ASTM_D_8393_-_21.pdf

Designation:D839321Standard Guide forDetermination of Pore Volume of Powdered Catalysts andCatalyst Carriers by Water Adsorption1This standard is issued under the fixed designation D8393;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.Scope1.1 This guide measures pore volume of powdered catalystsand catalyst carriers by titration with water.The water does notreact with material.The range of pore volume is 0.25 mL/g to0.46 mL/g.1.2 This guide is suitable for fine catalysts such as fluidcatalytic cracking(FCC)catalysts(fresh or equilibrium),catalyst additives and spray dried catalyst carriers or finishedcatalysts,or a combination thereof,and is typically applicableto powders with the majority of particles(above 90%)in thedistribution range between 20 and 150 m equivalent sphericaldiameter(determined by Test Method D4464)and with anaverage particle size between 60 and 100 m.NOTE1This technique is capable of measuring particles below andabove this range(for example,from 1 to 300 m)but no precision data isavailable.1.3 UnitsThe values stated in SI units are to be regardedas standard.No other units of measurement are included in thisstandard.1.4 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.1.5 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:2D1193 Specification for Reagent WaterD4284 Test Method for Determining Pore Volume Distribu-tion of Catalysts and Catalyst Carriers by Mercury Intru-sion PorosimetryD4464 Test Method for Particle Size Distribution of Cata-lytic Materials by Laser Light ScatteringE105 Guide for Probability Sampling of MaterialsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE456 Terminology Relating to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 capillary action,nthe ability of a liquid to flow innarrow spaces as induced by the intermolecular forces betweenthe liquid and surrounding solid surfaces.3.1.2 macropore,npore with internal width greater than50 nm.3.1.3 mesopore,npore with internal width between 2 nmand 50 nm.3.1.4 surface tension,nthe attractive force exerted uponthe surface molecules of a liquid by the molecules beneath thattends to draw the surface molecules into the bulk of the liquidand makes the liquid assume the shape having the least surfacearea.4.Summary of Guide4.1 This guide is intended to provide mesopore and mac-ropore volume information of powdered catalysts and catalystcarriers.It helps users to judge the end point during the titrationof catalytic material with water.4.2 The added water is drawn by capillarity action into thecatalytic materials mesopores and macropores.When the end1This guide is under the jurisdiction of ASTM Committee D32 on Catalysts andis the direct responsibility of Subcommittee D32.01 on Physical-Chemical Proper-ties.Current edition approved June 1,2021.Published August 2021.DOI:10.1520/D8393-21.2For 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.Copyright 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.1point of the titration is reached,water overflows and forms afilm on the surface of the water-saturated particles.Theparticles stick together by surface tension.They adhere to theinternal surface of the conical flask upon tapping against asuitable object(for example,the operators palm).4.3 The pore volume of the catalytic materials is obtainedbased on the amount of water being adsorbed at the end point.5.Significance and Use5.1 This guide is intended to determine meso-and mac-ropore volume which affects heavy oil cracking performance ofa catalyst.The informati