ASTM_D_7084_-_04_2009.pdf

Designation:D708404(Reapproved 2009)Standard Test Method forDetermination of Bulk Crush Strength of Catalysts andCatalyst Carriers1This standard is issued under the fixed designation D7084;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 test method covers the determination of bulk crushstrength of a bed of formed catalyst particles132to316in.(0.8to 4.8 mm)in diameter and is intended to provide informationconcerning the ability of the catalyst material to maintainphysical integrity.1.2 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.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:2D3766 Terminology Relating to Catalysts and CatalysisD4180 Test Method for Vibratory Packing Density ofFormed Catalyst Particles and Catalyst CarriersE177 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:3.1.1 See also Terminology D3766.3.1.2 bulk crush strengthpressure that generates 1%finesfor a sample contained in a cylindrical sample holder andcrushed with a piston.3.1.3 generated finesparticle size after crushing thatpasses through a sieve one-half of the diameter of the catalystpellet.4.Summary of Test Method4.1 Arepresentative sample is placed in a cylindrical sampleholder,which is fitted with a piston.The piston is allowed tocompress the catalyst at a known pressure.The percent ofgenerated fines is determined by sieving.5.Significance and Use5.1 This test method is a means of determining the crushingstrength of a catalyst in a bed.Techniques to measure thecrushing strength of formed catalyst particles is limited tocrushing of individual particles,which may not be related tohow the catalyst will crush in a reactor or bed.For somecatalysts,such as granules,this technique may be the onlyviable method for obtaining crushing strength.The productionof fines in a reactor is not desired because of the potential ofbed compaction and the pressure buildup in the reactor.6.Apparatus6.1 Hydraulic Press,capable of 3200 lb(1450 kg)loading,including a force gage.Maximum load capacity of the pressshould match with the accuracy measuring the applied force.NOTE1Lower maximum load may be acceptable for testing lessstrong materials.6.2 U.S.Standard Sieves,set(Tyler Equivalent).6.3 Test Cell,(Fig.1).NOTE2A top loading cell can be used,but reproducibility of this testis a function of the volume being crushed and therefore the constantvolume cell,as shown in Fig.1,is recommended.A smaller l/d ratio forthe cell will alter the results,and for certain applications,it may be moredesirable.3,46.4 Drying Oven.6.5 Balance,having a sensitivity of 0.1 g.1This test method is under the jurisdiction of ASTM Committee D32 onCatalysts and is the direct responsibility of Subcommittee D32.02 on Physical-Mechanical Properties.Current edition approved March 1,2009.Published March 2009.Originallyapproved in 2004.Last previous edition approved in 2004 as D708404.DOI:10.1520/D7084-04R09.2For 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.3Bradley,S.A.,Pitzer,E.,and Koves,W.J.,“Bulk Crush Testing of Catalysts,”Characterization and Catalyst Development,ACS Symposium Series 411,Bradley,S.A.,Gattuso,M.J.,and Bertolacini,R.J.,Eds.,1989,pp.398-406.4Adams,A.R.,Sartor,A.F.,and Welsh,J.G.,“Problems in StandardizingCatalyst Tests,”Chemical Engineering Progress,Vol 71,1975,pp.35-37.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.6 Glass Cylinders,with 250-mL feed capacity.Measure inaccordance with Test Method D4180.6.7 Vibrator,conventional,handheld,with hard rubber ormetal impactor,in accordance with Test Method D4180.6.8 Feed Funnel.6.9 Desiccator,with grade molecular sieve,such as 4A.7.Procedure7.1 Determine the bulk density in accordance with TestMethod D4180.7.2 Weigh 100 mL of the sample and dry at 673 6 15 K(400C)for 3 h.Cool the sample in a desiccator using freshlyregenerated 4A molecular sieves as a desiccant.NOTE3These conditions may not be appropriate