1、Designation: D4929 07 (Reapproved 2014)Standard Test Methods forDetermination of Organic Chloride Content in Crude Oil1This standard is issued under the fixed designation D4929; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear 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.1. Scope1.1 These test methods cover the determination of organicchloride (above 1 g/g organically-bound chlorine) in crude
3、oils, using either distillation and sodium biphenyl reduction ordistillation and microcoulometry.1.2 These test methods involve the distillation of crude oiltest specimens to obtain a naphtha fraction prior to chloridedetermination. The chloride content of the naphtha fraction ofthe whole crude oil
4、can thereby be obtained. See Section 5regarding potential interferences.1.3 Test Method A covers the determination of organicchloride in the washed naphtha fraction of crude oil by sodiumbiphenyl reduction followed by potentiometric titration.1.4 Test Method B covers the determination of organicchlo
5、ride in the washed naphtha fraction of crude oil byoxidative combustion followed by microcoulometric titration.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard. The preferred concentration units are micrograms ofchloride per
6、gram of sample.1.6 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 prior to use.
7、2. Referenced Documents2.1 ASTM Standards:2D86 Test Method for Distillation of Petroleum Products atAtmospheric PressureD1193 Specification for Reagent WaterD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD6
8、299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System Performance3. Summary of Test Method3.1 A crude oil distillation is performed to obtain thenaphtha cut at 204C (400F). The distillation method wasadapted from Test Method D
9、86 for the distillation of petroleumproducts. The naphtha cut is washed with caustic, repeatedlywhen necessary, until all hydrogen sulfide is removed. Thenaphtha cut, free of hydrogen sulfide, is then washed withwater, repeatedly when necessary, to remove inorganic halides(chlorides).3.2 There are t
10、wo alternative test methods for determinationof the organic chloride in the washed naphtha fraction, asfollows.3.2.1 Test Method A, Sodium Biphenyl Reduction andPotentiometryThe washed naphtha fraction of a crude oilspecimen is weighed and transferred to a separatory funnelcontaining sodium biphenyl
11、 reagent in toluene. The reagent isan addition compound of sodium and biphenyl in ethyleneglycol dimethyl ether. The free radical nature of this reagentpromotes very rapid conversion of the organic halogen toinorganic halide. In effect this reagent solubilizes metallicsodium in organic compounds. Th
12、e excess reagent isdecomposed, the mixture acidified, and the phases separated.The aqueous phase is evaporated to 25 to 30 mL, acetone isadded, and the solution titrated potentiometrically.3.2.2 Test Method B, Combustion and MicrocoulometryThe washed naphtha fraction of a crude oil specimen isinject
13、ed into a flowing stream of gas containing about 80 %oxygen and 20 % inert gas, such as argon, helium, or nitrogen.The gas and sample flow through a combustion tube main-tained at about 800C. The chlorine is converted to chlorideand oxychlorides, which then flow into a titration cell wherethey react
14、 with the silver ions in the titration cell. The silverions thus consumed are coulometrically replaced. The totalcurrent required to replace the silver ions is a measure of thechlorine present in the injected samples.3.2.3 The reaction occurring in the titration cell as chlorideenters is as follows:
15、1These test methods are under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and are the direct responsibilityof Subcommittee D02.03 on Elemental Analysis.Current edition approved May 1, 2014. Published July 2014. Originally approvedin 1989. Last previous e
16、dition approved in 2007 as D4929 07. DOI: 10.1520/D4929-07R14.2For 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
17、.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1Cl21Ag1AgCl s! (1)3.2.4 The silver ion consumed in the above reaction isgenerated coulometrically thus:AgAg11e2(2)3.2.5 These microequivalents of silver are equal to thenumber of microe
18、quivalents of titratable sample ion enteringthe titration cell.4. Significance and Use4.1 Organic chloride species are potentially damaging torefinery processes. Hydrochloric acid can be produced inhydrotreating or reforming reactors and the acid accumulates incondensing regions of the refinery. Une
19、xpected concentrationsof organic chlorides cannot be effectively neutralized anddamage can result. Organic chlorides are not known to benaturally present in crude oils and usually result from cleaningoperations at producing sites, pipelines, or tanks. It is importantfor the oil industry to have comm
20、on methods available for thedetermination of organic chlorides in crude oil, particularlywhen transfer of custody is involved.5. Interferences5.1 Test Method AOther titratable halides will also give apositive response. These titratable halides include HBr and HI.5.2 Test Method BOther titratable hal
21、ides will also give apositive response. These titratable halides include HBr and HI(HOBr and HOI do not precipitate silver). Since these oxyha-lides do not react in the titration cell, approximately 50 %microequivalent response is detected.5.2.1 This test method is applicable in the presence of tota
22、lsulfur concentration of up to 10 000 times the chlorine level.6. Purity of Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the
23、 American Chemical Society,where such specifications are available.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated, referencest
24、o water shall be understood to mean reagent water as definedby Type III of Specification D1193.DISTILLATION AND CLEANUP PROCEDURE7. Apparatus7.1 Round-Bottom Boiling Flask, borosilicate, 1 L, singleshort neck with 24/40 outer ground-glass joint.7.2 Tee Adapter, borosilicate, 75 angle side-arm, 24/40
25、ground-glass joints.7.3 Thermometer, ASTM thermometer 2C (5 to 300C) or2F, (20F to 580F).7.3.1 Other temperature measuring devices, such as thermo-couples or resistance thermometers, may be used when thetemperature reading obtained by these devices is determined toproduce the same naphtha fraction t
26、hat is obtained whenmercury-in-glass thermometers are used.7.4 Thermometer Adapter, borosilicate, 24/40 inner ground-glass joint.7.5 Liebig Condenser, borosilicate, 300-mm length, 24/40ground-glass joints.7.6 Vacuum Take-Off Adapter, borosilicate, 105 angle bend,24/40 ground-glass joints.7.7 Receivi
27、ng Cylinder, borosilicate, 250-mL capacity,24/40 outer ground-glass joint.7.8 Wire Clamps, for No. 24 ground-glass joints, stainlesssteel.7.9 Receiver Flask, for ice bath, 4 L.7.10 Copper Tubing, for heat exchanger to cool condenserwater, 6.4-mm outside diameter, 3-m length.7.11 Electric Heating Man
28、tle, Glas-Col Series 0, 1-L size,140-W upper heating element, 380-W lower heating element.7.12 Variacs, 2, for temperature control of upper and lowerheating elements, 120 V, 10 amps.8. Reagents and Materials8.1 Acetone, chloride-free. (WarningExtremelyflammable, can cause flash fires. Health hazard.
29、)8.2 Caustic Solution, 1 M potassium hydroxide(WarningCan cause severe burns to skin.) prepared indistilled/deionized water.8.3 Distilled/Deionized Water.8.4 Filter Paper, Whatman No. 41 or equivalent.8.5 Stopcock Grease.4,58.6 Toluene, chloride-free. (WarningFlammable. Healthhazard.)9. Sampling9.1
30、Obtain a test unit in accordance with Practice D4057 orD4177. To preserve volatile components, which are in somesamples, do not uncover samples any longer than necessary.Samples should be analyzed as soon as possible, after takingfrom bulk supplies, to prevent loss of organic chloride orcontaminatio
31、n due to exposure or contact with sample con-tainer. (WarningSamples that are collected at temperatures3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see An
32、nual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.4The sole source of supply of the stop-cock grease known to the committee atthis time is Dow Corning silicone, ava
33、ilable from Dow Corning Corporation,Corporate Center, PO Box 994, Midland, MI.5If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consider-ation at a meeting of the responsible technical committee,1which yo
34、u may attend.D4929 07 (2014)2below room temperature may undergo expansion and rupturethe container. For such samples, do not fill the container to thetop; leave sufficient air space above the sample to allow roomfor expansion.)9.2 If the test unit is not used immediately, then thoroughlymix in its c
35、ontainer prior to taking a test specimen. Some testunits can require heating to thoroughly homogenize.(Warning When heating is required, care should be taken sothat no organic chloride containing hydrocarbons are lost.)10. Preparation of Apparatus10.1 Clean all glassware by rinsing successively with
36、 tolu-ene and acetone. After completing the rinse, dry the glasswareusing a stream of dry nitrogen gas. Obtain and record themasses of the round-bottom flask and receiving cylinder.Assemble the glass distillation apparatus using stopcock greaseto seal all joints and wire clamps to prevent loosening
37、of thejoints. Adjust the thermometer position within the adapter teesuch that the lower end of the capillary is level with the highestpoint on the bottom of the inner wall of the adapter tee sectionthat connects to the condenser.NOTE 1A diagram illustrating the appropriate positioning of thethermome
38、ter can be found in Test Method D86.10.2 Form the copper tubing into a coil to fit inside thereceiver flask, leaving room in the center of the flask for thereceiving cylinder. With the PVC tubing, connect one end ofthe copper coil to the water source, and connect the other endof the coil to the lowe
39、r fitting of the Liebig condenser coolingjacket. Connect the upper condenser fitting to the water drain.Fill the receiver flask with an ice/water mixture, and turn on thewater. Maintain the temperature of the condenser below 10C.11. Procedure11.1 Add a 500-mL crude oil test specimen to tared roundbo
40、ttom flask. Obtain and record the mass of the crude oil-filledflask to the nearest 0.1 g. Connect the flask to the distillationapparatus. Place the heating mantle around the flask, andsupport the heating mantle/flask from the bottom. Connect theheating mantle to the variacs. Turn on the variacs and
41、start thedistillation. During the distillation, adjust the variac settings togive a distillation rate of approximately 5 mL/min. Continuethe distillation until a thermometer reading of 204C (400F) isattained. When the temperature reaches 204C (400F), end thedistillation by first disconnecting and re
42、moving the receivingcylinder. After the receiving cylinder has been removed, turnoff the variacs and remove the heating mantle from the flask.Obtain and record the mass of the receiving cylinder anddistillate.11.1.1 The precision and bias statements were determinedusing mercury-in-glass thermometers
43、 only. Therefore, whenalternate temperature measuring devices are used, the cut-offtemperature so obtained shall be that which will produce anaphtha cut similar to what would be yielded when mercury-in-glass thermometers are used. Such alternate temperaturemeasuring devices shall not be expected to
44、exhibit the sametemperature lag characteristics as mercury-in-glass thermom-eters.11.2 Transfer the naphtha fraction from the receiving cylin-der to the separatory funnel. Using the separatory funnel, washthe naphtha fraction three times with equal volumes of thecaustic solution (1 M KOH). Follow th
45、e caustic wash with awater wash, again washing three times with equal volumes.The caustic wash removes hydrogen sulfide, while the waterwash removes traces of inorganic chlorides either originallypresent in the crude or from impurities in the caustic solution.After the washings are complete, filter
46、the naphtha fraction toremove residual freestanding water. Store the naphtha fractionin a clean glass bottle. This naphtha fraction can now beanalyzed for organic chlorides by either sodium biphenyl orcombustion/microcoulometric techniques.11.3 Measure the density of the crude oil specimen and thena
47、phtha fraction by obtaining the mass of 10.0 mL (using a10-mL volumetric flask) of each to the nearest 0.1 g.12. Calculation12.1 Calculate naphtha fraction as follows:f 5 Mn/Mc(3)where:f = mass fraction of naphtha collected,Mn= mass of naphtha collected, andMc= mass of crude oil specimen.12.2 Calcul
48、ate the density as follows:Density, g/mL 5 m/v (4)where:m = mass of sample specimen, g, andv = volume of sample specimen, mL.TEST METHOD ASODIUM BIPHENYLREDUCTION AND POTENTIOMETRY13. Apparatus13.1 ElectrodesThe cleaning and proper care of electrodesare critical to the accuracy of this test. Manufac
49、turers instruc-tions for the care of electrodes shall be followed.13.1.1 Glass, general purpose. When glass electrodes are incontinuous use, weekly cleaning with chrome-sulfuric acid(WarningStrong oxidizer; can cause severe burns; recog-nized carcinogen), or other strongly oxidizing cleaningsolution, is recommended.13.1.2 Silver-Silver Chloride, billet-type.13.2 Titrator, potentiometric. The titrator is equipped with a5-mL or smaller buret and a magnetic stirring motor.14. Reagents and Materials14.1 Acetone, chloride-free. (WarningExtremelyflammab
