This Information Report provides interim background information and an interim specification of hydrogen fuel quality for commercial proton exchange membrane (PEM) fuel cell vehicles. This Report also provides background information on how this interim specification was developed by the Hydrogen Quality Task Force (HQTF) of the Interface Working Group (IWG) of the SAE Fuel Cell Standards Committee.
The constituents and thresholds listed in Table 1 are based on a survey of the industry, the published literature and reflects current and draft analytical test methods. Some of the allowable constituent levels are higher than desired because a published detection method is not available for the desired threshold. Some of the allowable constituent levels may be lower than desired due to incomplete evaluations and/or an attempt to minimize testing costs (such as including methane in total hydrocarbons).
Additional testing of the effects of impurities on fuel cells, fuel systems, and storage media is required. Furthermore, development is required on suitable, cost effective test methods, sampling methodologies and equipment for laboratory, in-line and field evaluation. The American Society of Testing and Materials (ASTM) D03 (Gaseous Fuels) Committee has been charged to address some of these issues.
This document is being revised to encompass changes indicative of industry progress in the determination of acceptable levels of contaminants and advances in the methodologies used to verify those levels.
Since the initial publication of this TIR, proposals have been introduced to the Interface Working Group (IWG) by members of the energy and specialty gas industries seeking to modify the values of contaminants initially contained in Table 1. These proposals were intended to bring the TIR into conformance with presently established norms for hydrogen production and delivery. These proposals have been discussed at length within the IWG and, by consensus, have been accepted. Acceptance of these proposals also dictated that the values of the Hydrogen Fuel Index and the Total allowable non-hydrogen, non-particulate constituents contained in Table 1 be updated.
This revision also contains clarifications of current works in progress pursuant to the enhanced test methodologies being developed by the ASTM D03 (Gaseous Fuels) Committee.
Additionally, there are numerous editorial corrections to the wording of the document to provide a) clarifications meant to enhance the understanding of the allowable levels of contaminant components (Table 1, Note e), b) correction of innacurate statements (wording of the definition of inert gases), c) correction of spelling errors, and d) basic information (contained in Appendix B) that provides a more generally accurate picture of the commonly agreed upon impact of hydrogen fuel contaminants to the PEM fuel cell stack, Balance of Plant of the fuel cell system, and hydrogen storage systems in use today.