Method for capture of carbon dioxide from ambient air and corresponding adsorber structures with a plurality of parallel surfaces

A method for separating gaseous carbon dioxide from ambient atmospheric air containing said gaseous carbon dioxide as well as further gases different from gaseous carbon dioxide,

• by cyclic adsorption/desorption using at least one sorbent material adsorbing said gaseous carbon dioxide,
• using a unit containing an adsorber structure with said at least one sorbent material,
• the adsorber structure being able to sustain a temperature of at least 60° C. for the desorption of at least said gaseous carbon dioxide and the unit being openable to flow-through of the ambient atmospheric air and for contacting it with the at least one sorbent material for the adsorption step,
• wherein the adsorber structure comprises an array of individual adsorber elements,
• each adsorber element comprising at least one support layer and at least one sorbent layer comprising the at least one sorbent material,
• where said at least one sorbent material offers selective adsorption of CO2 over other major non-condensable gases in air in the presence of moisture or water vapor, wherein the adsorber elements in the array are arranged essentially parallel to each other and spaced apart from each other forming parallel fluid passages for flow-through of at least one of ambient atmospheric air and steam,
• wherein the method comprises at least the following sequential and in this sequence repeating steps (a)-(e):
• (a) contacting said ambient atmospheric air with the at least one sorbent material to allow at least said gaseous carbon dioxide to adsorb on the at least one sorbent material by flow-through through said parallel fluid passages under ambient atmospheric pressure conditions and ambient atmospheric temperature conditions in an adsorption step;
• (b) isolating said at least one sorbent material with adsorbed carbon dioxide in said unit from said flow-through while maintaining the temperature in the at least one sorbent material;
• (c) injecting a stream of saturated or superheated steam by flow-through through said parallel fluid passages and thereby inducing an increase of the temperature of the at least one sorbent material to a temperature between 6° and 110° C., starting the desorption of CO2;
• (d) extracting at least the desorbed gaseous carbon dioxide from the unit and separating gaseous carbon dioxide from steam by condensation in or downstream of the unit, while still contacting the at least one sorbent material with steam by injecting and/or partial circulating saturated or superheated steam into said unit, thereby flushing and purging both steam and CO2 from the unit at a molar ratio of steam to carbon dioxide between 4:1 and 40:1, while regulating at least one of the extraction and the steam supply to essentially maintain the temperature in the at least one sorbent material at the end of the preceding step (c) or to essentially maintain the pressure in the at least one sorbent material at the end of the preceding step (c), or both;
• (e) bringing the at least one sorbent material to ambient atmospheric temperature conditions;
• wherein in step (a) the flow speed of the ambient atmospheric air through the adsorber structure is in the range of 2-9 m/s, and
• wherein at least in step (d) the flow speed of the steam through the adsorber structure is at least 0.2 m/s,
• wherein essentially exclusive use or fully exclusive use of steam is made in steps (c) and (d) for the delivery of heating energy during the desorption process.