Emissions

Average Biodiesel Emissions Compared to Conventional Diesel,
According To EPA

Emission Type B100 B20
Sulfates -100% -20%
PAH (Polycyclic Aromatic Hydrocarbons)* -80% -13%
Ozone potential of speciated HC -50% -10%

* Average reduction across all compounds measured

Source: National Biodiesel Board Fuel Fact Sheet

Tailpipe Emission Changes with Biodiesel Fuels

Emission Type B100* B20**
Carbon Monoxide -43.2% -12.6%
Hydrocarbons -56.3% -11.0%
Particulates -55.4% -18.0%
Nitrogen oxides +5.8% +1.2%
Air toxics -60% to -90% -12% to -20%
Mutagenicity -80% to -90% -20%
Carbon dioxide*** -78.3% -15.7%

* Average of data from 14 EPA FTP Heavy Duty Test Cycle tests, variety of stock engines

** Average of data from 14 EPA FTP Heavy Duty Cycle tests, variety of stock engines

*** Life cycle emissions

Source: Biodiesel Handling and Use Guidelines, K. Shane Tyson, NREL/TP-580-30004

Selected Fuel Properties
for Diesel and Biodiesel Fuels

Fuel Property Diesel Biodiesel
Fuel Standard ASTM D975 ASTM 6751
Fuel composition C10-C21 HC C12-C22 FAME
Lower Heating Value, Btu/gal 131,295 117,093
Kin. Viscosity, @ 40 C 1.3-4.1 1.9-6.0
Specific Gravity kg/l @ 60 F 0.85 <0.88/td>
Density, lb/gal @ 15C 7.079 7.328
Water, ppm by wt 161 .05% max
Carbon, wt % 87 77
Hydrogen, wt % 13 12
Oxygen, by dif. wt % 0 11
Sulfur, wt % .05 max 0.0 - 0.0024
Boiling Point, C 188-343 182-338
Flash Point, C 60-80 100-170
Cloud Point, C -15 to 5 -3 to 12
Pour Point, C -35 to -15 -15 to 10
Cetane Number 40-55 48-65
Stoichiometric:
Air/Fuel Ratio wt./wt. 15 13.8
BOCLE Scuff, grams 3,600 >7,000
HFRR, microns 685 314

Source: Biodiesel Handling and Use Guidelines, K. Shane Tyson, NREL/TP-580-30004