Alternative Fuel Extra: Getting Tested

The American Society for Testing & Materials has established standards which are the Holy Grail for diesel and biodiesel testing. Contractors and manufactures alike stress the importance of using tested and certified biodiesel, and suggest getting proof of certification from a supplier prior to use. Below are the factors tested. The tests with asterisks are biodiesel specific.

• Cloud Point – Determines the temperature at which wax crystals grow large enough to precipitate out of the fuel and become visible.
• Cold Filter Plugging Point – Determines the lowest operating limits of a diesel fuel.
• Pour Point – Determines the lowest observed temperature at which fuel will flow.
• Microbial Contamination – Determines if the fuel sample is infected by harmful micro-organisms, primarily bacteria and fungi, which can cause plugging of strainers, filters, nozzles and injectors as well as form deposits that can damage fuel tanks, lines and pumps.
• Flash Point – Determines the temperature at which the fuel vapors will ignite.
• Water and Sediment – A high content of water and sediment usually results from poor. handling and storage of the fuel, which can cause corrosion of equipment and clogging of fuel injection systems.
• *Free and Total Glycerin – Measures the amount of unconverted or partially converted fats and byproduct glycerin present in the fuel.*Acid
• Number – Is an indicator of free fatty acids and can be elevated if a fuel is not properly manufactured or has undergone oxidative degradation.
• Sulfated Ash – Measures the amount of residual alkali catalyst present in the biodiesel as well as any other ash-forming compounds that could contribute to injector deposits of fuel system fouling.
• *Rancimat Test – Acts as a modified stability test for “neat” 100 percent biodiesel.