Standard Test Method for Determination of Hydrogen Sulfide (H2S) in Natural Gas by Tunable Diode Laser Spectroscopy (TDLAS)

Importancia y uso:

5.1 H₂S measurements in natural gas are performed to ensure concentrations satisfy gas purchase contract criteria and to prevent pipeline and associated component corrosion.

5.2 Using TDLAS for the measurement of H₂S in natural gas enables a high degree of selectivity with minimal interference from common constituents in natural gas streams. The TDLAS analyzer can detect changes in concentration with a relatively rapid response compared to other methods so that operators may take swift action when designated H₂S concentrations are exceeded.

5.3 Primary applications covered in this test method are listed in 5.3.1 and 5.3.2. Each application may have differing requirements and methods for gas sampling. Additionally, different natural gas applications may require unique spectroscopic considerations.

5.3.1 Raw natural gas is found in production, gathering sites, and inlets to gas-processing plants characterized by potentially high levels of water (H₂O), carbon dioxide (CO₂), H₂S, and heavy hydrocarbons. Gas-conditioning plants and skids are normally used to remove H₂O, CO₂, H₂S, and other contaminants.

5.3.2 High-quality “sales gas” is found in transportation pipelines, natural gas distribution (utilities), and natural gas power plant inlets. The gas is characterized by a very high percentage of methane (90 to 100 %) with small quantities of other hydrocarbons and trace levels of contaminants.

Subcomité:

D03.12

Volúmen:

05.06

Número ICS:

75.060 (Natural gas)

Palabras clave:

hydrogen sulfide; H2S; natural gas; TDL; TDLAS; tunable diode laser absorption spectroscopy;