ASTM D4929-2015 Standard Test Methods for Determination of Organic Chloride Content in Crude Oil《测定原油中有机氯化物含量的标准试验方法》.pdf

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1、Designation: D4929 07 (Reapproved 2014)D4929 15Standard 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 revisio

2、n, 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.1. Scope Scope*1.1 These test methods cover the determination of organic chloride (above 1 g/g organically-bound ch

3、lorine) in crude oils,using either distillation and sodium biphenyl reduction or distillation and microcoulometry.1.2 These test methods involve the distillation of crude oil test specimens to obtain a naphtha fraction prior to chloridedetermination. The chloride content of the naphtha fraction of t

4、he whole crude oil can thereby be obtained. See Section 5 regardingpotential interferences.1.3 Test MethodAcovers the determination of organic chloride in the washed naphtha fraction of crude oil by sodium biphenylreduction followed by potentiometric titration.1.4 Test Method B covers the determinat

5、ion of organic chloride in the washed naphtha fraction of crude oil by oxidativecombustion followed by microcoulometric titration.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.The preferred concentration units are microg

6、rams 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. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimita

7、tions prior to use.2. Referenced Documents2.1 ASTM Standards:2D86 Test Method for Distillation of Petroleum Products at Atmospheric PressureD1193 Specification for Reagent WaterD4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4177 Practice for Automatic Sampling of Petroleum an

8、d Petroleum ProductsD6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measure-ment System Performance3. Summary of Test Method3.1 A crude oil distillation is performed to obtain the naphtha cut at 204C (400F).204 C (400 F). The distillat

9、ion methodwas adapted from Test Method D86 for the distillation of petroleum products. The naphtha cut is washed with caustic, repeatedlywhen necessary, until all hydrogen sulfide is removed. The naphtha cut, free of hydrogen sulfide, is then washed with water,repeatedly when necessary, to remove in

10、organic halides (chlorides).3.2 There are two alternative test methods for determination of the organic chloride in the washed naphtha fraction, as follows.3.2.1 Test Method A, Sodium Biphenyl Reduction and PotentiometryThe washed naphtha fraction of a crude oil specimen isweighed and transferred to

11、 a separatory funnel containing sodium biphenyl reagent in toluene. The reagent is an additioncompound of sodium and biphenyl in ethylene glycol dimethyl ether. The free radical nature of this reagent promotes very rapidconversion of the organic halogen to inorganic halide. In effect this reagent so

12、lubilizes metallic sodium in organic compounds. The1 These test methods are under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and are the direct responsibility ofSubcommittee D02.03 on Elemental Analysis.Current edition approved May 1, 2014June 1, 2015.

13、 Published July 2014June 2015. Originally approved in 1989. Last previous edition approved in 20072014 asD4929 07.D4929 07 (2014). DOI: 10.1520/D4929-07R14.10.1520/D4929-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For An

14、nual Book of ASTM Standardsvolume information, refer to the standards Document 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 b

15、e technically possible 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.*A Summary of Changes section appears at the end o

16、f this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1excess reagent is decomposed, the mixture acidified, and the phases separated. The aqueous phase is evaporated to 2525 mL to 30mL, 30 mL, acetone is added, and the solutio

17、n titrated potentiometrically.3.2.2 Test Method B, Combustion and Microcoulometry The washed naphtha fraction of a crude oil specimen is injected intoa flowing stream of gas containing about 80 % oxygen and 20 % inert gas, such as argon, helium, or nitrogen. The gas and sampleflow through a combusti

18、on tube maintained at about 800C.800 C. The chlorine is converted to chloride and oxychlorides, whichthen flow into a titration cell where they react with the silver ions in the titration cell. The silver ions thus consumed arecoulometrically replaced. The total current required to replace the silve

19、r ions is a measure of the chlorine present in the injectedsamples.3.2.3 The reaction occurring in the titration 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 si

20、lver are equal to the number of microequivalents of titratable sample ion entering the titrationcell.4. Significance and Use4.1 Usually organic chlorides do not occur naturally in crude oil. When present, they result from contamination in some manner,such as disposal of waste solvent or as use for d

21、ewaxing a pipeline or other equipment.4.1.1 While an uncontaminated crude oil will contain zero ppm of organic chloride, a very small amount is capable of beinghandled in a refinery.4.1.2 A rule of thumb used by refiners is 1 ppm organic chlorides in the whole crude, and 5 ppm in the light naphtha,

22、whenthe naphtha fraction is 20 % of the original sample.4.1.2.1 For refiners to ensure 1 ppm organic chloride in the crude oil, the amount measured in the naphtha fraction must be 1/f (where f is the naphtha fraction calculated with Eq 3).4.1.3 Any organic halide present in the crude oil almost alwa

23、ys distills into the naphtha fraction. Some varieties can break downduring fractionation but most survive this process and are destroyed during further refining usually during hydro-treating(desulfurization of the naphtha).4.2 Sometimes other halides have been used for dewaxing crude oil; in such ca

24、ses, any organic halides will cause the sameproblems as the organic chlorides.4.3 Organic chloride species are potentially damaging to refinery processes. Hydrochloric acid can be produced in hydrotreatingor reforming reactors and the acid accumulates in condensing regions of the refinery. Unexpecte

25、d 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 cleaning operations at producing sites, pipelines, or tanks. It is important for the oil industry to havecommon m

26、ethods available for the determination of organic chlorides in crude oil, particularly when transfer of custody isinvolved.5. Interferences5.1 Test Method AOther titratable halides will also give a positive response. These titratable halides include HBr and HI.5.2 Test Method BOther titratable halid

27、es will also give a positive response. These titratable halides include HBr and HI(HOBr and HOI do not precipitate silver). Since these oxyhalides 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 total

28、sulfur concentration of up to 10 00010 000 times the chlorine level.6. Purity of Reagents6.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents shall conform to the specifications of the Committee on Analytical Reagents o

29、f the American Chemical Society, wheresuch specifications are available.3 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently highpurity to permit its use without lessening the accuracy of the determination.6.2 Purity of WaterUnless otherwise indicated, ref

30、erences to water shall be understood to mean reagent water as defined byType III of Specification D1193.3 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

31、 Annual Standards 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 152DISTILLATION AND CLEANUP PROCEDURE7. Apparatus7.1 Round-Bottom Boiling Flask, borosilicate, 1 L, 1 L

32、, 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 (5(5 C to 300C)300 C) or 2F, (20F(20 F to 580F).580 F).7.3.1 Other temperature measuring devices, such as thermocouples or resistan

33、ce 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 are used.7.4 Thermometer Adapter, borosilicate, 24/40 inner ground-glass joint.7.5 Liebig Condenser, borosilicate,

34、300-mm300 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-mL250 mL capacity, 24/40 outer ground-glass joint.7.8 Wire Clamps, for No. 24 ground-glass joints, stainless steel.7.9 Receive

35、r Flask, for ice bath, 4 L.4 L.7.10 Copper Tubing, for heat exchanger to cool condenser water, 6.4-mm6.4 mm outside diameter, 3-m3 m length.7.11 Electric Heating Mantle, Glas-Col Series 0, 1-L1 Lsize, 140-W140 W upper heating element, 380-W380 W lower heatingelement.7.12 Variacs, 2, for temperature

36、control of upper and lower heating elements, 120 V, 10 amps.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 hydroxide (WarningCan cause severe burns to skin.) prepared in distil

37、led/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 Practice D4057 or D4177. To preserve volatile components, which ar

38、e 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 sample container.(WarningSamples that are collected at temperatures

39、 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 immediately, then thoroughly mix in its container prior to taking

40、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 glassware by rinsing successively with toluene and acetone. Aft

41、er 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 joints and wire clamps to prevent loosening of the joints. Adjust th

42、ethermometer 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.NOTE 1A diagram illustrating the appropriate positioning of the thermometer can be found in T

43、est Method D86.4 The sole source of supply of 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 Intern

44、ational Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee, 1 which you may attend.D4929 15310.2 Form the copper tubing into a coil to fit inside the receiver flask, leaving room in the center of the flask for the receivingcylinder. With

45、 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 receiverflask with an ice/water mixture, and turn on the water.

46、Maintain the temperature of the condenser below 10C.10 C.11. Procedure11.1 Add a 500-mL500 mL crude oil test specimen to tared round bottom flask. Obtain and record the mass of the crudeoil-filled flask to the nearest 0.1 g. 0.1 g. Connect the flask to the distillation apparatus. Place the heating m

47、antle around the flask,and support the heating mantle/flask from the bottom. Connect the heating mantle to the variacs. Turn on the variacs and start thedistillation. During the distillation, adjust the variac settings to give a distillation rate of approximately 55 mL mL/min. min.Continue the disti

48、llation until a thermometer reading of 204C (400F)204 C (400 F) is attained. When the temperature reaches204C (400F),204 C (400 F), end the distillation by first disconnecting and removing the receiving cylinder.After the receivingcylinder has been removed, turn off the variacs and remove the heatin

49、g mantle from the flask. Obtain and record the mass of thereceiving cylinder and distillate.11.1.1 The precision and bias statements were determined using mercury-in-glass thermometers only. Therefore, when alternatetemperature measuring devices are used, the cut-off temperature so obtained shall be that which will produce a naphtha cut similarto what would be yielded when mercury-in-glass thermometers are used. Such alternate temperature measuring devices shall notbe expected to exhibit the same temperature lag characteristics as m