Reduced Carbon Footprint Concrete Composition

Abstract

Aspects of the invention include methods of removing carbon dioxide (CO2) from a CO2 containing gas. In some instances, the methods include contacting CO2 containing gas with a bicarbonate buffered aqueous medium under conditions sufficient to produce a bicarbonate rich product. Where desired, the resultant bicarbonate rich product or a component thereof may then be stored or further processed, e.g., combined with a divalent alkaline earth metal cation, under conditions sufficient to produce a solid carbonate composition. Aspects of the invention further include systems for practicing the methods, as well as products produced by the methods.

1 - 54 . (canceled) 
     
     
         55 . A reduced-carbon footprint concrete composition comprising:
 CO 2 -sequestering aggregate that sequesters carbon dioxide (CO 2 ) from a CO 2  containing gas; and   cementitious material,   wherein the reduced-carbon footprint concrete composition has a reduced carbon footprint relative to an ordinary concrete composition.   
     
     
         56 . The reduced-carbon footprint concrete composition according to  claim 55 , wherein the CO 2  containing gas is obtained from an industrial plant. 
     
     
         57 . The reduced-carbon footprint concrete composition of  claim 55 , wherein the CO 2 -sequestering aggregate comprises a solid carbonate composition generated by sequestering CO 2  from the CO 2  containing gas. 
     
     
         58 . The reduced-carbon footprint concrete composition of  claim 57 , wherein the sequestering CO 2  from the CO 2  containing gas comprises:
 contacting the CO 2  containing gas with a bicarbonate buffered aqueous medium to produce a bicarbonate rich product; and   combining the bicarbonate rich product or a component thereof with a cation source to produce a CO 2 -sequestering solid carbonate composition without the use of an additional alkalinity source.   
     
     
         59 . The reduced-carbon footprint concrete composition of  claim 58 , wherein the bicarbonate buffered aqueous medium has a pH ranging from 8 to 10. 
     
     
         60 . The reduced-carbon footprint concrete composition according to  claim 59 , wherein the pCO 2  of the CO 2  containing gas in contact with bicarbonate buffered aqueous medium is 10 3  Pa or higher. 
     
     
         61 . The reduced-carbon footprint concrete composition according to  claim 58 , wherein the CO 2  containing gas is contacted with the aqueous medium in the presence of an LCP promoter. 
     
     
         62 . The reduced-carbon footprint concrete composition according to  claim 58 , wherein the aqueous medium comprises an amine. 
     
     
         63 . The reduced-carbon footprint concrete composition according to  claim 58 , wherein the bicarbonate rich product comprises droplets of a liquid condensed phase (LCP) in a bulk liquid. 
     
     
         64 . The reduced-carbon footprint concrete composition according to  claim 63 , wherein a concentration of bicarbonate anions in the LCP droplets is 10,000 ppm or higher. 
     
     
         65 . The reduced-carbon footprint concrete composition according to  claim 58 , wherein the CO 2  containing gas is contacted with the aqueous medium in the presence of a catalyst that mediates the conversion of CO 2  to bicarbonate. 
     
     
         66 . The reduced-carbon footprint concrete composition according to  claim 58 , wherein the cation source is a source of divalent cations. 
     
     
         67 . The reduced-carbon footprint concrete composition according to  claim 66 , wherein the divalent cations are alkaline earth metal cations. 
     
     
         68 . The reduced-carbon footprint concrete composition according to  claim 67 , wherein the divalent alkaline earth metal cations are selected from the group consisting of Ca 2+  and Mg 2+ , and combinations thereof. 
     
     
         69 . The reduced-carbon footprint concrete composition according to  claim 55 , wherein the CO 2 -sequestering aggregate has a solar reflectance ranging from 25 to 99%. 
     
     
         70 . The reduced-carbon footprint concrete composition according to  claim 55 , wherein the composition further comprises one or more pigments. 
     
     
         71 . The reduced-carbon footprint concrete composition according to  claim 70 , wherein the one or more pigments are CO 2 -sequestering pigments. 
     
     
         72 . The reduced-carbon footprint concrete composition according to  claim 55 , wherein the cementitious material comprises low hydraulic cement. 
     
     
         73 . A reduced-carbon footprint concrete composition produced by a method comprising:
 sequestering carbon dioxide (CO 2 ) from a CO 2  containing gas into CO 2 -sequestering aggregate; and   incorporating the CO 2 -sequestering aggregate into a concrete composition to generate the reduced-carbon footprint concrete composition,   wherein the reduced-carbon footprint concrete composition has a reduced carbon footprint relative to an ordinary concrete composition.