Designation:D4868−17StandardTestMethodforEstimationofNetandGrossHeatofCombustionofHydrocarbonBurnerandDieselFuels1ThisstandardisissuedunderthefixeddesignationD4868;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1ThistestmethodcoverstheestimationofthegrossandnetheatofcombustioninSIunits,megajoulesperkilogram,ofhydrocarbonfuelsandblendstocksfromthefueldensityandsulfur,water,andashcontents.1.1.1Thistestmethodisnotapplicabletofuelscontainingnon-hydrocarbonssuchasalcohols(forexample,ethanol,methanol),ethers(forexample,MTBE),oresters(forexample,biodiesel).NOTE1—TheequationforestimationofnetandgrossheatofcombustionusedinthismethodwasoriginallypublishedasNBSMiscellaneousPublicationNo.97.1.2Thistestmethodisespeciallyusefulforestimating,usingaminimumnumberoftests,theheatofcombustionofburneranddieselfuels(whichdonotcontainnon-hydrocarboncomponents)forwhichitisnotusuallycriticaltoobtainverypreciseheatdeterminations.NOTE2—Moreaccurateestimationmethodsareavailableforaviationfuels(TestMethodsD1405,D4529,andD3338).However,thoseestima-tionmethodsrequireadditionalteststothoserequiredinthistestmethod.1.3Thistestmethodispurelyempirical(Note1).ItwasderivedusingliquidhydrocarbonfuelsproducedbynormalrefiningprocessesfromconventionalcrudeoilthatconformtotherequirementsofspecificationsforpetroleumfuelsasdescribedinNote3.Thistestmethodisvalidforthosefuelsinthedensityrangefrom750kg/m3to1000kg/m3andthosethatdonotcontainanunusuallyhigharomaticcontent.Higharomaticcontentfuelswillnotnormallymeetsomefuelspecificationcriteria.NOTE3—Theestimationoftheheatofcombustionofahydrocarbonfuelfromitsdensityandsulfur,water,andashcontentisjustifiableonlywhenthefuelbelongstowell-definedclassesforwhicharelationshipbetweenthesequantitieshavebeenderivedfromaccurateexperimentalmeasurementsonr...
