Publications

Many sources of natural gas contain varying amounts and types of sulphur compounds. These compounds are odorous, corrosive to equipment, and can inhibit or destroy catalysts employed in gas processing. They andor their combustion products (SO2 and S03) are also toxic.The concentration of sulphur compounds in natural gas differs depending on the origin of the natural gas. Even traces of sulphur compounds in natural gas must be monitored. Hydrogen sulphide in the presence of water causes corrosion problems, and it may cause sulphide stress cracking even at very low concentrations.The quantitative determination of the sulphur content of natural gas concentration is thus essential. Several methods can be used for detecting sulphur in natural gas, differing in the concentration range in which they are effective. Methods published by the International Organization for Standardization (ISO) and American Society for Testing Materials (ASTM) are widely used, and both are improved techniques based on gas chromatography. These methods provide sufficient separation of all sulphur compounds, but they still have problems especially with trace concentrations.Because of the reactivity of the sulphur compounds, several factors should be considered to get the required accuracy in analyses: (1) sampling methods and containers are important, (2) separation efficiency depends on performance of the preconcentration step and (3) characteristics of the detection system.Careful attention to these factors will improve the accuracy and precision of analysis for sulphur compounds.