ASTM_D_8253_-_21.pdf

Designation:D825321Standard Test Method forDetermination of the Asphaltene Solvency Properties ofBitumen,Crude Oil,Condensate and/or Related Productsfor the Purpose of Calculating Stability,Compatibility forBlending,Fouling,and Processibility(Manual MicroscopyMethod)1This standard is issued under the fixed designation D8253;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 the use of a basic microscope todetermine the asphaltene solvency properties of bitumen,crudeoil,condensate or related products,or the combinationsthereof.These properties can be used to calculate the solubilityparameters required to calculate and predict asphaltene stabil-ity for blending purposes,refinery unit fouling,processibility,emulsion stabilization,pipeline and tank deposition,and equip-ment fouling.If the solubility properties are known for twoproducts,then the compatibility of potential blend ratios can bepredicted.1.2 This test method is limited to products that allowhandling at atmospheric pressure and room temperature con-ditions without a significant loss of light end components.Lossof light ends will result in changes in the solubility propertiesof the product and may alter or bias the results,or both.Samples with vapor pressures(VPCR4at 37.8 C using TestMethod D6377)greater than 100 kPa are not suitable for usewith this test method.1.3 This test method is primarily suited to products that arefreely flowing at test conditions.Samples that are too viscousto flow at test conditions,such as semi-solids,may need to beheated to allow handling(See Annex A1.)1.4 The values stated in SI units are to be regarded asstandard.The values given in parentheses after SI units areprovided for information only and are not considered standard.1.5 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D6560 Test Method for Determination of Asphaltenes(Hep-tane Insolubles)in Crude Petroleum and Petroleum Prod-uctsD6377 Test Method for Determination of Vapor Pressure ofCrude Oil:VPCRx(Expansion Method)3.Terminology3.1 Definitions:3.1.1 asphaltenes,n(rarely used in the singular),in pe-troleum technology,represent an oil fraction that is soluble ina specified aromatic solvent but separates upon the addition ofan excess of a specified paraffinic solvent.3.1.1.1 DiscussionAsphaltenes are found largely in crudeoils and in heavy fuel oils containing residual fractions.Theyare insoluble in alkanes such as heptane and pentane,butsoluble in aromatic solvents such as benzene or toluene.3.1.2 compatibility,nof crude oils or heavy fuel oils,theability of two or more crude oils or fuel oils to blend togetherwithin certain concentration ranges without evidence ofseparation,such as the formation of multiple phases.3.1.2.1 DiscussionIncompatible heavy fuel oils or crudeoils,when mixed or blended,result in flocculation or precipi-tation of asphaltenes.Some oils may be compatible within1This 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,Cleanliness and Compatibility of Liquid Fuels.Current edition approved Jan.1,2021.Published January 2021.Originallyapproved in 2020.Last previous edition approved in 2020 as D8253 20.DOI:10.1520/D8253-21.2For 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1certain concentration ranges in specific mixtures,but incom-patible outside those ranges.3.1.3 crude oil,na naturally occurring hy