AS ISO 19880.8-2021 pdf free download – Gaseous hydrogen — Fuelling stations Part 8: Fuel quality control.
The quality requirements of hydrogen fuel dispensed to PEM fuel cells for road vehicles are listed inISO 14687-2.
6Quality control approaches
6.1General
There are two common methods to control the quality of hydrogen at a fuelling station, by spot samplingand continuous monitoring.These methods can be used individually or together to ensure hydrogenquality levels.
6.2Sampling
Spot sampling at a fuelling station involves capturing a measured amount for chemical analysis.Sampling is used to perform an accurate and comprehensive analysis of impurities which is doneexternally, typically at a laboratory. Since the sampling process involves drawing a sample of gas, itis typically done on a periodic basis and requires specialized sampling equipment and personnel tooperate it. Sampling procedures shall conform to lS0 19880-1.The advantage of spot sampling is that amore detailed laboratory analysis can be conducted on the sample.The disadvantage of spot samplingis that it is not continuous and results in a detail analysis of a single point in time.
6.3Monitoring
A fuelling station can have real time monitoring of the hydrogen gas stream for one or more impuritieson a continuous or semi-continuous basis. A critical impurity can be monitored to ensure it does notexceed a critical level, or monitoring of indicator species are used to alert of potential issues withthe hydrogen production or purification process. Monitoring equipment is installed in line with thehydrogen gas stream and shall meet the process requirements of the fuelling station, as well as becalibrated on a periodic basis.Continuous monitoring compliments spot sampling by offsetting thedisadvantages.
7Potential sources of impurities
For a given fuelling station,the contaminants listed in the hydrogen specification referred to in Clause 5may or may not be potentially present. There are several parts of the supply chain where impurities canbe introduced.The potential impurities in each step of the supply chain are described in Annex D.
When a contaminant is classified as potentially present, it shall be taken into account in the qualityassurance methodology (risk assessment or prescriptive approach) described in Clause 8.
8Hydrogen quality assurance methodology
8.1General
A quality assurance plan for the entire supply chain shall be created to ensure that the hydrogenquality will meet the requirements listed in Clause 5. The methodology used to develop the qualityassurance plan can vary but shall include one of the two approaches described in this document. Thegeneral description of these two approaches are described in 8.2 and 8.3.Examples of these approaches1) prescriptive approach and 2) risk assessment for hydrogen quality, are presented in Annexes A, Band C, respectively. The quality assurance plan for the fuelling station shall include the following toensure hydrogen quality is properly maintained:
— identification of potential impurities;
— methods to control and remove these impurities;
— sampling impurities and frequency;
— monitoring of impurities or process controls;
— description of solid and liquid particulate filters;
— cleanliness and maintenance procedures.
It is important to understand that quality should be maintained throughout the complete supply chain of the product (from production source to fuelling station nozzle), such that the impurities that are given in the specification remain below the threshold values. Each component of the supply chain shall be investigated taking into account the already existing barriers for a given contaminant. NOTE  An effective quality control approach can further ensure the quality of the hydrogen by providing a proactive means to identify and control potential quality issues which can include sampling and monitoring. Additionally, use of quality assurance can improve the decision making if a quality problem arises.AS ISO 19880.8 pdf download.