PETRODIESEL
vs BIODIESEL
Biodiesel
is the only alternative fuel to have fully completed the health
effects testing requirements of the Clean Air Act. The use of
biodiesel in a conventional diesel engine results in substantial
reduction of unburned hydrocarbons, carbon monoxide, and particulate
matter compared to emissions from diesel fuel. In addition, the
exhaust emissions of sulfur oxides and sulfates (major components
of acid rain) from biodiesel are essentially eliminated compared
to diesel.
Of
the major exhaust pollutants, both unburned hydrocarbons and nitrogen
oxides are ozone or smog forming precursors. The use of biodiesel
results in a substantial reduction of unburned hydrocarbons. Emissions
of nitrogen oxides are either slightly reduced or slightly increased
depending on the duty cycle of the engine and testing methods
used. Based on engine testing, using the most stringent emissions
testing protocols required by EPA for certification of fuels or
fuel additives in the US, the overall ozone forming potential
of the speciated hydrocarbon emissions from biodiesel was nearly
50 percent less than that measured for diesel fuel.
Comparison of various properties of Bio Diesel with petroleum
diesel
Property
|
Bio
Diesel
|
Petroleum
diesel
|
|
|
(CARB
low-sulphur diesel)
|
Cetane
number
|
51
- 62
|
44
– 49
|
Lubricity
|
Much
greater than diesel. Comparable to oil lubricants
|
Low-sulphur
fuel has low lubricity factor
|
Biodegradability
|
Biodegrades
readily
|
Poor
biodegradability
|
Toxicity
|
Essentially
non-toxic
|
Highly
toxic
|
Oxygen
|
Up
to 11% free oxygen
|
Very
low
|
Aromatics
|
No
aromatic compounds
|
18-22%
|
Sulphur
|
None
|
0.05%
|
Flash
point
|
300-400
degrees. F
|
125
degrees. F
|
Spill
hazard
|
None
|
High
|
Material
compatibility
|
Degrades
natural, butyl rubber
|
No
effect on natural, butyl rubber
|
Shipping
|
Shipped
as non-hazardous and non-flammable material
|
Hazardous
|
Renewable
supply
|
Renewable
fuel
|
Non-renewable
|
Energy
security
|
Domestic
raw materials
|
Mix
of domestic and imports
|
Alternative
fuel
|
Yes
|
No |
Production
process
|
Chemical
Reaction
|
Reaction
+ Fractionation
|
Source
: National Biodiesel Board, USA
|