Various embodiments disclosed relate to extraction of target materials using a CZTS sorbent. A method of extracting a target material from a medium includes contacting a copper zinc tin sulfur (CZTS) sorbent with the target material in the medium including the target material to form a used CZTS sorbent that includes the target material.

A portable gas separator assembly utilizing carbon molecular sieve absorbents or elements to separate a compressed air stream to extract nitrogen and oxygen molecules. Components of the assembly include at least two charging towers so that one tower can be charged with compressed gas while the other of the at least two towers is purged.

A portable gas separator assembly utilizing carbon molecular sieve absorbents or elements to separate a compressed air stream to extract nitrogen and oxygen molecules. Components of the assembly include at least two charging towers so that one tower can be charged with compressed gas while the other of the at least two towers is purged.

Systems and/or methods are provided for the capture of carbon dioxide from flue gas generated within a building.

Systems and/or methods are provided for the capture of carbon dioxide from flue gas generated within a building.

Nitrogen is removed from biogas using a three-stage separation system based on gas separation membranes. The first stage separates a biomethane feed stream into a first permeate gas stream and a first retentate gas stream. The second stage separates the first permeate stream into a biomethane product gas and a first low quality biomethane gas stream. The third stage separates the first retentate into a second low quality biomethane gas stream and a waste gas. A biogas feed stream is pretreated to remove amounts of water, VOCs, and CO.sub.2 to yield a methane-enriched biogas stream. The methane-enriched biogas stream is compressed together with the first and second low quality biomethane gas streams to form the biomethane feed stream.

Nitrogen is removed from biogas using a three-stage separation system based on gas separation membranes. The first stage separates a biomethane feed stream into a first permeate gas stream and a first retentate gas stream. The second stage separates the first permeate stream into a biomethane product gas and a first low quality biomethane gas stream. The third stage separates the first retentate into a second low quality biomethane gas stream and a waste gas. A biogas feed stream is pretreated to remove amounts of water, VOCs, and CO.sub.2 to yield a methane-enriched biogas stream. The methane-enriched biogas stream is compressed together with the first and second low quality biomethane gas streams to form the biomethane feed stream.

A method for providing renewable natural gas (RNG) includes removing hydrogen sulfide and/or carbon dioxide from biogas to provide partially purified biogas, which may be stored in a mobile storage tank. The partially purified biogas is transported to a biogas upgrading facility, at least partially by truck, rail, or ship. At the biogas upgrading facility, the partially purified biogas is further purified to provide the RNG, which can be injected into a distribution system (e.g., natural gas grid) and/or provided for use in transportation.

A process for cooling quench effluent includes providing a quench column effluent to a quench column aftercooler condensate; cooling the quench column effluent to provide a quench column aftercooler condensate; and recirculating at least a portion of the quench column aftercooler condensate to the quench column aftercooler at a rate to prevent fouling of the quench column aftercooler.

A process for cooling quench effluent includes providing a quench column effluent to a quench column aftercooler condensate; cooling the quench column effluent to provide a quench column aftercooler condensate; and recirculating at least a portion of the quench column aftercooler condensate to the quench column aftercooler at a rate to prevent fouling of the quench column aftercooler.