One of the ways to decrease these impacts is to consider vegetable
oil as a source of renewable fuels for transportation and heating.
Waste fry oil from the food industry, fresh-pressed vegetable oil from
agriculture, and even animal fat can be used as materials for fuel.
The benefits of using these sources to displace fossil fuels can
include reduced air pollution, reduced greenhouse gas emissions, and
conservation of limited fossil fuels.
There are basically two common ways to use vegetable oil as a fuel
in an engine. One way is to use straight vegetable oil, either waste
fry oil or fresh-pressed oil. This requires an extra fuel tank and a
system for heating and filtering the oil before it reaches the engine,
because pure vegetable oil is too thick to work in the engine unless
the oil is heated up. Another way is to convert the vegetable oil into
biodiesel, which can be used in a diesel engine without any
What is Biodiesel?
Biodiesel is made from vegetable oil by a chemical reaction with
methanol and lye (sodium hydroxide). It can be made using waste
vegetable oil from the food industry, including french fry oil, or
from fresh-pressed vegetable oil. It is now being made in commercial
quantities of thousands of litres by numerous companies around the
world. It can also be made at home with some fairly simple equipment
and instructions. This requires care and caution because some of the
materials are caustic (the lye), flammable (the methanol), and
poisonous if ingested (both the lye and the methanol).
Pure biodiesel, called B100, works as a fuel in ordinary,
unmodified diesel engines, but certain precautions have to be observed
for good results. B100 has two characteristics that need to be
considered: (1) it can dissolve neoprene rubber over time, so you
would need to ensure that hoses and gaskets in the engine are made of
another material, such as Viton, that is resistant to biodiesel; and
(2) it "clouds" or "gels" at temperatures below
about +5 degrees Celsius, so you have to be careful not to allow the
fuel to get cold, or it will gel and block the fuel filter, preventing
the engine from running until it warms up again. Other than that,
there have been no serious changes in engine performance or durability
reported from using B100.
Blends of between 5% and 20% biodiesel (B5 to B20), with the rest
being petroleum diesel, have been used successfully in many kinds of
diesel vehicles such as buses, cars, and trucks, with no modification
to the vehicle. By using a lower blend, there is less risk of
dissolving fuel gaskets or gelling in cold weather. For example, 10%
biodiesel mixed with "winter" diesel should be operational
down to about minus 39 degrees Celsius, according to one operator of
biodiesel trucks in Quebec.
(photo: Falls Brook Centre)
In New Brunswick, Falls Brook Centre operated its "Climate
Change Bus" on a blend of 30% to 60% biodiesel during its 2003
season (May to October), with excellent success. Montreal's public
transportation system has also conducted a trial, using a biodiesel
blend in 150 urban transit buses for a full year, including winter.
Biodiesel can also displace heating oil. The Chewonki Foundation in
Maine, which produces its own biodiesel from local food industry
waste, is using biodiesel in fuel-oil furnaces, in addition to
fuelling diesel vehicles with straight B100 biodiesel.
this PDF file) .
Benefits of Biodiesel
When biodiesel displaces petroleum diesel, there is an estimated
78% average reduction of greenhouse gas emissions per litre, compared
with petroleum diesel, over the life cycle of the fuel (National
Biodiesel Board of the USA). Actual reductions depend on the source of
the materials used to make the biodiesel. Greenhouse gas savings could
be higher when biodiesel is made locally from waste food oil products.
Several toxic air pollutants are also reduced by using biodiesel,
including soot, particulates, carbon monoxide, and sulphur oxides,
although nitrous oxide emissions may increase slightly. Biodiesel is
non-toxic, biodegradable, and safer to handle than petroleum diesel.
It requires no special storage considerations, because its flash point
is higher than that of petroleum diesel.
Straight Vegetable Oil:
If you have a diesel vehicle and you are handy with modifying fuel
tanks and lines, another way to bring renewable fuel into your life is
to use waste fry oil directly in your vehicle. This requires you to
install an extra fuel tank and a fuel heating and filtering system
that uses the heat from the engine to keep the vegetable oil hot
enough to work. In this system, the engine is first started on regular
petroleum diesel (or any blend of biodiesel) in the regular tank, and
run until it warms up the vegetable oil tank to the proper
temperature. Then you turn a switch to bring the hot veggie oil to the
engine. Before shutting off the engine, you switch it back to diesel
for a couple of minutes.
Tim and Shelley Smith of Bridgewater, Nova Scotia, are using this
system to run a Volkswagen Jetta. Straight veggie oil in a similar
system was also used by New Brunswick's own Climate Change Caravan to
fuel their bus on its cross-Canada journey in 2001. These experiences
have shown that good filtering of the vegetable oil is important to
lengthen the life of the engine.
The straight vegetable oil system requires some work to the
vehicle, but it has advantages. The oil can be used directly, saving
the methanol, lye, and processing effort that would have been required
to make it into biodiesel.
The most comprehensive book on using vegetable oil as a fuel
is: From the Fryer to the Fuel Tank, by Joshua Tickell
Also, there are several people in New Brunswick who are using
and/or making fuels based on waste food oil. You can contact Wayne at
Falls Brook Centre if you have specific questions. If we don't know
the answer, we can try to direct you to someone who does. Phone: