1、Designation: D7084 04 (Reapproved 2017)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
2、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 part
3、icles132 to316 in. (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
4、 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, health, and environmental prac
5、tices and deter-mine the applicability of regulatory limitations prior to use.1.4 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 an
6、d Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.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 P
7、ractice 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 streng
8、thpressure 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
9、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. T
10、echniques 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 st
11、rength. 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
12、measuring the applied force.NOTE 1Lower maximum load may be acceptable for testing lessstrong materials.6.2 U.S. Standard Sieves, set (Tyler Equivalent).6.3 Test Cell, (Fig. 1).NOTE 2A top loading cell can be used, but reproducibility of this testis a function of the volume being crushed and therefo
13、re the constantvolume cell, as shown in Fig. 1, is recommended. A smaller l/d ratio for1This 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 Sept. 1, 2017. Publi
14、shed October 2017. Originallyapproved in 2004. Last previous edition approved in 2009 as D708404(2009).DOI: 10.1520/D7084-04R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informatio
15、n, 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 es
16、tablished 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.1the cell will alter the results, and for certain applications, it may be moredesirable.3,46.4 Drying O
17、ven.6.5 Balance, having a sensitivity of 0.1 g.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 molecula
18、r 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.NOTE 3These conditions may not be appropr
19、iate for all materials.NOTE 4Since many catalyst formulations are strong adsorbents, theuse of No. 4A indicating (cobalt treated) molecular sieve as a desiccatingmedium is suggested. The desiccant should be regenerated at 493 to 523K(220 to 260C) as required.7.3 Weigh the sample to determine the los
20、s during heating.Calculate the dry bulk density by the following equation:DBD 5 BD 1 2 OW 2 DW!/OW! (1)where:DBD = dry bulk density (see Test Method D4180),BD = bulk density,OW = weight of original sample, andDW = weight of dried sample.7.4 Calculate the weight of dried sample required to fill avolu
21、me of 49 cm3, and then calculate the original weight of thissample.7.5 Weigh sufficient sample for nine crushing operations.Sieve the sample using a sieve that is one-half the diameter ofthe catalyst pellet. If 10 % of the material passes through thescreen, use a smaller sieve size. Dry the sample a
22、t 673 K for 3h; do not exceed a bed height of 1 in. Cool the sample in adesiccator.7.6 Weigh a sample required to fill a volume of 49 cm3,asdetermined in 7.4. Keep the remaining sample in the desicca-tor.7.7 Fill the cell with the 49-cm3dried sample. Tap the cellwhile filling it. Place the entire ca
23、talyst sample into the cell.Place and center the cell into the hydraulic press.7.8 Apply a pressure to the cell at a rate of 50 lb/in.2/s (35kPa/s), and read the pressure. Hold the prescribed pressure for30 s, and then slowly release the pressure.3Bradley, S. A., Pitzer, E., and Koves, W. J., “Bulk
24、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, Vo
25、l 71, 1975, pp. 35-37.FIG. 1 Test CellD7084 04 (2017)27.9 Remove the cell from the press, and then remove thepiston from the cell. Brush all of the particles from the end ofthe piston into the sieve in 7.5. Pour the contents of the cellonto the sieve, and brush all particles from the cell into thesi
26、eve.7.10 After sieving the fines for 60 s into a weighing pan,weigh the catalyst in the pan. Perform sieving so as not toproduce additional fines.7.11 Crush strengths are determined in triplicate for at leasttwo different pressures that will produce both less than andmore than 1 weight percent fines
27、. Typical loads are between150 and 500 lb/in.2(1 and 3.5 MPa) for larger formed materialsand 15 and 50 lb/in.2(0.1 and 0.35 MPa) for granules.7.12 Use a fresh charge of catalyst for each loading in orderto prevent bias of damaged catalyst or being left with strongerpellets.7.13 Weight percent fines
28、is determined by:F 5 PW/DW 3100 (2)where:F = weight percent fines,PW = weight of fines in pan after sieving, andDW = dry weight of sample put into cell.7.14 Plot crushing pressure versus weight percent fines.Draw a straight line having the best correlation coefficient.Report the crush strength for 1
29、 % fines generation. Crushingstrength is the applied force divided by the cross-sectional areaof the interior of the cell. For the recommended cell the area is3.14 in.2(20.26 cm2).8. Report8.1 Report the following information:8.1.1 Plot of the crushing pressure versus the weight percentfines,8.1.2 C
30、orrelation coefficient,8.1.3 Interpolated crush pressure to produce 1 % fines,8.1.4 Sieve size used, and8.1.5 Detail of any changes in the loading cell.9. Precision and Bias9.1 Test ProgramAn interlaboratory study was conductedin which the named property was measured in three separatetest materials
31、in three separate laboratories. The three catalystsconducted in this study were of different geometries, densitiesand sizes. Practice E691 was followed for the data reduction.Analysis details are in the research report.59.2 PrecisionPairs of test results obtained by a proceduresimilar to that descri
32、bed in the study are expected to differ inabsolute value by less than 2.772*S, where 2.772*S is the 95 %probability interval limit on the difference between two testresults, and S is the appropriate estimate of standard deviation.Definitions and usage are given in Practice E177 and Termi-nology E456
33、.TestResult(Consensus Mean)95 % RepeatabilityInterval(Within Laboratory)95 % ReproducibilityInterval(Between Laboratories)189.3 psi (1.30 MPa) 26.02 psi (0.18 MPa)(13.75 % of mean)32.37 psi (0.22 MPa)(17.11 % of mean)198.5 psi (1.36 MPa) 25.60 psi (0.18 MPa)(12.89 % of mean)48.14 psi (0.33 MPa)(24.2
34、5 % of mean)186.5 psi (1.28 MPa) 34.41 psi (0.24 MPa)(18.45 % of mean)78.83 psi (0.54 MPa)(42.26 % of mean)9.3 BiasThe procedure in this test method has no knownbias because the value is defined only in terms of this testmethod.10. Keywords10.1 bulk crush strength; bulk density; formed catalystparti
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38、mittee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddr
39、ess or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D32-1040.D7084 04 (2017)3
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