About Biodiesel
Biodiesel:
Biodiesel is a clean burning alternative fuel, produced from renewable resources. Biodiesel contains no petroleum, but it can be blended at any level with petroleum diesel to create a biodiesel blend. It can be used in compression ignition (diesel) engines with little or no modifications.
Caveats Specifics:
- • Biodiesel provides a significant increase in combustion smoothness (anti-knock), due to its high Cetane content of over 50. Biodiesel’s oxygen content (11% w/w) provides better combustion – improving the efficiency of the engine.
- • The lifecycle production and use of Biodiesel produces approximately 80% less carbon dioxide emission, and almost 100% less sulfur dioxide.
- • Biodiesel is a solvent, meaning it may lossen and /or dissolve sediments in fuel tanks and fueling systems left from years of conventional diesel use. It is recommended that the fuel filter be changed 1-2 months after the first use of biodiesel.
- • Biodiesel may ‘gel’ at low temperatures (<17oC), which can cause filter plugging and/or stress on fuel pumps and fuel injection systems. It is recommended that in cold temperatures, low biodiesel blend levels be used (< B20).
- • Biodiesel use over time may soften and degrade certain type of rubber compounds found in the hoses and gaskets of older model cars and trucks (pre-1995). It is recommended that in such older vehicles, synthetic rubber hoses be used. This is the only engine modification that may be needed.
- • Biodiesel in fungible, meaning that if left n storage it will, over time, attract water and perhaps other microbes that may lead the fuel to become out of specification with international standards (ASTM/EN)
- • The recommended shelf life of biodiesel is between 6 – 9 months, with Palm Methyl Esters having the greatest stability of all possible feedstocks.
Running on Biodiesel:
The energy content of conventional diesel can vary up to 15% from supplier to supplier or from summer to winter. This variability in conventional diesel is due to changes in its composition which are determined by refining and blending practices.
The efficiency of diesel engines is the same whether using biodiesel, diesel, or biodiesel blends so differences in horsepower, torque or fuel economy are due entirely to volumetric energy content. The energy content of biodiesel is much less variable than that of petrodiesel, and with biodiesel meeting D6751 standards, the energy content is more dependent upon the feedstocks used than the particular process. Blends of biodiesel and diesel fuel fall between the parent fuels.
Selected Properties of Typical Diesel and Biodiesel Fuels
Fuel Property Diesel Biodiesel
Fuel Standard ASTM D975 ASTM D6751
Kinematic Viscosity 1.3 – 4.1 4.0 – 6.0
Specific Gravity, Kg/L @ 60oF 0.83 0.86
Water and Sediment, vol % 0.05 max. 0.05 max.
Carbon, wt % 87 77
Hydrogen, wt % 13 12
Oxygen, by dif. Wt % 0 11
Sulfur, wt % 0.05 max. 0 to 0.0024
Boiling Point oC 180 – 340 315 – 350
Flash Point oC 60 – 80 100 – 170
Cloud Point oC – 15 to 5 – 3 to 18
Pour Point oC – 35 to – 15 – 15 to 14
Cetane Number 40 – 55 48 – 65
Lubricity SLBOCLE, grams 2000 – 5000 > 7000
Lubricity HFRR, microns 300 – 600 < 300
