Compositions for carbon dioxide separation using steam regeneration, and method for preparing same

Abstract

Compositions and methods of preparing the compositions are disclosed for sorbents and other surfaces that can adsorb and desorb carbon dioxide. A sorbent or surface can include a metal compound such as an alkali or alkaline earth compound and a support. The sorbent can be prepared by several methods, including an incipient wetness technique. The sorbents have a CO 2 adsorption and desorption profile. A sorbent having high levels of a metal compound and adsorbed CO 2 is disclosed.

We claim: 
     
         1 . A CO 2  adsorption sorbent comprising a support and a metal compound selected from the group consisting of alkali and alkaline earth. 
     
     
         2 . The CO 2  adsorption sorbent of  claim 1 , wherein the sorbent consists essentially of the support and the metal compound, and any associated counterions. 
     
     
         3 . The CO 2  adsorption sorbent of  claim 1 , A wherein the sorbent consists of the support and the metal compound, and any associated counterions. 
     
     
         4 . The CO 2  adsorption sorbent of  claim 1 , wherein the metal compound is at least 5 wt % of the sorbent. 
     
     
         5 . The CO 2  adsorption sorbent of  claim 1 , wherein the metal compound is at least 7 wt % of the sorbent. 
     
     
         6 . The CO 2  adsorption sorbent of  claim 1 , wherein the metal compound comprises Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, or Ba, or a combination thereof. 
     
     
         7 . The CO 2  adsorption sorbent of  claim 1 , wherein the metal compound comprises Li, Na, K, Mg, or Ca, or a combination thereof. 
     
     
         8 . The CO 2  adsorption sorbent of  claim 1 , wherein the metal compound comprises Na or K. 
     
     
         9 . An adsorption-desorption sorbent comprising a metal compound and a support, wherein the sorbent has
 a carbon dioxide capacity of at least about 0.5 wt %,   a water capacity of at least about 1 wt %, and   a water/carbon dioxide selectivity that varies with the relative concentration of the two sorbates in the environment above the sorbent.   
     
     
         10 . The sorbent of  claim 9 , wherein the sorbent has a carbon dioxide capacity of at least 0.7 wt %. 
     
     
         11 . The sorbent of  claim 9 , wherein the sorbent has a carbon dioxide capacity of at least 1.0 wt %. 
     
     
         12 . The sorbent of  claim 9 , wherein the sorbent has a water capacity of at least 1.5 wt %. 
     
     
         13 . The sorbent of  claim 9 , wherein the sorbent has a water capacity of at least about 2 wt %. 
     
     
         14 . A CO 2  adsorption sorbent comprising
 a support;   a metal compound comprising Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, or Ba, or a combination thereof; and   adsorbed carbon dioxide,   
       wherein the metal compound is at least 5 wt % of the sorbent, and the adsorbed carbon dioxide is at least 0.7 wt %. 
     
     
         15 . The CO 2  adsorption sorbent of  claim 14 , wherein the metal compound is at least 7 wt % of the sorbent. 
     
     
         16 . The CO 2  adsorption sorbent of  claim 14 , wherein the metal compound is at least 10 wt % of the sorbent. 
     
     
         17 . The CO 2  adsorption sorbent of  claim 14 , wherein the metal compound comprises Li, Na, K, Mg, or Ca, or a combination thereof. 
     
     
         18 . The CO 2  adsorption sorbent of  claim 14 , wherein the metal compound comprises Na or K. 
     
     
         19 . The CO 2  adsorption sorbent of  claim 14 , wherein the adsorbed carbon dioxide is at least 1.0 wt %. 
     
     
         20 . The CO 2  adsorption sorbent of  claim 14 , wherein the adsorbed carbon dioxide is at least 1.5 wt %.