ASTM D4929-2016 Standard Test Method for Determination of Organic Chloride Content in Crude Oil《原油中有机氯化物含量测定的标准试验方法》.pdf

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1、Designation: D4929 15aD4929 16Standard Test MethodsMethod 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 year

2、 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. Scope*1.1 These test methodsThe procedures in this test method cover the determination of organic chloride (above 1 g/gorga

3、nically-bound chlorine) in crude oils, using either distillation and sodium biphenyl reduction or distillation and microcou-lometry.1.2 These test methodsThe procedures in this test method involve the distillation of crude oil test specimens to obtain a naphthafraction prior to chloride determinatio

4、n.The chloride content of the naphtha fraction of the whole crude oil can thereby be obtained.See Section 5 regarding potential interferences.1.3 Test Method ProcedureAcovers the determination of organic chloride in the washed naphtha fraction of crude oil by sodiumbiphenyl reduction followed by pot

5、entiometric titration.1.4 Test Method Procedure B covers the determination of organic chloride 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 as standard. No other units of measurement are

6、 included in this standard.The preferred concentration units are micrograms of chloride per gram of sample.1.5.1 The preferred concentration units are micrograms of chloride per gram of sample.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use.

7、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. Referenced Documents2.1 ASTM Standards:2D86 Test Method for Distillation of Petroleum Products and Liquid Fuels at Atmosp

8、heric PressureD1193 Specification for Reagent WaterD4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4177 Practice for Automatic Sampling of Petroleum and Petroleum ProductsD6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Anal

9、ytical Measure-ment System Performance3. Summary of Test Method3.1 Acrude oil distillation is performed to obtain the naphtha cut at 204 C (400 F). The distillation method was adapted fromTest Method D86 for the distillation of petroleum products. The naphtha cut is washed with caustic, repeatedly w

10、hen necessary,until all hydrogen sulfide is removed. The naphtha cut, free of hydrogen sulfide, is then washed with water, repeatedly whennecessary, to remove inorganic halides (chlorides).3.2 There are two alternative test methods procedures for determination of the organic chloride in the washed n

11、aphtha fraction,as follows.3.2.1 Test Method Procedure A, Sodium Biphenyl Reduction and PotentiometryThe washed naphtha fraction of a crude oilspecimen is weighed and transferred to a separatory funnel containing sodium biphenyl reagent in toluene. The reagent is an1 TheseThis test methods aremethod

12、 is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and areis the directresponsibility of Subcommittee D02.03 on Elemental Analysis.Current edition approved Dec. 1, 2015Oct. 1, 2016. Published December 2015October 2016. Originally approved in 1989. La

13、st previous edition approved in 2015 asD4929 15.D4929 15a. DOI: 10.1520/D4929-15A.10.1520/D4929-16.2 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 Docu

14、ment Summary page on the ASTM website.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 possible to adequately depict all changes accurately, ASTM r

15、ecommends 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box

16、 C700, West Conshohocken, PA 19428-2959. United States1addition compound of sodium and biphenyl in ethylene glycol dimethyl ether. The free radical nature of this reagent promotes veryrapid conversion of the organic halogen to inorganic halide. In effect this reagent solubilizes metallic sodium in o

17、rganiccompounds. The excess reagent is decomposed, the mixture acidified, and the phases separated. The aqueous phase is evaporatedto 25 mL to 30 mL, acetone is added, and the solution titrated potentiometrically.3.2.2 Test Method Procedure B, Combustion and Microcoulometry The washed naphtha fracti

18、on of a crude oil specimen isinjected into a flowing stream of gas containing about 80 % oxygen and 20 % inert gas, such as argon, helium, or nitrogen. Thegas and sample flow through a combustion tube maintained at about 800 C. The chlorine is converted to chloride andoxychlorides, which then flow i

19、nto a titration cell where they react with the silver ions in the titration cell. The silver ions thusconsumed are coulometrically replaced. The total current required to replace the silver ions is a measure of the chlorine presentin the injected samples.3.2.3 The reaction occurring in the titration

20、 cell as chloride enters is as follows:Cl21Ag1AgCls! (1)3.2.4 The silver ion consumed in the above reaction is generated coulometrically thus:AgAg11e2 (2)3.2.5 These microequivalents of silver are equal to the number of microequivalents of titratable sample ion entering the titrationcell.4. Signific

21、ance and Use4.1 Organic chlorides do not occur naturally in crude oil. When present, they result from contamination in some manner, suchas disposal of chlorinated solvent used in many dewaxing pipeline or other equipment operations.4.1.1 Uncontaminated crude oil will contain no detectable organic ch

22、loride, and most refineries can handle very small amountswithout deleterious effects.4.1.1.1 Most trade contracts specify that no organic chloride is present in the crude oil.4.1.2 Several pipelines have set specification limits at 1 mgkg organic chlorides in the whole crude, and 5 mgkg in the light

23、naphtha, on the basis of the naphtha fraction being 20 % of the original sample.4.1.2.1 To ensure 1 mgkg organic chloride in the crude oil, the amount measured in the naphtha fraction shall be 1/f (wheref is the naphtha fraction calculated with Eq 3).4.1.3 Organic chloride present in the crude oil (

24、for example, methylene chloride, perchloroethylene, etc.) is usually distilled intothe naphtha fraction. Some compounds break down during fractionation and produce hydrochloric acid, which has a corrosiveeffect. Some compounds survive fractionation and are destroyed during hydro-treating (desulfuriz

25、ation of the naphtha).4.2 Other halides can also be used for dewaxing crude oil; in such cases, any organic halides will have similar impact on therefining operations as the organic chlorides.4.3 Organic chloride species are potentially damaging to refinery processes. Hydrochloric acid can be produc

26、ed in hydrotreatingor reforming reactors and the acid accumulates in condensing regions of the refinery. Unexpected concentrations of organicchlorides cannot be effectively neutralized and damage can result. Organic chlorides are not known to be naturally present in crudeoils and usually result from

27、 cleaning operations at producing sites, pipelines, or tanks. It is important for the oil industry to havecommon methods available for the determination of organic chlorides in crude oil, particularly when transfer of custody isinvolved.5. Interferences5.1 Test Method Procedure AOther titratable hal

28、ides will also give a positive response. These titratable halides include HBrand HI.5.2 Test Method Procedure BOther titratable halides will also give a positive response. These titratable halides include HBrand HI (HOBr and HOI do not precipitate silver). Since these oxyhalides do not react in the

29、titration cell, approximately 50 %microequivalent response is detected.5.2.1 This test method procedure is applicable in the presence of total sulfur concentration of up to 10 000 times the chlorinelevel.6. Purity of Reagents6.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. U

30、nless otherwise indicated, it is intended that allreagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, wheresuch specifications are available.3 Other grades may be used, provided it is first ascertained that the reagent is of sufficie

31、ntly highpurity to permit its use without lessening the accuracy of the determination.3 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed bythe American Chemical Society, see Annual Standards

32、for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.D4929 1626.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mean reagent water as define

33、d byType III of Specification D1193.DISTILLATION AND CLEANUP PROCEDURE7. Apparatus7.1 Round-Bottom Boiling Flask, borosilicate, 1 L, single short neck with 24/40 outer ground-glass joint.7.2 Tee Adapter, borosilicate, 75 angle side-arm, 24/40 ground-glass joints.7.3 Thermometer, ASTM thermometer 2C

34、(5 C to 300 C) or 2F, (20 F to 580 F).7.3.1 Other temperature measuring devices, such as thermocouples or resistance thermometers, may be used when thetemperature reading obtained by these devices is determined to produce the same naphtha fraction that is obtained whenmercury-in-glass thermometers a

35、re used.7.4 Thermometer Adapter, borosilicate, 24/40 inner ground-glass joint.7.5 Liebig Condenser, borosilicate, 300 mm length, 24/40 ground-glass joints.7.6 Vacuum Take-Off Adapter, borosilicate, 105 angle bend, 24/40 ground-glass joints.7.7 Receiving Cylinder, borosilicate, 250 mL capacity, 24/40

36、 outer ground-glass joint.7.8 Wire Clamps, for No. 24 ground-glass joints, stainless steel.7.9 Receiver Flask, for ice bath, 4 L.7.10 Copper Tubing, for heat exchanger to cool condenser water, 6.4 mm outside diameter, 3 m length.7.11 Electric Heating Mantle, Glas-Col Series 0, 1 L size, 140 W upper

37、heating element, 380 W lower heating element.7.12 Variacs, 2, for temperature control of upper and lower heating elements, 120 V, 10 amps.8. Reagents and Materials8.1 Acetone, chloride-free. (WarningExtremely flammable, can cause flash fires. Health hazard.)8.2 Caustic Solution, 1 M potassium hydrox

38、ide (WarningCan cause severe burns to skin.) prepared in distilled/deionizedwater.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. Health hazard.)9. Sampling9.1 Obtain a test unit in accordance with Pra

39、ctice D4057 or D4177. 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 taking frombulk supplies, to prevent loss of organic chloride or contamination due to exposure or contact with samp

40、le container.(WarningSamples that are collected at temperatures below room temperature may undergo expansion and rupture the container.For such samples, do not fill the container to the top; leave sufficient air space above the sample to allow room for expansion.)9.2 If the test unit is not used imm

41、ediately, then thoroughly mix in its container prior to taking a test specimen. Some test unitscan require heating to thoroughly homogenize. (WarningWhen heating is required, care should be taken so that no organicchloride containing hydrocarbons are lost.)10. Preparation of Apparatus10.1 Clean all

42、glassware by rinsing successively with toluene and acetone. After completing the rinse, dry the glassware usinga stream of dry nitrogen gas. Obtain and record the masses of the round-bottom flask and receiving cylinder. Assemble the glassdistillation apparatus using stopcock grease to seal all joint

43、s and wire clamps to prevent loosening of the joints. Adjust thethermometer position within the adapter tee such that the lower end of the capillary is level with the highest point on the bottomof the inner wall of the adapter tee section that connects to the condenser.4 The sole source of supply of

44、 the stop-cock grease known to the committee at this time is Dow Corning silicone, available from Dow Corning Corporation, CorporateCenter, PO Box 994, Midland, MI.5 If you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will rece

45、ive careful consideration at ameeting of the responsible technical committee, 1 which you may attend.D4929 163NOTE 1A diagram illustrating the appropriate positioning of the thermometer can be found in Test Method D86.10.2 Form the copper tubing into a coil to fit inside the receiver flask, leaving

46、room in the center of the flask for the receivingcylinder. With the PVC tubing, connect one end of the copper coil to the water source, and connect the other end of the coil tothe lower fitting of the Liebig condenser cooling jacket. Connect the upper condenser fitting to the water drain. Fill the r

47、eceiverflask with an ice/water mixture, and turn on the water. Maintain the temperature of the condenser below 10 C.11. Procedure11.1 Add a 500 mL crude oil test specimen to tared round bottom flask. Obtain and record the mass of the crude oil-filled flaskto the nearest 0.1 g. Connect the flask to t

48、he distillation apparatus. Place the heating mantle around the flask, and support theheating mantle/flask from the bottom. Connect the heating mantle to the variacs. Turn on the variacs and start the distillation.During the distillation, adjust the variac settings to give a distillation rate of appr

49、oximately 5 mLmin. Continue the distillationuntil a thermometer reading of 204 C (400 F) is attained. When the temperature reaches 204 C (400 F), end the distillation byfirst disconnecting and removing the receiving cylinder. After the receiving cylinder has been removed, turn off the variacs andremove the heating mantle from the flask. Obtain and record the mass of the receiving cylinder and distillate.11.1.1 The precision and bias statements were determined using mercury-in-glass thermometers only. Therefore, when alternatetemperature meas