ISO 2611-1:2024
Analysis of natural gas
- Standard No.
- ISO 2611-1:2024
- Release Date
- 2024
- Published By
- International Organization for Standardization (ISO) IX / ISO
- Latest
- ISO 2611-1:2024
- Introduction
Analysis of the technical framework of the standard
This international standard establishes for the first time a systematic detection method for the content of hydrogen halides in biomethane, using an ion chromatography system combined with an alkali-impregnated quartz fiber filter sampling technique, with a detection range covering HCl 0.07-35 mg/m³ and HF 0.07-20 mg/m³.
Method principle and technological innovation
Based on the principle of chemical adsorption of gaseous HCl/HF on alkaline filter membranes, after extraction with ultrasonic aqueous solution, an ion chromatograph equipped with a conductivity detector is used to analyze chloride ions (Cl⁻) and fluoride ions (F⁻). The standard innovatively proposes two parallel sampling schemes:
Technical parameters Membrane filter method Adsorption tube method Sampling flow rate 1-3 L/min 0.1-1 L/min Key consumables Alkali-impregnated quartz fiber filter membrane (2.5µm) Activated silica gel adsorption tube (20-40 mesh) Applicable scenarios Conventional concentration detection High concentration sample collection
Key experimental operation specifications
1. Chromatographic system configuration
Standard requirements: The ion chromatography system must include: metal-free HPLC pump, pre-column (optional), separation column (resolution R≥1.3), conductivity detector and data recording device. Potassium hydroxide (KOH) gradient elution program is recommended.
2. Preparation of calibration solution
A multi-concentration point calibration curve needs to be established:
- Stock solution: 1000 mg/L Cl⁻/F⁻ single standard or mixed standard
- Working curve range: 0.05-0.5 mg/L (example)
- The calibration solution is prepared and used immediately, and stored in a polyethylene bottle
Measurement uncertainty analysis
Validation data show the expanded uncertainty of different methods (k=2):
Compound Concentration range (mg/m³) Uncertainty of membrane filter method Uncertainty of adsorption tube method HCl 0.49-23.3 10%-37% 12%-31% HF 0.71-15.3 13%-40% 50% The main sources of uncertainty include: repeatability, reproducibility, recovery rate and sampling process loss.
Recommendations for the implementation of the standard
1. Key points of quality control
- Laboratory blank and field blank tests shall be carried out simultaneously for each batch of samples
- The matrix interference shall be verified by the standard addition method
- The retention time deviation shall be controlled within ±10%
2. Direction of technological evolution
The dynamic gas generation method proposed in Appendix B of the standard can be used as a reference technology for method verification, and the adsorption loss of the sampling system can be evaluated by accurately controlling the concentration of HCl/HF gas.
3. Connection with industry applications
This method can directly support the quality assessment requirements of the EN 16723 series of standards for the injection of biomethane into the natural gas pipeline network, and the detection limit meets the EU threshold of 0.07 mg/m³.
ISO 2611-1:2024 Referenced Document
- ISO 10304-1 Water quality - Determination of dissolved anions by liquid chromatography of ions - Part 1: Determination of bromide, chloride, fluoride, nitrate, nitrite, phosphate and sulfate; Technical Corrigendum 1
- ISO 14532 Natural gas - Vocabulary
- ISO 3696 Water for analytical laboratory use; Specification and test methods
- ISO 6974-1 Natural gas - Determination of composition and associated uncertainty by gas chromatography - Part 1: General guidelines and calculation of composition; Technical Corrigendum 1
- ISO 6974-2 Natural gas - Determination of composition and associated uncertainty by gas chromatography - Part 2: Uncertainty calculations
- ISO 6974-3 Natural gas — Determination of composition and associated uncertainty by gas chromatography — Part 3: Precision and bias
- ISO 6976 Natural gas - Calculation of calorific values, density, relative density and Wobbe indices from composition
ISO 2611-1:2024 history
- 2024 ISO 2611-1:2024 Analysis of natural gas
