ASTM) issued Specification D 6751 for all biodiesel fuel
bought and sold in the U.S. in March of 2002, marking a major
milestone for the biodiesel industry.
Having a full standard in place helps
protect consumers from poor products and reduce the cost of
buying and selling biodiesel. While many adopted the provisional
specification in 1999 (PS 121), those that didn't had to negotiate
a specification. The final passage of D 6751 streamlines the
procurement process.
Those interested in getting a copy
of the standard can buy it at www.astm.org.
To contact ASTM customer service directly, call (610) 832-9585
or e-mail service@astm.org.
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 recirculation. Soy biodiesel reduces
carbon dioxide by 78% on a life cycle basis.
Click here for emissions
data
Click
here for a DOE life cycle report
Click here for
Tier I and Tier II Health Effects data
Please assist us
in advancing the biodiesel
product and in keeping this site current and
informative by completing a short survey.
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