What is biodiesel?
Biodiesel is a liquid fuel made up of fatty acid alkyl esters, fatty acid methyl esters (FAME), or long-chain mono alkyl esters. It is produced from renewable sources such as new and used vegetable oils and animal fats and is a cleaner-burning replacement for petroleum-based diesel fuel. It is nontoxic and biodegradable. Biodiesel has physical properties similar to those of petroleum diesel:
| Biodiesel's Physical Characteristics | |
|---|---|
| Specific gravity | 0.88 |
| Kinematic viscosity at 40°C | 4.0 to 6.0 |
| Cetane number | 48 to 65 |
| Higher heating value, Btu/gal | 127,042 |
| Lower heating value, Btu/gal | 118,170 |
| Density, lb/gal at 15.5°C | 7.3 |
| Carbon, wt% | 77 |
| Hydrogen, wt% | 12 |
| Oxygen, by dif. wt% | 11 |
| Boiling point, °C | 315-350 |
| Flash point, °C | 100-170 |
| Sulfur, wt% | 0.0 to 0.0024 |
| Cloud point, °C | -3 to 15 |
| Pour point, °C | -5 to 10 |
Like petroleum diesel, biodiesel is used to fuel compression-ignition (diesel) engines. Low-level blends of biodiesel with petroleum diesel also provide benefits.