In this unit, various Sulfur compounds present in the feed are adsorbed by one of the molecular sieve beds, and the treated stream, after removal of these compounds, exits the system. Once the adsorption capacity of the bed for Sulfur species is exhausted, the feed is switched to another bed, while the saturated bed enters the regeneration stage. During regeneration, the adsorbed Sulfur compounds and other trapped impurities are released from the bed by reducing the bed pressure and passing hot gas through it. After regeneration and preparation, the bed is returned to the process stream and placed back into service.