ASTM D7164-05
(Practice)Standard Practice for On-line/At-line Heating Value Determination of Gaseous Fuels by Gas Chromatography
Standard Practice for On-line/At-line Heating Value Determination of Gaseous Fuels by Gas Chromatography
SIGNIFICANCE AND USE
On-line, at-line, in-line and other near-real time monitoring systems that measure fuel gas characteristics such as the heating value are prevalent in the natural gas and fuel gas industries. The installation and operation of particular systems vary on the specific objectives, process type, regulatory requirements, and internal performance requirements needed by the user. This protocol is intended to provide guidelines for standardized start-up procedures, operating procedures, and quality assurance practices for on-line, at-line, in-line and other near-real time heating value monitoring systems.
SCOPE
1.1 This practice is for the determination of heating value in high methane content gaseous fuels such as natural gas using an on-line/at-line gas chromatograph.
1.2 The values stated in SI units are standard. Values stated in other units are for information only.
1.3 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.
General Information
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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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D7164–05
Standard Practice for
On-line/At-line Heating Value Determination of Gaseous
Fuels by Gas Chromatography
This standard is issued under the fixed designation D7164; 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 tivariate Process Infrared Spectrophotometer Based Ana-
lyzer Systems
1.1 This practice is for the determination of heating value in
D6299 Practice for Applying Statistical Quality Assurance
high methane content gaseous fuels such as natural gas using
and Control Charting Techniques to Evaluate Analytical
an on-line/at-line gas chromatograph.
Measurement System Performance
1.2 The values stated in SI units are standard. Values stated
D6621 Practice for PerformanceTesting of ProcessAnalyz-
in other units are for information only.
ers for Aromatic Hydrocarbon Materials
1.3 This standard does not purport to address all of the
E260 Practice for Packed Column Gas Chromatography
safety concerns, if any, associated with its use. It is the
E594 Practice for Testing Flame Ionization Detectors Used
responsibility of the user of this standard to establish appro-
in Gas or Supercritical Fluid Chromatography
priate safety and health practices and determine the applica-
E1510 Practice for Installing Fused Silica Open Tubular
bility of regulatory limitations prior to use.
Capillary Columns in Gas Chromatographs
2. Referenced Documents
3. Terminology
2.1 ASTM Standards:
3.1 Definitions:
D1070 Test Methods for Relative Density of Gaseous Fuels
3.1.1 direct sampling—sampling where there is no direct
D1945 Test Method for Analysis of Natural Gas by Gas
connection between the medium to be sampled and the
Chromatography
analytical unit.
D1946 Practice for Analysis of Reformed Gas by Gas
3.1.2 in-line instrument—instrument with an active element
Chromatography
installed in a pipeline, which is used to measure pipeline
D3588 PracticeforCalculatingHeatValue,Compressibility
contents or conditions.
Factor, and Relative Density of Gaseous Fuels
3.1.3 on-line instrument—instrument that samples gas di-
D3764 Practice for Validation of the Performance of Pro-
rectly from a pipeline, but is installed externally.
cess Stream Analyzer Systems
3.1.4 at-line instrument—instrumentation requiring opera-
D4626 Practice for Calculation of Gas Chromatographic
tor interaction that samples gas directly from the pipeline.
Response Factors
3.1.5 continuous fuel monitor—instrument that samples gas
D5287 Practice for Automatic Sampling of Gaseous Fuels
directly from the pipeline on a continuous or semi-continuous
D5503 Practice for Natural Gas Sample-Handling and Con-
basis.
ditioning Systems for Pipeline Instrumentation
3.1.6 heating value—in general terms, the heating value is
D6122 Practice for Validation of the Performance of Mul-
the total energy per volume transferred as heat from the
complete, ideal combustion of the gas at a specified tempera-
ture and pressure. The heating value can be reported on a net
This practice is under the jurisdiction of ASTM Committee D03 on Gaseous
or gross basis for a gaseous stream that is assumed to be fully
Fuels and is the direct responsibility of Subcommittee D03.12 on On-Line/At-Line
water vapor saturated.
Analysis of Gaseous Fuels.
3.1.7 gross heating value—(also called higher heating
Current edition approved June 15, 2005. Published June 2005. DOI: 10.1520/
D7164-05.
value)—the amount of energy per volume transferred as heat
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
from the complete, ideal combustion of the gas at standard
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
temperature in which all the water formed by the reaction
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. condenses to liquid.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D7164–05
3.1.8 net heating value—(also called lower heating that a representative sample is analyzed. The locations and
value)—the amount of energy per volume transferred as heat orientation of sampling components should be selected based
from the complete, ideal combustion of the gas at standard upon sound analytic and engineering considerations. Sampling
temperature in which all the water formed by the reaction practices for gaseous fuels can be found in Practice D5287.
remains in the vapor state.
6.3 Sample Inlet System—The siting and installation of an
at-line or on-line monitor is critical for collecting representa-
4. Summary of Practice
tive information on heating value content. Factors that should
be considered in siting an instrument include ease of calibra-
4.1 ArepresentativesampleoftheGaseousFuelisextracted
from a process pipe or a pipeline and is transferred in a timely tion, ease of access for repair or maintenance, sample unifor-
mity at the sampling point, appropriateness of samples from a
manner to an analyzer sampling system. After appropriate
conditioning steps that maintain the sample integrity are sampling location, ambient conditions, and of course safety
completed, a precise volume of sample is injected onto an issues. An automated gas sampling valve is required in many
appropriate gas chromatographic column. Excess extracted applications. All sampling system components in contact with
process or pipeline sample is vented to atmosphere, a flare the fuel stream must be constructed of inert or passivated
header, or is returned to the process in accordance with materials. Care should be taken to ensure that the extracted
applicable economic and environmental requirements and sample is maintained in a single clean gaseous phase. The
regulations.
addition of heat at the point of pressure reduction or along the
4.2 Sample constituents are separated in the column to elute sample line to the analyzer may be required to ensure that the
individuallyforidentificationandquantificationbythedetector
sample is maintained in the gas phase. The need for heat
and its data handling system. The heating value is calculated tracing and the extent to which it is required will be site
using the results of the compositional analysis using an
specific. In general, considerations impacting heat tracing
appropriate algorithm.
decisions include sample compositions and the expected varia-
4.3 Calibration, maintenance, and performance protocols
tions, ambient temperature fluctuations, operating pressures,
provide a means to validate the analyzer operation.
and anticipated pressure differentials in sample system com-
ponents. Sample filtration should be utilized as required to
5. Significance and Use remove particulate matter from the extracted sample. The
samplingfrequencyrelativetotheprocessbandwidthiscritical
5.1 On-line, at-line, in-line and other near-real time moni-
to ensuring that the reported analytical results adequately
toring systems that measure fuel gas characteristics such as the
represent the process being monitored. The Nyquist-Shannon
heating value are prevalent in the natural gas and fuel gas
sampling criterion of a sampling frequency that exceeds twice
industries. The installation and operation of particular systems
the process bandwidth can be used to establish a minimum
vary on the specific objectives, process type, regulatory re-
analytical cycle time. Sample handling and conditioning sys-
quirements, and internal performance requirements needed by
tem practices can be found in Practice D5503
the user. This protocol is intended to provide guidelines for
standardized start-up procedures, operating procedures, and 6.3.1 Carrier and Detector Gas Control—Constant flow
control of carrier and detector gases is critical for optimum and
qualityassurancepracticesforon-line,at-line,in-lineandother
near-real time heating value monitoring systems. consistent analytical performance. Control is achieved by use
of pressure regulators and fixed flow restrictors. Temperature
control is generally vital for ensuring consistent operation of
6. Apparatus
these devices. The gas flow is measured by appropriate means
6.1 Instrument—Any instrument of standard manufacture,
and adjusted as necessary. Mass flow controllers, capable of
with hardware necessary for interfacing to a natural gas or
maintaining gas flow constant to 61 % at the flow rates
otherfuelgaspipelineandcontainingallthefeaturesnecessary
necessary for optimal instrument performance are generally
for the intended application(s) can be used.
used.
6.1.1 Chromatographic-based Systems—The chromato-
6.3.2 Detectors—A thermal conductivity detector (TCD) is
graphic parameters employed generally should be capable of
commonly used. Other detectors, such as the flame ionization
obtaining a relative retention time repeatability of 0.05 min (3
detector (FID), Practice E594, can be used but should at least
s) for duplicate measurements. Instrumentation should satisfy
meet TCD linearity, sensitivity, and selectivity in the selected
or exceed other chromatographic and analytic performance
application.
characteristics for accuracy and precision for the intended
application without encountering unacceptable interference or 6.4 Columns—A variety of columns, ranging from packed
bias. In addition, components in contact with sample streams columns to open tubular capillary columns, can be used in the
suchastubingandvalvingmustbeconstructedofsuitableinert determination of the Heating Value of a gaseous fuel. Packed
materials to ensure constituents in the fuel stream do not columns and open tubular capillary columns are covered in
degrade these components or alter the composition of the Practices E260 and E1510 respectively. Columns should be
sampled gas. Additional information related to analyzing conditioned in accordance with the manufacturer’s recommen-
gaseous fuels using gas chromatography can be found in Test dations. The selected column must provide retention and
Method D1945 and Practice D1946. resolution characteristics that satisfy the intended application.
6.2 Sample Probes/Sample Extraction—The location and The column must be inert towards gaseous fuel components. If
orientation of sampling components are critical for ensuring the selected column utilizes a liquid phase, bleeding at high
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