Method 2
Gas chromatograph:
Kristall 2000M or Chromatec-Crystal 5000/9000
Detectors:
FID or TCD
Injection system:
Heated 6-port or 10-port valve
Chromatographic column:
Packed column 2–3 m with HayeSep sorbent
or
Capillary column
Additional equipment:
Hydrogen generator (when using FID)
Air compressor (when using FID)
Gas fittings kit 4.078.000
Method Description
In the gas industry, methanol is used as a hydrate formation inhibitor. Traditionally, the main method of preventing hydrate formation in the gas industry is the use of methanol.
According to STO Gazprom 5.45, methanol can be analyzed without preconcentration in the range from 0.0020% to 0.05%.
In accordance with the method, at least five certified reference gas mixtures with methanol molar fractions of 0.0025%, 0.005%, 0.010%, 0.025%, and 0.05% are used to construct the calibration curve over the full analytical range.
This method is less sensitive, but simpler to operate.
As a rule, this method is often implemented in the same chromatograph together with gas composition analysis according to GOST 31371.
Standard
STO Gazprom 5.45-2013
Natural combustible gas. Determination of methanol molar fraction by chromatographic method.
(Developer: D.I. Mendeleev All-Russian Research Institute for Metrology)
Method 1
Gas chromatograph:
Kristall 2000M or Chromatec-Crystal 5000/9000
Detector:
FID
Injection system:
Packed-column evaporator
Concentrator device with absorber traps
Packed column:
Guard column 0.3 m × 3 mm, HayeSep Q
Separation column 2 m × 3 mm, HayeSep Q
Additional equipment:
Hydrogen generator
Air compressor
Gas fittings kit 4.078.000
Spare absorber traps
SGE-Chromatec microsyringes, 0.2–10 µL
Method Description
In the gas industry, methanol is used as a hydrate formation inhibitor. Traditionally, the main method of preventing hydrate formation in the gas industry is the use of methanol.
STO Gazprom 5.36 allows the determination of the molar fraction of methanol in natural gas samples collected using absorber traps filled with water, in the range from 0.0001% to 0.5%.
A similar approach is also provided in STO Gazprom 5.45, but with a narrower range of 0.0010% to 0.05%.
Chromatec recommendations for methanol analysis with preconcentration on absorber traps filled with water are prepared strictly in accordance with STO Gazprom 5.36.
The method is based on chromatographic analysis of methanol предварительно concentrated from gas in two water-filled absorber traps. Detection is performed using FID, and calculation is carried out by the absolute calibration method.
For methanol sampling and concentration from the gas sample, Chromatec recommends using the Concentrator Device with Absorber Traps in accordance with STO Gazprom 5.36 and STO Gazprom 5.45.
Concentrator Device with Absorber Traps
Concentrator Device with Absorber Traps according to STO Gazprom 5.36 (front view)
Concentrator Device with Absorber Traps according to STO Gazprom 5.36 (front view)
If required, this method can be combined in a single instrument with gas composition analysis methods according to GOST 31371.
Standards
STO Gazprom 5.36-2011
Separation gas. Procedure for determination of chemical composition.
(Developer: Research Institute of Natural Gases and Gas Technologies – Gazprom VNIIGAZ)
STO Gazprom 5.45-2013
Natural combustible gas. Determination of methanol molar fraction by chromatographic method.
(Developer: D.I. Mendeleev All-Russian Research Institute for Metrology)