Method for reducing energy and water demands of scrubbing co2 from co2-lean waste gases

Abstract

Methods and systems for reducing greenhouse gas emissions, including producing a waste gas stream comprising form greater than 0 vol % to less than 20 vol %, inclusive, carbon dioxide, pre-concentrating the waste gas stream to increase a concentration of carbon dioxide, producing a concentrated byproduct stream comprising more than 40 vol %, dissolving carbon dioxide contained in the concentrated byproduct stream in water, producing a dissolved byproduct stream and an undissolved byproduct stream, injecting the dissolved byproduct stream or a portion thereof into a reservoir containing mafic rock, and allowing components of the dissolved byproduct stream to react in situ with components of the mafic rock to precipitate and store components of the byproduct stream in the reservoir.

1 .- 11 . (canceled) 
     
     
         12 . A system for reducing greenhouse gas emissions, the system comprising:
 a facility configured to produce a waste gas stream comprising from greater than 0 vol % to less than 40 vol % carbon dioxide;   a pre-concentrator configured for increasing a concentration of carbon dioxide in the waste gas stream, producing a concentrated byproduct stream;   a water dissolution system configured for dissolving the carbon dioxide in water, producing a dissolved byproduct stream and an undissolved byproduct stream; and   an injection well operable to inject the dissolved byproduct stream into a reservoir containing mafic or ultramafic rock to allow components of the concentrated byproduct stream to react in situ with components of the mafic rock to precipitate and store components of the byproduct stream in the reservoir.   
     
     
         13 . The system according to  claim 12 , where the mafic rock comprises a basaltic rock or a silicate rock reactive with CO 2 . 
     
     
         14 . The system according to  claim 12 , wherein the pre-concentrator is one or more selected from the group consisting of a monoethanolamine (MEA) solution absorption unit, a pressure swing adsorption (PSA) unit, a metal-organic framework (MOF) unit, a membrane gas separation unit, and a chemical looping combustion unit. 
     
     
         15 . The system according to  claim 12 , wherein the pre-concentrator is configured to increase the CO 2  concentration from less than 10 vol % to above 40 vol %. 
     
     
         16 . The system according to  claim 12 , where the facility is selected from the group consisting of a power production facility, a desalination plant, a refinery, a chemical production plant, an ore smelting plant, a cement production plant, a logging plant, a landfill, a fertilizer production plant, and other industrial facilities. 
     
     
         17 . The system according to  claim 12 , where the reservoir is between about 250 m and about 500 m below the surface and is between about 150° C. and about 280° C. 
     
     
         18 . The system according to  claim 12 , where the reservoir is between about 350 m and about 1,500 m below the surface and is less than about 325° C. 
     
     
         19 .- 21 . (canceled)