ASTM D1159-98
(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
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 D 86) under 327C (626F). 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, max 2Under 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 D 2710. If the bromine number is less than 0.5, then Test Method D 2710 or the comparable bromine index methods for industrial aromatic hydrocarbons, Test Methods D 1492 or D 5776 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 inch-pound units given in parentheses are for information purposes 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 precautionary statements, see Sections 7, 8, and 9.
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NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
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Designation: D 1159 – 98 An American National Standard
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 D 1159; 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 (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope constituents can be obtained by using Test Method D 2710. If
the bromine number is less than 0.5, then Test Method D 2710
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 D 1492 or D 5776 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 D 86) 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, and oxygenated fuels), kerosine, and distillates in the
1.4 The values stated in SI units are to be regarded as the
gas oil range that fall in the following limits:
standard. The inch-pound units given in parentheses are for
90 % Distillation Point,° C (°F) Bromine Number, max
information purposes only.
Under 205 (400) 175
205 to 327 (400 to 626) 10
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1.2 Commercial olefins that are essentially mixtures of
responsibility of the user of this standard to establish appro-
aliphatic mono-olefins and that fall within the range of 95 to
priate safety and health practices and determine the applica-
165 bromine number (see Note 1). This test method has been
bility of regulatory limitations prior to use. For specific
found suitable for such materials as commercial propylene
precautionary statements, see Note 3 through Note 11.
trimer and tetramer, butene dimer, and mixed nonenes, octenes,
and heptenes. This test method is not satisfactory for normal
2. Referenced Documents
alpha-olefins.
2.1 ASTM Standards:
NOTE 1—These limits are imposed since the precision of this test 3
D 86 Test Method for Distillation of Petroleum Products
method has been determined only up to or within the range of these
D 1193 Specification for Reagent Water
bromine numbers.
D 1492 Test Method for Bromine Index of Aromatic Hy-
1.2 The magnitude of the bromine number is an indication 5
drocarbons by Coulometric Titration
of the quantity of bromine-reactive constituents, not an iden-
D 2710 Test Method for Bromine Index of Petroleum Hy-
tification of constituents; therefore, its application as a measure 6
drocarbons by Electrometric Titration
of olefinic unsaturation should not be undertaken without the
D 5776 Test Method for Bromine Index Aromatic of Hy-
study given in Annex A1. 5
drocarbons by Electrometric Titration
1.3 For petroleum hydrocarbon mixtures of bromine num-
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 D-2 on
3.1.1 bromine number—the number of grams of bromine
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
D02.04.0D on Physical Methods.
In the IP, this test method is under the jurisdiction of the Standardization
Committee.
Current edition approved Apr. 10, 1998. Published September 1998. Originally Annual Book of ASTM Standards, Vol 05.01.
published as D 1159 – 51 T. Last previous edition D 1159 – 93. Annual Book of ASTM Standards, Vol 11.01.
2 5
See Dubois, H. D., and Skoog, D. A., “Determination of Bromine Addition Annual Book of ASTM Standards, Vol 06.04.
Numbers,” Analytical Chemistry, Vol 20, 1948, pp. 624–7. Annual Book of ASTM Standards, Vol 05.02.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 1159
that will react with 100 g of the specimen under the conditions used, provided it is first ascertained that the reagent is of
of the test. sufficiently high purity to permit its use without lessening the
accuracy of the determination.
4. Summary of Test Method
7.2 Purity of Water— Unless otherwise indicated, refer-
ences to water shall be understood to mean reagent water as
4.1 A known weight of the specimen dissolved in the
selected solvent (see Note 9) maintained at 0 to 5°C (32 to defined by Type III of Specification D 1193.
7.3 Acetic Acid, Glacial—(Warning—See Note 3.)
41°F) is titrated with standard bromide-bromate solution. The
end point is indicated by a sudden change in potential on an
NOTE 3—Warning: Poison, corrosive-combustible, may be fatal if
electrometric end point titration apparatus due to the presence
swallowed. Causes severe burns, harmful if inhaled.
of free bromine.
7.4 Bromide-Bromate, Standard Solution (0.2500 M as
Br )— Dissolve 51.0 g of potassium bromide (KBr) and 13.92
5. Significance and Use
g of potassium bromate (KBrO ) each dried at 105°C (220°F)
5.1 The bromine number is useful as a measure of aliphatic
for 30 min in water and dilute to 1 L.
unsaturation in petroleum samples. When used in conjunction
7.4.1 If the determinations of the bromine number of the
with the calculation procedure described in Annex A2, it can be
reference olefins specified in Section 8 using this solution do
used to estimate the percentage of olefins in petroleum distil-
not conform to the prescribed limits, or if for reasons of
lates boiling up to approximately 315°C (600°F).
uncertainties in the quality of primary reagents it is considered
5.2 The bromine number of commercial aliphatic monoole-
desirable to determine the molarity of the solution, the solution
fins provides supporting evidence of their purity and identity.
shall be standardized and the determined molarity used in
subsequent calculations. The standardization procedure shall
6. Apparatus
be as follows:
6.1 Electrometric End Point Titration Apparatus—Any ap-
7.4.1.1 To standardize, place 50 mL of glacial acetic acid
paratus designed to perform titrations to pre-set end points (see
and 1 mL of concentrated hydrochloric acid (Warning—See
Note 10) may be used in conjunction with a high-resistance
Note 4 in a 500-mL iodine number flask. Chill the solution in
polarizing current supply capable of maintaining approxi-
a bath for approximately 10 min and, with constant swirling of
mately 0.8 V across two platinum electrodes and with a
the flask, add from a 10-mL calibrated buret, 5 6 0.01 mL of
sensitivity such that a voltage change of approximately 50 mV
the bromide-bromate standard solution at the rate of 1 or 2
at these electrodes is sufficient to indicate the end point. Other
drops per second. Stopper the flask immediately, shake the
types of commercially available electronic titrimeters, includ-
contents, place it again in the ice bath, and add 5 mL of Kl
ing certain pH meters, have also been found suitable.
solution in the lip of the flask. After 5 min remove the flask
from the ice bath and allow the Kl solution to flow into the
NOTE 2—Pre-set end point indicated with polarized electrodes provides
a detection technique similar to the dead stop technique specified in flask by slowly removing the stopper. Shake vigorously, add
previous versions of this test method.
100 mL of water in such a manner as to rinse the stopper, lip
and walls of the flask, and titrate promptly with sodium
6.2 Titration Vessel— A jacketed glass vessel approximately
thiosulfate (Na S O ) solution. Near the end of the titration,
120 mm high and 45 mm in internal diameter and of a form that 2 2 3
add 1 mL of starch indicator solution and titrate slowly to
can be conveniently maintained at 0 to 5°C (32 to 41°F).
disappearance of the blue color. Calculate the molarity of the
6.3 Stirrer—Any magnetic stirrer system.
bromide-bromate solution as follows:
6.4 Electrodes—A platinum wire electrode pair with each
wire approximately 12 mm long and 1 mm in diameter. The
AM
M 5 (1)
wires shall be located 5 mm apart and approximately 55 mm
~5! ~2!
below the level of the titration solvent. Clean the electrode pair
where:
at regular intervals with 65 % nitric acid and rinse with
M = molarity of the bromide-bromate solution, as Br ,
1 2
distilled water before use.
A = millilitres of Na S O solution required for titration
2 2 3
6.5 Buret—Any delivery system capable of measuring ti-
of the bromide-bromate solution, and,
trant in 0.05 mL or smaller graduations.
M = molarity of Na S O solution,
2 2 2 3
5 = millilitres of bromide—bromate solution, and
7. Reagents
2 = number of electrons transferred during redox titra-
7.1 Purity of Reagents—Reagent grade chemicals shall be
tion of bromide-bromate solution.
used in all tests. Unless otherwise indicated, it is intended that
Repeat the standardization until duplicate determinations do
all reagents shall conform to the specifications of the commit-
not differ from the mean by more than 60.002 M.
tee on Analytical Reagents of the American Chemical Society,
NOTE 4—Warning: Poison corrosive. May be fatal if swallowed.
where such specifications are available. Other grades may be
Liquid and vapor causes severe burns. Harmful if inhaled; relative density
1.19.
7 7.5 Methanol—(Warning—See Note 5.)
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
NOTE 5—Warning: Flammable. Vapor harmful. Can be fatal or cause
listed by the American Chemical Society, see Analar Standards for Laboratory,
blindness if swallowed or inhaled. Cannot be made non-poisonous.
BDH Ltd., Poole, Dorset, U.K. and the United States Pharmacopeia and National
Formulary, U. S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD. 7.6 Potassium Iodide Solution (150 g/L)—Dissolve 150 g of
D 1159
NOTE 10—Warning: Flammable.
potassium iodide (Kl) in water and dilute to 1 L.
7.7 Sodium Thiosulfate, Standard Solution (0.1 M)—
8.2 If the reagents and techniques are correct, values within
Dissolve 25 g of sodium thiosulfate (Na S O ·5H O) in water
2 2 3 2 the following should be obtained:
and add 0.1 g of sodium carbonate (Na CO ) to stabilize the
2 3
Bromine
solution. Dilute to 1 L and mix thoroughly by shaking.
Standard Number
Cyclohexene, purified (see 7.4.1, 9.3, and Note 11) 187 to 199 (see 9.5)
Standardize by any accepted procedure that determines the
Note 10)
molarity with an error not greater than 60.0002. Restandardize
Cyclohexene, 10 % solution 18 to 20
at intervals frequent enough to detect changes of 0.0005 in Diisobutene, purified (see 7.4.1, 8.3, and Note 11) 136 to 144 (see 9.5)
Note 10)
molarity.
Diisobutene, 10 % solution 13 to 15
7.8 Starch Indication Solution—Mix5gof soluble starch
The reference olefins yielding the above results are charac-
with about 3 to 5 mL of water. If desired, add about 0.65 g
terized by the properties shown in Table 1. The theoretical
salicylic acid as preservative. Add the slurry to 500 mL of
bromine numbers of cyclohexene and diisobutene are 194.6
boiling water and continue boiling for 5 to 10 min. Allow to
and 142.4, respectively.
cool, and decant the clear, supernatant liquid into glass bottles
8.3 Purified samples of cyclohexene and diisobutene can be
and seal well. Starch solutions (some preserved with salicylic
prepared from cyclohexene and diisobutene, by the following
acid) are also commercially available and may be substituted.
procedure:
7.9 Sulfuric Acid (1 + 5)—Carefully mix one volume of
8.3.1 Add 65 g of activated silica gel, 75 to 150 μm (100 to
concentrated sulfuric acid (H SO , rel dens 1.84) with five
2 4
200 mesh) manufactured to ensure minimum olefin polymer-
volumes of water.
ization to a column approximately 16 mm in inside diameter
NOTE 6—Warning: Poison. Corrosive. Strong oxidizer. Contact with
and 760 mm in length, that has been tapered at the lower end
organic material can cause fire. Can be fatal if swallowed.
and that contains a small plug of glass wool at the bottom.
7.10 Titration Solvent—Prepare 1 L of titration solvent by
A100-mL buret, or any column that will give a height-to-
mixing the following volumes of materials: 714 mL of glacial
diameter ratio of the silica gel of at least 30:1, will be suitable.
acetic acid, 134 mL of 1,1,1-trichloroethane (or dichlo-
Tap the column during the adding of the gel to permit uniform
romethane), 134 mL of methanol, and 18 mL of H SO (1 + 5).
2 4
packing.
7.11 1,1,1-Trichloroethane—(Warning—See Note 7.)
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
NOTE 7—Warning: Harmful if inhaled. High concentrations can cause
methanol. Discard the first 10 mL of percolate and collect the
unconsciousness or death. Contact may cause skin irritation and derma-
titis.
next 10 mL that is the purified olefin for test of the bromine
number procedure. Determine and record the density and
7.12 Dichloromethane—(Warning—See Note 8.)
refractive index of the purified samples at 20°C. Discard the
NOTE 8—The replacement of 1,1,1-trichloroethane, an ozone-depleting
remaining percolate.
chemical, is necessary because its manufacture and import has been
discontinued. Dichloromethane is temporarily being allowed as an alter-
NOTE 11—Caution: If distillation of impure olefins is needed as a
native to 1,1,1-trichloroethane until a permanent replacement can be
pre-purification step, a few pellets of potassium hydroxide should be
identified and adopted by ASTM. A program to identify and evaluate
placed in the distillation flask and at least 10 % residue should remain to
candidate solvents is currently underway in Subcommittee D02.04.
minimize the hazards from decomposition of any peroxides that may be
NOTE 9—The user of this test method may choose to use either
present.
1,1,1-trichloroethane or dichloromethane to the exclusion of the other
solvent. The selected solvent is to be used for all operations, that is, in the 9. Procedure
preparation of the titration solvent, for the dilution of samples, and as the
9.1 Place 10 mL of 1,1,1-trichloroethane or dichlo-
titration blank.
romethane in a 50-mL volumetric flask and, by means of a
pipet, introduce a test specim
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