Method of adsorptive gas separation using thermally conductive contactor structure
A method of adsorption allows separation of a first fluid component from a fluid mixture comprising at least the first fluid component in an adsorptive separation system having a parallel passage adsorbent contactor with parallel flow passages having cell walls which include an adsorbent material. The method provides for transferring heat from the heat of adsorption in a countercurrent direction along at least a portion of the contactor during adsorption and transferring heat in either axial direction along the contactor and/or a direction transverse to the axial direction, to provide at least a portion of the heat of desorption during a desorption step. A carbon dioxide separation process to separate carbon dioxide from flue gas also includes steps transferring heat from adsorption or for desorption along the parallel passage adsorbent contactor.
1. An adsorption method for separating a fluid mixture comprising at least first and second fluid components, the method comprising:
(a) admitting said fluid mixture into a parallel passage adsorbent contactor comprising an inlet end, an outlet end, and an adsorbent material, to flow from said inlet end to said outlet end;
(b) adsorbing at least a portion of said first fluid component on said adsorbent material, releasing a heat of adsorption, and causing a thermal front to flow towards said outlet end;
(c) recovering a first product fluid depleted in said first fluid component relative to said fluid mixture from said outlet end of said parallel passage adsorbent contactor;
(d) terminating admission of said fluid mixture into said inlet end of said parallel passage adsorbent contactor;
(e) desorbing at least a portion of said first fluid component adsorbed on at least one said adsorbent material by heating said adsorbent material; and
(f) recovering a desorbed second product fluid enriched in said first fluid component from at least one of said inlet end and said outlet end of said parallel passage adsorbent contactor.
2. The method of claim 1 , wherein said step of terminating admission of said fluid mixture into said inlet end of said parallel passage adsorbent contactor occurs when said thermal front is within said parallel passage adsorbent contactor.
3. The method of claim 1 or 2 , comprising during step (e), admitting a purge fluid into said outlet end of said parallel passage adsorbent contactor to flow towards said inlet end of said parallel passage adsorbent contactor.
4. The method of claim 3 , wherein said heating of said adsorbent material is provided by said purge fluid.
5. The method of claim 4 , wherein said purge fluid is condensable, and additionally comprising condensing said purge fluid out of said desorbed second product fluid following step (f).
6. The method of claim 1 , 2 or 3 , comprising, during step (e), transferring said heat of adsorption and/or thermal front along said parallel passage adsorbent contactor towards said inlet end to provide at least a portion of a heat of desorption for desorbing said first fluid component from said adsorbent material.
7. The method of claim 1 , wherein said fluid mixture is a flue gas or a natural gas and said first component is carbon dioxide.