Process for accelerated capture of carbon dioxide

Abstract

The present invention generally relates to the removal of carbon dioxide from a gas stream, particularly a flue gas, hydrogen gas from a reformer, natural gas, or gas from a cement kiln. Immobilized enzymes for use in carbon capture and other systems are also disclosed.

1 - 20 . (canceled) 
     
     
         21 . A process for removing CO 2  from a CO 2 -containing gas, the process comprising
 contacting an aqueous liquid with a CO 2 -containing gas to promote diffusion of the CO 2  into the aqueous liquid; and contacting the CO 2  in the aqueous liquid with immobilized carbonic anhydrase entrapped in the pores of a polymeric immobilization material to catalyze hydration of the CO 2  and form a treated liquid containing hydrogen ions and bicarbonate ions; wherein the polymeric immobilization material stabilizes the carbonic anhydrase and wherein the carbonic anhydrase retains at least about 15% of its initial catalytic activity for at least about 5 days when continuously catalyzing a chemical transformation at a temperature from about 30° C. to about 100° C.;   wherein the treated liquid is further contacted with particles coated with immobilized carbonic anhydrase entrapped in a polymeric immobilization material, wherein the carbonic anhydrase catalyzes conversion of the hydrogen ions and the bicarbonate ions into concentrated CO 2  and water.   
     
     
         22 . The process of  claim 21  wherein the aqueous liquid and CO 2 -containing gas are contacted in a co-current configuration. 
     
     
         23 . The process of  claim 21  wherein the process is performed in a reaction vessel which comprises a bottom portion including a gas inlet and a liquid outlet, a top portion including a liquid inlet and a gas outlet, and a middle portion containing a plurality of particles comprising immobilized carbonic anhydrase or coated with immobilized carbonic anhydrase entrapped in the polymeric immobilization material; the process comprising contacting an aqueous liquid which enters the liquid inlet and flows downward in the reaction vessel with a CO 2 -containing gas which enters the gas inlet and flows upward in the reaction vessel to promote diffusion of the CO 2  into the aqueous liquid and catalyze hydration of the CO 2  in the aqueous liquid in the presence of the immobilized carbonic anhydrase to form a treated liquid containing hydrogen ions and bicarbonate ions and a treated gas; evacuating the treated liquid from the liquid outlet and evacuating the treated gas from the gas outlet. 
     
     
         24 . The process of  claim 23  wherein the CO 2 -containing gas enters the gas inlet in the form of microbubbles. 
     
     
         25 . The process of  claim 21  wherein the aqueous liquid comprises a base. 
     
     
         26 . The process of  claim 25  wherein the base is a metal hydroxide, a quaternary ammonium hydroxide, a metal carbonate, a conjugate base of a weak acid, a quaternary ammonium carbonate, a quaternary ammonium alkoxide, a metal amide, a metal alkyl, a metal alkoxide, metal silanoate, an amine, an alkanolamine, or a combination thereof. 
     
     
         27 . The process of  claim 21  wherein the immobilization material entraps the carbonic anhydrase, the immobilization material being permeable to a compound smaller than the carbonic anhydrase and having the structure of either Formulae 5, 6, 7, or 8: 
       
         
           
           
               
               
           
         
       
       wherein
 R 21  and R 22  are independently hydrogen, alkyl, or substituted alkyl, provided that the average number of alkyl or substituted alkyl groups per repeat unit is at least 0.1; 
 R 23  and R 24  are independently hydrogen, alkyl, or substituted alkyl, provided that the average number of alkyl or substituted alkyl groups per repeat unit is at least 0.1; 
 R 25  is hydrogen, alkyl, or substituted alkyl, provided that the average number of alkyl or substituted alkyl groups per repeat unit is at least 0.1; 
 R 32  and R 33  are independently hydrogen, alkyl, aryl, or substituted alkyl, provided that the average number of alkyl or substituted alkyl groups per repeat unit is at least 0.1 and 
 m, n, o, and p are integers of at least 10. 
 
     
     
         28 . The process of  claim 27  wherein the immobilization material has a structure of Formula 8. 
     
     
         29 . The process of  claim 28  wherein R 32  and R 33  are independently hydrogen, alkyl, aryl, -(substituted alkylene)-acid or a salt thereof, -(substituted alkylene)-base or a salt thereof, —(CH 2 ) q O—(CH 2 —CH 2 —O) z —R t , —CH 2 —O—(CH(CH 3 )—CH 2 —O) z —R t , or a combination thereof, wherein z is an integer corresponding to a weight average molecular weight of about 150 Da to about 8000 Da, R t  is hydrogen, alkyl, substituted alkyl, aryl, or substituted aryl, and q is an integer of 2, 3, or 4. 
     
     
         30 . The process of  claim 29  wherein the acid group comprises a carboxylic, a phosphonic, a phosphoric, a sulfonic, a sulfuric, a sulfamate, a salt thereof, or a combination thereof. 
     
     
         31 . The process of  claim 29  wherein the base comprises a tertiary amine, a quaternary amine, a nitrogen heterocycle, a salt thereof, or a combination thereof. 
     
     
         32 . The process of  claim 28  wherein R 32  and R 33  are independently hydrogen, alkyl, aryl, —(CH 2 ) 3 —O—((CH 2 ) 2 —O) z —CH 3 , —(CH 2 ) 2 —C(O)—O—(CH 2 ) 2 -imidazolium, or —(CH 2 ) 3 —O—CH 2 —CH(OH)—N(CH 3 )—(CH 2 ) 2 —SO 3 Na and z is an integer corresponding to a weight average molecular weight of about 150 Da to about 8000 Da. 
     
     
         33 . The process of  claim 21  using a system for removing CO 2  from a CO 2 -containing gas comprising a reaction vessel having a bottom portion containing a gas inlet and a liquid outlet, a top portion containing a liquid inlet and a gas outlet, and a middle portion containing a plurality of particles comprising immobilized carbonic anhydrase or coated with immobilized carbonic anhydrase entrapped in the polymeric immobilization material, the carbonic anhydrase being capable of catalyzing hydration of CO 2  into hydrogen ions and bicarbonate ions, wherein the polymeric immobilization material stabilizes the carbonic anhydrase and comprises a micellar or inverted micellar material. 
     
     
         34 . The process of  claim 21  wherein the carbonic anhydrase retains at least about 45% of its initial catalytic activity for at least about 5 days when continuously catalyzing a chemical transformation at a temperature from about 30° C. to about 100° C. 
     
     
         35 . The process of  claim 21  wherein the carbonic anhydrase retains at least about 60% of its initial catalytic activity for at least about 5 days when continuously catalyzing a chemical transformation at a temperature from about 30° C. to about 100° C. 
     
     
         36 . The process of  claim 21  wherein the carbonic anhydrase retains at least about 75% of its initial catalytic activity for at least about 5 days when continuously catalyzing a chemical transformation at a temperature from about 30° C. to about 100° C. 
     
     
         37 . The process of  claim 21  wherein the carbonic anhydrase retains at least about 50% of its initial catalytic activity for at least about 10 days when continuously catalyzing a chemical transformation at a temperature from about 30° C. to about 100° C. 
     
     
         38 . The process for removing CO 2  from a CO 2 -containing gas of  claim 33  further comprising a second reaction vessel, the second reaction vessel containing particles coated with immobilized carbonic anhydrase entrapped in a polymeric immobilization material wherein the carbonic anhydrase is capable of catalyzing conversion of the hydrogen ions and the bicarbonate ions into concentrated CO 2  and water. 
     
     
         39 . The process of  claim 38  wherein the second reaction vessel contains an immobilization material comprising a micellar or inverted micellar material. 
     
     
         40 . The process of  claim 38  wherein the polymeric immobilization material stabilizes the carbonic anhydrase and wherein the carbonic anhydrase retains at least about 15% of its initial catalytic activity for at least about 5 days when continuously catalyzing a chemical transformation at a temperature from about 30° C. to about 100° C.