@GC-PFPD Analysis of Sulfur Impurities in Natural Gas

The liquefied gas sample is kept under constant pressure by means of the Pressure Station. After vaporising the sample with a heated vaporizer, a gas sampling valve is filled. To ensure a stable (atmospheric) pressure inside the loop, after the GSV loop is sufficiently flushed, the flow is manually stopped using the pressure station. Next the GC method and data acquisition are started by pressing the start button on the manual interface. The GSV is switched in flow with the total flow line, transporting the volume of the loop to the split inlet. In the inlet, the sample is transferred onto an analytical column. The column separates compounds based on their boiling points. After eluting from the column sulfur containing compounds are detected by the PFPD detector.

@Applications & Benefits

The analyzer complies with ISO 19739 and has a detection range for 

sulfur compounds from 20 to 20 000 picograms (pg) of sulfur. This is equivalent to 0.02 to 20 mg/m3 or 0.014 to 14 ppmv of sulfur based upon the analysis of a 1-mL sample.

@Configuration & Options

The Sulfur analyzer is based on an Agilent Gas Chromatograph configured with:

- Pulsed Flame Photometric Detector (PFPD)

- Inert Split/Splitless injection port to accommodate (liquefied) gases

- Capillary column

- Hastelloy Gas Sampling Valve

- DVLS Liquefied Gas Injector, LGI (optional)

- DVLS Pressure Station (optional)

- Agilent Autoinjector (optional)

- AlyTech Gasmix (optional)

The Agilent GC is controlled by Agilent OpenLab EZChrom or Chemstation software. The OpenLAB software is used for instrument control, data acquisition, peak integration and calibration.