COEI-2-CONGAZ Analyses of gas control by gaseous chromatography

1. Principle

The gases are controlled by chromatography in gaseous phase using a "molecular sieve" type column and detection by catharometer or flame ionisation.

2. Sampling

Either use

• a stainless steel flask for sampling gas
• a Teflon sampling bag for gas.

3. Injection method

Use of a unheated gas valve with a 250 μl ring.

4. Separation of light cases

4.1.    Column (for example)

Phase: Molecular sieve Chromosorb 101, Porapak Q

• diameter of particles  5 μm

• granulometry: 80 to 100 mesh

Dimensions: length: 2 m, internal diameter: 2 mm.

4.2.    Vector Gas

• Helium (He), flow: 3 ml/mn
  3.     Oven temperature: 40°C isotherm
  4.     Detector: Catharometer, Intensity 190 μA

 

5. Separation of light hydrocarbons

5.1.    Column (for example)

Wide bore

Phase: apolar, diameter of particles: 5 μm

Length: 30 m, internal diameter: 0.53 mm

5.2.    Vector gas

Nature: Helium, Flow: 3 ml/mn

Oven temperature 35°C to 200°C  rise: 10°C/mn

5.3.    Detector: Flame ionisation, temperature 220°C.