1、Designation: D7084 04 (Reapproved 2017)D7084 18Standard 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
2、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 crush strength of a bed of formed cata
3、lyst particles 132 to 316 in. (0.8 to4.8 mm) in diameter and is intended to provide information concerning the ability of the catalyst material to maintain physicalintegrity.1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematicalconv
4、ersions to SI units that are provided for information only and are not considered standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety, health, and envi
5、ronmental practices and determine the applicability ofregulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards,
6、 Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D3766 Terminology Relating to Catalysts and CatalysisD4180 Test Method for Vibratory Packing Density of Formed Catalyst Particles and Catalyst Carr
7、iersE11 Specification for Woven Wire Test Sieve Cloth and Test SievesE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE456 Terminology Relating to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3. Termin
8、ology3.1 Definitions:3.1.1 See also Terminology D3766.3.1.2 bulk crush strengthpressure that generates 1 % fines for a sample contained in a cylindrical sample holder and crushedwith a piston.3.1.3 generated finesparticle size after crushing that passes through a sieve one-half of the diameter of th
9、e catalyst pellet.4. Summary of Test Method4.1 A representative sample is placed in a cylindrical sample holder, which is fitted with a piston. The piston is allowed tocompress the catalyst at a known pressure. The percent of generated fines is determined by sieving.5. Significance and Use5.1 This t
10、est method is a means of determining the crushing strength of a catalyst in a bed. Techniques to measure the crushingstrength of formed catalyst particles is limited to crushing of individual particles, which may not be related to how the catalyst will1 This test method is under the jurisdiction of
11、ASTM Committee D32 on Catalysts and is the direct responsibility of Subcommittee D32.02 on Physical-MechanicalProperties.Current edition approved Sept. 1, 2017May 1, 2018. Published October 2017May 2018. Originally approved in 2004. Last previous edition approved in 20092017 asD708404(2009).D708404(
12、2017). DOI: 10.1520/D7084-04R17.10.1520/D7084-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This documen
13、t is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as app
14、ropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1crush in a reactor or bed. For some catalysts, such as granu
15、les, this technique may be the only viable method for obtaining crushingstrength. The production of fines in a reactor is not desired because of the potential of bed compaction and the pressure buildupin the reactor.6. Apparatus6.1 Hydraulic Press, capable of 3200 lb (1450 kg) loading, including a f
16、orce gage. Maximum load capacity of the press shouldmatch with the accuracy measuring the applied force.NOTE 1Lower maximum load may be acceptable for testing less strong materials.6.2 U.S. Standard Sieves, set (Tyler Equivalent).in accordance with E11.6.3 Test Cell, (Fig. 1).NOTE 2A top loading cel
17、l can be used, but reproducibility of this test is a function of the volume being crushed and therefore the constant volumecell, as shown in Fig. 1, is recommended. A smaller l/d ratio for the cell will alter the results, and for certain applications, it may be more desirable.3,46.4 Drying Oven.6.5
18、Balance, having a sensitivity of 0.1 g.6.6 Glass Cylinders, with 250-mL feed capacity. Measure in accordance with Test Method D4180.6.7 Vibrator, conventional, handheld, with hard rubber or metal impactor, in accordance with Test Method D4180.6.8 Feed Funnel.6.9 Desiccator, with grade molecular siev
19、e, such as 4A.7. Procedure7.1 Determine the bulk density in accordance with Test Method 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 appropriate
20、 for all materials.3 Bradley, 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. 398-406.4 Adams, A. R., Sartor, A. F., and Welsh, J. G., “
21、Problems in Standardizing Catalyst Tests,” Chemical Engineering Progress, Vol 71, 1975, pp. 35-37.FIG. 1 Test CellD7084 182NOTE 4Since many catalyst formulations are strong adsorbents, the use of No. 4Aindicating (cobalt treated) molecular sieve as a desiccating mediumis suggested. The desiccant sho
22、uld be regenerated at 493 to 523K (220 to 260C) as required.7.3 Weigh the sample to determine the loss during heating. Calculate the dry bulk density by the following equation:DBD5BD 12OW2DW!/OW! (1)where:DBD = dry bulk density (see Test Method D4180),BD = bulk density,OW = weight of original sample
23、, andDW = weight of dried sample.7.4 Calculate the weight of dried sample required to fill a volume 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 of thecatalyst pe
24、llet. If 10 % of the material passes through the screen, use a smaller sieve size. Dry the sample at 673 K for 3 h; do notexceed a bed height of 1 in. Cool the sample in a desiccator.7.6 Weigh a sample required to fill a volume of 49 cm3, as determined in 7.4. Keep the remaining sample in the desicc
25、ator.7.7 Fill the cell with the 49-cm3 dried sample. Tap the cell while filling it. Place the entire catalyst sample into the cell. Placeand center the cell into the hydraulic press.7.8 Apply a pressure to the cell at a rate of 50 lb/in.2/s (35 kPa/s), and read the pressure. Hold the prescribed pres
26、sure for 30s, and then slowly release the pressure.7.9 Remove the cell from the press, and then remove the piston from the cell. Brush all of the particles from the end of the pistoninto the sieve in 7.5. Pour the contents of the cell onto the sieve, and brush all particles from the cell into the si
27、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 to produceadditional fines.7.11 Crush strengths are determined in triplicate for at least two different pressures that will produce both less than and morethan 1 weight percent fin
28、es. Typical loads are between 150 and 500 lb/in.2 (1 and 3.5 MPa) for larger formed materials and 15 and50 lb/in.2 (0.1 and 0.35 MPa) for granules.7.12 Use a fresh charge of catalyst for each loading in order to prevent bias of damaged catalyst or being left with strongerpellets.7.13 Weight percent
29、fines is determined by:F 5PW/DW3100 (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 thecrush strength
30、for 1 % fines generation. Crushing strength is the applied force divided by the cross-sectional area of the interiorof the cell. For the recommended cell the area is 3.14 in.2 (20.26 cm2).8. Report8.1 Report the following information:8.1.1 Plot of the crushing pressure versus the weight percent fine
31、s,8.1.2 Correlation 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 conducted in which the named property was measured in three separate test
32、materials in three separate laboratories. The three catalysts conducted in this study were of different geometries, densities and sizes.Practice E691 was followed for the data reduction. Analysis details are in the research report.55 Supporting data have been filed at ASTM International Headquarters
33、 and may be obtained by requesting Research Report RR:D32-1040.D7084 1839.2 PrecisionPairs of test results obtained by a procedure similar to that described 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 differen
34、ce between two test results,and S is the appropriate estimate of standard deviation. Definitions and usage are given in Practice E177 and Terminology E456.TestResult(Consensus Mean)95 % RepeatabilityInterval(Within Laboratory)95 % ReproducibilityInterval(Between Laboratories)189.3 psi (1.30 MPa) 26.
35、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)(24.25 % 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 meth
36、od has no known bias because the value is defined only in terms of this test method.10. Keywords10.1 bulk crush strength; bulk density; formed catalyst particlesASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this sta
37、ndard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be revi
38、ewed every five years andif not revised, either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsibl
39、e technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Con
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