AS ISO 19880.8:2021 pdf free download – Gaseous hydrogen- Fuelling stations Part 8: Fuel quality control

AS ISO 19880.8:2021 pdf free download – Gaseous hydrogen- Fuelling stations Part 8: Fuel quality control.
This document specifies the protocol for ensuring the quality of the gaseous hydrogen at hydrogen distribution facilities and hydrogen fuelling stations for proton exchange membrarw (PEM) fuel cells for road vehicles.
2 Normative references
The following documents are referred to In the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 19880.1, Gaseous hydrogen — Fuelliog stations — Part 1: General requirements
3 Terms and definitions
For the purposes of this document, the lollowing terms and definitions apply.
ISO and IEC maintain terminnlogical databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www .org/ubp
— IEC Electropedia: available at ht1p/JwwweIectropetha.org/
3.1
authority having jurisdIction
AH
organization, office or individual responsible for approving a facility along with an equipment, an installation, or a procedure
3.2
indicator species
one or more constituents (13) In the gas stream which can signal thu presence of other chemical constituents because it has the highest probability of presence in a fuel produced by a given process
3.3
constituent
component (or compound) tound within a hydrogen fuel mixture
3.4
contaminant
,npurl1y (19) that adversely affects the components within the fuel cell system (1k) or the hydrogen storage system
Note ito entry; An adverse effect can be reversible or Irreversible.
3.5
filter
equipment to remove undesired parrlculates (115) from the hydrogen
A.1 General
This annex gives a brief description of the Impact of impurities on the stack, fuel cell components, and the complete fuel cell powertrain. Detailed Information can be found In the relevant literature and lournal publications. It shall be noted that this annex refers to known impurities and their effects on the fuel cell powertrain at the time of publication. It cannot be excluded that other impurities exist. Furthermore, in most cases only the impact of a single impurity has been Investigated and there Is still the need for fundamental research regarding the Impact of a combination of the different Impurities on the fuel cell powertrain.
A.2 Inert gases
The main effect due to the presence of inert gases such as Ar and N2 Is to lower the cell potential due to the dilution effect of the inert species (dilution of the hydrogen gas) and inertial (diffusion) effects. Nevertheless, under consideration of the threshold value current stack designs, fuel cell components and fuel cell powertrains are not adversely affected by inert constituents. High inert gas concentrations will lead to power losses, Increased fuel consumption, and loss of efficiency. Furthermore. H2 starvation caused by high inert gas concentrations may lead to permanent damage of the fuel cell stack or vehicle stop. Inert gases will accumulate in the anode loop and may affect venting and recycle blower control. Further sources report that the presence of N2 hinders desorption of adsorbed CO from the surface of the anode catalyst. It should also be noted that inert gases can affect the accuracy of mass metering instruments for hydrogen dispensing.
A.3 Oxygen
Oxygen may have a detrimental effect on the fuel cell anode, but the concentration where this effect occurs is not fully known. Higher levels of oxygen may have an impacron metal hydride storage materials.
A.4 Carbon dioxide
The contamination effects of CO2 depend on the concentration, fuel cell operation conditions, and anode catalyst composition. Firstly, CO2 dilutes the hydrogen gas and may affect venting and recycle blower control of the fuel cell powertrain. Furthermore, very high concentrations of CO2 can be catalytically converted via a reverse water gas shift reaction into CO which In consequence poisons the catalyst, In addition. co•occurrence of CO and CO2 in hydrogen has an accumulated influence on cell performance. CO2 may adversely affect on-hoard hydrogen storage systems using metal hydride alloys.