New Standard Specification for Triglyceride Burner Fuel
There is a new ASTM Standard Specification. In April 2012, ASTM released ASTM D7666-12 Standard Specification for Triglyceride Burner Fuel. The specification establishes two grades of fuel suitable for use in commercial or industrial air or steam-atomized fuel oil burning equipment for the purpose of heat generation. Triglyceride Burner Fuel (TBF) consists of triglycerides as well as naturally occurring components of triglyceride materials including monoglyceride and diglyceride compounds and free fatty acids. The two grades are identified as TBF5 and TBF6 which are distinguished by limits set for Pour Point as measured in accordance with ASTM D97. TBF5 burner fuel must have a pour point value less than 21oC (70oF); TBF6 burner fuel is designated by a pour point result equal to or greater than 21oC (70oF). Triglyceride burner fuels are not intended for blending with conventional fuel oils, nor are they intended for residential burners, small pressure atomization burners, internal combustion engines, or marine applications. The following test methods are required for a complete evaluation of TBF: pour point (ASTM D97), flash point (ASTM D93), water and sediment (D1796 or D2709), kinematic viscosity at 100oC (ASTM D445), density (ASTM D1298 or D4052), titer (ASTM D1982), acid number (ASTM D664), ash (ASTM D482), sulfur (ASTM D4294 or D5453), insolubles (ASTM D128), and gross heating value (ASTM D240). Many of the methods required by the new D7666 specification require that only a test result be reported wherein there is no specified limit. Pour point is essential to the evaluation to determine if the material will qualify as a TBF5 or TBF6 grade fuel. Other critical tests to consider evaluating early on include ash and gross heating value, since the specification limits for these properties tend to screen off-spec material. By starting with these tests first, particularly with a new material you are developing, you can potentially avoid un-necessary testing costs if the material fails to meet these D7666 specifications. If you would like more information about this new specification, please feel free to contact Gorge Analytical, LLC for a free consultation.
Recent studies and data review by task groups have lead to the development of a new addition to the ASTM standard specification for biodiesel intended to improve the performance of biodiesel-petroleum diesel blends. The quality of biodiesel is critical to performance and acceptance in the market. ASTM International has established the standards by which biodiesel fuel quality is evaluated. These standards are defined by the ASTM Standard Specification D6751. ASTM unites subject matter experts from industry, original engine manufacturers (OEMs), and the scientific and engineering community to develop standards to ensure product performance. The current D6751 standard specification for biodiesel quality designates criteria for a low sulfur (S15) blendstock and a high sulfur (S500) blendstock. A new set of criteria is expected to be released by ASTM within the next couple of months that will maintain the current criteria as the “No.2 grade” fuel while defining a new “No.1 grade” fuel. The No.1 grade fuel will be distinguished by new specification limits for two of the current test methods existing in the standard specification; adjustment of these limits is intended to support improved low temperature operability of biodiesel when mixed with petroleum diesel. Particularly, the new No.1 grade criteria will require that the Total Monoglyceride content not exceed 0.400 % mass. The Total Monoglyceride content is a component of the Total Glycerin content. Review of data suggests that a limit of 0.400 % mass will lower the presence of saturated monoglyceride molecules which have a higher melting point and more readily participate in nucleation to initiate crystal formations that can grow in size and plug filters. In addition to the revised standard for Total Monoglycerides, the new No.1 grade criteria will also require that the Cold Soak Filtration Test results not exceed 200 seconds; (the current limit is a max of 360 seconds). Analysis of monoglyceride compounds is performed by gas chromatography in accordance with ASTM standard method D6584; analysis of cold soak filtration is performed with specific temperature set points in accordance with D7501. If you would like more information about these test methods or the forthcoming new standard specification, please feel free to contact Gorge Analytical, LLC for a free consultation. Additionally, we can assist you in optimizing your process to achieve the new specification limits if producing No.1 grade biodiesel is important to your operation.