|What is Biodiesel?
Biodiesel is obtained from a chemical reaction. The reaction converts esters from long chain fatty acids into mono alkyl esters. The fatty acid (oil) source for the reaction can be from plants or animals, so it is generally renewable. The oil can be fresh or used (like waste oil from restaurant fuyers). Biodiesel is a direct fuel substitute for #2 petroleum diesel.
The biodiesel reaction requires a catalyst such as lye (NaOH) to split the oil molecules, and an alcohol (methanol or ethanol) to combine with the separated esters. The main byproduct is glycerin. The process reduces the viscosity of the end product.
The single most positive attribute of biodiesel is the fact it is similar to conventional diesel fuel. Changes in existing engines, or fuel infrastructure and storage, are not required. Biodiesel can be used neat (at 100% rate) in any Diesel engine (direct or indirect injection). It can also be blended at any rate with petroleum diesel. Lubrication is improved with biodiesel blends as low as 1%. Winter operating procedures are the same for biodiesel as with #2 petroleum diesel. Biodiesel-fueled engines deliver similar mileage, torque and horsepower.
Biodiesel production can be completed on a small scale with relatively inexpensive equipment. The process is straightforward and methodical and can produce consistent results. Some engine manufacturers, such as Caterpillar, include biodiesel use in their warranties if the biodiesel is produced to specific standards.
Biodiesel is a renewable fuel source. It can be produced from oil from plants or from animal fats that are byproducts in meat processing. Biodiesel and petroleum diesel have comparable life cycle energy efficiencies - about 80% for biodiesel and 83% for diesel. In terms of fossil fuel energy efficiency, biodiesel yields about 3.2 units of fuel product energy for every unit of fossil energy input. Petroleum diesel yields only 0.83 fuel energy units per unit of fossil energy input.
Carbon Dioxide emissions, Total Particulate Matter, and Carbon Monoxide emissions are reduced with biodiesel. Nitrogen Oxide emissions seem to be increased. However, because biodiesel does not contain sulfur, catalytic converter technology is more effective at countering nitrogen oxide emissions. Biodiesel degrades quickly in the environment, and is nontoxic. It is safer than diesel because it has a high flash point (over 300° F/150° C).
The real cost of biodiesel technology is contained in the oil feedstock. Batch processing methods used for transesterification (the chemical reaction) are not greatly affected by economies of scale. A small scale producer would see about the same benefit as larger scale production, assuming oil costs were the same. A biodiesel producer may be able to obtain sufficient quantities of waste vegetable oil to supply their fuel requirements at zero or minimal charge. If producing an oil seed crop to be pressed for oil for biodiesel, close consideration must be given to yield and cost of inputs. An oil extruder would be required unless the extraction was contracted out.
What Are Some Problems with Biodiesel?
Biodiesel is typically problem-free when used as a direct replacement for #2 petroleum diesel in Diesel engines. Degradation of rubber components will occur over time and could be replaced preventatively or as required.
Carbon deposits left by petroleum diesel will be lifted and may foul the fuel filter on initial break in period. Biocide additives may be required when biodiesel is stored in hot and humid conditions. The initial cost of setting up small scale production could be as low as a few hundred dollars. However, (depending on the cost of the oil source) the finished product may be less cost effective than conventional diesel at this time.
Where Can I Obtain Biodiesel?
Biodiesel is not presently available for retail sale in Canada. It could be produced by individuals on a small scale by chemical transesterification of oil feedstock in a batch process. Fuel taxes may need to be remitted according to applicable regulations. Biodiesel can be mixed at any rate with petroleum diesel, or used at a 100% rate in any Diesel engine.
For more information
Kelly Lund , E.I.T.
#306, 7000 - 113 Street
Edmonton, Alberta T6H 5T6