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

 

   
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