1、Designation: D 5154 05Standard Test Method forDetermining Activity and Selectivity of Fluid CatalyticCracking (FCC) Catalysts by Microactivity Test1This standard is issued under the fixed designation D 5154; the number immediately following the designation indicates the year oforiginal adoption or,
2、in the case of revision, the year 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 determining the activity andselectivity of either equili
3、brium or laboratory deactivated fluidcatalytic cracking (FCC) catalysts. The activity is evaluated onthe basis of mass percent conversion of gas oil in a microac-tivity unit. The selectivities are evaluated on the basis of masspercent yields of specifically defined products resulting fromthe catalyt
4、ic cracking of gas oil.1.2 The values stated in SI units are to be regarded asstandard. The values given in parentheses are provided forinformation only.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 th
5、is 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:2D 2887 Test Method for Boiling Range Distribution ofPetroleum Fractions by Gas ChromatographyD 3907 Test Method for Tes
6、ting Fluid Catalytic Cracking(FCC) Catalysts by Microactivity TestD 4463 Guide for Metals Free Steam Deactivation of FreshFluid Catalytic Cracking CatalystsE 105 Practice for Probability Sampling of MaterialsE 177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE 456 Terminology
7、Relating to Quality and StatisticsE 691 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 activitycalculated as conversion divided by thedifference of 100 minus conversion.3.1.2 ASTM refer
8、ence catalystsa set of equilibrium FCCcatalysts within the useful range of this test method is used toimprove the reproducibility of test results between differentlaboratories. Each catalyst has a consensus mean conversionvalue assigned to it by Committee D32. Samples of the ASTMreference catalysts
9、can be obtained through NIST.3.1.3 ASTM standard feeda specific batch of gas oil that isused as feedstock in the described test method.33.1.4 catalyst/oil (C/O) ratiothe mass of catalyst used inthe test divided by the mass of feed fed to the reactor. Inpractice, the mass of catalyst is usually maint
10、ained at aconstant value and the total mass of feed is varied.3.1.5 contact timecalculated as 3600/(WHSV C/O). Thisis the delivery time, in seconds, during which feed is intro-duced to the reactor.3.1.6 HCOthe heavy cycle oil product defined to have aminimum boiling point of 343C (650F).3.1.7 LCOthe
11、 light cycle oil product defined to have aboiling point range of 216 to 343C (421 to 650F).3.1.8 measured conversioncalculated as the differencebetween the mass of feed used and the mass of unconvertedmaterial divided by the mass of feed used times 100 %. Theunconverted material is defined as all li
12、quid product with aboiling point above 216C (42F).3.1.9 normalized product yieldthe result obtained wheneach product yield has been corrected for non-perfect massbalances. For a run to be judged acceptable, the total recovery,wt % of feed, should be in the range of 96 to 101 % prior tonormalization.
13、 If the recovery is outside this range the test datashould be discarded.3.1.10 product yieldone hundred times the mass of aspecific product divided by the mass of feed used in the test.3.1.11 reaction severityan indication of the severity of thecracking reaction which allows a range of conversions t
14、o beobtained from any particular catalyst without changing reactortemperature. Changing reaction severity is achieved by chang-ing WHSV or C/O ratio or both.1This test method is under the jurisdiction of ASTM Committee D32 onCatalysts and is the direct responsibility of Subcommittee D32.04 on Cataly
15、ticProperties.Current edition approved Oct. 1, 2005. Published November 2005. Originallyapproved in 1991. Last previous edition approved in 2003 as D 515403.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of AS
16、TMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from National Institute of Standards and Technology (NIST), 100Bureau Dr., Stop 3460, Gaithersburg, MD 20899-3460.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshoh
17、ocken, PA 19428-2959, United States.3.1.12 weight hourly space velocity (WHSV)the oil feedrate in grams per hour divided by the mass of catalyst in grams.Units are hr-1.4. Summary of Test Method4.1 At least two samples of FCC catalysts, one of which ischosen as a reference, are separately contacted
18、with gas oil(ASTM Standard Feed or other suitable feedstock) in a fixedbed reactor at a specified reaction temperature and at more thanone reaction severity. Reaction products (liquid, gas, and cokeon catalyst) are analyzed. Conversion, activity, and productyields are calculated for each experiment.
19、4.2 Following analysis of the products, the total recovery(that is, mass balance) of the feed as converted and uncon-verted products is determined. If the recovery is less than 96 %or greater than 101 %, the test is rejected as unsatisfactory.4.3 For each catalyst tested, normalized product yields a
20、replotted against conversion or activity to generate a yield curve.The data comprising the yield curve may be used to obtain theparameters of an appropriate mathematical expression for thecurve. Comparisons among catalysts can be made by interpo-lating the yield curves to obtain the product yields a
21、t somespecified conversion.5. Significance and Use5.1 The microactivity test provides data to assess the rela-tive performance of FCC catalysts. Because results are affectedby catalyst pretreatment, feedstock characteristics, test equip-ment, and operating parameters, adherence to this test methodis
22、 a prerequisite for correct interpretation of results. Apparatus,test conditions, and analytical procedures actually used shouldclosely resemble those described in this test method. Signifi-cant variations in apparatus, test conditions and/or analyticalprocedures may result in activity and selectivi
23、ty data which donot correlate with data developed by other laboratories onidentical catalyst/feedstock samples.5.2 The standard method reaction temperature is 516C(960F). Other reaction temperatures can be used; however,catalyst selectivity data developed at temperatures other than516C may not corre
24、late with selectivity data developed at516C. Also, precision at other reaction temperatures maychange compared to data obtained at 516C.6. Apparatus6.1 The apparatus of this test method is essentially thatdescribed in Test Method D 3907, as shown in Figs. 1-4, withthe addition of a gas collection sy
25、stem on the effluent gas ventline. In a typical gas collection system, a fluid is displaced bythe collected gas and the volume of displaced liquid providesa quantitative measurement of the amount of gas collected. Tominimize the solubility of gases like H2and H2S in the fluid,a saturated brine (NaCl
26、) solution is recommended. Somepublications have appeared which give example flow schemat-ics and more detailed descriptions of typical apparatus.4Alternatively, there are several vendors as listed in ResearchReport RR: D32-10305who can provide specific equipment forperforming this test. However, Co
27、mmittee D32 can onlysuggest and will not recommend nor certify any specificvendor. Significant variations from the test apparatus of thismethod most likely will result in significantly different activityand selectivity data from identical catalyst samples.6.2 Chromatographic Equipment:6.2.1 Liquid p
28、roduct analyses should be performed usingTest Method D 2887 on a gas chromatograph (G.C.) equippedwith a flame ionization detector.6.2.2 Gas product analyses may be accomplished in twoparts. First, an analysis using a G.C. equipped with a thermalconductivity detector, employing N2as a carrier gas, a
29、nd usinga G.C. column that permits the separation and quantitativeidentification of H2and H2S. Second, an analysis using a G.C.equipped with a FID or TCD, employing He as a carrier gasand using a column that permits the separation and quantitativeidentification of methane, ethane, ethylene, propane,
30、 propy-lene, n-butane, iso-butane, 1-butene and iso-butene, cis-2-butene, and trans-2-butene, C5s and a C5+lump that is notresolved. The C5s and the C5+group are included as part of thegasoline fraction.4Campagna, R. J., Wick, J. P., Brady, M. F., and Fort, D. L., “Fresh FCC CatalystTests Predict Pe
31、rformance,” OGJ, March 24, 1986, p. 85.5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D321030.NOTEThis drawing is not to scale. For engineering details, see otherdrawings.FIG. 1 Microactivity Flow ChartD51540526.3 Carbon analy
32、sis of a representative sample of the spentcatalyst (that is, after the cracking reaction has been com-pleted) may be accomplished using a commercially availablecarbon analyzer.7. Sampling7.1 A sampling procedure is needed. Practice E 105 isappropriate.8. Sample Preparation8.1 Equilibrium CatalystsD
33、ry samples or decoke, or both,by heating a shallow (less than 10 mm thick) bed of catalyst ina porcelain crucible at 590 6 20C (1094 6 36F) for a lengthof time sufficient to remove any coke. This typically requiresapproximately three hours. Sufficient air should be available inthe furnace to burn th
34、e sample free of coke. Insufficientdecoking is indicated by a difference in color of the top andFIG. 2 Microactivity ReactorD5154053FIG. 3 Reactor Feed Tube InsertD5154054bottom layers. The hot crucible is cooled in a desiccator toprevent moisture pickup.NOTE 1Heavily coked samples may be damaged by
35、 sintering ordeactivation if oxidation is allowed to occur too rapidly, leading toartificially low catalytic activity and surface area.8.2 Fresh CatalystsFresh catalyst samples should besteam treated prior to selectivity testing. Steaming proceduressuch as those specified in Guide D 4463 may be used
36、.However, specific conditions (temperature, partial pressure ofsteam, and time) should be chosen such that the steamedcatalyst properties (activity, zeolite and matrix surface areas,and unit cell size) approximate those found in equilibrium FCCcatalysts of the same type.9. Procedure9.1 Reactor Prepa
37、ration:9.1.1 Rinse feed line with acetone or other suitable solventand dry with air. Periodic cleaning of the insert is recom-mended by air purge at 550C (1022F) for one hour at leastonce every 12 tests.9.1.2 Wash the reactor and product receiver thoroughly withacetone or other suitable solvent and
38、dry. If necessary, burn outany coke deposited in the reactor by heating in air at 516C(960F) prior to washing.9.1.3 Insert a plug of quartz or borosilicate glass wool(about 20 mm length) until it reaches the constricted region ofthe reactor. Optionally, a reactor with a fritted disc may be usedto po
39、sition the catalyst. Add 4.00 to 4.05 g of catalyst in afree-flowing manner. Tap the reactor lightly to ensure goodradial distribution (do not pack). Insert another plug of quartzor glass wool and add approximately 10 cc of 80 to 100 meshglass microspheres or crushed glass particles. These act as ap
40、reheat bed and aid in feed dispersion, especially at higherWHSVs.9.1.4 Inspect the oil insert needle to ensure it is clear ofdeposits. Place insert in reactor and adjust if necessary so thatthe bottom of the oil insert needle is just touching the top of theglass microsphere preheat bed (about 20 mm
41、above the catalystbed). Inspect the reactor insert before using to be sure the tip ofthe thermocouple (see Fig. 3, Detail 2) is bent under the tip ofthe syringe needle. (This is necessary to control the oil preheattemperature accurately.) Place the reactor in the furnace thathas been preheated to 51
42、6C (960F) and connect the nitrogenpurge line directly to the reactor feed line. Purge with 30 seem(30 mL/min) of nitrogen for at least 30 minutes.9.1.5 Make electrical connections on the integral oil feedpreheater and connect the thermocouple to the recorder.9.2 Preparation of Syringe and Liquid Pro
43、duct Receiver:9.2.1 Preheat the gas oil feedstock to 40 6 5C (104 6 9F)to allow filling of the syringe. Before testing, calibrate thesyringe pump to the correct feed rate by collecting the oil,preheated to 40 6 5C (104 6 9F), outside the reactor andweighing the oil or by weighing the syringe before
44、and afterdelivery to assure the appropriate mass of oil delivered overunit time.NOTE 2If heavier feedstocks are used, a syringe temperature of 70 65C (158 6 9F) should be used for obtaining accurate feed rates.9.2.2 Fill the syringe with preheated feedstock and invert toallow air to rise. Remove the
45、 air bubbles. The syringe shouldcontain a small amount of oil in excess of the nominal volumeto be charged.9.2.3 After the syringe is filled and the valve is in the correctposition, blow excess oil out of the valve and clean the outsideof the syringe.9.2.4 Weigh the syringe assembly and record the m
46、ass.9.2.5 Attach the syringe and syringe valve to the reactormaking sure the valve is in the nitrogen flow position. Athermocouple may be placed on the syringe body to monitorthe syringe temperature during oil injection.9.2.6 Obtain the initial mass of the liquid product receiv-er(s). If necessary,
47、a second liquid receiver cooled by dry icemay be added in-line to aid collection of the lighter liquidproducts (mainly C5and C6s). If such a receiver is used, itshould also be weighed. Optionally, a small piece of glass woolin the receiver sidearm may be used to reduce the carryover ofC5+products in
48、to the gas collection vessel.9.2.7 Install receiver(s) and connect the gas line to the gascollection system. Open the gas vent valve to prevent prema-ture collection of purge gas.9.2.8 Prepare and install wet ice (and dry ice) bath(s) for thereceiver(s). Immerse the receiver(s) to the level of the g
49、asoutlet line(s). Optionally, a controlled temperature circulatingbath may be used in place of the wet ice bath.9.2.9 Pressurize the reactor to 20 kPa (150 mm Hg) nitrogenand close the gas vent and nitrogen supply valves. Watch thepressure gages for two minutes to determine if any significantleaks occur. If no leaks are apparent, open the gas vent valvecarefully to release pressure.9.3 Run Conditions:9.3.1 Check syringe temperature, 40 6 5C (104 6 9F),and reactor insert temperature, 516 6 1C (960 6 2F).9.3.2 Set syringe pump to del
