ASTM D7652-11

Low operating temperature fuel cells such as proton exchange membrane fuel cells (PEMFCs) require high purity hydrogen for maximum material performance and lifetime. Sulfur compounds are present in many of the materials used in hydrogen production and small quantities typically remain after processing and purification. Part-per-billion concentrations of sulfur gases such as hydrogen sulfide (H₂S), carbonyl sulfide (COS) and mercaptans diminish single fuel cell capacity.

1.1 This test method describes a procedure primarily for the determination of hydrogen sulfide, carbonyl sulfide, methyl mercaptan, and carbon disulfide (Table 1) in hydrogen fuels for fuel cell vehicles (FCV) by gas chromatograph with sulfur chemiluminescence detection. The reporting limit is 0.02 ppbv (nanomole per mole as volume), based upon the analysis of a 500 mL hydrogen sample. The procedures described in this method were designed to satisfy sulfur contaminant determination requirements contained in SAE TIRJ2719 and the California Code of Regulations, CFR , Title 4, Division 9, Chapter 6, Article 8, Sections 4180 – 4181.

1.2 This test method can be extended to other sulfur species in hydrogen fuel that are eluted through a chromatographic column.

1.3 This test method can be modified to analyze all sulfur compounds present without chromatographic separation; thus, providing a total sulfur estimation without speciation (Appendix X1).

1.4    If any new sulfur compounds need to be analyzed in hydrogen fuel, the calibration or spiking sulfur standards must include these new compounds after their method detection limit study. In addition, no co-elution is allowed in the chromatographic analysis of the calibration standard containing both the newly added and the existing sulfur target compounds. If necessary, the chromatographic conditions may be modified to achieve this goal.

1.5 Although, primarily intended for determining sulfur in hydrogen used as a fuel for fuel cell or internal combustion engine powered vehicles, this test method can also be used to measure sulfur compounds in other gaseous fuels and gaseous matrices provided data quality objectives are satisfied.

1.6 The values stated in SI units are standard. The values stated in inch-pound units are for information only.

1.7 Mention of trade names in this standard does not constitute endorsement or recommendation for use. Other manufacturers of equipment or equipment models can be used.

1.8 Alternative Detectors—This test method is written primarily for the use of sulfur chemiluminescent detectors but other detectors can be used provided they can detect hydrogen sulfide, carbonyl sulfide, methyl mercaptan, and carbon disulfide at 0.02 ppbv in hydrogen and meet data quality objectives for the intended use.

1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For safety issues related to liquid nitrogen, refer to material safety data sheet (MSDS) from liquid nitrogen supplier.