Methods of sequestering co2

Abstract

Methods of sequestering carbon dioxide (CO 2 ) are provided. Aspects of the methods include precipitating a storage stable carbon dioxide sequestering product from an alkaline-earth-metal-containing water and then disposing of the product, e.g., by placing the product in a disposal location or using the product as a component of a manufactured composition. Also provided are systems for practicing methods of the invention.

1 - 20 . (canceled) 
     
     
         21 . A method of making artificial reef structure, comprising:
 treating at least a portion of flue gas from an industrial plant, wherein said flue gas comprises carbon dioxide, with a proton removing agent to produce a solution comprising carbonate ions;   treating said solution with alkaline-earth-metal-ions to produce a precipitate comprising carbonate wherein said carbonate comprises metastable carbonate; and   using said precipitate to make artificial reef structure.   
     
     
         22 . The method of  claim 21 , further comprising dewatering said precipitate to produce a slurry comprising said precipitate. 
     
     
         23 . The method of  claim 22 , further comprising pouring said slurry into a mold and allowing said slurry to solidify into the shape of the mold. 
     
     
         24 . The method of  claim 23 , further comprising depositing said mold in a suitable ocean location to produce an artificial reef. 
     
     
         25 . The method of  claim 21 , wherein said precipitate comprises calcium carbonate, magnesium carbonate, calcium magnesium carbonate, or combination thereof. 
     
     
         26 . The method of  claim 21 , wherein said precipitate comprises strontium in an amount ranging from 3 to 10,000 ppm. 
     
     
         27 . The method of  claim 21 , wherein said alkaline-earth-metal-ions comprise saltwater or fresh water. 
     
     
         28 . The method of  claim 27 , wherein said saltwater is brackish water, sea water, or brine. 
     
     
         29 . The method of  claim 21 , wherein said alkaline-earth-metal-ions are obtained from a mineral selected from the group consisting of serpentine, olivine, and combination thereof. 
     
     
         30 . The method of  claim 21 , wherein said alkaline-earth-metal-ions comprise calcium ions, magnesium ions, silica ions, or combination thereof. 
     
     
         31 . The method of  claim 21 , wherein said solution further comprises bicarbonate ions. 
     
     
         32 . The method of  claim 21 , wherein said proton removing agent raises a pH of said solution to 9.5 or higher. 
     
     
         33 . The method of  claim 21 , wherein said proton removing agent is selected from the group consisting of oxide, hydroxide, carbonate, mineral, ash, natural body of alkaline water, slag, and combination thereof. 
     
     
         34 . The method of  claim 33 , wherein said hydroxide is made using an electrochemical process. 
     
     
         35 . The method of  claim 21 , wherein said industrial plant is selected from the group consisting of power plants, chemical processing plants, mechanical processing plants, refineries, cement plants, steel plants, other industrial plants that produce CO 2  as a byproduct of fuel combustion or other processing step, and combination thereof. 
     
     
         36 . The method of  claim 21 , wherein said artificial reef structure has a negative carbon footprint. 
     
     
         37 . The method of  claim 21 , wherein about 10 to 100% of the carbon present in the artificial reef structure is from the carbon dioxide source. 
     
     
         38 . The method of  claim 21 , wherein said metastable carbonate comprises vaterite. 
     
     
         39 . The method of  claim 21 , wherein said precipitate is dried before making the artificial reef structure. 
     
     
         40 . An artificial reef structure formed by the method of  claim 21 .