1、Designation: D 7084 04Standard Test Method forDetermination of Bulk Crush Strength of Catalysts andCatalyst Carriers1This standard is issued under the fixed designation D 7084; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 particles132 to316
3、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 provided forinformation only.1.3 This standa
4、rd 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 AST
5、M Standards:2D 3766 Terminology Relating to Catalysts and CatalysisD 4180 Test Method for Vibratory Packing Density ofFormed Catalyst Particles and Catalyst CarriersE 177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE 456 Terminology for Relating to Quality and StatisticsE 691
6、 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definitions:3.1.1 See also Terminology D 3766.3.1.2 bulk crush strengthpressure that generates 1 % finesfor a sample contained in a cylindrical sample holder andcrushed with a piston.3.1.3 g
7、enerated 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 pr
8、essure. 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, whi
9、ch 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 bui
10、ldup 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.NOTE 1Lower maximum load may be acceptable for testing lessstrong materials.6.2 U.S. Standard
11、 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 therefore the constantvolume cell, as shown in Fig. 1, is recommended. A smaller l/d ratio forthe cell will alter the results, a
12、nd for certain applications, it may be moredesirable.3,46.4 Drying Oven.6.5 Balance, having a sensitivity of 0.1 g.6.6 Glass Cylinders, with 250-mL feed capacity. Measure inaccordance with Test Method D 4180.6.7 Vibrator, conventional, handheld, with hard rubber ormetal impactor, in accordance with
13、Test Method D 4180.1This 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 Oct. 1, 2004. Published October 2004.2For referenced ASTM standards, visit the ASTM webs
14、ite, 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 D
15、evelopment, 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. 35-37.1Copyright ASTM International, 100 Ba
16、rr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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 D 4180.7.2 Weigh 100 mL of the sample and dry at 673 6 15 K(400C) for 3 h. Coo
17、l the sample in a desiccator using freshlyregenerated 4A molecular sieves as a desiccant.NOTE 3These conditions may not be appropriate for all materials.NOTE 4Since many catalyst formulations are strong adsorbents, theuse of No. 4A indicating (cobalt treated) molecular sieve as a desiccatingmedium i
18、s suggested. The desiccant should 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:DBD 5 BD 1 2 OW 2 DW!/OW! (1)where:DBD = dry bulk density (see Test Method D 4180),BD = bulk den
19、sity,OW = weight of original sample, andDW = weight of dried sample.7.4 Calculate the weight of dried sample required to fill avolume 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-ha
20、lf the diameter ofthe catalyst pellet. If 10 % of the material passes through thescreen, use a smaller sieve size. Dry the sample at 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 r
21、emaining sample in the desicca-tor.7.7 Fill the cell with the 49-cm3dried sample. Tap the cellwhile filling it. Place the entire catalyst 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 pressur
22、e. Hold the prescribed pressure for30 s, and then slowly release the pressure.7.9 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
23、from the cell into thesieve.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 tha
24、n 1 weight percent fines. 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.FI
25、G. 1 Test CellD70840427.13 Weight percent fines is determined by:F 5 PW/DW 3 100 (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 correl
26、ation coefficient.Report the crush strength for 1 % 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 crushin
27、g pressure versus the weight percentfines,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 conductedin which the named prope
28、rty was measured in three separatetest materials in three separate laboratories. The three catalystsconducted in this study were of different geometries, densitiesand sizes. Practice E 691 was followed for the data reduction.Analysis details are in the research report.59.2 PrecisionPairs of test res
29、ults obtained by a proceduresimilar 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 difference between two testresults, and S is the appropriate estimate of standard deviation.Definitions and usag
30、e are given in Practice E 177 and Termi-nology E 456.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
31、(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 method has no knownbias because the value is defined only in terms of this testmethod.10. Keywords10.1 bul
32、k crush strength; bulk density; formed catalystparticlesASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent
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35、ring 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 Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard
36、 may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D32-1040.D7084043
