Hysweet® Technology: A Major Progress in Sour Gas Processing

Abstract

Removing mercaptans from sour natural gas is becoming an important issue with the global trend towards more stringent specifications for commercial gases. Amines have been extensively used on account of their ability to meet severe H 2 S and CO 2 specifications and very high acid gas selectivity over hydrocarbons. Amines however present very limited mercaptans removal capabilities, an additional treatment step is generally required to achieve a stringent specification of total sulfur specification in the sales gas or upstream liquefaction plant.Total, taking advantage of its extensive know-how and experiences in acid gas removal, has developed the HySWEET ® processes, for simultaneous absorption of acid gases and mercaptans. This technology relies on a new hybrid solvent formulation allowing limited coabsorption of hydrocarbons and improved energy efficiency. The HySWEET ® process has been in operation since 2008, and the entire gas production of the Lacq plant, France is now treated with this new hybrid solvent. The industrial feedback has confirmed not only higher mercaptan removal, but also lower energy consumption when compared to the AdvAmine™ HiLoadDEA process which has allowed for Lacq gas treatment during most of the lifetime of the field.The development of the HySWEET ® DEA process is now completed and ready for commercialization. An optimized design can now be proposed for any application case targeting total CO 2 and H 2 S removal along with a stringent total sulfur specification. Thousands of laboratory measurements (i.e. thermodynamics, kinetics, physical properties) have been used to develop a rigorous simulation tool which relies on rate-based transfer models validated against extensive pilot and operational test-runs.The HySWEET ® MDEA process is under development, for the selective elimination of sulfur compounds over CO 2 . Improved mercaptan removal and high energy efficiency have been demonstrated during pilot tests. These pilot test results will be later used to validate the prediction of the simulation tool currently under development.