Overview - EN ISO 2615:2024 (biomethane compressor oil analysis)
EN ISO 2615:2024 provides guidance for the sampling and gas chromatographic analysis of compressor oil in biomethane and compressed natural gas (CNG). The standard defines how to collect samples on coalescing filters under specific operational conditions (the first two cubic metres of gas, at standard conditions, delivered at a refuelling station) and how to determine the compressor oil mass fraction. The method applies only to compressed gas (p > 18 MPa) and covers a measurement range of 3 mg/kg to 30 mg/kg. This standard supports traceable, fit‑for‑purpose testing needed for trade, conformity assessment and quality control of renewable gases.
Key topics and technical requirements
- Scope and applicability: Biomethane and CNG at high pressure (>18 MPa); mass fraction reporting between 3–30 mg/kg.
- Sampling protocol: Use of coalescing filters and sampling apparatus; sampling defined as the first two cubic metres at refuelling stations (standard conditions).
- Recovery and extraction methods: Procedures include ultrasonic extraction with nitrogen flush and pressurised fluid extraction to recover oil from filters.
- Analytical techniques: Gas chromatographic methods are specified (GC/MS and GC/FID are described in the standard) with requirements for capillary columns and calibration standards.
- Apparatus and materials: Lists necessary equipment-gas chromatograph, ultrasonic bath, pressurised fluid extractor, filter housings, solvents and calibration materials.
- Calculations and uncertainty: Procedures for expressing compressor oil as a mass fraction, calculation details and guidance on measurement uncertainty (referencing ISO/IEC Guide 98-3).
- Reporting: Test report content and example chromatograms (GC/MS and GC/FID) to aid interpretation.
Applications - who uses EN ISO 2615:2024
- Biomethane producers and biogas upgrading facilities monitoring oil contamination.
- CNG and refuelling station operators validating delivered gas quality.
- Analytical laboratories performing accredited gas analysis and chromatographic testing.
- Gas network operators and pipeline/injection stakeholders ensuring gas compatibility and protecting downstream equipment.
- Regulators and conformity assessment bodies setting or enforcing quality criteria for renewable gas trade.
EN ISO 2615:2024 helps maintain fuel quality, protect compressors and engines, and support commercial transactions in biomethane and high‑pressure CNG.
Related standards
- ISO 15403-1 (specifications for biomethane fuel quality)
- EN 16723 series (biomethane for injection and transport)
- ISO 6974 (natural gas composition by GC)
- ISO 6976 (calorific values and derived properties)
- ISO/IEC Guide 98-3 (GUM, measurement uncertainty)
Keywords: EN ISO 2615:2024, biomethane, compressor oil, CNG, gas chromatographic analysis, coalescing filters, sampling, mass fraction, GC/MS, GC/FID.
