ASTM D1159-07(2012)
(Test Method)Standard Test Method for Bromine Numbers of Petroleum Distillates and Commercial Aliphatic Olefins by Electrometric Titration
Standard Test Method for Bromine Numbers of Petroleum Distillates and Commercial Aliphatic Olefins by Electrometric Titration
SIGNIFICANCE AND USE
The bromine number is useful as a measure of aliphatic unsaturation in petroleum samples. When used in conjunction with the calculation procedure described in Annex A2, it can be used to estimate the percentage of olefins in petroleum distillates boiling up to approximately 315°C (600°F).
The bromine number of commercial aliphatic monoolefins provides supporting evidence of their purity and identity.
SCOPE
1.1 This test method covers the determination of the bromine number of the following materials:
1.1.1 Petroleum distillates that are substantially free of material lighter than isobutane and that have 90 % distillation points (by Test Method D86) under 327°C (626°F). This test method is generally applicable to gasoline (including leaded, unleaded, and oxygenated fuels), kerosine, and distillates in the gas oil range that fall in the following limits: 90 % Distillation Point, °C (°F)Bromine Number, max2 Under 205 (400)175 205 to 327 (400 to 626) 10
1.1.2 Commercial olefins that are essentially mixtures of aliphatic mono-olefins and that fall within the range of 95 to 165 bromine number (see Note 1). This test method has been found suitable for such materials as commercial propylene trimer and tetramer, butene dimer, and mixed nonenes, octenes, and heptenes. This test method is not satisfactory for normal alpha-olefins.
Note 1—These limits are imposed since the precision of this test method has been determined only up to or within the range of these bromine numbers.
1.2 The magnitude of the bromine number is an indication of the quantity of bromine-reactive constituents, not an identification of constituents; therefore, its application as a measure of olefinic unsaturation should not be undertaken without the study given in Annex A1.
1.3 For petroleum hydrocarbon mixtures of bromine number less than 1.0, a more precise measure for bromine-reactive constituents can be obtained by using Test Method D2710. If the bromine number is less than 0.5, then Test Method D2710 or the comparable bromine index methods for industrial aromatic hydrocarbons, Test Methods D1492 or D5776 must be used in accordance with their respective scopes. The practice of using a factor of 1000 to convert bromine number to bromine index is not applicable for these lower values of bromine number.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific warning statements, see Sections 7, 8, and 9.
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Designation:D1159 −07 (Reapproved 2012)
Designation: 130/98
Standard Test Method for
Bromine Numbers of Petroleum Distillates and Commercial
Aliphatic Olefins by Electrometric Titration
This standard is issued under the fixed designation D1159; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* constituents can be obtained by using Test Method D2710.If
2 the bromine number is less than 0.5, then Test Method D2710
1.1 This test method covers the determination of the
or the comparable bromine index methods for industrial
bromine number of the following materials:
aromatic hydrocarbons, Test Methods D1492 or D5776 must
1.1.1 Petroleum distillates that are substantially free of
be used in accordance with their respective scopes. The
material lighter than isobutane and that have 90 % distillation
practice of using a factor of 1000 to convert bromine number
points (by Test Method D86) under 327°C (626°F). This test
to bromine index is not applicable for these lower values of
method is generally applicable to gasoline (including leaded,
bromine number.
unleaded,andoxygenatedfuels),kerosine,anddistillatesinthe
gas oil range that fall in the following limits: 1.4 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
90 % Distillation Point, °C (°F) Bromine Number, max
Under 205 (400) 175
only.
205 to 327 (400 to 626) 10
1.5 This standard does not purport to address all of the
1.1.2 Commercial olefins that are essentially mixtures of
safety concerns, if any, associated with its use. It is the
aliphatic mono-olefins and that fall within the range of 95 to
responsibility of the user of this standard to establish appro-
165 bromine number (see Note 1). This test method has been
priate safety and health practices and determine the applica-
found suitable for such materials as commercial propylene
bility of regulatory limitations prior to use. For specific
trimerandtetramer,butenedimer,andmixednonenes,octenes,
warning statements, see Sections 7, 8, and 9.
and heptenes. This test method is not satisfactory for normal
alpha-olefins. 2. Referenced Documents
2.1 ASTM Standards:
NOTE 1—These limits are imposed since the precision of this test
method has been determined only up to or within the range of these
D86 Test Method for Distillation of Petroleum Products at
bromine numbers.
Atmospheric Pressure
D1193 Specification for Reagent Water
1.2 The magnitude of the bromine number is an indication
of the quantity of bromine-reactive constituents, not an iden- D1492 Test Method for Bromine Index of Aromatic Hydro-
carbons by Coulometric Titration
tificationofconstituents;therefore,itsapplicationasameasure
of olefinic unsaturation should not be undertaken without the D2710 Test Method for Bromine Index of Petroleum Hydro-
carbons by Electrometric Titration
study given in Annex A1.
D5776 Test Method for Bromine Index of Aromatic Hydro-
1.3 For petroleum hydrocarbon mixtures of bromine num-
carbons by Electrometric Titration
ber less than 1.0, a more precise measure for bromine-reactive
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
This test method is under the jurisdiction of ASTM Committee D02 on
3.1.1 bromine number—the number of grams of bromine
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.06 on Analysis of Liquid Fuels and Lubricants.
that will react with 100 g of the specimen under the conditions
In the IP, this test method is under the jurisdiction of the Standardization
of the test.
Committee.
Current edition approved April 15, 2012. Published April 2012. Originally
approved in 1951. Last previous edition approved in 2007 as D1159–07. DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/D1159-07R12. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Dubois, H. D., and Skoog, D. A., “Determination of Bromine Addition Standards volume information, refer to the standard’s Document Summary page on
Numbers,” Analytical Chemistry, Vol 20, 1948, pp. 624–627. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D1159−07 (2012)
4. Summary of Test Method sufficiently high purity to permit its use without lessening the
accuracy of the determination.
4.1 A known weight of the specimen dissolved in the
selected solvent (see 8.1) maintained at 0 to 5°C (32 to 41°F) 7.2 PurityofWater—Unlessotherwiseindicated,references
is titrated with standard bromide-bromate solution. The end to water shall be understood to mean reagent water as defined
point is indicated by a sudden change in potential on an by Type III of Specification D1193.
electrometric end point titration apparatus due to the presence
7.3 Acetic Acid, Glacial—(Warning—Poison, corrosive-
of free bromine.
combustible, may be fatal if swallowed. Causes severe burns,
harmful if inhaled.)
5. Significance and Use
7.4 Bromide-Bromate, Standard Solution(0.2500 M as Br )
5.1 The bromine number is useful as a measure of aliphatic
—Dissolve 51.0 g of potassium bromide (KBr) and 13.92 g of
unsaturation in petroleum samples. When used in conjunction
potassium bromate (KBrO ) each dried at 105°C (220°F) for
withthecalculationproceduredescribedinAnnexA2,itcanbe
30 min in water and dilute to 1 L.
used to estimate the percentage of olefins in petroleum distil-
7.4.1 If the determinations of the bromine number of the
lates boiling up to approximately 315°C (600°F).
reference olefins specified in Section 8 using this solution do
5.2 The bromine number of commercial aliphatic monoole-
not conform to the prescribed limits, or if for reasons of
fins provides supporting evidence of their purity and identity.
uncertainties in the quality of primary reagents it is considered
desirable to determine the molarity of the solution, the solution
6. Apparatus
shall be standardized and the determined molarity used in
6.1 Electrometric End Point Titration Apparatus—Any ap-
subsequent calculations. The standardization procedure shall
paratus designed to perform titrations to pre-set end points (see
be as follows:
Note 2) may be used in conjunction with a high-resistance
7.4.1.1 To standardize, place 50 mL of glacial acetic acid
polarizing current supply capable of maintaining approxi-
and 1 mL of concentrated hydrochloric acid ( Warning—
mately 0.8 V across two platinum electrodes and with a
Poison corrosive. May be fatal if swallowed. Liquid and vapor
sensitivity such that a voltage change of approximately 50 mV
causes severe burns. Harmful if inhaled; relative density 1.19.)
at these electrodes is sufficient to indicate the end point. Other
in a 500-mL iodine number flask. Chill the solution in a bath
types of commercially available electronic titrimeters, includ-
for approximately 10 min and, with constant swirling of the
ing certain pH meters, have also been found suitable.
flask, add from a 10-mL calibrated buret, 5 6 0.01 mL of the
bromide-bromate standard solution at the rate of 1 or 2 drops
NOTE 2—Pre-set end point indicated with polarized electrodes provides
per second. Stopper the flask immediately, shake the contents,
a detection technique similar to the dead stop technique specified in
previous versions of this test method.
place it again in the ice bath, and add 5 mL of Kl solution in
the lip of the flask. After 5 min remove the flask from the ice
6.2 Titration Vessel—Ajacketed glass vessel approximately
bath and allow the Kl solution to flow into the flask by slowly
120mmhighand45mmininternaldiameterandofaformthat
removing the stopper. Shake vigorously, add 100 mL of water
can be conveniently maintained at 0 to 5°C (32 to 41°F).
in such a manner as to rinse the stopper, lip and walls of the
6.3 Stirrer—Any magnetic stirrer system.
flask, and titrate promptly with sodium thiosulfate (Na S O )
2 2 3
6.4 Electrodes—A platinum wire electrode pair with each
solution. Near the end of the titration, add 1 mL of starch
wire approximately 12 mm long and 1 mm in diameter. The
indicator solution and titrate slowly to disappearance of the
wires shall be located 5 mm apart and approximately 55 mm
blue color. Calculate the molarity of the bromide-bromate
below the level of the titration solvent. Clean the electrode pair
solution as follows:
at regular intervals with 65 % nitric acid and rinse with
AM
distilled water before use.
M 5 (1)
~5!~2!
6.5 Buret—Any delivery system capable of measuring
where:
titrant in 0.05 mL or smaller graduations.
M = molarity of the bromide-bromate solution, as Br ,
1 2
7. Reagents A = millilitresofNa S O solutionrequiredfortitrationof
2 2 3
the bromide-bromate solution, and,
7.1 Purity of Reagents—Reagent grade chemicals shall be
M = molarity of Na S O solution,
2 2 2 3
used in all tests. Unless otherwise indicated, it is intended that
5 = millilitres of bromide—bromate solution, and
all reagents shall conform to the specifications of the commit-
2 = number of electrons transferred during redox titration
tee onAnalytical Reagents of theAmerican Chemical Society,
of bromide-bromate solution.
where such specifications are available. Other grades may be
Repeat the standardization until duplicate determinations do
used, provided it is first ascertained that the reagent is of
not differ from the mean by more than 60.002 M.
7.5 Methanol—(Warning—Flammable. Vapor harmful.
Reagent Chemicals, American Chemical Society Specifications, American
Canbefatalorcauseblindnessifswallowedorinhaled.Cannot
Chemical Society, Washington, DC. For Suggestions on the testing of reagents not
listed by the American Chemical Society, see Annual Standards for Laboratory be made non-poisonous.)
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
7.6 Potassium Iodide Solution(150g/L)—Dissolve150gof
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
MD. potassium iodide (Kl) in water and dilute to 1 L.
D1159−07 (2012)
TABLE 1 Physical Properties of Purified Olefins
7.7 Sodium Thiosulfate, Standard Solution (0.1 M)—
Dissolve 25 g of sodium thiosulfate (Na S O ·5H O) in water Index of
2 2 3 2
Boiling Point, Density at
Compound Refraction,
and add 0.1 g of sodium carbonate (Na CO ) to stabilize the
°C 20°C, g/mL
2 3
D Line at 20°C
solution. Dilute to 1 L and mix thoroughly by shaking.
Cyclohexene 82.5 to 83.5 0.8100 1.4465
A
Diisobutene 101 to 102.5 0.7175 ± 0.0015 1.4112
Standardize by any accepted procedure that determines the
A
molaritywithanerrornotgreaterthan 60.0002.Restandardize Only the 2,4,4-trimethyl-1-pentene isomer.
at intervals frequent enough to detect changes of 0.0005 in
molarity.
Bromine
7.8 Starch Indication Solution —Mix5gof soluble starch
Standard Number
with about 3 to 5 mL of water. If desired, add about 0.65 g
Cyclohexene, purified (see 7.4.1, 9.3, and 8.1) 187 to 199 (see 9.5)
Cyclohexene, 10 % solution 18 to 20
salicylic acid as preservative. Add the slurry to 500 mL of
Diisobutene, purified (see 7.4.1, 8.3, and 8.1) 136 to 144 (see 9.5)
boiling water and continue boiling for 5 to 10 min. Allow to
Diisobutene, 10 % solution 13 to 15
cool, and decant the clear, supernatant liquid into glass bottles
The reference olefins yielding the above results are charac-
and seal well. Starch solutions (some preserved with salicylic
terized by the properties shown in Table 1. The theoretical
acid) are also commercially available and may be substituted.
bromine numbers of cyclohexene and diisobutene are 194.6
and 142.4, respectively.
7.9 Sulfuric Acid (1+5)—Carefully mix one volume of
concentrated sulfuric acid (H SO , rel dens 1.84) with five
2 4 8.3 Purified samples of cyclohexene and diisobutene can be
volumes of water. (Warning—Poison. Corrosive. Strong oxi-
prepared from cyclohexene and diisobutene, by the following
dizer.Contactwithorganicmaterialcancausefire.Canbefatal
procedure:
if swallowed.)
8.3.1 Add 65 g of activated silica gel, 75 to 150 µm (100 to
200 mesh) manufactured to ensure minimum olefin polymer-
7.10 Titration Solvent—Prepare 1 L of titration solvent by
ization to a column approximately 16 mm in inside diameter
mixing the following volumes of materials: 714 mL of glacial
and 760 mm in length, that has been tapered at the lower end
acetic acid, 134 mL of 1,1,1-trichloroethane (or
and that contains a small plug of glass wool at the bottom.
dichloromethane), 134 mL of methanol, and 18 mL of
A100-mL buret, or any column that will give a height-to-
H SO (1 + 5).
2 4
diameter ratio of the silica gel of at least 30:1, will be suitable.
7.11 1,1,1-Trichloroethane—(Warning—Harmful if in- Tap the column during the adding of the gel to permit uniform
packing.
haled. High concentrations can cause unconsciousness or
death. Contact may cause skin irritation and dermatitis.) 8.3.2 To the column add 30 mL of the olefin to be purified.
When the olefin disappears into the gel, fill the column with
7.12 Dichloromethane—(Warning—The replacement of
methanol. Discard the first 10 mL of percolate and collect the
1,1,1-trichloroethane, an ozone-depleting chemical, is neces-
next 10 mL that is the purified olefin for test of the bromine
sary because its manufacture and import has been discontin-
number procedure. Determine and record the density and
ued. Dichloromethane is temporarily being allowed as an
refractive index of the purified samples at 20°C. Discard the
alternative to 1,1,1-trichloroethane until a permanent replace-
remaining percolate. (Warning—If distillation of impure ole-
ment can be identified and adopted by ASTM International. A
fins is needed as a pre-purification step, a few pellets of
programtoidentifyandevaluatecandidatesolventsiscurrently
potassium hydroxide should be placed in the distillation flask
underway in Subcommittee D02.04.)
and at least 10 % residue should remain to minimize the
hazards from decomposition of any peroxides that may be
NOTE 3—Commercially available reagents can be used in place of
present.)
laboratory preparations.
9. Procedure
8. Check Procedure
9.1 Place 10 mL of 1,1,1-trichloroethane or dichlorometh-
8.1 In case of doubt in applying the procedure to actual
ane in a 50-mL volumetric flask and, by means of a pipet,
samples, the reagents and techniques can be checked by means
introduce
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