Atmospheric steam desorption for direct air capture

A method for separating gaseous carbon dioxide from a gas mixture, containing said gaseous carbon dioxide as well as further gases different from gaseous carbon dioxide by cyclic adsorption/desorption processes, comprising:

• providing a sorbent material capable of adsorbing said gaseous carbon dioxide,
• providing a container containing an adsorber structure with said sorbent material,
• the adsorber structure being heatable to a temperature of at least 60° C. for the desorption of at least said gaseous carbon dioxide and
• the container being openable to flow-through of the gas mixture and for contacting the gas mixture it with the sorbent material for adsorption,
• wherein the method comprises the following sequential and in this sequence repeating steps:
• (a) contacting said gas mixture with the sorbent material to allow at least said gaseous carbon dioxide to adsorb on the sorbent material under ambient atmospheric pressure and ambient atmospheric temperature in an adsorption step, using a speed of an adsorption gas flow;
• (b0) isolating said sorbent material with adsorbed carbon dioxide in said container from flow-through of the gas mixture while maintaining the temperature in the sorbent material;
• (b1) injecting a stream of saturated steam essentially at ambient atmospheric pressure and thereby inducing an increase of the temperature of the sorbent material from ambient atmospheric temperature to a temperature between 60 and 110° C. while pushing out air contained in the container while not yet directing an outflow of said container to product collection,
• (b2-b3) extracting at least the desorbed gaseous carbon dioxide from the container and separating gaseous carbon dioxide from water, including by condensation, in or downstream of the container, while still injecting and/or circulating saturated steam at ambient atmospheric pressure into said container, thereby flushing and purging both steam and CO2 from the container;
• (c) bringing the sorbent material to ambient atmospheric temperature;
• wherein the speed of steam flow through the container in step (b1) and/or on average in steps (b1)-(b3) is in the range of 0.5-10 times the speed of the adsorption gas flow in step (a),
• wherein the gas flow mixture in step (a) flows along a gas flow path having a cross-section, and the injected steam flows along a different gas flow path in steps (b1)-(b3), and the cross-section of the gas flow path of the gas mixture in step (a) is larger than the gas flow path of the steam through said container by a factor of 1.5;
• or wherein the gas flow mixture in step (a) flows along a gas flow path having a cross-section, and the injected steam flows along a different gas flow path in steps (b1)-(b3) through said container.

A method for separating gaseous carbon dioxide from a gas mixture, containing said gaseous carbon dioxide as well as further gases different from gaseous carbon dioxide by cyclic adsorption/desorption processes, comprising:

• providing a sorbent material capable of adsorbing said gaseous carbon dioxide,
• providing a container containing an adsorber structure with said sorbent material,
• the adsorber structure being heatable to a temperature of at least 60° C. for the desorption of at least said gaseous carbon dioxide and
• the container being openable to flow-through of the gas mixture and for contacting the gas mixture with the sorbent material for adsorption,
• wherein the method comprises the following sequential and in this sequence repeating steps:
• (a) contacting said gas mixture with the sorbent material to allow at least said gaseous carbon dioxide to adsorb on the sorbent material under ambient atmospheric pressure and ambient atmospheric temperature in an adsorption step, using a speed of an adsorption gas flow;
• (b0) isolating said sorbent material with adsorbed carbon dioxide in said container from flow-through of the gas mixture while maintaining the temperature in the sorbent material;
• (b1) injecting a stream of saturated steam essentially at ambient atmospheric pressure and thereby inducing an increase of the temperature of the sorbent material from ambient atmospheric temperature to a temperature between 60 and 110° C. while pushing out air contained in the container while not yet directing an outflow of said container to product collection,
• (b2-b3) extracting at least the desorbed gaseous carbon dioxide from the container and separating gaseous carbon dioxide from water, including by condensation, in or downstream of the container, while still injecting and/or circulating saturated steam at ambient atmospheric pressure into said container, thereby flushing and purging both steam and CO2 from the container;
• (c) bringing the sorbent material to ambient atmospheric temperature;
• wherein the speed of steam flow through the container in step (b1) and/or on average in steps (b1)-(b3) is in the range of 0.5-10 times the speed of the adsorption gas flow in step (a),
• wherein the specific steam flow rate of the desorption process in steps (b1)-(b3) is constant.

A method for separating gaseous carbon dioxide from a gas mixture, containing said gaseous carbon dioxide as well as further gases different from gaseous carbon dioxide by cyclic adsorption/desorption processes, comprising:

• providing a sorbent material capable of adsorbing said gaseous carbon dioxide,
• providing a container containing an adsorber structure with said sorbent material,
• the adsorber structure being heatable to a temperature of at least 60° C. for the desorption of at least said gaseous carbon dioxide and
• the container being openable to flow-through of the gas mixture and for contacting the gas mixture it with the sorbent material for adsorption,
• wherein the method comprises the following sequential and in this sequence repeating steps:
• (a) contacting said gas mixture with the sorbent material to allow at least said gaseous carbon dioxide to adsorb on the sorbent material under ambient atmospheric pressure and ambient atmospheric temperature in an adsorption step, using a speed of an adsorption gas flow;
• (b0) isolating said sorbent material with adsorbed carbon dioxide in said container from flow-through of the gas mixture while maintaining the temperature in the sorbent material;
• (b1) injecting a stream of saturated steam essentially at ambient atmospheric pressure and thereby inducing an increase of the temperature of the sorbent material from ambient atmospheric temperature to a temperature between 60 and 110° C. while pushing out air contained in the container while not yet directing an outflow of said container to product collection,
• (b2-b3) extracting at least the desorbed gaseous carbon dioxide from the container and separating gaseous carbon dioxide from water, including by condensation, in or downstream of the container, while still injecting and/or circulating saturated steam at ambient atmospheric pressure into said container, thereby flushing and purging both steam and CO2 from the container;
• (c) bringing the sorbent material to ambient atmospheric temperature;
• wherein the speed of steam flow through the container in step (b1) and/or on average in steps (b1)-(b3) is in the range of 0.5-10 times the speed of the adsorption gas flow in step (a),
• wherein the extraction of carbon dioxide is started when the carbon dioxide concentration at an outlet of a separation device is above 20%
• or the extraction of carbon dioxide is stopped when the carbon dioxide flow at the outlet of the separation device is below 1.2 or 0.7 l/min/kg sorbent material.

A method for separating gaseous carbon dioxide from a gas mixture, containing said gaseous carbon dioxide as well as further gases different from gaseous carbon dioxide by cyclic adsorption/desorption processes, comprising:

• providing a sorbent material capable of adsorbing said gaseous carbon dioxide,
• providing a container containing an adsorber structure with said sorbent material,
• the adsorber structure being heatable to a temperature of at least 60° C. for the desorption of at least said gaseous carbon dioxide and
• the container being openable to flow-through of the gas mixture and for contacting the gas mixture with the sorbent material for adsorption,
• wherein the method comprises the following sequential and in this sequence repeating steps:
• (a) contacting said gas mixture with the sorbent material to allow at least said gaseous carbon dioxide to adsorb on the sorbent material under ambient atmospheric pressure and ambient atmospheric temperature in an adsorption step, using a speed of an adsorption gas flow;
• (b0) isolating said sorbent material with adsorbed carbon dioxide in said container from flow-through of the gas mixture while maintaining the temperature in the sorbent material;
• (b1) injecting a stream of saturated steam essentially at ambient atmospheric pressure and thereby inducing an increase of the temperature of the sorbent material from ambient atmospheric temperature to a temperature between 60 and 110° C. while pushing out air contained in the container while not yet directing an outflow of said container to product collection,
• (b2-b3) extracting at least the desorbed gaseous carbon dioxide from the container and separating gaseous carbon dioxide from water, including by condensation, in or downstream of the container, while still injecting and/or circulating saturated steam at ambient atmospheric pressure into said container, thereby flushing and purging both steam and CO2 from the container;
• (c) bringing the sorbent material to ambient atmospheric temperature;
• wherein the speed of steam flow through the container in step (b1) and/or on average in steps (b1)-(b3) is in the range of 0.5-10 times the speed of the adsorption gas flow in step (a),
• wherein the duration of steps (b1)-(b3), or of steps (b0)-(b3), is less than 6 minutes.

A method for separating gaseous carbon dioxide from a gas mixture, containing said gaseous carbon dioxide as well as further gases different from gaseous carbon dioxide by cyclic adsorption/desorption processes, comprising:

• providing a sorbent material capable of adsorbing said gaseous carbon dioxide,
• providing a container containing an adsorber structure with said sorbent material,
• the adsorber structure being heatable to a temperature of at least 60° C. for the desorption of at least said gaseous carbon dioxide and
• the container being openable to flow-through of the gas mixture and for contacting the gas mixture with the sorbent material for adsorption,
• wherein the method comprises the following sequential and in this sequence repeating steps:
• (a) contacting said gas mixture with the sorbent material to allow at least said gaseous carbon dioxide to adsorb on the sorbent material under ambient atmospheric pressure and ambient atmospheric temperature in an adsorption step, using a speed of an adsorption gas flow;
• (b0) isolating said sorbent material with adsorbed carbon dioxide in said container from flow-through of the gas mixture while maintaining the temperature in the sorbent material;
• (b1) injecting a stream of saturated steam essentially at ambient atmospheric pressure and thereby inducing an increase of the temperature of the sorbent material from ambient atmospheric temperature to a temperature between 60 and 110° C. while pushing out air contained in the container while not yet directing an outflow of said container to product collection,
• (b2-b3) extracting at least the desorbed gaseous carbon dioxide from the container and separating gaseous carbon dioxide from water, including by condensation, in or downstream of the container, while still injecting and/or circulating saturated steam at ambient atmospheric pressure into said container, thereby flushing and purging both steam and CO2 from the container;
• (c) bringing the sorbent material to ambient atmospheric temperature;
• wherein the speed of steam flow through the container in step (b1) and/or on average in steps (b1)-(b3) is in the range of 0.5-10 times the speed of the adsorption gas flow in step (a)
• using at least at least 8 containers each containing an adsorber structure with said sorbent material, the adsorber structure being heatable to a temperature of at least 60° C. for the desorption of at least said gaseous carbon dioxide and the containers being openable to flow-through of the gas mixture and for contacting it-the gas mixture with the sorbent material for an adsorption step,
• wherein the operation of the containers is synchronised in that there is at least one step for each container in one cycle of a set of containers, wherein the flow of steam and desorbate exiting a first one of the containers in at least one of steps (b1)-(b3) is not directly fed to a steam or water/carbon dioxide separation device including a condenser but is first passing at least one further container downstream of said first one of the containers.