US 11,738,301 B2Granted

Continuous processes and systems to reduce energy requirements of using zeolites for carbon capture under humid conditions

AssigneeCarbon Capture Inc.

InventorsBrian J. Holman, William T. Gross, Andrea Pedretti, Saeb Besarati, Alex Welch, Dan Fang

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Abstract

The direct air capture (DAC) systems and methods efficiently and economically regenerate a desiccant bed without adding any thermal energy and without requiring any pressurization or depressurization of the desiccant reactors. The methods leverage water concentration differences in stream flows, the water concentration profile across a desiccant bed, and, optionally, exothermic water adsorption. These three elements, working in combination, are referred to as “reverse dry flow regeneration” or a “reverse dry air swing” regeneration process. Systems and methods for reverse flow regeneration include those for CO2 DAC applications, but they are also applicable to point source carbon capture and other similar technologies that require initial gas dehydration before exposure to a hydrophilic material.

Claims19

Dependent claims

A direct air capture (DAC) method for separating carbon dioxide (CO2) from ambient air while regenerating a desiccant reactor, the method comprising:

adsorption and desorption of carbon dioxide (CO2) and water,
wherein the adsorption includes:
drawing a first ambient air stream (101) into a direct air capture plant along a first flow path (F1);
receiving the first drawn-in ambient air stream (102) in a portion of a first desiccant reactor (119);
removing humidity from the first drawn-in ambient air stream (102) with the first desiccant reactor (119) to create a first relatively dry inlet gas stream (103);
receiving the first relatively dry inlet gas stream (103) in a first solid sorbent bed (121),
adsorbing remaining humidity and carbon dioxide (CO2) with the first solid sorbent bed (121) to create a first dry outlet gas stream (104);
passing the first dry outlet gas stream (104) through a second desiccant reactor (169);
removing water from the second desiccant reactor (169) as the first dry outlet gas stream (104) reacts with a desiccant in the second desiccant reactor (169);
and
re-adsorbing the removed water into ambient air (140);
and
wherein the desorption includes:
applying a vacuum to a third solid sorbent bed and a fourth solid sorbent bed to remove air from the third solid sorbent bed and from the fourth solid sorbent bed and to remove nitrogen from a solid sorbent in the third solid sorbent bed and in the fourth solid sorbent bed;
and
heating the solid sorbent in the third solid sorbent bed and in the fourth solid sorbent bed to desorb carbon dioxide (CO2) and water.

13 more elements

A direct air capture (DAC) method for separating carbon dioxide (CO2) from ambient air while regenerating desiccant reactors, the method comprising:

separating carbon dioxide (CO2) from ambient air including:
drawing a first ambient air stream (801) into a direct air capture plant along a first flow path (F1),
receiving the first drawn-in humid inlet gas stream (801) in a portion of a first desiccant reactor (883) to create a first relatively dry inlet gas stream (802),
receiving the first relatively dry inlet gas stream (802) in a solid sorbent bed (887), and
adsorbing remaining humidity and carbon dioxide (CO2) in the solid sorbent bed (887) to create a first dry outlet gas stream (803);
regenerating a second desiccant reactor (891) including:
receiving the first dry outlet gas stream (803) in a portion of the second desiccant reactor (891),
removing water from the second desiccant reactor (891) as the first dry outlet gas stream (803) reacts with a desiccant in the second desiccant reactor (891), and
re-adsorbing the removed water into ambient air (804);
drawing a second ambient air stream (811) into the direct air capture plant along a second flow path (F2), wherein the second flow path F2) is in a direction opposite to the first flow path (F1);
receiving the second drawn-in ambient air stream (811) in a portion of the second desiccant reactor (891) to create a second relatively dry inlet gas stream (812);
receiving the second relatively dry inlet gas stream (812) in a second solid sorbent bed (889);
adsorbing remaining humidity and carbon dioxide (CO2) in the second solid sorbent bed (889) to create a second dry outlet gas stream (813);
and
regenerating the first desiccant reactor (883) including:
receiving the second dry outlet gas stream (813) in a portion of the first desiccant reactor (883),
removing water from the first desiccant reactor (883) as the second dry outlet gas stream (813) reacts with a desiccant in the first desiccant reactor (883), and
re-adsorbing the removed water into ambient air (830),
wherein the first flow path (F1) and the second flow path (F2) are continuous adsorption streams that enter the direct air capture plant from opposite directions.

16 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/823,016Filed 29 Aug 2022 · us provisional application
Priority: 29 Aug 2021
Published: US 2023/0073553 A19 Mar 2023
Granted: 29 Aug 2023
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

B01D 53/06
By adsorption, e.g. preparative gas chromatography: with moving adsorbents, e.g. rotating beds
B01D 53/08
With moving adsorbents, e.g. rotating beds: according to the "moving bed" method
B01D 53/0462
With stationary adsorbents: temperature swing adsorption
B01D 53/0476
Pressure swing adsorption: vacuum pressure swing adsorption