ASTM D5773-2007 374 Standard Test Method for Cloud Point of Petroleum Products (Constant Cooling Rate Method)《测定石油产品始凝点的标准试验方法》.pdf

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1、Designation: D 5773 07Designation: 446/99An American National StandardStandard Test Method forCloud Point of Petroleum Products (Constant Cooling RateMethod)1This standard is issued under the fixed designation D 5773; the number immediately following the designation indicates the year oforiginal ado

2、ption or, in the 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.INTRODUCTIONThis test method describes an alternative procedure for the determinati

3、on of cloud point ofpetroleum products Test Method D 2500/IP 219 using an automatic apparatus. The temperature resultsfrom this test method have been found to be equivalent to Test Method D 2500/IP 219. Whenspecification requires Test Method D 2500/IP 219, do not substitute this test method or any o

4、thermethod without obtaining comparative data and agreement from the specifier.1. Scope*1.1 This test method covers the determination of the cloudpoint of petroleum products and biodiesel fuels that aretransparent in layers 40 mm in thickness by an automaticinstrument using a constant cooling rate.1

5、.2 This test method covers the range of temperatures from60 to +49C with temperature resolution of 0.1C, however,the range of temperatures included in the 1997 interlaboratorycooperative test program only covered the temperature range of56 to +34C.1.3 The values stated in SI units are to be regarded

6、 as thestandard. The values given in parentheses are for informationonly.1.4 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

7、the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 2500 Test Method for Cloud Point of Petroleum ProductsD 4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD 4177 Practice for Automatic Sampling of Petroleum andPetroleum Products

8、2.2 Energy Institute Standard:3IP 219 Test Method for Cloud Point of Petroleum Products3. Terminology3.1 Definitions:3.1.1 biodiesel, na fuel comprised of mono-alkyl esters oflong-chain fatty acids derived from vegetable oils or animalfats, designated B100.3.1.1.1 DiscussionBiodiesel is typically pr

9、oduced by areaction of vegetable oil or animal fat with an alcohol such asmethanol or ethanol in the presence of a catalyst to yieldmono-esters and glycerin. The fuel typically may contain up to14 different types of fatty acids that are chemically transformedinto fatty acid methyl esters (FAME).3.1.

10、2 biodiesel blend, na blend of biodiesel fuel withpetroleum-based diesel fuel designated BXX, where XX is thevolume percentage of biodiesel.3.1.3 cloud point, nin petroleum products and biodieselfuels, the temperature of a liquid specimen when the smallestobservable cluster of hydrocarbon crystals f

11、irst occurs uponcooling under prescribed conditions.3.1.3.1 DiscussionThe cloud point occurs when the tem-perature of the specimen is low enough to cause hydrocarboncrystals to precipitate. In a homogeneous liquid, the cloud isalways noted first at the location in the specimen where thespecimen temp

12、erature is the lowest. The cloud point is thetemperature at which the crystals first occur, regardless of theirlocation in the specimen, and not after extensive crystallization1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct resp

13、onsibility of SubcommitteeD02.07 on Flow Properties.Current edition approved Dec. 1, 2007. Published January 2008. Originallyapproved in 1995. Last previous edition approved in 2005 as D 577305.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at s

14、erviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from the Energy Institute, 61 New Cavendish Street, London,England WIM 8AR.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM

15、 International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.has taken place. The hydrocarbon crystals that precipitate atlower temperatures are typically, but not excluded to, straightchain hydrocarbons commonly called “wax crystals.”3.1.3.2 DiscussionThe purp

16、ose of the cloud point is tomeasure the wax crystals in the specimen; however, traceamounts of water and inorganic compounds may also bepresent.The intent of the cloud point measurement is to capturethe temperature at which the liquid fuel in the specimen beginsto change from a single liquid phase t

17、o a two-phase systemcontaining solid and liquid. It is not the intent of this testmethod to monitor the phase transition of the trace componentssuch as water.3.2 Definitions of Terms Specific to This Standard:3.2.1 automatic cloud point, nthe temperature of a speci-men, when the appearance of the cl

18、oud is determined under theconditions of this test method.3.2.1.1 DiscussionThe cloud point in this test method isdetermined by an automatic instrument using an optical devicefor detection of the crystal formation. The apparatus and theconditions are different from those established for Test MethodD

19、 2500, although according to interlaboratory examination, theresults have been determined to be equivalent to Test MethodD 2500.3.2.2 D 2500/IP 219 equivalent cloud point, nthe tem-perature of a specimen, in integers, calculated by rounding theresults of this test method to the next lower integer.3.

20、2.2.1 DiscussionThis test method produces results with0.1C resolution. Should the user wish to provide results witha similar format to Test Method D 2500, then this calculationcan be performed. Some apparatus can perform this calculationautomatically.3.2.3 Peltier device, na solid state thermoelectr

21、ic deviceconstructed with dissimilar semiconductor materials and con-figured in such a way that it will transfer heat to or away froma test specimen dependent on the direction of electric currentapplied to the device.4. Summary of Test Method4.1 A specimen is cooled by a Peltier device at a constant

22、rate of 1.5 6 0.1C/min while continuously being illuminatedby a light source. The specimen is continuously monitored byan array of optical detectors for the first appearance of a cloudof wax crystals. The detectors are sufficient in number toensure that any solid phase hydrocarbon crystals that may

23、formare detected. The temperature at which the appearance of acloud of wax crystals is first detected in the specimen isrecorded to 0.1C resolution. When the recorded temperature isrounded to the next lower integer temperature, it is designatedas the D 2500/IP 219 equivalent cloud point per Test Met

24、hodD 5773.5. Significance and Use5.1 The cloud point of petroleum products and biodieselfuels is an index of the lowest temperature of their utility forcertain applications. Wax crystals of sufficient quantity canplug filters used in some fuel systems.5.2 Petroleum blending operations require a prec

25、ise mea-surement of the cloud point.5.3 This test method can determine the temperature of thetest specimen at which wax crystals have formed sufficiently tobe observed as a cloud with a resolution of 0.1C.5.4 This test method provides results that are equivalent toTest Method D 2500.NOTE 1This is ba

26、sed on the Test Method D 2500 equivalent cloudpoint in which the 0.1C result is rounded to the next lower integer.5.5 This test method determines the cloud point in a shorterperiod of time than Test Method D 2500.NOTE 2In cases of samples with cloud points near ambient tempera-tures, time savings ma

27、y not be realized.5.6 This test method eliminates most of the operator timerequired of Test Method D 2500.5.7 This test method does not require the use of a mechani-cal refrigeration apparatus.NOTE 3In certain cases of high ambient temperature, a source ofcooling water may be required to measure low

28、 temperature cloud points(see 7.1).6. Apparatus6.1 Automatic Apparatus4The automatic cloud point ap-paratus described in this test method consists of a test chambercontrolled by a microprocessor that is capable of controllingthe heating and cooling of the test specimen, optically observ-ing the firs

29、t appearance of a cloud of wax crystals andrecording the temperature of the specimen described in detailin Annex A1.6.2 The apparatus shall be equipped with a specimen cup,optical detector array, light source, digital display, Peltierdevice, and a specimen temperature measuring device.6.3 The Peltie

30、r device shall be capable of heating or coolingthe test specimen at a constant rate of 1.5 6 0.1C/min.6.4 The temperature measuring device in the specimen cupshall be capable of measuring the temperature of the testspecimen from 40 to +70C at a resolution of 0.1C.6.5 The apparatus shall be equipped

31、with fittings to permitthe circulation of a liquid cooling medium, if required, toremove heat generated by the Peltier device and other elec-tronic components of the apparatus.NOTE 4Some apparatus are designed to use ambient air as a coolingmedium. In such cases, a built-in fan is available to provi

32、de circulation ofair and there is no need for fittings as described for a liquid coolingmedium. The function of the cooling medium is to remove heat from theelectronic components. The choice of the cooling medium has no impactwhatsoever on the test results.6.6 The apparatus shall be equipped with fi

33、ttings to permitthe circulation of purge gas to purge the test chamber contain-ing the specimen cup of any atmospheric moisture.4The sole source of supply of the PhaseTechnology Cloud PointAnalyzer modelseries 10, 30, 70, 70V, and 70X known to the committee at this time is PhaseTechnology, 11168 Ham

34、mersmith Gate, Richmond, B.C. Canada V7A 5H8. Thevarious model series mentioned above are differentiated by their cooling capacitiesand user interfaces; however, all of them are capable of covering the entiretemperature range specified in the scope. If you are aware of alternative suppliers,please p

35、rovide this information to ASTM International Headquarters. Your com-ments will receive careful consideration at a meeting of the responsible technicalcommittee,1which you may attend.D57730727. Reagents and Materials7.1 Cooling MediumAir, tap water, or other liquid heatexchange medium sufficient to

36、remove heat generated by thePeltier device and other electronic components from theapparatus. To achieve specimen cooling to 40C, supplycirculation of liquid cooling medium at +25C or lower to theapparatus. For an apparatus which relies on air as coolingmedium, the ambient air temperature has to be

37、below +30C toachieve specimen cooling to 40C.7.2 Purge GasA gas such as air, nitrogen, helium, orargon with a dew point below the lowest operating temperatureof the analyzer. (WarningCompressed gas under high pres-sure.) (WarningInert gas can be an asphyxiant when in-haled.)7.3 Precision VolumeDispe

38、nsing Device, capable of dis-pensing 0.15 6 0.01 mL of sample.7.4 Cotton SwabsPlastic or paper shaft cotton swabs usedto clean the sample cup. (WarningThe use of swabs withwooden shafts may damage the mirrored surface of thespecimen cup.)8. Sampling8.1 Obtain a sample in accordance with Practices D

39、4057 orD 4177.8.2 Samples of very viscous materials may be warmed untilthey are reasonably fluid before they are tested. However, nosample should be heated more than absolutely necessary.8.3 The sample shall not be heated above 70C. When thesample is heated above 70C, allow the sample to cool below7

40、0C before filtering or inserting into the apparatus.8.4 When moisture is present in the sample, remove themoisture by a method, such as filtration through dry lint-freefilter paper, until the oil is perfectly clear, but make suchfiltration at a temperature at least 14C above the expectedcloud point.

41、NOTE 5Moisture will be noticed in the sample as a separate phase oras a haze throughout the entire sample. Generally, a slight haze will notinterfere with the detection of the wax cloud.9. Preparation of Apparatus9.1 Prepare the instrument for operation in accordance withthe manufacturers instructio

42、ns.9.2 Make liquid cooling medium connections if required(see Note 4) and ensure that they do not leak.9.3 Make purge gas connections and ensure that they do notleak.9.4 Turn on the liquid cooling medium if required (see Note4).9.5 Turn on the purge gas.9.6 Turn on the main power switch of the analy

43、zer.After theautomatic self diagnostics startup sequence is completed, theinstrument will display a READY message.10. Calibration and Standardization10.1 Ensure that all of the manufacturers instructions forcalibrating, checking, and operating the apparatus are fol-lowed.10.2 A sample with a mutuall

44、y agreed upon cloud point canbe used to verify performance of the apparatus.11. Procedure11.1 Inspect the specimen cup to ensure it is clean and dry.If not, clean the cup (see 11.3).11.2 Deliver 0.15 6 0.01 mLof specimen into the specimencup. Pipette, syringe, or precision positive-displacement de-v

45、ices are suitable for use in delivering the specimen.11.3 Clean the specimen out of the cup. The cup must becleaned to the point where no visible droplets of specimenremain in the cup. Non-abrasive absorbent materials such ascotton swabs are suitable for use in cleaning the specimen cup.Cleaning sol

46、vents able to clean the specimen and compatiblewith the components of the apparatus can also be used.Naphtha, hexane, heptane, and toluene are suitable as cleaningsolvents.11.4 Repeat steps 11.2 and 11.3.11.5 Carefully measure 0.15 6 0.01 mL of specimen intothe specimen cup.11.6 Close and lock the t

47、est chamber lid.11.7 Select the PRE-HEAT menu on the apparatus if theexpected cloud point is less than 14C below the specimenambient temperature. The specimen ambient temperature isdisplayed on the front panel of the apparatus. With thisselection, the apparatus will automatically heat the specimen t

48、oa starting temperature of 50C prior to cooling. If the PRE-HEAT menu is not selected, the apparatus will cool thespecimen from ambient temperature without any initial heat-ing. When the cloud point is expected to be higher than 35C,select a higher starting temperature according to manufactur-ers in

49、structions. The highest starting temperature that can beprogrammed is 70C.11.8 Start the operation of the apparatus in accordance withthe manufacturers instructions.The apparatus will allow theflow of liquid cooling medium, if required, (see Note 4) and theflow of purge gas through the apparatus. (WarningTheapparatus will display appropriate warning signals if any ofthese flows are not properly established. Refer to manufactur-ers operating manual for corrective procedures.)11.9 The specimen is heated if specified as described