ISO 14687-3:2014

INTERNATIONAL ISO
STANDARD 14687-3
First edition
2014-02-01
Hydrogen fuel — Product
specification —
Part 3:
Proton exchange membrane (PEM)
fuel cell applications for stationary
appliances
Carburant hydrogène - Spécification de produit —
Partie 3: Applications des piles à combustible à membrane à échange
de protons (PEM) pour appareils stationnaires
Reference number
ISO 14687-3:2014(E)
©
ISO 2014

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ISO 14687-3:2014(E)

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© ISO 2014
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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Published in Switzerland
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ISO 14687-3:2014(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2  Normative references . 1
3  Terms and definitions . 1
4  General design requirements . 3
4.1 Classification . 3
4.2 Categories . 3
4.3 Limiting characteristics . 3
4.4 Hydrogen production guidance . 4
5  Quality verification . 5
5.1 General requirements . 5
5.2 Analytical requirements of the qualification tests . 5
5.3 Report results . 5
6  Sampling . 5
6.1 Sample size . 5
6.2 Selection of the sampling point . 5
6.3 Sampling procedure . 6
6.4 Particulates in gaseous hydrogen . 6
7  Analytical methods. 6
7.1 General . 6
7.2 Parameters of analysis. 6
7.3 Water content . 6
7.4 Total hydrocarbon content . 7
7.5 Oxygen content . 7
7.6 Helium content. 7
7.7 Argon and nitrogen contents . 7
7.8 Carbon dioxide content. 7
7.9 Carbon monoxide content . 8
7.10 Total sulfur content . 8
7.11 Formaldehyde content . 8
7.12 Formic acid content . 9
7.13 Ammonia content . 9
7.14 Total halogenated compounds . 9
7.15 Particulates concentration . 9
7.16 Particulate size . 9
8  Detection limit and determination limit .10
9  Safety .10
Annex A (informative) Guidance on the selection of the boundary point .11
Annex B (informative) Rationale for the selection of hydrogen impurities to be measured .14
Annex C (informative) Pressure swing adsorption and applicability of CO as canary species .16
Annex D (informative) Detection and determination limits of the analytical methods for
determination of the limiting characteristics of hydrogen .17
Bibliography .19
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ISO 14687-3:2014(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 197, Hydrogen technologies.
ISO 14687 consists of the following parts, under the general title Hydrogen fuel— Product specification:
— Part 1: All applications except proton exchange membrane (PEM) fuel cell for road vehicles
— Part 2: Proton exchange membrane (PEM) fuel cell applications for road vehicles
— Part 3: Proton exchange membrane (PEM) fuel cell applications for stationary appliances
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ISO 14687-3:2014(E)

Introduction
This part of ISO 14687 provides an initial, albeit incomplete, basis for describing a common fuel to be
used by proton exchange membrane (PEM) fuel cell applications for stationary appliances in the near
term.
A large number of fuel cells are presently commercialized as power sources for stationary applications,
such as distributed, supplementary, and back-up power generation and as stationary heat and power
cogeneration systems. Most stationary fuel cells are equipped with a fuel processing system which
converts fossil fuel to hydrogen-rich fuel composed primarily of hydrogen and carbon dioxide. Some
of the stationary fuel cells use hydrogen fuel of high purity supplied through high pressure tanks or
pipeline from a distant hydrogen production plant.
The purpose of this part of ISO 14687 is to establish an international standard of quality characteristics
of hydrogen fuel for stationary fuel cells.
Types of fuel cells other than proton exchange membrane fuel cells (PEMFC), such as phosphoric acid
fuel cell (PAFC), molten carbonate fuel cells (MCFC) and solid oxide fuel cells (SOFC), may require similar
standards in future. Thus, it is anticipated that in the future PAFC, MCFC and SOFC hydrogen fuel quality
requirements will be added as amendments to this part of ISO 14687.
This part of ISO 14687 is intended to consolidate the hydrogen fuel product specification needs
anticipated by PEM fuel cell manufacturers and hydrogen fuel suppliers as both industries proceed
toward achieving wide-spread commercialization. Monitoring hydrogen fuel quality is necessary
because specific impurities will adversely affect the fuel cell power system. In addition, there may
be performance implications in the fuel cell power system if certain non-hydrogen constituent levels
are not controlled. Methods to monitor the hydrogen fuel quality that is delivered to these stationary
appliances are addressed.
This part of ISO 14687 specifies one grade of hydrogen, Type I, grade E, with three categories for different
target applications. Quality verification should be determined at the inlet point of a PEM fuel cell power
system.
Since PEM fuel cell applications for stationary appliances and related technologies are developing rapidly,
this part of ISO 14687 will be revised according to technological progress as necessary. Additionally,
some of the impurity limits are dictated by current analytical capabilities, which are also in the process
of development. Technical Committee ISO/TC 197, Hydrogen technologies, will monitor this technology
trend. It is also noted that this part of ISO 14687 has been prepared to assist in the development of PEM
fuel cell applications for stationary appliances and related technologies.
Further research and development efforts should focus on, but not be limited to:
— PEM fuel cell catalyst and fuel cell tolerance to hydrogen fuel impurities;
— Effects/mechanisms of impurities on fuel cell power systems and components;
— Impurity detection and measurement techniques for laboratory, production, and in-field operations;
and,
— Stationary fuel cell demonstration results.
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INTERNATIONAL STANDARD  ISO 14687-3:2014(E)
Hydrogen fuel — Product specification —
Part 3:
Proton exchange membrane (PEM) fuel cell applications
for stationary appliances
1 Scope
This part of ISO 14687 specifies the quality characteristics of hydrogen fuel in order to ensure uniformity
of the hydrogen product for utilization in stationary proton exchange membrane (PEM) fuel cell power
systems.
2  Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 6142, Gas analysis — Preparation of calibration gas mixtures — Gravimetric method
ISO 6145 (all parts), Gas analysis — Preparation of calibration gas mixtures using dynamic methods
ISO 14687-1, Hydrogen fuel — Product specification — Part 1: All applications except proton exchange
membrane (PEM) fuel cell for road vehicles
ISO 14687-2, Hydrogen fuel — Product specification — Part 2: Proton exchange membrane (PEM) fuel cell
applications for road vehicles
IEC/TS 62282-1, Fuel cell technologies — Terminology
3  Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 14687-1, IEC/TS 62282-1 and
the following apply.
3.1
boundary point
point between the hydrogen fuel supply equipment and the PEM fuel cell power system at which the
quality characteristics of the hydrogen fuel are to be determined
3.2
constituent
component (or compound) found within a hydrogen fuel mixture
3.3
contaminant
impurity that adversely affects the component parts within the fuel cell power system or the hydrogen
storage system
Note 1 to entry: An adverse effect can be reversible or irreversible.
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ISO 14687-3:2014(E)

3.4
customer
party responsible for sourcing hydrogen fuel in order to operate the fuel cell power system
3.5
detection limit
lowest quantity of a substance that can be distinguished from the absence of that substance with a
stated confidence limit
3.6
determination limit
lowest quantity which can be measured at a given acceptable level of uncertainty
3.7
fuel cell
electrochemical device that converts the chemical energy of a fuel and an oxidant to electrical energy
(DC power), heat and other reaction products
3.8
hydrogen fuel
gas containing a concentration of hydrogen equal to or larger than 50 % used for stationary fuel cell
applications
3.9
hydrogen fuel index
fraction or percentage of a fuel mixture that is hydrogen
3.10
hydrogen fuel supply equipment
equipment used for the transportation or on-site generation of hydrogen fuel, and subsequently for
delivery to the fuel cell power system, including additional storage, vaporization, and pressure regulation
as appropriate
3.11
irreversible effect
effect, which results in a permanent degradation of the fuel cell power system performance that cannot
be restored by practical changes of operational conditions and/or gas composition
3.12
particulate
solid or aerosol particle, including oil mist, that may be entrained in the hydrogen entering a fuel cell
3.13
reversible effect
effect, which results in a temporary degradation of the fuel cell power system performance that can be
restored by practical changes of operational conditions and/or gas composition
3.14
stationary proton exchange membrane (PEM) fuel cell power system
self-contained assembly of integrated PEM fuel cell systems used for the generation of electricity which
is fixed in place in a specific location, typically containing the following subsystems: fuel cell stack,
air processing, thermal management, water management, and automatic control system and which is
used in applications such as: distributed power generation, back-up power generation, remote power
generation, electricity and heat co-generation for resident and commercial applications
Note 1 to entry: For the purposes of this part of ISO 14687, the PEM fuel cell power system does not contain a fuel
processing system due to the location of the boundary point.
3.15
system integrator
integrator of equipment between the PEM fuel cell power system and the hydrogen supply
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ISO 14687-3:2014(E)

4  General design requirements
4.1  Classification
Hydrogen fuel for PEM fuel cell applications for stationary appliances shall be classified as Type I, grade
E, gaseous hydrogen fuel for PEM fuel cell stationary appliance systems.
NOTE 1 Type I, grade A, B, C, Type II, grade C and Type III, which are applicable for all applications except PEM
fuel cells for road vehicles and stationary appliances, are defined in ISO 14687-1.
NOTE 2 Type I, grade D and Type II, grade D, which are applicable for PEM fuel cells for road vehicles are
defined in ISO 14687-2.
4.2  Categories
Type I, grade E hydrogen fuel for PEM fuel cell applications for stationary appliances specifies the
following subcategories for the convenience of both PEM fuel cell manufacturers and hydrogen fuel
suppliers:
— Type I, grade E, Category 1
— Type I, grade E, Category 2
— Type I, grade E, Category 3
These categories are defined to meet the needs of different stationary applications, depending on the
requirements specified by the manufacturer.
4.3  Limiting characteristics
The fuel quality at the boundary point set between the hydrogen fuel supply equipment and the PEM fuel
cell power system, as applicable to the aforementioned grades of hydrogen fuel for stationary appliance
systems, shall meet the requirements of Table 1.
NOTE 1 Please see Annex A for the selection of the boundary point.
NOTE 2 Annex B provides the rationale for the selection of the impurities specified in Table 1.
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ISO 14687-3:2014(E)

Table 1 — Directory of limiting characteristics
a
Characteristics Type I, grade E
(assay) Category 1 Category 2 Category 3
Hydrogen fuel index (mini-
50 % 50 % 99,9 %
mum mole fraction)
Total non-hydrogen gases
50 % 50 % 0,1 %
(maximum mole fraction)
Non-condensing at all Non-condensing at all Non-condensing at all
b
Water (H O)
2
ambient conditions ambient conditions ambient conditions
Maximum concentration of individual contaminants
Total hydrocarbons
10 μmol/mol 2 μmol/mol 2 μmol/mol
c
(C basis)
1
Oxygen (O ) 200 μmol/mol 200 μmol/mol 50 μmol/mol
2
Nitrogen (N ),
2
Argon (Ar), Helium (He) 50 % 50 % 0,1 %
(mole fraction)
Included in total non- Included in total non-
Carbon dioxide (CO ) 2 μmol/mol
2
hydrogen gases hydrogen gases
Carbon monoxide (CO) 10 μmol/mol 10 μmol/mol 0,2 μmol/mol
d
Total sulfur compounds 0,004 μmol/mol 0,004 μmol/mol 0,004 μmol/mol
Formaldehyde (HCHO) 3,0 μmol/mol 0,01 μmol/mol 0,01 μmol/mol
Formic acid (HCOOH) 10 μmol/mol 0,2 μmol/mol 0,2 μmol/mol
Ammonia (NH ) 0,1 μmol/mol 0,1 μmol/mol 0,1 μmol/mol
3
Total halogenated com-
0,05 μmol/mol 0,05 μmol/mol 0,05 μmol/mol
e
pounds
Maximum particulates con-
1 mg/kg 1 mg/kg 1 mg/kg
centration
Maximum particle diameter 75 μm 75 μm 75 μm
NOTE For the constituents that are additive (i.e. total hydrocarbons, total sulfur compounds and total halogenated
compounds), the sum of the constituents shall be less than or equal to the specifications in the table. It is therefore important
that the analytical method used measures the total concentration of these families of compounds, and not the concentration
of single compounds within these families, which are subsequently summed to give a total amount of fraction. The latter
approach risks a false negative being reported. For more details, see Clause 7.
a
Maximum concentration of impurities against the total gas content shall be determined on a dry-basis.
b
Each site shall be evaluated to determine the appropriate maximum water content based on the lowest expected
ambient temperature and the highest expected storage pressure.
c
Total hydrocarbons are measured on a carbon basis (μmolC/mol). The specification for total hydrocarbons includes
oxygenated hydrocarbons. The measured amount fractions of all oxygenated hydrocarbons shall therefore contribute to
the measured amount fraction of total hydrocarbons. Specifications for some individual oxygenated hydrocarbons (e.g.
formaldehyde and formic acid) are also given in the table. These, however, also contribute to the measured amount fraction
of total hydrocarbons. These species have been assigned their own specifications based on their potential to impair the
performance of PEM fuel cells. Total hydrocarbons may exceed the limit due only to the presence of methane, in which case
the methane shall not exceed 5 % for Category 1, 1 % for Category 2 or 100 μmol/mol of hydrogen fuel for Category 3.
d As a minimum, total sulfur compounds include H S, COS, CS and mercaptans, which are typically found in natural gas.
2 2
e Includes, for example, hydrogen bromide (HBr), hydrogen chloride (HCl), chlorine (Cl ), and organic halides (R-X).
2
4.4  Hydrogen production guidance
Hydrogen fuel may be produced in a number of ways, including reformation of natural gas or other fossil
or renewable fuels, the electrolysis of water and numerous biological methods. Hydrogen fuel can be
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ISO 14687-3:2014(E)

generated on-site, generally in relatively small quantities, or in a larger scale production system off-site,
then transported under pressure or as a liquid to the point of use.
NOTE Biological sources of hydrogen can contain additional species that affect fuel cell performance (e.g.
siloxanes and mercury). Such species are not included in Table 1 due to insufficient data.
5  Quality verification
5.1  General requirements
Quality verification requirements shall be determined at the boundary point using the sampling and
analytical methods specified in Clauses 6 and 7 respectively. Alternatively, the quality verification may
be performed at other locations or under other methods by written agreement between the supplier and
the customer.
Analysis of all limiting characteristics in Table 1 may not be necessary for all hydrogen production
methods, if acceptable to the customer.
All analyses conducted in this part of ISO 14687 shall be undertaken using gaseous calibration standards
(or other calibration devices) that are traceable to the International System of Units (SI) via national
standards, where such standards are available.
5.2  Analytical requirements of the qualification tests
The frequency of testing and analytical requirements for the qualification tests shall be specified by
the supplier and the customer. Consideration shall be given to the consistency of hydrogen supply in
determining test frequency and constituents to be tested.
NOTE Annex C provides a recommended practice of the quality assurance for steam methane reforming
(SMR) hydrogen production processes using pressure swing adsorption (PSA) purification.
5.3 Report results
The detection and determination limits for analytical methods and instruments used shall be reported
along with the results of each test and the date the sample was taken.
6  Sampling
6.1  Sample size
Where possible, the quantity of hydrogen in a single sample container should be sufficient to perform
the analyses for the limiting characteristics. If a single sample does not contain a sufficient quantity of
hydrogen to perform all of the analyses required to assess the quality level, additional samples from
the same lot shall be taken under similar conditions. A large sample or sample with a greater pressure,
where applicable, may be required if multiple tests are to be conducted.
6.2  Selection of the sampling point
A boundary point shall be established so that gaseous samples are representative of the hydrogen
supplies to the PEM fuel cell power systems.
NOTE Annex A provides guidance to assist in the identification of the party responsible for the quality of
hydrogen at the boundary point and also the selection of the boundary point.
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ISO 14687-3:2014(E)

6.3  Sampling procedure
Gaseous hydrogen samples shall be representative of the hydrogen supply, and withdrawn from the
boundary point through a suitable connection into an appropriately sized sample container. No
contamination of the hydrogen fuel shall be introduced between the boundary point and the sample
container (a suitable purge valve may be used).
Attention shall be paid to ensure that the sampled hydrogen is not contaminated with residual gases
inside the sample container by evacuating it. If evacuation is not possible, the sample container shall be
cleaned using repeated purge cycles.
Sampled gases are flammable and potentially toxic. Measures shall be taken to avoid hazardous
situations as per Clause 9.
6.4  Particulates in gaseous hydrogen
Particulates in hydrogen shall be sampled from the boundary point, using a filter, if practical, under
the same conditions (pressure and flow rate) as employed in the actual hydrogen supplying condition.
Appropriate measures shall be taken for the sample gas not to be contaminated by particulates coming
from the connection device and/or the ambient air.
7  Analytical methods
7.1  General
The analytical methods specified in Clause 7 shall be used for measuring characteristics listed in Table 1.
Annex D provides a list of standard analytical techniques.
7.2  Parameters of analysis
The determination limits as defined in Clause 8 for the analytical methods listed should be less than or
equal to the limiting characteristics of hydrogen for all impurities listed in Table 1. Detection limits shall
be at least three times lower than the specifications listed in Table 1.
Calibration gas standards that contain the applicable gaseous components at applicable concentrations
and standardized dilution procedures shall be used to calibrate the analytical instruments used to
determine the limiting characteristics of hydrogen. The calibration gas mixture shall be prepared in
accordance with ISO 6142 or ISO 6145.
The calibration of measuring equipment shall be traceable
...