1、Designation: D 3907 03Standard Test Method forTesting Fluid Catalytic Cracking (FCC) Catalysts byMicroactivity Test1This standard is issued under the fixed designation D 3907; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r 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 ofequilibrium or laboratory-deactivated fluid catalytic crackin
3、g(FCC) catalysts, or both. This is evaluated on the basis ofweight percent conversion of gas oil in a microactivity unit.The selectivity of FCC catalysts can be determined using TestMethod D 5154.1.2 The values stated in SI units are to be regarded asstandard. The values given in parentheses are pro
4、vided 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 this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations pr
5、ior to use.2. Referenced Documents2.1 ASTM Standards:2D 2887 Test Method for Boiling Range Distribution ofPetroleum Fractions by Gas ChromatographyD 5154 Test Method for Determining the Activity andSelectivity of Fluid Catalytic Cracking (FCC) Catalysts byMicroactivity Test3E 105 Practice for Probab
6、ility Sampling of MaterialsE 177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE 456 Terminology 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
7、 This Standard:3.1.1 ASTM consensus mean conversioneach referencecatalyst has a consensus mean conversion value assigned to itby Committee D32 (see 11.2).3.1.2 ASTM reference catalystsa set of equilibrium fluidcracking catalysts with conversions within the useful range ofthis test method is used to
8、improve the reproducibility of testresults between different laboratories. Samples of the ASTMreference catalysts can be obtained from NIST.3.1.3 ASTM standard feeda specific batch of gas oil that isused as feedstock in the described test method. This standardfeed can be obtained from the National I
9、nstitute of Standardsand Technology (NIST).43.1.4 conversion calibration curvea calibration curve canbe obtained by plotting the consensus mean conversion valuesfor the ASTM reference catalysts (see 11.2) versus the indi-vidual laboratory-measured conversion for the same catalysts.3.1.5 measured con
10、versionis calculated as the differencebetween the weight of feed used and the weight of unconvertedmaterial, divided by the weight of feed used, times 100 %. Theunconverted material is defined as all liquid product with aboiling point above 216C (421F).4. Summary of Test Method4.1 A sample of cracki
11、ng catalyst in a fixed-bed reactor iscontacted with gas oil (ASTM standard feed). Cracked liquidproducts are analyzed for unconverted material and the con-version is calculated.4.2 A corrected conversion value can be obtained from themeasured conversion and the conversion calibration curve.5. Signif
12、icance and Use5.1 The microactivity test provides data to assess the rela-tive performance of FCC catalyst. Because results are affectedby catalyst pretreatment, feedstock characteristics, test equip-ment, and operating parameters, adherence to this test methodis a prerequisite for correct interpret
13、ation of results. Apparatus,test conditions, and analytical procedures actually used shouldclosely resemble those described in this test method.5.2 Caution should be used in interpreting results above 80weight % conversion due to the significance of overcracking.1This test method is under the jurisd
14、iction of ASTM Committee D32 onCatalysis and is the direct responsibility of Subcommittee D32.04 on CatalyticProperties.Current edition approved Oct. 1, 2003. Published October 2003. Originallyapproved in 1992. Discontinued in 2001 and reinstated as D 390703. Last previousedition approved in 2000 as
15、 D 390700.2For 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.3Withdrawn.4Available from National Institute of St
16、andards and Technology (NIST), 100Bureau Dr., Stop 3460, Gaithersburg, MD 20899-3460.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Apparatus6.1 Flow ChartThe flow chart is given in Fig. 1. During75 s, gas oil from a syringe is f
17、orced over4gofcatalyst in afixed-bed reactor. Liquid products are collected in a receiverand kept at a wet ice temperature.6.2 SyringeA syringe with 2.5 mL capacity is used for oiladdition. It should be equipped with a multiport, high-pressurevalve to allow nitrogen and oil entry to the reactor thro
18、ugh acommon feed line.6.3 Syringe HeaterHeat syringe to 40 6 5C (104 6 9F)using a heat lamp or resistance heater or any other suitablemeans.6.4 Syringe PumpA syringe pump that can deliver uni-form flow of 1.33 6 0.03 g of gas oil in 75 6 1s.6.5 FurnaceA three-zone furnace is used: middle zone,150-mm
19、 (6-in.) length, and top and bottom zones, 75-mm(3-in.) length. The catalyst bed is positioned in the middlezone. The temperature controllers of the three zones arecalibrated to achieve a constant temperature 482 6 1C (900 62F) over the whole length of the catalyst bed (actual bedtemperature).6.6 Re
20、actor and InsertA glass or stainless steel reactor of15.6 mm internal diameter is used. Dimensions are shown inFig. 2. Details of the reactor insert are shown in Figs. 2 and 3.NOTE 1General dimensions are given in SI units. Dimensions givenin SAE, U.S. Standard gage sizes for sheet, tubing, and wire
21、 areconsidered standard. In general, the closest metric equivalent should beadequate for proper functioning.6.7 Liquid Product Collection SystemLiquid product iscollected in the receiver shown in Fig. 4.6.8 Analytical Balance and WeightsThe balance used toweigh the sample, the receiver, and the syri
22、nge shall have aprecision of 1 mg. Analytical weights shall be precision gradeor calibrated against a set of certified standard weights.6.9 Chromatographic EquipmentThe gas chromato-graphic equipment specified in Test Method D 2887 is sug-gested for the analysis of liquid product. A flame ionization
23、detector is recommended.7. Sampling7.1 If a sampling procedure is desired, Practice E 105 isrecommended.8. Sample Preparation8.1 Dry samples or decoke, or both, by heating a shallow(less than 10 mm thick) bed of catalyst in a porcelain crucibleas follows:120 6 20C (248 6 36F) for 1 h120C (248F) to 5
24、90C (1094F) for approximately 1 h590 6 20C (1094 6 36F) for 3 h8.2 Sufficient air should be available in the furnace to burnthe sample free of coke. Insufficient decoking is indicated by adifference in color of the top and bottom layers. The hotcrucible is cooled in a desiccator to prevent moisture
25、pickup.9. Procedure9.1 Reactor Preparation:9.1.1 Rinse the feed line with acetone or other suitablesolvent and dry with air. Periodic cleaning of the insert isrecommended by an air purge at 482C (900F) for 1 h, at leastonce every 12 tests.9.1.2 Wash the reactor and product receiver thoroughly withac
26、etone or other suitable solvent and dry. If necessary, burn outany coke deposited in the reactor by heating in air at 482C(900F) prior to washing.9.1.3 Insert a plug of quartz or borosilicate glass wool(about 20-mm length) into the reactor. Add 4.00 6 0.05 g ofcatalyst in a free-flowing manner. Tap
27、the reactor lightly toensure good radial distribution (do not pack). Position anotherplug of quartz or glass wool (about 6-mm length) above thecatalyst bed. Do not tamp wool plugs excessively.9.1.4 Inspect the reactor feed tube insert to be sure it is freeof deposits and the tip of the thermocouple
28、(see Fig. 3, Detail2) is bent under the tip of the syringe needle. (This is necessaryto control the oil preheat temperature accurately.) Place theinsert in the reactor and adjust, if necessary, so that the insertneedle is between 10 to 50 mm above the catalyst bed. Placethe reactor in the furnace th
29、at has been preheated to 482C(900F) and connect the nitrogen purge line directly to thereactor feed line. Purge with 30-mL/min of nitrogen for at least30 min.9.1.5 Make electrical connections on the integral oil feedpreheater and connect the thermocouple to the recorder.9.2 Preparation of Syringe an
30、d Liquid Product Receiver:9.2.1 Fill the syringe with ASTM standard feed and invert toallow air to rise.NOTEThis drawing is not to scale. For engineering details, see otherdrawings.FIG. 1 Microactivity Flow ChartD3907032NOTE 2The ASTM standard feed is very viscous at 30C; therefore,loading the syrin
31、ge and removal of air bubbles can be facilitated bypreheating the oil to 40 6 5C (104 6 9F).9.2.2 Remove the air bubbles. The syringe should contain asmall amount of oil in excess of the nominal volume to becharged.9.2.3 After the syringe is filled and the valve is in correctposition, blow excess oi
32、l out of the valve and clean the outsideof the syringe.9.2.4 Weigh the syringe assembly and record the weight.9.2.5 Disconnect the nitrogen from the reactor feed line,install the syringe, and connect the nitrogen to the syringevalve. Make sure the valve is in the nitrogen flow position.Place a therm
33、ocouple on the syringe body to detect the syringetemperature. Set the syringe temperature at 40 6 5C (104 69F).9.2.6 Obtain the tare weight of the liquid product receiverand record.9.2.7 Install the receiver and connect the gas line to the vent.9.2.8 Prepare and install a wet ice bath for the liquid
34、 productreceiver. Immerse the receiver to the level of the gas outlet line.Optionally, a controlled temperature circulating bath may beused in place of the wet ice bath.FIG. 2 Microactivity ReactorD39070339.2.9 Pressure test the entire system at 26.7 kPa (200 mmHg). The pressure test can be performe
35、d by closing the ventline, allowing the pressure to build to 26.7 kPa, and thenclosing the nitrogen supply valve. The pressure should notchange significantly over a 2 min period.9.3 Run Conditions:9.3.1 Check the syringe temperature, 40 6 5C (104 69F), and the reactor temperatures 482 6 1C (900 6 2F
36、).9.3.2 Set the syringe pump to deliver 1.33 6 0.03 g of feedin 75 6 1s.9.3.3 Bring the syringe drive head flush with the syringeplunger.FIG. 3 Reactor Feed Tube InsertD39070349.3.4 Switch the syringe multiport valve from the nitrogenflow to the oil feed position. Note that the position of the valve
37、can be: joint-feed only, nitrogen flow, or pure-feed only.9.3.5 Start the syringe pump and deliver 1.33 6 0.03 g offeed over 75 6 1 s to the reactor.9.3.6 The oil preheat temperature, as measured by thethermocouple at the oil exit point above the bed, shall be 4826 5C (900 6 9F).9.3.7 Note that fine
38、 particle samples can cause excessivecatalyst bed differential pressures, significantly affecting re-sults. Back pressures up to 13.3 kPa (100 mm Hg) measuredduring oil addition (see Fig. 3, Detail 1A) are not detrimental.More typical back pressures are in the range from 4.0 to 8.0kPa (30 to 60 mm H
39、g). If the catalyst bed differential pressureexceeds 13.3 kPa (100 mm Hg), it is recommended that thecatalyst be screened free of particles finer than 325 mesh (45m) and the test be repeated with the larger-sized particles.9.3.8 Immediately after the oil addition, restart the nitrogen-only flow at 3
40、0 mL/min by switching the multiport valve topurge the reactor and liquid product receiver.9.3.9 Purge the reactor and product recovery system for 15min at 30 mL/min nitrogen, with a wet ice bath. Optionally, acontrolled temperature circulating bath may be used in place ofthe wet ice bath.9.3.10 Remo
41、ve the product receiver from the reactor, seal,dry, and weigh immediately. Record weight of liquid inreceiver as Wl. If sample cannot be analyzed immediately, storein a sealed vial and refrigerate.9.3.11 Collect the liquid holdup in the reactor exit line andaround the reactor-receiver joint with a t
42、ared cotton swab orother suitable material. Determine the weight of this liquid andrecord as WQ.NOTE 3Experience indicates this liquid material is predominantlyunconverted material.9.3.12 Remove the syringe from the reactor, reweigh it, andrecord the weight of oil feed as Wf.9.3.13 Remove the reacto
43、r from the furnace. After cooling,the catalyst can be removed from the reactor for analysis orregeneration, or both.9.4 Analysis of Liquid Product:9.4.1 Analyze the liquid product by gas chromatographyusing a simulated distillation technique described by TestMethod D 2887.9.4.2 Use a retention time
44、of a 216C (421F) material (thatis, n-dodecane) as a standard for determining the end point ofconverted product.9.4.3 Express integrated peak area of material boiling above216C (421F) as a percentage of total peak area and record asR.10. Calculation10.1 Calculate the measured conversion as follows:Me
45、asured conversion, weight % 5Wf2R 3 WL1002 WQWf3 100 (1)where:Wf= ASTM standard feed, g,R = weight percentage of material boiling above 216C(421F) in liquid product receiver,WL= liquid product in receiver, g, andWQ= liquid holdup at reactor exit line and around reactor-receiver joint, g.10.2 A corre
46、cted conversion value may be obtained by usingthe conversion calibration curve obtained in 3.1.4.11. Precision and Bias11.1 Test ProgramAn interlaboratory study was con-ducted in which the MAT conversion was measured in sixseparate test materials (RR-1 to RR-6) with ASTM standardfeed in nine separat
47、e laboratories. Not all materials wereFIG. 4 Liquid Product ReceiverD3907035measured by all laboratories. Practice E 691, modified fornonuniform data sets, was followed for the data reduction.511.2 PrecisionPairs of test results obtained by the proce-dure described in the study arc expected to diffe
48、r in absolutevalue 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 Terminology E 456 andPractice E 177, respectively.ASTMStandardSampleNo.AS
49、TM Con-sensus MeanConversion,Weight %95 % RepeatabilityLimit (Within-Laboratory),Weight %95 % ReproducibilityLimit (Between-Laboratories),Weight %RR-1 59.4 2.5 5.2RR-2 64.9 2.8 8.1RR-3 76.1 2.6 8.7RR-4 76.2 2.8 7.4RR-5 80.9 2.8 7.2RR-6 70.1 1.2 7.311.3 BiasThe procedure described is without known bias,since there is by definition no absolute standard for compari-son.12. Keywords12.1 catalysts; FCC; fluid cracking catalyst; MAT;microactivityASTM International takes no position respecting the validity of any patent rights ass
