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What is Biodiesel?

Biodiesel is a renewable fuel. It is used to fuel diesel engine vehicles with no change to the engine. It is biodegradable and non-toxic and has significantly fewer emissions than petrodiesel when burned. Typically biodiesel is blended with low sulfur petrodiesel to produce fuel grades B5 (5% biodiesel) and B20 (20% biodiesel).

Biodiesel Production

Biodiesel is made from straight vegetable oil (soy, canola, palm, castor); waste vegetable oil; or animal fats and reacted with methanol using a high performance organic base catalyst like Green Catalysts’ SMO 30 to produce a methyl ester (biodiesel) and glycerine.

Biodiesel production  uses an organic chemical process called transesterification . Vegetable oils and animal fats are typically made of triglycerides which are esters of free fatty acids with the trihydric alcohol, glycerol. In the transesterification, the alcohol is deprotonated with a base to make it a stronger nucleophile. Commonly, methanol is used. The resultant methyl ester (biodiesel) has excellent properties for use as a biofuel in compression ignition engines. Glycerin is a byproduct.

Green Catalysts’ SMO 30 and SMO 25

Green Catalysts ultra low moisture SMO 30 and SMO 25 are ideal organic base catalysts for biodiesel production. They provide several advantages to commercial-scale biodiesel producers including:

  • Improved biodiesel yield
  • Reduced soap formation
  • Higher quality glycerin
  • Lower production cost

University of Idaho, College of Agricultural and Life Sciences

Technical Note: Comparison of Alkaline Catalysts for Biodiesel Production.

Process tech graphic

Biodiesel Facts

Biodiesel is much cleaner than fossil-fuel diesel (“dinodiesel”). It can be used in any diesel engine with no need for modifications – in fact diesel engines run better and last longer with biodiesel. And it can easily be made from a common waste product – used cooking oil.

  • Biodiesel fuel burns up to 75% cleaner than conventional diesel fuel made from fossil fuels
  • Biodiesel substantially reduces unburned hydrocarbons, carbon monoxide and particulate matter in exhaust fumes
  • Sulphur dioxide emissions are eliminated (biodiesel contains no sulphur)
  • Biodiesel is plant-based and adds no CO2 to the atmosphere
  • The ozone-forming potential of biodiesel emissions is nearly 50% less than conventional diesel fuel
  • Nitrogen oxide (NOx) emissions may increase or decrease but can be reduced to well below conventional diesel fuel levels by adjusting engine timing and other means
  • Biodiesel exhaust is not offensive and doesn’t cause eye irritation (it smells like French fries!)
  • Biodiesel is environmentally friendly: it is renewable, “more biodegradable than sugar and less toxic than table salt” (US National Biodiesel Board)
  • Biodiesel can be used in any diesel engine
  • Fuel economy is the same as conventional diesel fuel
  • Biodiesel is a much better lubricant than conventional diesel fuel and extends engine life — a German truck won an entry in the Guinness Book of Records by travelling more than 1.25 million km (780,000 miles) on biodiesel with its original engine
  • Biodiesel has a high cetane rating, which improves engine performance: 20% biodiesel added to conventional diesel fuel improves the cetane rating 3 points, making it a Premium fuel
  • Biodiesel can be mixed with ordinary petroleum diesel fuel in any proportion, with no need for a mixing additive.
  • Even a small amount of biodiesel means cleaner emissions and better engine lubrication: 1% biodiesel will increase lubricity by 65%
  • Biodiesel can be produced from any fat or vegetable oil, including waste cooking oil.


Biodiesel Resources

National Biodiesel Board

European Biodiesel Board

University of Idaho – Biodiesel Fuel Education Program

Biodiesel – Wikipedia