Harvesting atmospheric water using natural gas that would typically be flared and wasted

Abstract

A method and system for harvesting water from the atmosphere using unwanted combustible gas, where the unwanted combustible gas refers to combustible gas (e.g., natural gas) that would normally be flared off by the oil and gas operator or by a plant (e.g., petrochemical plant). The energy produced by burning the unwanted combustible gas is used to power vapor compression or vapor absorption based refrigeration units which provide the cooling capacity to condense water. The condensers may be coated with specialized condensation promoting coatings that increase the condensation heat transfer performance thereby enabling compact combustible gas powered atmospheric water harvesters. The water collected can be used for oilfield operations, hydraulic fracturing, waterflooding, etc.

1 . A method for harvesting atmospheric water, the method comprising:
 receiving an unwanted combustible gas stream that would normally be flared off;   purging said unwanted combustible gas stream to remove oxygen from said unwanted combustible gas;   distributing said combustible gas to a gas conditioning module to condition said combustible gas to be utilized by a gas engine;   sending said conditioned combustible gas to said gas engine to run a refrigeration cycle;   extracting water from the atmosphere using said refrigeration cycle; and   storing said extracted water in a water storage unit.   
     
     
         2 . The method as recited in  claim 1 , wherein said unwanted combustible gas stream is received from a wellhead, refinery or a plant. 
     
     
         3 . The method as recited in  claim 1  further comprising:
 removing impurities from an exhaust of said gas engine. 
 
     
     
         4 . The method as recited in  claim 3  further comprising:
 capturing carbon dioxide from said exhaust comprising flue gas. 
 
     
     
         5 . The method as recited in  claim 4  further comprising:
 extracting water from water vapor of said flue gas; and 
 storing said extracted water in said water storage unit. 
 
     
     
         6 . A system for harvesting atmospheric water, the system comprising:
 a gas-based cooling system powered by unwanted combustible gas that would normally be flared, wherein said unwanted combustible gas is received from a wellhead, a refinery or a plant;   a water condenser with a cooling capacity powered by said gas-based cooling system, wherein said water condenser is configured to condense water vapor from the atmosphere into liquid; and   a water storage unit connected to said water condenser, wherein said water storage unit is configured to store said water droplets.   
     
     
         7 . The system as recited in  claim 6 , wherein a surface of said water condenser is coated with hydrophobic or superhydrophobic coatings. 
     
     
         8 . The system as recited in  claim 6 , wherein said gas-based cooling system comprises:
 a gas distribution manifold configured to condition said unwanted combustible gas to be utilized by a gas engine configured to power a refrigeration cycle that utilizes said water condenser for condensing water from the atmosphere.   
     
     
         9 . The system as recited in  claim 8 , wherein said gas distribution manifold comprises a knockout drum configured to separate liquids in said unwanted combustible gas. 
     
     
         10 . The system as recited in  claim 8 , wherein said gas distribution manifold comprises a scrubber configured to remove impurities from said unwanted combustible gas. 
     
     
         11 . The system as recited in  claim 6 , wherein said gas-based cooling system further comprises:
 a carbon dioxide capture module configured to capture carbon dioxide from an exhaust of said gas engine comprising flue gas.   
     
     
         12 . The system as recited in  claim 11 , wherein said gas-based cooling system further comprises:
 a flue gas water harvesting system connected to said carbon dioxide capture module, wherein said flue gas water harvesting system is configured to extract water from water vapor of said flue gas, wherein said extracted water is stored in said water storage unit.   
     
     
         13 . The system as recited in  claim 6 , wherein said gas-based cooling system comprises:
 a purging unit configured to remove oxygen from said unwanted combustible gas.   
     
     
         14 . The system as recited in  claim 13 , wherein said gas-based cooling system further comprises:
 a knockout drum configured to remove liquids accompanying said unwanted combustible gas.   
     
     
         15 . The system as recited in  claim 6 , wherein said gas-based cooling system comprises a steam turbine driven chiller. 
     
     
         16 . The system as recited in  claim 6 , wherein said gas-based cooling system comprises a single-effect absorption chiller. 
     
     
         17 . The system as recited in  claim 6 , wherein said gas-based cooling system comprises a direct-fired double-effect absorption chiller. 
     
     
         18 . The system as recited in  claim 6 , wherein said gas-based cooling system comprises a gas turbine. 
     
     
         19 . The system as recited in  claim 6 , wherein said gas-based cooling system comprises a desiccant dehumidification system.