Systems and methods for recycling fluid streams during fluid purification

A process for fluid purification, the process comprising:

• feeding a first feed stream into a first feed compression unit, wherein the first feed compression unit is configured to compress the first feed stream to a first pressure generating a first compressed feed stream;
• feeding the first compressed feed stream into a hydrogen sulfide removal unit configured to remove a portion of hydrogen sulfide from the first compressed feed stream and to generate a pretreated fluid stream;
• feeding the pretreated fluid stream into a second feed compression unit configured to receive the pretreated fluid stream and to generate a second compressed fluid stream at a second pressure;
• feeding the second compressed fluid stream into a regenerative unit configured to generate a waste gas stream and a treated fluid stream;
• feeding the treated fluid stream into a volatile organic carbons (VOC) polishing bed configured to generate a VOC treated stream;
• feeding the VOC treated stream into one or more membrane separation units configured to generate a methane-rich stream and one or more permeate recycle streams;
• and
• feeding one or more permeate recycle streams via, a flow path, to a position upstream of the VOC polishing bed and downstream of the regenerative unit.

A system comprising:

• a first compression unit configured to receive a feed stream and to compress the feed stream to a first pressure, wherein the first pressure is between 10 and 100 psig;
• a hydrogen sulfide removal unit configured to receive the compressed feed stream and to generate a pretreated fluid stream;
• a second compression unit configured to receive the pretreated fluid stream and to compress the pretreated fluid stream to a second pressure that is greater than the first pressure;
• and
• a regenerative unit configured to receive the pretreated fluid stream compressed to the second pressure and generate a treated fluid stream.

A system, comprising:

• a pretreatment subsystem configured to receive a methane-containing feed stream and generate a compressed pretreated stream based on the methane-containing feed stream;
• a regenerative adsorption subsystem configured to receive the compressed pretreated stream and generate a treated fluid stream based on the compressed pretreated stream;
• a separation subsystem configured to receive the treated fluid stream along a first flow path, and wherein the separation subsystem is configured to generate a permeate recycle stream and a methane-rich fluid based on the treated fluid stream;
• and
• a recycle subsystem configured to receive the permeate recycle stream, wherein the recycle subsystem comprises a second flow path that includes the permeate recycle stream and is directed into the first flow path at a position downstream of the regenerative adsorption subsystem with respect to the first flow path.