Biodiesel Basics: What you need to know

Biodiesel Basics: What you need to know

June 25, 2018 0 By Ray Bohacz

Biodiesel’s roots grow deep in the soil of American farms. Yet there is a great deal of misinformation.


The amount of biodiesel in fuel is identified alphanumerically (the letter B and a number). B100 is pure biodiesel. B20 is a blend of 20% biodiesel and 80% petroleum-based diesel.


Biodiesel is manufactured instead of refined. The majority of biodiesel is made from soybeans but it can be made from other grain stocks, oils, or fats.


The soybean is crushed and yields approximately 80% high-protein meal and 20% oil (used for biodiesel). Soybean-based biodiesel is also very efficient; it returns 5.5 units of energy for every 1 unit consumed.


A misconception is that biodiesel requires engine modifications. It is so similar to petroleum diesel that blends of up to B20 work in any engine with no modification. B100 has the ability to degrade rubber lines and gaskets. These need to be replaced with Viton-made parts.


Due to the renewable energy mandate most No. 2 diesel sold is actually B5.


You should not group a biodiesel blend into the same category as B100. This is the major cause of bad information. In your area there may be blends from B5 to B100 and anything in between.


Biodiesel advantages


Biodiesel has a number of advantages over conventional fuel:

  • High lubricity even in blends with as little as 2%.
  • Energy content between 118,170 and 127,042 Btu per gallon. This is similar to #1 diesel but is slightly less than #2 fuel.
  • A high cetane rating. B100 is a minimum of 50 cetane compared to a national average of 40 cetane for conventional fuel.
  • Reduction in emissions. On newer EPA tier-rated engines, biodiesel provides more efficient conversion of pollutants in exhaust system-based controls.


Good practices


Biodiesel has a natural cleaning action and will remove gunk and varnish from fuel storage facilities, equipment fuel tanks, and the engine’s fuel system.


When switching to biodiesel it is best to change all fuel filters (engine and storage tank), and then again at one-half the normal interval. Follow this for two filter changes. Then a normal routine can be employed.


If your on-farm storage tank has a good deal of deposits it would be wise to have it cleaned prior to the delivery of B20 or higher blends.


Biodiesel pitfalls


A pitfall to B100 is that it is too easy to make a poor-quality product. The fuel you purchase must always meet the ASTM standard 6571-12 and needs to be registered in the BQ-9000 Fuel Quality Program. Have the supplier provide proof of meeting these standards.


B20 will cloud and gel at temperatures 10°F warmer than No. 2 petroleum diesel. B100 will gel even sooner. Traditional cold performance additives work just as effectively in biodiesel.


Biodiesel is good for your farm, your engine and America. Use it with pride and confidence!