ASTM D7620-10

Standard Test Method for Determination of Total Sulfur in Liquid Hydrocarbon Based Fuels by Continuous Injection, Air Oxidation and Ultraviolet Fluorescence Detection

SIGNIFICANCE AND USE
Some process catalysts used in refining can be poisoned when trace amounts of sulfur bearing materials are contained in the feedstocks. There are also government regulations as to how much sulfur is permitted to be present in commercial transportation fuels. This test method can be used to determine sulfur in process and downstream distribution streams. It can also be used for purposes of screening and quality control of finished hydrocarbon fuel products.
SCOPE
1.1 This test method covers the determination of total sulfur in liquid hydrocarbon based fuel with a final boiling point of up to 450°C. It is applicable to analysis of natural, processed and final product materials containing sulfur in the range of 4.0 to 830 mg/kg (see Note 1).
Note 1— For liquid hydrocarbons containing less than 4.0 mg/kg total sulfur or more than 830 mg/kg total sulfur, Test Method D5453 may be more appropriate.
1.2 This test method is applicable for total sulfur determination in liquid hydrocarbons containing less than 0.35% (m/m) halogen(s).
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 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 hazard statements, see 4.1, 8.3, and Section 9.

General Information

• Status: Historical
• Publication Date: 31-Aug-2010
• ICS: 75.160.20 - Liquid fuels
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.03 - Elemental Analysis

Relations

• Replaced By: ASTM D7620-10(2015) - Standard Test Method for Determination of Total Sulfur in Liquid Hydrocarbon Based Fuels by Continuous Injection, Air Oxidation and Ultraviolet Fluorescence Detection
• Effective Date: 01-Jul-2015
• Referred By: ASTM D7455-19 - Standard Practice for Sample Preparation of Petroleum and Lubricant Products for Elemental Analysis
• Effective Date: 01-Sep-2010

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D7620 − 10
StandardTest Method for
Determination of Total Sulfur in Liquid Hydrocarbon Based
Fuels by Continuous Injection, Air Oxidation and Ultraviolet
Fluorescence Detection
This standard is issued under the fixed designation D7620; 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.
1. Scope D4175 Terminology Relating to Petroleum, Petroleum
Products, and Lubricants
1.1 This test method covers the determination of total sulfur
D4177 Practice for Automatic Sampling of Petroleum and
inliquidhydrocarbonbasedfuelwithafinalboilingpointofup
Petroleum Products
to 450°C. It is applicable to analysis of natural, processed and
D5453 Test Method for Determination of Total Sulfur in
final product materials containing sulfur in the range of 4.0 to
Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel
830 mg/kg (see Note 1).
Engine Fuel, and Engine Oil by Ultraviolet Fluorescence
NOTE 1— For liquid hydrocarbons containing less than 4.0 mg/kg total
D6299 Practice for Applying Statistical Quality Assurance
sulfur or more than 830 mg/kg total sulfur, Test Method D5453 may be
and Control Charting Techniques to Evaluate Analytical
more appropriate.
Measurement System Performance
1.2 This test method is applicable for total sulfur determi-
D6300 Practice for Determination of Precision and Bias
nation in liquid hydrocarbons containing less than 0.35%
Data for Use in Test Methods for Petroleum Products and
(m/m) halogen(s).
Lubricants
D6792 Practice for Quality System in Petroleum Products
1.3 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this and Lubricants Testing Laboratories
standard.
3. Terminology
1.4 This standard does not purport to address all of the
3.1 Definitions:
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 3.1.1 See Terminology D4175 for definitions of other terms
priate safety and health practices and determine the applica- used in this test method.
bility of regulatory limitations prior to use. For specific hazard 3.1.2 oxidative pyrolysis, n—process in which a sample
statements, see 4.1, 8.3, and Section 9. undergoes complete combustion in an appropriate oxygen
containing environment at a sufficiently elevated temperature.
2. Referenced Documents
3.1.2.1 Discussion—Organic compounds pyrolytically oxi-
dize to carbon dioxide and water and oxides of other elements
2.1 ASTM Standards:
that are in the sample.
D1298 Test Method for Density, Relative Density, or API
Gravity of Crude Petroleum and Liquid Petroleum Prod-
4. Summary of Test Method
ucts by Hydrometer Method
D4052 Test Method for Density, Relative Density, and API 4.1 A small, very controlled flow of hydrocarbon sample is
Gravity of Liquids by Digital Density Meter
continuously injected during measurement. It is introduced via
D4057 Practice for Manual Sampling of Petroleum and a syringe into a high temperature combustion tube containing
Petroleum Products
air where sulfur is oxidized to sulfur dioxide (SO ). Water
produced during the sample combustion is removed, as
required, and the sample combustion gases are next exposed to
This test method is under the jurisdiction of ASTM Committee D02 on
ultraviolet (UV) light. The SO absorbs the energy from the
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
UV light and is converted to excited sulfur dioxide (SO *).
Subcommittee D02.03 on Elemental Analysis.
Fluorescence emitted from the excited SO * as it returns to a
Current edition approved Sept. 1, 2010. Published September 2010.
DOI:10.1520/D7620–10.
stable state SO is detected by a photomultiplier tube and the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
resulting signal is a measure of the sulfur contained in the
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
sample. (Warning—Exposure to excessive quantities of ultra-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. violet light is injurious to health. The operator shall avoid
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7620 − 10
FIG. 1 Basic Block Diagram Describing Sulfur Determination
exposing their body, especially their eyes, not only to direct
UV light but also to secondary or scattered radiation that is
present.)
4.2 Fig. 1 illustrates a basic block diagram describing sulfur
determination. Sample collection and conditioning, sample
introduction, detection system and data handling are depicted.
5. Significance and Use
5.1 Some process catalysts used in refining can be poisoned
whentraceamountsofsulfurbearingmaterialsarecontainedin
the feedstocks. There are also government regulations as to
how much sulfur is permitted to be present in commercial
transportation fuels. This test method can be used to determine
sulfur in process and downstream distribution streams. It can
also be used for purposes of screening and quality control of
finished hydrocarbon fuel products.
6. Interferences
6.1 Halogens above 0.35 % (mass/mass) will interfere with
accurate sulfur determination.
6.2 Bound nitrogen at concentration greater than 150 mg
N/kg can causea1mg S/kg positive bias.
6.3 Excessive moisture produced during the combustion
step will interfere if not removed prior to the detector.
7. Apparatus
7.1 Furnace—An electric furnace held at a temperature
sufficient to pyrolyze the entire sample (typically 1050 6
25°C) and oxidize sulfur to SO .
7.2 Combustion Tube—A quartz combustion tube con-
structed to allow the direct injection of a continuous flow of
sample into the heated oxidation zone of the furnace. The
oxidation section shall be large enough to ensure complete
combustion of the sample. Fig. 2 illustrates a typical combus-
tion tube (Note 2).
NOTE 2—Other combustion tube configurations are acceptable if
precision and accuracy are not degraded.
7.3 Flow Control—The apparatus shall be equipped with
suitable flow control apparatus capable of maintaining a
FIG. 2 Typical Combustion Tube
constant supply of air.
7.4 Drier Tube—The apparatus shall be equipped with a
mechanism for the removal of excessive water vapor. The accomplished with a membrane drying tube, or a permeation
oxidation reaction produces water vapor which must be elimi- dryer, that utilizes a selective capillary action for water
nated prior to measurement by the detector. This may be removal.
D7620 − 10
TABLE 1 Typical Operating Conditions
7.5 UV Fluorescence Detector—A quantitative detector ca-
pableofmeasuringtheenergyemittedfromthefluorescenceof Furnace Temperature 1050°C
Furnace Pressure 28 kPa
sulfur dioxide by UV light.
Photo Multiplier Tube (PMT) 40°C
Temperature
7.6 Millilitre Syringe—A disposable 1 mL syringe capable
PMT Voltage 900 V
of accurately delivering a controlled and constant flow of
Optics Purge Flow 80 to 100 mL/min
calibration and sample materials. The syringe shall accommo-
date a disposable tip to aid the filling of the syringe and a
disposable septum seal to accommodate penetration and
9. Hazards
sample flow.
9.1 Consult current OSHA regulations, suppliers’ Material
7.7 Sample Inlet System—An automatic sample injection
Safety Data Sheets, and local regulations for all materials used
device that is compatible with a disposable 1 mL syringe is
in this test method.
required. The injector shall allow the introduction of an
9.2 High temperature is employed in this test method.
appropriate continuous flow of sample into a combustion tube
Exercise extra care when using flammable materials near the
carrierstream,whichdirectsthesampleintotheoxidationzone
oxidative pyrolysis furnace.
at a controlled and repeatable rate.
9.3 Duetothetypesofsamplesanalyzedinthistestmethod,
7.8 Strip Chart Recorder—Equivalent electronic data
chemicalresistantglovesshouldbewornwhenperformingthis
logger, integrator or recorder (optional).
test method.
7.9 Balance—With a precision of 6 0.01 mg (optional).
10. Sampling
8. Reagents and Materials
10.1 CollectthesamplesinaccordancewithPracticeD4057
8.1 Purity of Reagents—Reagent grade chemicals shall be
or Practice D4177. To preserve volatile components which are
used in tests. Unless otherwise indicated, it is intended that all
in some samples, do not uncover samples any longer than
reagents shall conform to the specifications of the Committee
necessary.
on Analytical Reagents of the American Chemical Society,
where such specifications are available. Other grades may be
11. Preparation of Apparatus
used, provided, it is first ascertained that the reagent is of
11.1 Place the analyzer in service in accordance with the
sufficiently high purity to permit its use without lessening the
manufacturer’s instructions.
accuracy of the determination.
11.2 Typical instrument parameters are listed in Table 1.
8.2 Air—Filtered (witha2µm filter).
11.3 Prepare the sample introduction accessories, if
8.3 Iso-octane, Toluene, Xylenes—Reagent grade.
required, according to the manufacturer’s instructions.
(Warning—Organic solvents are flammable.)
11.4 Adjust the instrument sensitivity and baseline stability
8.4 Thiophene—FW84.14, Sulfur content 38.10 % (m/m).
and perform instrument blanking procedure following manu-
8.4.1 Other sources of sulfur and diluent materials may be
facturer’s guidelines.
used if precision and accuracy are not degraded.
8.4.2 Apply the appropriate correction for chemical impu-
12. Calibration
rity.
12.1 Choose which type of calibration method is required
8.5 Sulfur Stock Solution—1000 µg S/mL. Prepare a stock
(mass/volume or mass/mass), and prepare a calibration stan-
solutionbyaccuratelyweighing0.2624 60.013gofthiophene
dard from the stock solution (8.5) by volume or mass dilution.
into a tared 100 mL volumetric flask. Dilute to volume with
12.2 Ifamass/massanalysisisbeingdonewithacalibration
selected solvent. This stock may be fur
...