ASTM D7941/D7941M-14
(Test Method)Standard Test Method for Hydrogen Purity Analysis Using a Continuous Wave Cavity Ring-Down Spectroscopy Analyzer
Standard Test Method for Hydrogen Purity Analysis Using a Continuous Wave Cavity Ring-Down Spectroscopy Analyzer
SIGNIFICANCE AND USE
5.1 Proton exchange membranes (PEM) used in fuel cells are susceptible to contamination from a number of species that can be found in hydrogen. It is critical that these contaminants be measured and verified to be present at or below the amounts stated in SAE J2719, ISO 14687-2 and ISO 14687-3 to ensure both fuel cell longevity and optimum efficiency. Contaminant concentrations as low as single-figure ppb for some species can seriously compromise the life span and efficiency of PEM fuel cells. The presence of contaminants in fuel-cell-grade hydrogen can, in some cases, have a permanent adverse impact on fuel cell efficiency and usability. It is critical to monitor the concentration of key contaminants in hydrogen during the production phase through to delivery of the fuel to a fuel cell vehicle or other PEM fuel cell application. In ISO 14687-2 and ISO 14687-3, the upper limits for the aforementioned contaminants are specified. Refer to SAE J2719 and the California Code of Regulations (see 2.3) for example specific national and regional requirements. For hydrogen fuel that is transported and delivered as a cryogenic liquid, there is additional risk of introducing impurities during transport and delivery operations. For instance, moisture can build up over time in liquid transfer lines, critical control components, and long-term storage facilities, which can lead to icing up within the system and subsequent blockages that pose a safety risk or the introduction of contaminants into the gas stream upon evaporation of the liquid. Users are reminded to consult Practice D7265 for critical thermophysical property such as the ortho/para hydrogen spin isomer inversion that can lead to additional hazards in liquid hydrogen usage. In addition to this test method employing CRDS, test methods such as D7649 (carbon dioxide, argon, nitrogen, oxygen and water) and D7653 (IR active species) are used to measure impurities in hydrogen fuel.
SCOPE
1.1 This test method describes contaminant determination in fuel-cell-grade hydrogen as specified in relevant ASTM and ISO standards using cavity ring-down spectroscopy (CRDS). This standard test method is for the measurement of one or multiple contaminants including, but not limited to, water (H2O), oxygen (O2), methane (CH4), carbon dioxide (CO2), carbon monoxide (CO), ammonia (NH3), and formaldehyde (H2CO), henceforth referred to as “analyte.”
1.2 This test method applies to CRDS analyzers with one or multiple sensor modules (see 3.3 for definition), each of which is designed for a specific analyte. This test method describes sampling apparatus design, operating procedures, and quality control procedures required to obtain the stated levels of precision and accuracy.
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the 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.
General Information
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: D7941/D7941M − 14
Standard Test Method for
Hydrogen Purity Analysis Using a Continuous Wave Cavity
1
Ring-Down Spectroscopy Analyzer
This standard is issued under the fixed designation D7941/D7941M; 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 D7606 Practice for Sampling of High Pressure Hydrogen
and Related Fuel Cell Feed Gases
1.1 This test method describes contaminant determination in
D7649 Test Method for Determination of Trace Carbon
fuel-cell-grade hydrogen as specified in relevant ASTM and
Dioxide, Argon, Nitrogen, Oxygen and Water in Hydrogen
ISO standards using cavity ring-down spectroscopy (CRDS).
Fuel by Jet Pulse Injection and Gas Chromatography/
This standard test method is for the measurement of one or
Mass Spectrometer Analysis
multiple contaminants including, but not limited to, water
D7653 Test Method for Determination of Trace Gaseous
(H O), oxygen (O ), methane (CH ), carbon dioxide (CO ),
2 2 4 2
Contaminants in Hydrogen Fuel by Fourier Transform
carbon monoxide (CO), ammonia (NH ), and formaldehyde
3
Infrared (FTIR) Spectroscopy
(H CO), henceforth referred to as “analyte.”
2
3
2.2 ISO Standards:
1.2 This test method applies to CRDS analyzers with one or
ISO/DIS 14687-2 Hydrogen fuel—Product specification—
multiple sensor modules (see 3.3 for definition), each of which
Part 2: Proton exchange membrane (PEM) fuel cell
is designed for a specific analyte. This test method describes
applications for road vehicles
sampling apparatus design, operating procedures, and quality
ISO/DIS 14687-3 Hydrogen fuel—Product Specification—
control procedures required to obtain the stated levels of
Part 3: Proton exchange membrane (PEM) fuel cell
precision and accuracy.
applications for stationary appliances
1.3 The values stated in either SI units or inch-pound units 2.3 U.S.-Specific Standards:
are to be regarded separately as standard. The values stated in
SAE J2719-2011 (2011) Hydrogen Fuel Quality for Fuel
4
each system may not be exact equivalents; therefore, each Cell Vehicles
system shall be used independently of the other. Combining
2.3.7 California Code of Regulations, Title 4, Division 9,
values from the two systems may result in non-conformance
Chapter 6, Article 8, Sections 4180-4181 – Hydrogen fuel
5
with the standard. quality requirements
Environmental Protection Agency 40 CFR: Protection of the
1.4 This standard does not purport to address all of the
Environment, Appendix B to Part 136 – Definition and
safety concerns, if any, associated with its use. It is the
Procedure for the Determination of the Method Detection
responsibility of the user of this standard to establish appro-
6
Limit
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
3. Terminology
2. Referenced Documents
3.1 Definitions:
2
3.1.1 For definitions of terms used in this test method, refer
2.1 ASTM Standards:
to Terminology D4150.
D4150 Terminology Relating to Gaseous Fuels
3.2 Acronyms:
D5287 Practice for Automatic Sampling of Gaseous Fuels
3.2.1 AIST, n—National Institute of Advanced Industrial
D7265 Specification for Hydrogen Thermophysical Property
Science and Technology
Tables
1 3
This test method is under the jurisdiction of ASTM Committee D03 on Gaseous Available from International Organization for Standardization (ISO), 1, ch. de
Fuels and is the direct responsibility of Subcommittee D03.14 on Hydrogen and la Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland, http://www.iso.org.
4
Fuel Cells. Available from SAE International (SAE), 400 Commonwealth Dr., Warrendale,
Current edition approved June 1, 2014. Published July 2014. DOI: 10.1520/ PA 15096-0001, http://www.sae.org.
5
D7941_D7941M-14 Available from the California Office of Administrative Law, 300 Capitol Mall,
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Suite 1250, Sacramento, CA 95814, http://www.oal.ca.gov/ccr.htm.
6
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Available from United States Environmental Protection Agency (EPA), William
Standards volume information, refer to the standard’s Document Summary page on Jefferson Clinton Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20004,
the ASTM website. http://www.epa.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D7941/D7941M − 14
3.2.2 CRDS, n—cavity ring-down spectroscopy and subsequent blockages that pose a safety risk or
...








Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.