Overview
SIST EN ISO 2613-2:2024 is a European and international standard that specifies a method for the determination of siloxane content in biomethane using gas chromatography with ion mobility spectrometry (GC-IMS). Developed by the Slovenian Institute for Standardization (SIST) and aligned with ISO 2613-2:2023, this standard facilitates accurate measurement and control of siloxane impurities in natural gas and biomethane streams.
Siloxanes are organic silicon compounds that originate from various household and industrial sources and can end up in biogas streams. The presence of siloxanes in biomethane can lead to operational issues such as equipment fouling and the formation of silica deposits, negatively impacting gas processing and use, especially in vehicle fuel applications.
Key Topics
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Scope of the Method: The standard covers the GC-IMS analysis of specific siloxanes considered critical in biomethane, including:
- Hexamethyldisiloxane (L2)
- Octamethyltrisiloxane (L3)
- Decamethyltetrasiloxane (L4)
- Dodecamethylpentasiloxane (L5)
- Hexamethylcyclotrisiloxane (D3)
- Octamethylcyclotetrasiloxane (D4)
- Decamethylcyclopentasiloxane (D5)
- Dodecamethylcyclohexasiloxane (D6)
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Measurement Range and Conditions: Suitable for quantifying siloxanes in biomethane at concentrations around and above 0.3 mg/m³ (14 µmol/mol), within absolute pressure ranges of 1–2 bar, temperatures from 0°C to 40°C, and relative humidity below 90%.
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Calibration and Measurement: Provides detailed guidance on:
- Preparing traceable calibration gas mixtures
- Setting up the GC-IMS apparatus with appropriate temperature and pressure control
- Employing certified reference materials and ensuring proper instrument calibration
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Sampling and Handling: Emphasizes the importance of representative sampling, materials compatibility to prevent siloxane adsorption, and consistent operating conditions to avoid analytical bias.
Applications
The SIST EN ISO 2613-2:2024 standard is essential for:
- Biomethane Producers: Enables reliable siloxane measurement to ensure gas quality and compliance with contractual and regulatory specifications.
- Gas Grid and Utility Operators: Supports quality assurance for biomethane injected into the natural gas grid, safeguarding infrastructure and customer equipment.
- Analytical Laboratories: Provides a standard procedure for accredited testing of siloxane content, contributing to reproducibility and comparability of results.
- Environmental and Regulatory Compliance: Helps organizations meet the demands of gas quality regulations, especially in Europe, where siloxane limits are part of national and EU-wide standards.
Related Standards
This standard is closely linked with other international natural gas and biogas quality standards, such as:
- ISO 6142-1: Preparation of calibration gas mixtures-Gravimetric method
- ISO 6143: Comparison methods for calibration gas mixtures
- ISO 6144: Static volumetric method for calibration gas mixtures
- ISO 6145-1: Dynamic methods for gas analysis
- ISO 10715: Natural gas-Gas sampling
- ISO 10723: Performance evaluation for gas analytical systems
- EN 16723-1 and EN 16723-2: Standards for biomethane and natural gas quality requirements
Summary
SIST EN ISO 2613-2:2024 provides a robust, standardized approach for the analysis and monitoring of siloxane levels in biomethane using GC-IMS. By ensuring accurate detection of siloxane contaminants, this standard supports operational efficiency, equipment longevity, and regulatory compliance in the natural gas and renewable energy industries. Adopting these methods helps stakeholders maintain gas quality, enhance process control, and promote the safe and sustainable use of biomethane.
