Measuring H2S in Sour Gas / Sulfur Recovery Unit (SRU)

Application Summary

Analysis Point Analyte Typ. Range Suitable Analyzer
Sour Gas (SRU) H2S 0-100% H2S OMA-300 Process Analyzer


H2S is an extremely dangerous chemical which occurs naturally in fossil fuels and is removed through refining processes. Gas that contains significant amounts of H2S is considered “sour gas” due to the foul aroma from H2S and other sulfur containing compounds.

The primary process for removing H2S from sour natural gas, sour water stripper gas and hydrotreater gas is the amine treatment process in a Sulfur Recovery Unit (SRU). The sour gas is run through an absorption tower containing an aqueous amine solution. The amine selectively absorbs the H2S from the gas stream, which results in a treated “sweet gas”. To achieve efficient control of the amine unit cycle time, the operator must know the concentration of the H2S in the sour gas.

The OMA-300 Process Analyzer can be implemented in this process to provide H2S measurements in the incoming sour gas stream. The OMA-300 Process Analyzer continuously outputs H2S readings, providing new measurements every 5 seconds. Response time is critical in the amine treatment unit in order to keep it running as efficiently as possible.

System Benefits

  • Continuously measures H2S level in sour feed gas stream using UV-Vis spectrophotometer
  • Totally solid-state build with no moving parts — modern design for low maintenance
  • Additional software benches for up to 4 chemical analytes
  • Ultra-safe fiber optic design with no sample gas inside analyzer unit — world’s safest solution for this application

Schematic of Amine Unit

In the diagram below, the sour gas analysis point is identified by AT1.

Sulfur Recovery Unit Feed Forward Analysis--Flow-Diagram-SRU

The specifications below represent performance of the OMA-300 Process Analyzer in a typical sour gas application.

For technical details about the OMA-300 Process Analyzer, see the data sheet:
DS-001A: OMA-300 Process Analyzer

All performance specifications are subject to the assumption that the sample conditioning system and unit installation are approved by Applied Analytics. For any other arrangement, please inquire directly with Sales.

Application Data
Performance Specifications
Accuracy Custom measurement ranges available; example ranges below.
OMA-300(UV-Vis) H2S 0-100%: ±1% full scale
*Whichever is larger

Note: Subject to modifications. Specified product characteristics and technical data do not serve as guarantee declarations.

Further Reading