ISO 14687-2:2012 download.Hydrogen fuel — Product specification — Part 2: Proton exchange membrane (PEM) fuel cell applications for road vehicles.
This part of ISO 14687 specifies the quality characteristics olhydrogen fuel in order to ensure uniformity of the hydrogen product as dispensed for utilization in proton exchange membrane (PEM) fuel cell road vehicle systems.
2 Normative references
The following documents, In whole or In part, are normatively referenced In ISO 14687 and are Indispensable for Its application. For dated references, only the edition cited applies For undated references, the latest edftlon of the referenced document (including any amendments) applies.
ISO 6145 (all parts) ,Gosanalysis—Preparation of calibration gas rnixt ures using dynamic volumet nc methods
ISO 14687-i, Hydrogen fuel — Product specification — Part 1: All applications except proton exchange
membrane (PEP4)fuel cell for road vehicles
3 Terms and definitions
For the purposes of ISO 14687, the terms and definitions given in ISO 14687-1 and the followingapply.
3.1
constituent
component (or compound) found within a hydrogen fuel mixture
3.2
contaminant
Impurity that adversely affects the components within the fuel cell system or the hydrogen storage system
NOTE An adverse cifect can be reversible or irreversible.
3.3
detection limit
lowest quantity of a substance that can be distinguished from the absence of that substance with a stated con lidence limit
3.4
determination limit
lowest quantity which can be measured at a given acceptable level of uncertainty
3.5
fuel cell system
power system used forthe generation ofelectricity on a fuel cell vehicle, typically containing the following subsystems: fuel cell stack, air processing, fuel processing, thermal management and water management
5.2 Report results
The detection and determination limits for analytical methods and instruments used shall be reported along with the results of each test as well as the employed analytical method, the employed sampling method and the amount of sample gas.
6 SamplIng
6.1 Sample size
The quantity of hydrogen in a single sample container should be sufficient to perform the analyses for the limiting characteristics specified In Table 1. If a single sample does not contain a sufficient quantity of hydrogen to perform all or the analyses required to assess the quality level, additional samples from the same lot shall be taken under similar conditions.
6.2 Gaseous hydrogen
Gaseous hydrogen samples shall be representative of the dispensed hydrogen, The sampling location shall be In accordance with 5.1.
A sample from the dispenser nozzle shall be withdrawn through a suitable connection that does not
contaminate the sample or compromise safety. Attention shall be paid to ensure that the sampled
hydrogen is not contaminated with residual gases inside the sample container by repeated purge cycles.
A validated sampling method should be used (see Annex B for guidance).
Clause 9 provIdes guidance relative to managing hazards associated with withdrawing samples from the high pressure hydrogen system,
6.3 Particulates in gaseous hydrogen
Particulates In hydrogen should be sampled from a dispenser nozzle. Samples shall be collected In a manner that does not compromise safety. Appropriate measures should be taken for the sample gas not to be contaminated by particulates coming from the connection device and/or the ambient air. When using a filter, samples should be collected if possible under the same conditions (pressure and flow rate) as employed in the actual refuelling operation. To avoid trapping particles or contaminating the sample. no regulator should be used between the dispenser nozzle and the particulate filter.
6.4 LiquId hydrogen
Vaporized liquid samples shall be representative of the liquid hydrogen supply. Samples shall be obtained in a manner that does not compromise safety. For example, one of the following procedures can be used to obtain samples:
a) vaporizing, in the sampling line, liquid hydrogen [rum the supply contalner
b) flowing liquid hydrogen from the supply container into or through a suitable container in which a representative sample is collected and then vaporized.
7 Analytical methods
7.1 General
The analytical methods suitable for measuring characteristics listed in Table I are described below. Other analytical methods are acceptable if their performances, including safety of use are equivalent to those of the methods listed below.
7.6 HelIum content
The helium content in hydrogen can be determined using a gas chromatograph with thermal conductivity detector (GC/TCD) or a gas chrnmatographmass spectrometer (GC-MS).
7.7 Argon and nitrogen contents
The argon and nitrogen contents can be determined using one of the following instruments:
a) a gas chromatograph with thermal conductivity detector (GC/TCD) or a gas chromatograph with a pulsed discharge helium Ionization detector (GC/PDHID);
b) a gas chromatograph.mass spectrometer (GC’MS) and ct pulse injection.
7.8 Carbon dioxide content
The carbon dioxide content can be determined using one of the following Instruments:
a) a gas chromatograph-mass spectrometer (GC-MS) and jet pulse injection:
b) a gas chromatograph equipped with a catalytic methanizer and a flame ionization detector (GC/FID with methanizer);
c) a gas chromatograph with a pulsed discharge helium ionization detector (GC/PDHIDJ:
d) a fourier transform infrared spectrometer(FTIR) with suitable cell path length, scan wavelength and detector.
7.9 Carbon monoxide content
The carbon monoxide content can be determined usmg one of the following instruments:
a) a gas chromatograph equipped with a catalytic methanizer and a flame ionization detector (GC/FID with methanizer);
b) a gas chromatograph with a pulsed discharge helium ionization detector (GC/PDHID);
c) a fourier transform infrared spectrometer (FTIR) with suitable cell path length, scan wavelength and detector.
7.10 Total sulfur content
The content of inorganic and organic sulfur compounds shall be determined using a gas chromatograph (GC) and a chemiluminescence detector with concentration device.
Alternatively, the total sulfur content may be determined using the following procedure. An oxy• hydrogen flame, whose sulfur contents have been removed completely by absorption or by other suitable method, may be used to burn the sample at a high temperature. The combustion products are absorbed in hydrogen peroxide/water to oxidize the sulfur to sulfuric acid, after which the content is determined and caLculated as sulfur dioxide. The sulfur content analysis can be conducted with an ion chromatograph (IC). capable of separating and detecting the desired component. Appropriate impurity. concentrating techniques may be used to attain the sensitivity.
7.11 Formaldehyde content
The formaldehyde content can be determined using one of the following instruments:
a) a gas chromatograph with a flame ionization detector (GC/FID);
b) a gas chromatograph with a pulsed discharge helium ionization detector (GC/PDHID);