Enriched acid gas for sulfur recovery

A system of enriching acid gas for feeding a sulfur recovery unit, the system comprising:

• an acid gas stream connector configured to receive an acid gas stream;
• a contactor configured to separate the acid gas stream received from the acid gas stream connector into a carbon dioxide rich stream and a purified acid gas stream, the acid gas stream comprising hydrogen sulfide (H2S), carbon dioxide (CO2), and hydrocarbons;
• a regenerator in fluid communication with the contactor such that the regenerator is configured to separate the purified acid gas stream to create a hydrogen sulfide rich stream and a hydrogen sulfide lean stream, the hydrogen sulfide rich stream having a concentration of hydrogen sulfide;
• a recycle stream conduit fluidly coupled between the regenerator to the contactor and configured to supply at least a portion of the hydrogen sulfide rich stream from the regenerator to the contactor;
• and
• an acid gas recycle valve coupled to the recycle stream conduit that opens and closes a fluid pathway from the regenerator to the contactor based on an H2S content in the hydrogen sulfide rich stream to direct the hydrogen sulfide rich stream exiting the regenerator to combine with the acid gas stream at the acid gas stream connector prior to the combination of the hydrogen sulfide rich stream and the acid gas stream entering the contactor.

A system of enriching acid gas for feeding a sulfur recovery unit, the system comprising:

• an acid gas stream connector configured to receive an acid gas stream;
• a contactor connected to the acid gas stream connector by a conduit, the contactor configured to separate the acid gas stream from the acid gas stream connector into a carbon dioxide rich stream and a purified acid gas stream, the acid gas stream comprising hydrogen sulfide (H2S), carbon dioxide (CO2), and hydrocarbons;
• a regenerator in fluid communication with the contactor, the regenerator configured to separate the purified acid gas stream to create a hydrogen sulfide rich stream and a hydrogen sulfide lean stream, the hydrogen sulfide rich stream having a concentration of hydrogen sulfide;
• a recycle valve positioned in another conduit between the regenerator and the acid gas stream connector to direct the hydrogen sulfide rich stream exiting the regenerator to combine with the acid gas stream at the acid gas stream connector prior to the combination of the hydrogen sulfide rich stream and the acid gas stream entering the contactor;
• and
• a controller configured to operate recycle valve based on an H2S content in the hydrogen sulfide rich stream, wherein the recycle valve, when in an open state, is configured to separate at least a portion of the hydrogen sulfide rich stream exiting from the regenerator and to feed the portion of the hydrogen sulfide rich stream to the contactor, and wherein the recycle valve, when in an closed state, is configured to purge an entire hydrogen sulfide rich stream exiting from the regenerator.