Trace H2S analysis in complex gas mixtures

Hydrogen  sulphide  (H2S)  is  a  very  flammable,  corrosive  and  toxic  gas,  with  a characteristic  odour  of  rotten  eggs. Even when present  at  low  trace-level  concentrations, H2S can  damage  equipment,  pipelines  and  lead  to catalyst poisoning. Therefore, it must be carefully monitored and controlled in industrial processes where it is generated or used.

Chromatotec®’s H2S MEDOR analyser measures H2S  in  gas  samples  at  trace-level  concentration  ranges  (0-1ppm). It  consists  of an  automatic  process  gas  chromatograph  (autoGC)  equipped  with  a sulphur  specific electrochemical wet cell detector (ED) which only reacts with sulphur compounds and provides excellent results down  to  1ppb.  All  compounds  have  a  linear  response  with  the  ED,  with  R2>  0.995.  Moreover,  theMEDOR® detectoris not affected by the moisture in the sample, which can be up to 100% relative humidity.

The H2S MEDOR   is   available   with   a dedicated   configuration   for   safe   and   hazardous   areas   (ATEX,   IECEx,   CSA   and   CSA international  certifications)  including  an  integrated  N2 generator.  Its  simplicity  for  online  application  in refineries  and  petrochemical  plants  is  achieved  thanks  to  its  flameless  detector for which no  hydrogen  is  required.  Specially designed for on-field deployment, this standalone solution includes a built-in nitrogen generator and a  touch  screen display  behind  the  front  door  of the wall-mounted  cabinet.  It  is  temperature controlled  for  outdoor installation to provide the best performance for operation from -10 to +55°C.

The versatile and robust H2S MEDOR analyser has been used for H2S measurement in a recycle gas stream composed of up to 60% of H2 as well as in reactor’s effluent gas with very high concentrations of COS (5000 ppm).

The  H2S  MEDOR  is  a  reliable,  simple  and  robust  turnkey  solution.  It  is  fully  autonomous  thanks  to its integrated gas generators which avoid the need for gas cylinders and embedded, internal calibration for automatic data validation. Moreover, this process analyser is designed to have very low maintenance requirements.