Surfaces and coatings for the removal of carbon dioxide

Abstract

Apparatus suited for removing carbon dioxide from gases are disclosed. The apparatus may employ bodies having a photocatalytic film. Associated methods and compositions are also disclosed.

What is claimed is: 
     
         1 . A method comprising:
 contacting a body comprising a photocatalytic film with a carbon dioxide-containing gas, wherein the photocatalytic film comprises:
 a matrix; 
 semiconductor particles within the matrix; and 
 a charge transfer agent within the matrix; and 
   converting, via the body, at least 10 ppm/minute carbon dioxide to non-carbon dioxide products per square meter of photocatalytic film surface area.   
     
     
         2 . The method of  claim 1 , wherein the converting step comprises:
 reacting, in the presence of light, carbon dioxide gas with at least one of the semiconductor material and the charge transfer agent to produce a non-carbon dioxide product.   
     
     
         3 . The method of  claim 1 , wherein the converting step occurs at about ambient conditions. 
     
     
         4 . The method of  claim 3 , wherein the converting step comprises:
 producing a carbonate-containing end product via a receptor agent.   
     
     
         5 . The method of  claim 1 , wherein the charge transfer agent comprises a first alkaline material and wherein the receptor agent comprises a second alkaline material, different than the first alkaline material. 
     
     
         6 . The method of  claim 5 , wherein the first alkaline material comprises sodium and the second alkaline material comprises calcium. 
     
     
         7 . A method comprising:
 flowing an incoming gas stream comprising carbon dioxide through a gas scrubbing apparatus comprising a photocatalytic film, wherein the photocatalytic film comprises:
 a matrix; 
 semiconductor particles within the matrix; and 
 a charge transfer agent within the matrix; and 
   removing, via the photocatalytic film, at least 10 ppm/minute carbon dioxide from the incoming gas stream.   
     
     
         8 . The method of  claim 7 , wherein carbon dioxide is removed from the incoming gas stream at a rate of at least about 0.5 vol. % per hour. 
     
     
         9 . The method of  claim 7 , wherein the flowing and producing steps occur at about ambient conditions. 
     
     
         10 . The method of  claim 9 , comprising:
 discharging an effluent gas stream from the gas scrubbing apparatus, wherein the concentration of carbon dioxide in the effluent gas stream is at least about 1% less than the concentration of carbon dioxide in the incoming gas stream.   
     
     
         11 . The method of  claim 10 , wherein the concentration of carbon dioxide in the effluent gas stream is at least about 5% less than the concentration of carbon dioxide in the incoming gas stream. 
     
     
         12 . A gas scrubbing apparatus comprising:
 a gas entrance;   a gas exit; and   a plurality of bodies located between the gas entrance and the gas exit, wherein at least some of the bodies comprise a photocatalytic film and a receptor agent, and wherein the substrate is capable of removing at least about 10 ppm/minute carbon dioxide from a gas comprising 1 vol. % carbon dioxide.