1、Designation: D3907 03 (Reapproved 2008)D3907/D3907M 13Standard Test Method forTesting Fluid Catalytic Cracking (FCC) Catalysts byMicroactivity Test1This standard is issued under the fixed designation D3907;D3907/D3907M; the number immediately following the designation indicatesthe year of original a
2、doption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers determining the activity of equilibrium or la
3、boratory-deactivated fluid catalytic cracking (FCC)catalysts, or both. This is evaluated on the basis of weight percent conversion of gas oil in a microactivity unit. The selectivity ofFCC catalysts can be determined using Test Method D5154.1.2 The values stated in either SI units or inch-pound unit
4、s are to be regarded separately as the standard. The values given inparentheses are for information only. stated in each system may not be exact equivalents; therefore, each system shall be usedindependently of the other. Combining values from the two systems may result in non-conformance with the s
5、tandard.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 and health practices and determine the applicability of regulatorylimitations prior to use.2. Refere
6、nced Documents2.1 ASTM Standards:2D2887 Test Method for Boiling Range Distribution of Petroleum Fractions by Gas ChromatographyD5154 Test Method for DeterminingActivity and Selectivity of Fluid Catalytic Cracking (FCC) Catalysts by Microactivity TestE105 Practice for Probability Sampling of Material
7、sE177 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. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 ASTM c
8、onsensus mean conversioneach reference catalyst has a consensus mean conversion value assigned to it byCommittee D32 (see 11.2).3.1.2 ASTM reference catalystsa set of equilibrium fluid cracking catalysts with conversions within the useful range of thistest method is used to improve the reproducibili
9、ty of test results between different laboratories. Samples of the ASTM referencecatalysts can be obtained from NIST.3.1.3 ASTM standard feeda specific batch of gas oil that is used as feedstock in the described test method. This standard feedcan be obtained from the National Institute of Standards a
10、nd Technology (NIST).33.1.4 conversion calibration curvea calibration curve can be obtained by plotting the consensus mean conversion values forthe ASTM reference catalysts (see 11.2) versus the individual laboratory-measured conversion for the same catalysts.3.1.5 measured conversionis calculated a
11、s the difference between the weight of feed used and the weight of unconvertedmaterial, divided by the weight of feed used, times 100 %. The unconverted material is defined as all liquid product with a boilingpoint above 216C (421F). 421F.1 This test method is under the jurisdiction of ASTM Committe
12、e D32 on Catalysts and is the direct responsibility of Subcommittee D32.04 on Catalytic Properties.Current edition approved April 1, 2008March 1, 2013. Published April 2008 March 2013. Originally approved in 1992. Last previous edition approved in 20032008 asD3907D390703(2008).03. DOI: 10.1520/D3907
13、-03R08.10.1520/D3907_D3907M-13.2 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.3 Available from National Inst
14、itute of Standards and Technology (NIST), 100 Bureau Dr., Stop 3460, Gaithersburg, MD 20899-3460.This document 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 p
15、ossible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. 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,
16、 West Conshohocken, PA 19428-2959. United States14. Summary of Test Method4.1 Asample of cracking catalyst in a fixed-bed reactor is contacted with gas oil (ASTM standard feed). Cracked liquid productsare analyzed for unconverted material and the conversion is calculated.4.2 A corrected conversion v
17、alue can be obtained from the measured conversion and the conversion calibration curve.5. Significance and Use5.1 The microactivity test provides data to assess the relative performance of FCC catalyst. Because results are affected bycatalyst pretreatment, feedstock characteristics, test equipment,
18、and operating parameters, adherence to this test method is aprerequisite for correct interpretation of results. Apparatus, test conditions, and analytical procedures actually used should closelyresemble those described in this test method.5.2 Caution should be used in interpreting results above 80 w
19、eight % conversion due to the significance of overcracking.6. Apparatus6.1 Flow ChartThe flow chart is given in Fig. 1. During 75 s, gas oil from a syringe is forced over 4 g of catalyst in a fixed-bedreactor. Liquid products are collected in a receiver and kept at a wet ice temperature.6.2 SyringeA
20、syringe with 2.5 mLcapacity is used for oil addition. It should be equipped with a multiport, high-pressure valveto allow nitrogen and oil entry to the reactor through a common feed line.6.3 Syringe HeaterHeat syringe to 4065C (10410469F)9F using a heat lamp or resistance heater or any other suitabl
21、emeans.6.4 Syringe PumpA syringe pump that can deliver uniform flow of 1.33 6 0.03 g of gas oil in 75 6 1 s.6.5 FurnaceA three-zone furnace is used: middle zone, 150-mm (6-in.)6-in. length, and top and bottom zones, 75-mm(3-in.)3-in. length. The catalyst bed is positioned in the middle zone. The tem
22、perature controllers of the three zones are calibratedto achieve a constant temperature 482 6 1C (900900 6 2F)2F over the whole length of the catalyst bed (actual bedtemperature).6.6 Reactor and InsertA glass or stainless steel reactor of 15.6 mm internal diameter is used. Dimensions are shown in Fi
23、g.2. Details of the reactor insert are shown in Figs. 2 and 3.NOTE 1This drawing is not to scale. For engineering details, see other drawings.FIG. 1 Microactivity Flow ChartD3907/D3907M 132NOTE 1General dimensions are given in SI units. Dimensions given in SAE, U.S. Standard gage sizes for sheet, tu
24、bing, and wire are consideredstandard. In general, the closest metric equivalent should be adequate for proper functioning.6.7 Liquid Product Collection SystemLiquid product is collected in the receiver shown in Fig. 4.6.8 Analytical Balance and WeightsThe balance used to weigh the sample, the recei
25、ver, and the syringe shall have a precisionof 1 mg. Analytical weights shall be precision grade or calibrated against a set of certified standard weights.6.9 Chromatographic EquipmentThe gas chromatographic equipment specified in Test Method D2887 is suggested for theanalysis of liquid product. A fl
26、ame ionization detector is recommended.7. Sampling7.1 If a sampling procedure is desired, Practice E105 is recommended.FIG. 2 Microactivity ReactorD3907/D3907M 1338. Sample Preparation8.1 Dry samples or decoke, or both, by heating a shallow (less than 10 mm thick) bed of catalyst in a porcelain cruc
27、ible asfollows:120 20C (248 36F) for 1 h120C (248F) to 590C (1094F) for approximately 1 h590 20C (1094 36F) for 3 h120 20C 248 36F for 1 h120C 248F to 590C 1094F for approximately 1 h590 20C 1094 36F for 3 hFIG. 3 Reactor Feed Tube InsertD3907/D3907M 1348.2 Sufficient air should be available in the
28、furnace to burn the sample free of coke. Insufficient decoking is indicated by adifference in color of the top and bottom layers. The hot crucible is cooled in a desiccator to prevent moisture pickup.9. Procedure9.1 Reactor Preparation:9.1.1 Rinse the feed line with acetone or other suitable solvent
29、 and dry with air. Periodic cleaning of the insert is recommendedby an air purge at 482C (900F)900F for 1 h, at least once every 12 tests.9.1.2 Wash the reactor and product receiver thoroughly with acetone or other suitable solvent and dry. If necessary, burn outany coke deposited in the reactor by
30、heating in air at 482C (900F)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 of catalyst ina free-flowing manner. Tap the reactor lightly to ensure good radial distribution (do not pack). Position another plug of
31、 quartz orglass wool (about 6-mm length) above the catalyst bed. Do not tamp wool plugs excessively.9.1.4 Inspect the reactor feed tube insert to be sure it is free of deposits and the tip of the thermocouple (see Fig. 3, Detail 2)is bent under the tip of the syringe needle. (This is necessary to co
32、ntrol the oil preheat temperature accurately.) Place the insertin the reactor and adjust, if necessary, so that the insert needle is between 10 to 50 mm above the catalyst bed. Place the reactorin the furnace that has been preheated to 482C (900F)900F and connect the nitrogen purge line directly to
33、the reactor feedline. Purge with 30-mL/min of nitrogen for at least 30 min.9.1.5 Make electrical connections on the integral oil feed preheater and connect the thermocouple to the recorder.9.2 Preparation of Syringe and Liquid Product Receiver:9.2.1 Fill the syringe with ASTM standard feed and inver
34、t to allow air to rise.NOTE 2TheASTM standard feed is very viscous at 30C; therefore, loading the syringe and removal of air bubbles can be facilitated by preheatingthe oil to 40 6 5C (104104 6 9F).9F.9.2.2 Remove the air bubbles. The syringe should contain a small amount of oil in excess of the nom
35、inal volume to be charged.9.2.3 After the syringe is filled and the valve is in correct position, blow excess oil out of the valve and clean the outside ofthe 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,
36、 and connect the nitrogen to the syringe valve. Makesure the valve is in the nitrogen flow position. Place a thermocouple on the syringe body to detect the syringe temperature. Setthe syringe temperature at 40 6 5C (104104 6 9F).9F.9.2.6 Obtain the tare weight of the liquid product receiver and reco
37、rd.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 product receiver. Immerse the receiver to the level of the gas outlet line.Optionally, a controlled temperature circulating bath may be used in place of the wet ice bath.9.2.9 P
38、ressure test the entire system at 26.7 kPa (200200 mm Hg).Hg. The pressure test can be performed by closing the ventline, allowing the pressure to build to 26.7 kPa, and then closing the nitrogen supply valve. The pressure should not changesignificantly over a 2 min period.FIG. 4 Liquid Product Rece
39、iverD3907/D3907M 1359.3 Run Conditions:9.3.1 Check the syringe temperature, 40 6 5C (104104 6 9F),9F, and the reactor temperatures 482 6 1C (900900 62F).2F.9.3.2 Set the syringe pump to deliver 1.33 6 0.03 g of feed in 75 6 1 s.9.3.3 Bring the syringe drive head flush with the syringe plunger.9.3.4
40、Switch the syringe multiport valve from the nitrogen flow to the oil feed position. Note that the position of the valve canbe: joint-feed only, nitrogen flow, or pure-feed only.9.3.5 Start the syringe pump and deliver 1.33 6 0.03 g of feed over 75 6 1 s to the reactor.9.3.6 The oil preheat temperatu
41、re, as measured by the thermocouple at the oil exit point above the bed, shall be 482 6 5C(900900 6 9F).9F.9.3.7 Note that fine particle samples can cause excessive catalyst bed differential pressures, significantly affecting results. Backpressures up to 13.3 kPa (100100 mm Hg)Hg measured during oil
42、 addition (see Fig. 3, Detail 1A) are not detrimental. Moretypical back pressures are in the range from 4.0 to 8.0 kPa (3030 to 60 mm Hg).Hg. If the catalyst bed differential pressureexceeds 13.3 kPa (100100 mm Hg),Hg, it is recommended that the catalyst be screened free of particles finer than 325
43、mesh(45 m)45 m and the test be repeated with the larger-sized particles.9.3.8 Immediately after the oil addition, restart the nitrogen-only flow at 30 mL/min by switching the multiport valve to purgethe reactor and liquid product receiver.9.3.9 Purge the reactor and product recovery system for 15 mi
44、n at 30 mL/min nitrogen, with a wet ice bath. Optionally, acontrolled temperature circulating bath may be used in place of the wet ice bath.9.3.10 Remove the product receiver from the reactor, seal, dry, and weigh immediately. Record weight of liquid in receiver asWl. If sample cannot be analyzed im
45、mediately, store in a sealed vial and refrigerate.9.3.11 Collect the liquid holdup in the reactor exit line and around the reactor-receiver joint with a tared cotton swab or othersuitable material. Determine the weight of this liquid and record as WQ.NOTE 3Experience indicates this liquid material i
46、s predominantly unconverted material.9.3.12 Remove the syringe from the reactor, reweigh it, and record the weight of oil feed as Wf.9.3.13 Remove the reactor from the furnace. After cooling, the catalyst can be removed from the reactor for analysis orregeneration, or both.9.4 Analysis of Liquid Pro
47、duct:9.4.1 Analyze the liquid product by gas chromatography using a simulated distillation technique described by Test MethodD2887.9.4.2 Use a retention time of a 216C (421F)421F material (that is, n-dodecane) as a standard for determining the end pointof converted product.9.4.3 Express integrated p
48、eak area of material boiling above 216C (421F)421F as a percentage of total peak area and recordas R.10. Calculation10.1 Calculate the measured conversion as follows:Measured conversion,weight %5Wf2R3WL100 2WQWf 3100 (1)where:Wf = ASTM standard feed, g,R = weight percentage of material boiling above
49、 216C (421F) in liquid product receiver,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 corrected conversion value may be obtained by using the conversion calibration curve obtained in 3.1.4.11. Precision and Bias11.1 Test ProgramAn interlaboratory study was conducted in wh
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