1、Designation: D 1159 07Designation: 130/98An American National StandardStandard Test Method forBromine Numbers of Petroleum Distillates and CommercialAliphatic Olefins by Electrometric Titration1This standard is issued under the fixed designation D 1159; the number immediately following the designati
2、on indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by age
3、ncies of the Department of Defense.1. Scope*1.1 This test method2covers the determination of thebromine number of the following materials:1.1.1 Petroleum distillates that are substantially free ofmaterial lighter than isobutane and that have 90 % distillationpoints (by Test Method D86) under 327C (6
4、26F). This testmethod is generally applicable to gasoline (including leaded,unleaded, and oxygenated fuels), kerosine, and distillates in thegas oil range that fall in the following limits:90 % Distillation Point, C (F) Bromine Number, max2Under 205 (400) 175205 to 327 (400 to 626) 101.1.2 Commercia
5、l olefins that are essentially mixtures ofaliphatic mono-olefins and that fall within the range of 95 to165 bromine number (see Note 1). This test method has beenfound suitable for such materials as commercial propylenetrimer and tetramer, butene dimer, and mixed nonenes, octenes,and heptenes. This
6、test method is not satisfactory for normalalpha-olefins.NOTE 1These limits are imposed since the precision of this testmethod has been determined only up to or within the range of thesebromine numbers.1.2 The magnitude of the bromine number is an indicationof the quantity of bromine-reactive constit
7、uents, not an iden-tification of constituents; therefore, its application as a measureof olefinic unsaturation should not be undertaken without thestudy given in Annex A1.1.3 For petroleum hydrocarbon mixtures of bromine num-ber less than 1.0, a more precise measure for bromine-reactiveconstituents
8、can be obtained by using Test Method D 2710.Ifthe bromine number is less than 0.5, then Test Method D 2710or the comparable bromine index methods for industrialaromatic hydrocarbons, Test Methods D 1492 or D 5776 mustbe used in accordance with their respective scopes. Thepractice of using a factor o
9、f 1000 to convert bromine numberto bromine index is not applicable for these lower values ofbromine number.1.4 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.5 This standard does not purport to address all of thesafety conce
10、rns, 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 Sections 7, 8, and 9.2. Referenced Documents2.
11、1 ASTM Standards:3D86 Test Method for Distillation of Petroleum Products atAtmospheric PressureD 1193 Specification for Reagent WaterD 1492 Test Method for Bromine Index of Aromatic Hy-drocarbons by Coulometric TitrationD 2710 Test Method for Bromine Index of Petroleum Hy-drocarbons by Electrometric
12、 TitrationD 5776 Test Method for Bromine Index of Aromatic Hy-drocarbons by Electrometric Titration3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 bromine numberthe number of grams of brominethat will react with 100 g of the specimen under the conditionsof the test.1This test
13、method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.04.0D on Physical and Chemical Methods.In the IP, this test method is under the jurisdiction of the StandardizationCommittee.Current edition approved May 1,
14、2007. Published May 2007. Originallyapproved in 1951. Last previous edition approved in 2001 as D 115901.2See Dubois, H. D., and Skoog, D. A., “Determination of Bromine AdditionNumbers,” Analytical Chemistry, Vol 20, 1948, pp. 624627.3For referenced ASTM standards, visit the ASTM website, www.astm.o
15、rg, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box
16、C700, West Conshohocken, PA 19428-2959, United States.4. Summary of Test Method4.1 A known weight of the specimen dissolved in theselected solvent (see 8.1) maintained at 0 to 5C (32 to 41F)is titrated with standard bromide-bromate solution. The endpoint is indicated by a sudden change in potential
17、on anelectrometric end point titration apparatus due to the presenceof free bromine.5. Significance and Use5.1 The bromine number is useful as a measure of aliphaticunsaturation in petroleum samples. When used in conjunctionwith the calculation procedure described inAnnexA2, it can beused to estimat
18、e the percentage of olefins in petroleum distil-lates boiling up to approximately 315C (600F).5.2 The bromine number of commercial aliphatic monoole-fins provides supporting evidence of their purity and identity.6. Apparatus6.1 Electrometric End Point Titration ApparatusAny ap-paratus designed to pe
19、rform titrations to pre-set end points (seeNote 2) may be used in conjunction with a high-resistancepolarizing current supply capable of maintaining approxi-mately 0.8 V across two platinum electrodes and with asensitivity such that a voltage change of approximately 50 mVat these electrodes is suffi
20、cient to indicate the end point. Othertypes of commercially available electronic titrimeters, includ-ing certain pH meters, have also been found suitable.NOTE 2Pre-set end point indicated with polarized electrodes providesa detection technique similar to the dead stop technique specified inprevious
21、versions of this test method.6.2 Titration VesselAjacketed glass vessel approximately120 mm high and 45 mm in internal diameter and of a form thatcan be conveniently maintained at 0 to 5C (32 to 41F).6.3 StirrerAny magnetic stirrer system.6.4 ElectrodesA platinum wire electrode pair with eachwire ap
22、proximately 12 mm long and 1 mm in diameter. Thewires shall be located 5 mm apart and approximately 55 mmbelow the level of the titration solvent. Clean the electrode pairat regular intervals with 65 % nitric acid and rinse withdistilled water before use.6.5 BuretAny delivery system capable of measu
23、ring ti-trant in 0.05 mL or smaller graduations.7. Reagents7.1 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 American Chemical Societ
24、y,where such specifications are available.4Other 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.7.2 Purity of Water Unless otherwise indicated, refer-ences to water shall be under
25、stood to mean reagent water asdefined by Type III of Specification D 1193.7.3 Acetic Acid, Glacial(WarningPoison, corrosive-combustible, may be fatal if swallowed. Causes severe burns,harmful if inhaled.)7.4 Bromide-Bromate, Standard Solution (0.2500 M asBr2) Dissolve 51.0 g of potassium bromide (KB
26、r) and 13.92g of potassium bromate (KBrO3) each dried at 105C (220F)for 30 min in water and dilute to 1 L.7.4.1 If the determinations of the bromine number of thereference olefins specified in Section 8 using this solution donot conform to the prescribed limits, or if for reasons ofuncertainties in
27、the quality of primary reagents it is considereddesirable to determine the molarity of the solution, the solutionshall be standardized and the determined molarity used insubsequent calculations. The standardization procedure shallbe as follows:7.4.1.1 To standardize, place 50 mL of glacial acetic ac
28、idand 1 mL of concentrated hydrochloric acid (WarningPoison corrosive. May be fatal if swallowed. Liquid and vaporcauses severe burns. Harmful if inhaled; relative density 1.19.)in a 500-mL iodine number flask. Chill the solution in a bathfor approximately 10 min and, with constant swirling of thefl
29、ask, add from a 10-mL calibrated buret, 5 6 0.01 mL of thebromide-bromate standard solution at the rate of 1 or 2 dropsper second. Stopper the flask immediately, shake the contents,place it again in the ice bath, and add 5 mL of Kl solution inthe lip of the flask. After 5 min remove the flask from t
30、he icebath and allow the Kl solution to flow into the flask by slowlyremoving the stopper. Shake vigorously, add 100 mL of waterin such a manner as to rinse the stopper, lip and walls of theflask, and titrate promptly with sodium thiosulfate (Na2S2O3)solution. Near the end of the titration, add 1 mL
31、 of starchindicator solution and titrate slowly to disappearance of theblue color. Calculate the molarity of the bromide-bromatesolution as follows:M15AM25! 2!(1)where:M1= molarity of the bromide-bromate solution, as Br2,A = millilitres of Na2S2O3solution required for titrationof the bromide-bromate
32、 solution, and,M2= molarity of Na2S2O3solution,5 = millilitres of bromidebromate solution, and2 = number of electrons transferred during redox titra-tion of bromide-bromate solution.Repeat the standardization until duplicate determinations donot differ from the mean by more than 60.002 M.7.5 Methano
33、l(WarningFlammable. Vapor harmful.Can be fatal or cause blindness if swallowed or inhaled. Cannotbe made non-poisonous.)7.6 Potassium Iodide Solution (150 g/L)Dissolve 150 g ofpotassium iodide (Kl) in water and dilute to 1 L.7.7 Sodium Thiosulfate, Standard Solution (0.1 M)Dissolve 25 g of sodium th
34、iosulfate (Na2S2O35H2O) in water4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K.,
35、and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D1159072and add 0.1 g of sodium carbonate (Na2CO3) to stabilize thesolution. Dilute to 1 L and mix thoroughly by shaking.Standardize by any accepted procedure that determines themolarit
36、y with an error not greater than 60.0002. Restandardizeat intervals frequent enough to detect changes of 0.0005 inmolarity.7.8 Starch Indication SolutionMix5gofsoluble starchwith about 3 to 5 mL of water. If desired, add about 0.65 gsalicylic acid as preservative. Add the slurry to 500 mL ofboiling
37、water and continue boiling for 5 to 10 min. Allow tocool, and decant the clear, supernatant liquid into glass bottlesand seal well. Starch solutions (some preserved with salicylicacid) are also commercially available and may be substituted.7.9 Sulfuric Acid (1 + 5)Carefully mix one volume ofconcentr
38、ated sulfuric acid (H2SO4, rel dens 1.84) with fivevolumes of water. (WarningPoison. Corrosive. Strong oxi-dizer. Contact with organic material can cause fire. Can be fatalif swallowed.)7.10 Titration SolventPrepare 1 L of titration solvent bymixing the following volumes of materials: 714 mL of glac
39、ialacetic acid, 134 mL of 1,1,1-trichloroethane (or dichlo-romethane), 134 mL of methanol, and 18 mL of H2SO4(1 + 5).7.11 1,1,1-Trichloroethane(WarningHarmful if in-haled. High concentrations can cause unconsciousness ordeath. Contact may cause skin irritation and dermatitis.)7.12 Dichloromethane(Wa
40、rningThe replacement of1,1,1-trichloroethane, an ozone-depleting chemical, is neces-sary because its manufacture and import has been discontin-ued. Dichloromethane is temporarily being allowed as analternative to 1,1,1-trichloroethane until a permanent replace-ment can be identified and adopted by A
41、STM International. Aprogram to identify and evaluate candidate solvents is currentlyunderway in Subcommittee D02.04.)NOTE 3Commercially available reagents can be used in place oflaboratory preparations.8. Check Procedure8.1 In case of doubt in applying the procedure to actualsamples, the reagents an
42、d techniques can be checked by meansof determinations on freshly purified cyclohexene or di-isobutene. (WarningThe user of this test method maychoose to use either 1,1,1-trichloroethane or dichloromethaneto the exclusion of the other solvent. The selected solvent is tobe used for all operations, tha
43、t is, in the preparation of thetitration solvent, for the dilution of samples, and as the titrationblank.) Proceed in accordance with Section 9, using a sampleof either 0.6 to 1 g freshly purified cyclohexene or diisobutene(see Table 1) or 6 to 10 g of 10 mass percent solutions of thesematerials in
44、1,1,1-trichlorethane. (WarningFlammable.)8.2 If the reagents and techniques are correct, values withinthe following should be obtained:StandardBromineNumberCyclohexene, purified (see 7.4.1, 9.3, and 8.1) 187 to 199 (see 9.5)Cyclohexene, 10 % solution 18 to 20Diisobutene, purified (see 7.4.1, 8.3, an
45、d 8.1) 136 to 144 (see 9.5)Diisobutene, 10 % solution 13 to 15The reference olefins yielding the above results are charac-terized by the properties shown in Table 1. The theoreticalbromine numbers of cyclohexene and diisobutene are 194.6and 142.4, respectively.8.3 Purified samples of cyclohexene and
46、 diisobutene can beprepared from cyclohexene and diisobutene,5by the followingprocedure:8.3.1 Add 65 g of activated silica gel, 75 to 150 m (100 to200 mesh) manufactured to ensure minimum olefin polymer-ization6to a column approximately 16 mm in inside diameterand 760 mm in length, that has been tap
47、ered at the lower endand that contains a small plug of glass wool at the bottom.A100-mL buret, or any column that will give a height-to-diameter ratio of the silica gel of at least 30:1, will be suitable.Tap the column during the adding of the gel to permit uniformpacking.8.3.2 To the column add 30
48、mL of the olefin to be purified.When the olefin disappears into the gel, fill the column withmethanol. Discard the first 10 mL of percolate and collect thenext 10 mL that is the purified olefin for test of the brominenumber procedure. Determine and record the density andrefractive index of the purif
49、ied samples at 20C. Discard theremaining percolate. (WarningIf distillation of impure ole-fins is needed as a pre-purification step, a few pellets ofpotassium hydroxide should be placed in the distillation flaskand at least 10 % residue should remain to minimize thehazards from decomposition of any peroxides that may bepresent.)9. Procedure9.1 Place 10 mL of 1,1,1-trichloroethane or dichlo-romethane in a 50-mL volumetric flask and, by means of apipet, introduce a test specimen as indicated in Table 2. Either5The sole source of supply of
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