(7.1)-任务1（1.1）测定水溶性酸、碱的意义

Task1(1.1)SignificanceofDeterminationofWaterSolubleAcidandAlkaliⅠ.thesignificanceofdeterminingwater-solubleacidsandalkalis1.Water-solubleacid,alkali

water-solubleacidandalkaliinpetroleumproducts,refertothosemixedwithoilproductsduringrefining,transport,andstorage,whichwillaffectthequalityofoilproducts.Similarly,iflawenforcementofficersdeceiveormisleadpeople,notonlydoesitharmthelegitimateinterestsofthepeoplebutalsoshaketheParty'spositionamongthepeople.Therefore,thePartyshouldbestrictlygoverned.

2.Meaningofdetermination(1)Itispredictedthatthecorrosivewater-solubleacidoftheoilhasastrongcorrosiveeffectonalmostallmetals,especiallywhenthereiswaterintheoil,itscorrosionismoreserious.(2)Water-solubleacid,unqualifiedalkaliandrefinedoilarenotallowedtoleavethefactory.(3)thedetectionofwater-solubleacidandalkaliinGuidetheproductionofoilproductsindicatesthattheacid-baserefiningprocessisnotcompletelytreatedandtheprocessconditionsneedtobeoptimized.II.OverviewofMethodofdeterminationAccordingtoGB/T259-1988StandardTestMethodforDeterminationofWater-solutionAcidandAlkaliinPetroleumProducts.Suitableforthedeterminationofliquidpetroleumproducts,additives,greases,paraffinwax,groundwaxandwater-solubleacidsandalkaliscontainingwaxcomponents.

Measurementfundamentals:mixthesamplewithdistilledwaterofequalvolume,Aftershaking,oilandwateraresufficientlycontactedwitheachother.Thewater-solubleacidandalkaliareextractedintowater.SeparatethewaterphasefromthebottomoftheseparatingfunnelUsemethylorange,phenolphthaleinindicatororanacidimetertomeasureitspHvaluesoastodetermineifthereiswater-solubleacidandalkaliinthesampleII.OverviewofMethodofdetermination

Forgasoline,solventoilandotherlightpetroleumproducts,extractsampleswithdistilledwateratnormaltemperaturewhosekinematicviscositygreaterthan75mm2/sat50℃.Thesampleneedstobedilutedwithaneutralsolventandthenbeextractedbyadding50~60℃distilledwater;Forsolidsamples,adddistilledwateraftersamplingandheatittoasolidmeltingstateII.OverviewofMethodofdeterminationSampleExtractionmethodLightPetroleumProductsExtractwithdistilledwateratroomtemperatureKinematicviscosityat50℃isgreaterthan75mm2/sAfterdilutingthesamplewithneutralsolvent,add50～60℃distilledwaterforextractionSolidstateAdddistilledwatertothesampleandheatituntilthesolidsaremeltedforextractionIfemulsionthatisnoteasytoseparateisshapedwhenthesampleismixedwithdistilledwater,use50~60℃95%ethanolwatersolutionat1:1ratiotoextract.AdddilutionsolventifnecessarytoreducetheviscosityofthesamplesoastorealizeUseacid-alkaliindicatortojudgetheexistenceofwater-solubleacidandalkaliinthesample:Ifthesolutiondoesnotdiscolormethylorange,thesampledoesnotcontainwater-solubleacid.Ifthesolutiondoesnotdiscolorphenolphthalein,thesampledoesnotcontainwater-solublealkali.ThepHvalueisusedtojudgeiftherearewater-solubleacidandalkaliinthesampleasshowninTable7-1.Whenthereisaninconsistencyinthequalityevaluationofoilproducts,thearbitrationtestofwater-solubleacidandalkalishouldapplytheacidimetermethod.2．Maininfluencingfactorsoftesting(1)SamplinguniformityThesampleshouldbeshakenthoroughlybeforesampling.Whenmeasuringwater-solubleacidandalkaliinsolidpetroleumproductslikeparaffinandozoceritewhichcontainswaxingredients,heatandmeltthesamplebeforesampling.(2)Reagentandvesselcleanness.Dilutionsolventssuchasextractionsolventsandgasolinemustbeneutral,andinstrumentsmustbeclean.

(3)Sampleviscosity.Ifthekinematicviscosityofthesampleisgreaterthan75mm2/sat50℃,thesamplecanbedilutedwithadiluentsolventandheatedtoacertaintemperaturebeforebeingmeasured.(4)Oilemulsification.Whenthesampleismixe