Significance and Use
This test method provides a measurement of the oxidation stability of biodiesel and biodiesel blends.
The test method may not provide a prediction of the quantity of insolubles that will form in field storage over any given period of time. The amount of insolubles formed in such field storage is subject to the specific storage conditions, which are too variable for this test method to predict accurately.
This test method yields results more rapidly than Test Method D4625, the 43°C bottle test. However, as a result of the significantly elevated temperature and the pure oxygen atmosphere, the nature and amount of insolubles may deviate to a greater extent than Test Method D4625 from those formed in field storage.
1.1 This test method covers a measurement of the oxidation stability of biodiesel (B100) blendstock as specified in Specification D6751 and blends of biodiesel with middle distillate petroleum fuels, including B6 to B20 blends as specified in Specification D7467 under specified oxidizing conditions at 95°C. Specifically, the oxidation stability is assessed by the formation and measurement of insoluble degradation materials.
Note 1—Biodiesel B100, composed of alkyl esters, can have good solubility for some products of oxidative degradation. Thus some B100 samples could undergo significant degradation, but show little or no sediment formation. By contrast, many petroleum diesel fuels have relatively poor solubility for products of oxidative degradation, so Bxx blends, such as B20, could show higher sediment levels. Refer to Appendix X1 for a suggested paraffinic dilution procedure to evaluate oxidative degradation of B100 for degradation materials that are soluble in B100, but insoluble in iso-octane.
Note 2—No. 1 and No. 2 grades in Specifications D396 or D975 currently allow up to 5% biodiesel meeting Specification D6751. This method is preferred for testing these fuels that may contain biodiesel blendstock rather than Test Method D2274 due to the incompatibility of biodiesel blendstock with the membrane filters specified in Test Method D2274.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D381 Test Method for Gum Content in Fuels by Jet Evaporation
D396 Specification for Fuel Oils
D943 Test Method for Oxidation Characteristics of Inhibited Mineral Oils
D975 Specification for Diesel Fuel Oils
D1193 Specification for Reagent Water
D2274 Test Method for Oxidation Stability of Distillate Fuel Oil (Accelerated Method)
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
D4625 Test Method for Middle Distillate Fuel Storage Stability at 43C (110F)
D6751 Specification for Biodiesel Fuel Blend Stock (B100) for Middle Distillate Fuels
D7467 Specification for Diesel Fuel Oil, Biodiesel Blend (B6 to B20)
adherent insolubles; biodiesel fuel; filterable insolubles; oxidation stability; Biodiesel; Biodiesel fuel (B100) blend stock; Middle distillate fuels; Oxidation stability;
ICS Number Code 75.160.20 (Liquid fuels)
ASTM International is a member of CrossRef.
Citing ASTM Standards
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