ISO 2611-1:2024

Overview

ISO 2611-1:2024 - Analysis of natural gas - Halogen content of biomethane - Part 1: HCl and HF content by ion chromatography - specifies a laboratory method for measuring hydrochloric acid (HCl) and hydrofluoric acid (HF) in biomethane (and biogas). The method traps gaseous HCl and HF on an alkali‑impregnated quartz fibre filter or in a sorbent trap, extracts the adsorbed anions, and determines chloride and fluoride by ion chromatography (IC) with conductimetric detection. Concentrations are reported as equivalent HCl and HF under standard reference conditions (see ISO 13443).

Keywords: ISO 2611-1:2024, biomethane halogen content, HCl HF ion chromatography, biomethane analysis, biogas HCl HF measurement, conductimetric detection.

Key topics and technical requirements

• Scope and applicability
  • Applicable to biomethane and biogas.
  • Measurement ranges: HCl: 0.07–35 mg/m³, HF: 0.07–20 mg/m³ (under standard reference conditions).
• Sampling approaches
  • Filter‑based method using alkali‑impregnated quartz fibre filters.
  • Cartridge/sorbent tube trapping for alternative sampling.
  • Gas volume measurement and flow control during sampling are required.
• Sample pre‑treatment
  • Aqueous extraction of collected material (includes sonication) to transfer chloride and fluoride ions to solution for analysis.
• Analytical technique
  • Ion chromatography (IC) with conductimetric detector (CD) for chloride and fluoride quantification.
  • Calibration procedures, blank controls and calibration checks are defined to ensure data quality.
• Reporting and calculations
  • Results expressed as gaseous concentration (µg/m³ or mg/m³) at reference conditions; formulae and symbols are provided.
• Quality and performance
  • Performance characteristics, calibration verification and method validation information are included (see Annex A).

Practical applications and users

• Who uses it: accredited testing laboratories, biomethane producers, gas grid operators, injection/commercial certification bodies, environmental and regulatory authorities, and process engineers.
• Why it matters: ensures conformity assessment of biomethane/biogas to quality specifications (e.g., EN 16723 series), protects downstream equipment and catalysts from halogen corrosion, and supports fuel quality monitoring for pipeline injection and transport applications.

Related standards

• ISO 13443 (reference conditions)
• EN 16723 series (biomethane specifications)
• ISO 10304-1 (dissolved anions by liquid ion chromatography)
• ISO 3696, ISO 6974 series, ISO 14532 (referenced for laboratory water, composition, terminology)

This standard provides a validated, traceable IC-based procedure for reliable measurement of HCl and HF in biomethane - essential for quality control, regulatory compliance and safe gas network injection.