Adsorption-membrane-distillation direct air capture systems and methods

A method for capturing carbon dioxide from air, including:

• directing an air stream containing carbon dioxide to a first separation stage;
• concentrating the carbon dioxide in the first separation stage to produce a first enriched stream having a higher carbon dioxide concentration than the air stream;
• directing the first enriched stream to a second separation stage;
• and
• concentrating the carbon dioxide in the second separation stage to produce a second enriched stream having a higher carbon dioxide concentration than the first enriched stream,
• wherein the first separation stage and the second separation stage employ different separation technologies selected from the group consisting of adsorption, membrane separation, and distillation.

A direct air capture system, including:

• an adsorption stage including a rotary adsorber configured to receive an air stream containing carbon dioxide and to produce a first enriched stream having a carbon dioxide concentration higher than the air stream;
• a mechanical vapor recompression system configured to receive a desorbed mixture from the rotary adsorber and to separate water from carbon dioxide;
• a membrane separation stage configured to receive a stream from the mechanical vapor recompression system and to produce a second enriched stream having a higher carbon dioxide concentration than the first enriched stream;
• and
• a distillation stage configured to receive the second enriched stream and to produce liquid carbon dioxide having a higher carbon dioxide concentration than the second enriched stream.