Gas Processors Association Europe

Torsten Katz, Volker Giesen – BASF gas Treatment Group, Germany

Parallel to the necessity for safe operations, the removal of trace sulfur components, such as mercaptans or carbonyl sulphide (COS), is a major challenge in designing the gas conditioning process. The pros and cons of several design options for deep COS removal are discussed in a case study, where the results of a hybrid solvent are compared with the performance of a BASF solvent.  These are compared to measurements from an operating plant. In a water-saturated reservoir, hydrogen sulphide (H2S) and carbon dioxide (CO2) are in thermodynamic equilibrium with COS. Thus a concentration of up to several hundred ppmv COS in the feed gas is not unusual.