Method
Chromatographic system based on:
Chromatec-Crystal 5000/9000
Detectors:
TCD and FID; the number of detectors depends on the analytical task
Packed columns or packed and capillary columns:
Packed Column M, 3 m × 2 mm, HayeSep R (Porapak R), 80/100 mesh
Packed Column M, 3 m × 2 mm, NaX, 80/100 mesh
Packed Column M, 2 m × 3 mm, NaX, 60/80 mesh
Capillary Column BP-1, 60 m × 0.32 mm × 1.0 µm, Cat. No. 054810
Other columns may also be used
Injection system:
Chromatec or Valco 6-port and 10-port valves with loop volumes from 0.1 to 2 mL, depending on the column used
4-port and 6-port switching valves
Heated transfer line
Gas flow indicator
Additional data processing software:
Chromatec Gas
Additional equipment:
Hydrogen generator (when using FID)
Air compressor (when using FID)
Gas fittings kit 4.078.000 – 2 pcs. (argon and helium)
Catalytic air purification filter 20.0-01
Certified gas mixtures (PGS, IPG) for instrument calibration
Adjustable pneumatic resistance RPS 5.150.019 for operation with standard gas mixtures and sampling devices
Method Description
GOST R 57975.1-2017. Associated petroleum gas. Determination of composition by gas chromatography.
Measurement ranges of molar fractions of components and fractions of associated petroleum gas
| Component | Formula | Molar Fraction, % |
|---|---|---|
| Methane | CH4 | From 5 to 99.7 inclusive |
| Ethane | C2H6 | From 0.1 to 30 inclusive |
| Propane | C3H8 | From 0.1 to 30 inclusive |
| Isobutane | C4H10 | From 0.01 to 10 inclusive |
| n-Butane | C4H10 | From 0.01 to 10 inclusive |
| Neopentane | C5H12 | From 0.001 to 0.1 inclusive |
| Isopentane | C5H12 | From 0.001 to 5 inclusive |
| n-Pentane | C5H12 | From 0.001 to 5 inclusive |
| Cyclopentane | C5H10 | From 0.001 to 0.1 inclusive |
| C6 hydrocarbons | — | From 0.001 to 1 inclusive |
| C7 hydrocarbons | — | From 0.001 to 0.5 inclusive |
| C8 hydrocarbons | — | From 0.001 to 0.1 inclusive |
| C9 hydrocarbons | — | From 0.001 to 0.05 inclusive |
| C10 hydrocarbons | — | From 0.001 to 0.01 inclusive |
| C6+ hydrocarbons | — | From 0.001 to 2 inclusive |
| C7+ hydrocarbons | — | From 0.001 to 1 inclusive |
| C8+ hydrocarbons | — | From 0.001 to 0.2 inclusive |
| Carbon Dioxide | CO2 | From 0.005 to 15 inclusive |
| Helium | He | From 0.001 to 1 inclusive |
| Hydrogen | H2 | From 0.001 to 1 inclusive |
| Oxygen + Argon | O2 + Ar | From 0.005 to 0.1 inclusive |
| Nitrogen | N2 | From 0.005 to 40 inclusive |
| Hydrogen Sulfide | H2S | From 0.1 to 10 inclusive |
| Methanol | CH3OH | From 0.002 to 0.1 inclusive |
Scope of the Method
GOST R 57975.1-2017 applies to associated petroleum gas generated during the production, treatment, and processing of oil, as well as to other types of gases whose list of components and fractions, and the molar fraction ranges of these components and fractions, correspond to the table above.
The document allows the use of different chromatograph configurations depending on the list of target components, their concentrations, and customer requirements.
In this example, we consider one of the most effective configurations: a 4-channel chromatograph with detectors TCD-TCD-TCD-FID-FID.
Recommended 4-Channel Configuration
Channel 1:
High-sensitivity TCD (carrier gas: argon)
Column: M ss316 1/8'' (type 3), 3 × 2.1, NaX 80/100
Determined components: helium, hydrogen
Channel 2:
TCD (carrier gas: helium)
Column: M ss316 (type 3), 2 × 3, NaX 60/80
Determined components: oxygen + argon, nitrogen
Channel 3:
TCD-FID in series (carrier gas: helium)
Column: M 1/8'' (type 3), 3 × 2.1, HayeSep R 80/100
Determined components: carbon dioxide, ethane, hydrogen sulfide, propane, methanol, C1-C6 hydrocarbons, C6+ hydrocarbons
Channel 4:
FID (carrier gas: helium)
Column: CR-1, 60 m × 0.32 mm × 1.0 µm
Determined components: C1-C10 hydrocarbons
Additional Notes
This configuration is similar to the chromatograph configuration used for natural gas analysis according to GOST 31371.7. In practice, one system is often used for both methods.
All calculations required by GOST R 57975.1 are performed automatically when the corresponding special calculation module (optional feature) is activated.