ASTM_D_7462_-_11.pdf

Designation:D746211Standard Test Method forOxidation Stability of Biodiesel(B100)and Blends ofBiodiesel with Middle Distillate Petroleum Fuel(AcceleratedMethod)1This standard is issued under the fixed designation D7462;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers a measurement of the oxidationstability of biodiesel(B100)blendstock as specified in Speci-fication D6751 and blends of biodiesel with middle distillatepetroleum fuels,including B6 to B20 blends as specified inSpecification D7467 under specified oxidizing conditions at95C.Specifically,the oxidation stability is assessed by theformation and measurement of insoluble degradation materials.NOTE1Biodiesel B100,composed of alkyl esters,can have goodsolubility for some products of oxidative degradation.Thus some B100samples could undergo significant degradation,but show little or nosediment formation.By contrast,many petroleum diesel fuels haverelatively poor solubility for products of oxidative degradation,so Bxxblends,such as B20,could show higher sediment levels.Refer toAppendix X1 for a suggested paraffinic dilution procedure to evaluateoxidative degradation of B100 for degradation materials that are soluble inB100,but insoluble in iso-octane.NOTE2No.1 and No.2 grades in Specifications D396 or D975currently allow up to 5%biodiesel meeting Specification D6751.Thismethod is preferred for testing these fuels that may contain biodieselblendstock rather than Test Method D2274 due to the incompatibility ofbiodiesel blendstock with the membrane filters specified in Test MethodD2274.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D381 Test Method for Gum Content in Fuels by Jet Evapo-rationD396 Specification for Fuel OilsD943 Test Method for Oxidation Characteristics of InhibitedMineral OilsD975 Specification for Diesel Fuel OilsD1193 Specification for Reagent WaterD2274 Test Method for Oxidation Stability of Distillate FuelOil(Accelerated Method)D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD4625 Test Method for Middle Distillate Fuel StorageStability at 43 C(110 F)D6751 Specification for Biodiesel Fuel Blend Stock(B100)for Middle Distillate FuelsD7467 Specification for Diesel Fuel Oil,Biodiesel Blend(B6 to B20)3.Terminology3.1 Definitions:3.1.1 adherentinsolubles(formerlyadherentgum),nmaterial that is produced in the course of stressing distillatefuel under the conditions of this test and which adheres to theglassware after fuel has been flushed from the system.3.1.2 filterable insolubles,nmaterial that is produced inthe course of stressing the sample fuel under the conditions ofthis test and can be removed from the fuel by filtration.This1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.14 on Stability and Cleanliness of Liquid Fuels.Current edition approved Jan.1,2011.Published March 2011.Originallyapproved in 2008.Last previous edition approved in 2008 as D746208.DOI:10.1520/D7462-11.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 includes both material suspended in the fuel and material easilyremoved from the oxidation cell and oxygen delivery tube withhydrocarbon solvent.3.1.3 total insolubles,nsum of the adherent and filterableinsolubles.3.2 Definitions of Terms Specific to This Standard:3.2.1 zero time,ntime the first of a batch of oxidation cellsis placed in the heating bath.3.2.1.1 DiscussionThis is the time taken as the start of the16 h of residence in the heating bath.4.Summary of Test Method4.1 A 350-mL volume of filtered sample is aged at 95C for16 h while oxygen is bubbled through the sample at a rate of3 L/h.After aging,the sample is cooled to approximately roomtemperature before filtering to obtain the filterable insolublesquantity.The interior of the oxidation cell is also washed withhydrocarbon solvent to re