1、Designation: D4006 11 (Reapproved 2012)1Manual of Petroleum Measurement Standards (MPMS), Chapter 10.2Standard Test Method forWater in Crude Oil by Distillation1This standard is issued under the fixed designation D4006; the number immediately following the designation indicates the year oforiginal a
2、doption 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.This standard has been approved for use by agencies of the Department of Defense.
3、1NOTEAPI information was editorially corrected in July 2013.1. Scope*1.1 This test method covers the determination of water incrude oil by distillation.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does n
4、ot 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. For specificwarning statements, see 6.
5、1 and A1.1.2. Referenced Documents2.1 ASTM Standards:2D95 Test Method for Water in Petroleum Products andBituminous Materials by Distillation (API MPMS Chapter10.5)D473 Test Method for Sediment in Crude Oils and Fuel Oilsby the Extraction Method (API MPMS Chapter 10.1)D665 Test Method for Rust-Preve
6、nting Characteristics ofInhibited Mineral Oil in the Presence of WaterD1796 Test Method for Water and Sediment in Fuel Oils bythe Centrifuge Method (Laboratory Procedure) (APIMPMS Chapter 10.6)D4057 Practice for Manual Sampling of Petroleum andPetroleum Products (API MPMS Chapter 8.1)D4177 Practice
7、for Automatic Sampling of Petroleum andPetroleum Products (API MPMS Chapter 8.2)D4928 Test Method for Water in Crude Oils by CoulometricKarl Fischer Titration (API MPMS Chapter 10.9)E123 Specification forApparatus for Determination ofWaterby Distillation2.2 API Standards:MPMS Chapter 8.1 Manual Samp
8、ling of Petroleum andPetroleum Products (ASTM Practice D4057)MPMS Chapter 8.2 Automatic Sampling of Petroleum andPetroleum Products (ASTM Practice D4177)MPMS Chapter 10.1 Test Method for Sediment in CrudeOils and Fuel Oils by the Extraction Method (ASTM TestMethod D473)MPMS Chapter 10.4 Determinatio
9、n of Water and/or Sedi-ment in Crude Oil by the Centrifuge Method (FieldProcedure)MPMS Chapter 10.5 Test Method for Water in PetroleumProducts and Bituminous Materials by Distillation(ASTM Test Method D95)MPMS Chapter 10.6 Test Method for Water and Sediment inFuel Oils by the Centrifuge Method (Labo
10、ratory Proce-dure) (ASTM Test Method D1796)MPMS Chapter 10.9 Test Method for Water in Crude Oils byCoulometric Karl Fischer Titration (ASTM Test MethodD4928)3. Summary of Test Method3.1 The sample is heated under reflux conditions with awater immiscible solvent which co-distills with the water in th
11、esample. Condensed solvent and water are continuously sepa-rated in a trapthe water settles in the graduated section of thetrap, and the solvent returns to the distillation flask.4. Significance and Use4.1 A knowledge of the water content of crude oil isimportant in the refining, purchase, sale, or
12、transfer of crudeoils.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and the API Committee on Petroleum Measure-ment and is the direct responsibility of Subcommittee D02.02 /COMQ on Hydro-carbon Measurement for Custody Transfer (Joint ASTM-API).
13、Current edition approved Nov. 1, 2012. Published December 2012. Originallyapproved in 1981. Last previous edition approved in 2011 as D400611. DOI:10.1520/D4006-11R12E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annu
14、al Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.2 This tes
15、t method may not be suitable for crude oils thatcontain alcohols that are soluble in water. In cases where theimpact on the results may be significant, the user is advised toconsider using another test method, such as Test MethodD4928 (API MPMS Chapter 10.9).5. Apparatus5.1 The preferred apparatus,
16、shown in Fig. 1, consists of aglass distillation flask, a condenser, a graduated glass trap,3anda heater. Other types of distillation apparatus are specified inSpecification E123. Any of these apparatus will be acceptablefor this test method provided it can be demonstrated that theyoperate within th
17、e precision established with the preferredapparatus.5.1.1 Distillation FlaskA 1000-mL round-bottom, glass,distillation flask fitted with a 24/40 female taper joint shall beused. This flask receives a 5-mL calibrated, graduated watertrap with 0.05-mL graduations. The trap will be fitted with a400-mm
18、Liebig condenser. A drying tube filled with desiccant(to prevent entrance of atmospheric moisture) is placed on topof the condenser.5.1.2 HeaterAny suitable gas or electric heater that canuniformly distribute heat to the entire lower half of the flaskmay be used. An electric heating mantle is prefer
19、red for safetyreasons.5.1.3 The apparatus used in this test will be accepted whensatisfactory results are obtained by the calibration techniquedescribed in Section 8.6. Solvent6.1 Xylenereagent grade (WarningExtremely flam-mable. Vapor harmful. See AnnexA1.)Asolvent blank will beestablished by placi
20、ng 400 mL of solvent in the distillationapparatus and testing as outlined in Section 9. The blank willbe determined to the nearest 0.025 mL and used to correct thevolume of water in the trap as in Section 10.6.2 The xylene used in this procedure is generally a mixtureof ortho, meta, and para isomers
21、 and may contain some ethylbenzene. The typical characteristics for this reagent are:Color (APHA) not more than 10Boiling range 137144CResidue after evaporation 0.002 %Sulfur compounds (as S) 0.003 %Substances darkened by H2SO4Color pass testWater (H2O) 0.02 %Heavy metals (as Pb) 0.1 ppmCopper (Cu)
22、0.1 ppmIron (Fe) 0.1 ppmNickel (Ni) 0.1 ppmSilver (Ag) 0.1 ppm7. Sampling, Test Samples, and Test Units7.1 Sampling is defined as all steps required to obtain analiquot of the contents of any pipe, tank, or other system and toplace the sample into the laboratory test container.7.1.1 Laboratory Sampl
23、eOnly representative samples ob-tained as specified in Practice D4057 (API MPMS Chapter 8.1)and Practice D4177 (API MPMS Chapter 8.2) shall be used forthis test method.7.1.2 Preparation of Test SamplesThe following samplehandling procedure shall apply in addition to those covered in7.1.1.7.1.2.1 The
24、 sample size shall be selected as indicated belowbased on the expected water content of the sample:Expected Water Content,weight or volume %Approximate Sample Size,gormL50.1100.0 525.1 50.0 1010.1 25.0 205.1 10.0 501.1 5.0 1000.5 1.0 200less than 0.5 2007.1.2.2 If there is any doubt about the unifor
25、mity of themixed sample, determinations should be made on at least threetest portions and the average result reported as the watercontent.7.1.2.3 To determine water on a volume basis, measuremobile liquids in a 5, 10, 20, 50, 100, or 200-mL calibrated,graduated cylinder (NBS Class A) depending on th
26、e samplesize indicated in 7.1.2.1. Take care to pour the sample slowlyinto the graduated cylinder to avoid entrapment of air and toadjust the level as closely as possible to the appropriategraduation. Carefully pour the contents of the cylinder into thedistillation flask and rinse the cylinder five
27、times with portionsof xylene equivalent to one-fifth of the capacity of the3Available on special order from Scientific GlassApparatus Co., Bloomfield, NJ07003.FIG. 1 Distillation ApparatusD4006 11 (2012)12graduated cylinder and add the rinsings to the flask. Drain thecylinder thoroughly to ensure co
28、mplete sample transfer.7.1.2.4 To determine water on a mass basis, weigh a testportion of sample in accordance with 7.1.2.1, pouring thesample directly into the distillation flask. If a transfer vessel(beaker or cylinder) must be used, rinse it with at least fiveportions of xylene and add the rinsin
29、gs to the flask.8. Calibration8.1 Calibrate both the trap and the entire assembly prior toinitial use and after any equipment changes as indicated in8.1.1-8.1.3. Additionally, calibrate both the trap and the entireassembly periodically, at a frequency not to exceed yearly.8.1.1 Verify the accuracy o
30、f the graduation marks on thetrap by adding 0.05-mL increments of distilled water, at 20C,from a 5-mL microburet or a precision micro-pipet readable tothe nearest 0.01 mL. If there is a deviation of more than0.050 mL between the water added and water observed, rejectthe trap or recalibrate.8.1.2 Als
31、o calibrate the entire apparatus. Put 400 mL of dry(0.02 % water maximum) xylene in the apparatus and test inaccordance with Section 9. When complete, discard the con-tents of the trap and add 1.00 6 0.01 mLof distilled water fromthe buret or micro-pipet, at 20C, directly to the distillationflask an
32、d test in accordance with Section 9. Repeat 8.1.2 andadd 4.50 6 0.01 mL directly to the flask. The assembly of theapparatus is satisfactory only if trap readings are within thetolerances specified here:Limits Capacity Volume of Water Permissible forof Trap at 20C, Added at 20C, Recovered WatermL mL
33、at 20C, mL5.005.001.004.501.00 0.0254.50 0.0258.1.3 A reading outside the limits suggests malfunctioningdue to vapor leaks, too rapid boiling, inaccuracies in gradua-tions of the trap, or ingress of extraneous moisture. Thesemalfunctions must be eliminated before repeating 8.1.2.9. Procedure9.1 The
34、precision of this test method can be affected bywater droplets adhering to surfaces in the apparatus andtherefore not settling into the water trap to be measured. Tominimize the problem, all apparatus must be chemicallycleaned at least daily to remove surface films and debris whichhinder free draina
35、ge of water in the test apparatus. Morefrequent cleaning is recommended if the nature of the samplesbeing run causes persistent contamination.9.2 To determine water on a volume basis, proceed asindicated in 7.1.2.3. Add sufficient xylene to the flask to makethe total xylene volume 400 mL.9.2.1 To de
36、termine water on a mass basis, proceed asindicated in 7.1.2.4. Add sufficient xylene to the flask to makethe total xylene volume 400 mL.9.2.2 A magnetic stirrer is the most effective device toreduce bumping. Glass beads or other boiling aids, althoughless effective, have been found to be useful.9.3
37、Assemble the apparatus as shown in Fig. 1, making sureall connections are vapor and liquid-tight. It is recommendedthat glass joints not be greased. Insert a drying tube containingan indicating desiccant into the end of the condenser to preventcondensation of atmospheric moisture inside the condense
38、r.Circulate water, between 20 and 25C, through the condenserjacket.9.4 Apply heat to the flask. The type of crude oil beingevaluated can significantly alter the boiling characteristics ofthe crude-solvent mixture. Heat should be applied slowlyduring the initial stages of the distillation (approximat
39、ely12 to1 h) to prevent bumping and possible loss of water from thesystem. (Condensate shall not proceed higher than threequarters of the distance up the condenser inner tube (Point A inFig. 1).) To facilitate condenser wash-down, the condensateshould be held as close as possible to the condenser ou
40、tlet.After the initial heating, adjust the rate of boiling so that thecondensate proceeds no more than three quarters of thedistance up the condenser inner tube. Distillate should dis-charge into the trap at the rate of approximately 2 to 5 drops persecond. Continue distillation until no water is vi
41、sible in anypart of the apparatus, except in the trap, and the volume ofwater in the trap remains constant for at least 5 min. If there isa persistent accumulation of water droplets in the condenserinner tube, flush with xylene. (A jet spray washing tube, seeFig. 2, or equivalent device is recommend
42、ed.) The addition ofan oil-soluble emulsion breaker at a concentration of 1000 ppmto the xylene wash helps dislodge the clinging water drops.After flushing, redistill for at least 5 min (the heat must be shutoff at least 15 min prior to wash-down to prevent bumping).After wash-down, apply heat slowl
43、y to prevent bumping.Repeat this procedure until no water is visible in the condenserand the volume of water in the trap remains constant for at least5 min. If this procedure does not dislodge the water, use theTFE-fluorocarbon scraper, pick shown in Fig. 2, or equivalentdevice to cause the water to
44、 run into the trap.9.5 When the carryover of water is complete, allow the trapand contents to cool to 20C. Dislodge any drops of wateradhering to the sides of the trap with the TFE-fluorocarbonscraper or pick and transfer them to the water layer. Read thevolume of the water in the trap. The trap is
45、graduated in0.05-mL increments, but the volume is estimated to the nearest0.025 mL.10. Calculation10.1 Calculate the water in the sample as follows:Volume% 5A 2 B!C3100 (1)Volume% 5A 2 B!M/D!3100 (2)Mass% 5A 2 B!M3100 (3)where:A = mL of water in trap,B = mL of solvent blank,C = mL of test sample,M =
46、 g of test sample, andD4006 11 (2012)13D = density of sample, g/mL.Volatile water-soluble material, if present, may bemeasured as water.11. Report11.1 Report the result as the water content to the nearest0.025 %, reporting water content of less than 0.025 % as 0 %,and reference this Test Method D400
47、6 (API MPMS Chapter10.2) as the procedure used.12. Precision and Bias12.1 The precision of this test method, as obtained bystatistical examination of interlaboratory test results in therange from 0.01 to 1.0 %, is described in 12.1.1 and 12.1.2.12.1.1 RepeatabilityThe difference between successivete
48、st results, obtained by the same operator with the sameapparatus under constant operating conditions on identical testmaterial, would, in the long run, in the normal and correctoperation of the test method, exceed the following value inonly one case in twenty:From 0.0 % to 0.1 % water, see Fig. 3.Gr
49、eater than 0.1 % water, repeatability is constant at 0.08.12.1.2 ReproducibilityThe difference between the twosingle and independent test results obtained by differentoperators working in different laboratories on identical testmaterial, would, in the long run, in the normal and correctoperation of the test method, exceed the following value inonly one case in twenty:From 0.0 % to 0.1 % water, see Fig. 3Greater than 0.1 % water, reproducibility is constant at 0.11.13. Keywords13.1 crude oil; distillation; waterFIG. 2 Pick, Scraper, and Jet Spray
