Cigarettes and cigarette filters including activated carbon for removing nitric oxide

Abstract

Filters and cigarettes include an activated carbon sorbent capable of selectively removing nitric oxide from mainstream tobacco smoke. Methods for making cigarette filters and cigarettes using the activated carbon sorbent and methods for treating mainstream tobacco smoke produced by smoking a cigarette including the sorbent are also provided.

What is claimed is: 
     
         1 . A method of treating mainstream tobacco smoke produced by a cigarette including a cigarette filter comprising an activated carbon sorbent, wherein the activated carbon sorbent is produced by heating a porous carbon material in an oxygen-containing environment under conditions effective to enhance the capability of the carbon material to remove nitric oxide from mainstream tobacco smoke by sorption, wherein the activated carbon sorbent contains pores having a pore size of from about 5 Å to about 10 Å and has a BET surface area of from about 1000 m 2 /g to about 2,000 m 2 /g, the method comprising heating or lighting the cigarette to form smoke, and drawing the smoke through the cigarette, the activated carbon sorbent removing nitric oxide from mainstream tobacco smoke. 
     
     
         2 . The method of  claim 1 , wherein the activated carbon sorbent removes the nitric oxide from the gas stream by sorption. 
     
     
         3 . The method of  claim 1 , wherein the activated carbon sorbent catalyzes the reaction of nitric oxide to N 2  and O 2  and/or to NO 2 . 
     
     
         4 . The method of  claim 1 , wherein a majority of the pores of the activated carbon sorbent have a size of from about 5 Å to about 10 Å. 
     
     
         5 . The method of  claim 1 , wherein the activated carbon sorbent has a BET surface area of from about 1000 m 2 /g to about 3,000 m 2 /g. 
     
     
         6 . A method of treating a gas stream containing nitric oxide, comprising:
 passing a gas stream containing nitric oxide through an activated carbon sorbent to remove nitric oxide from the gas stream, wherein a majority of the pores of the activated carbon sorbent have a size of less than about 30 Å, the activated carbon sorbent contains pores having a D-R micropore volume of from about 0.2 cm 3 /g to about 1.0 cm 3 /g in the pore size range of from about 5 Å to about 10 Å.   
     
     
         7 . The method of  claim 6 , wherein the activated carbon sorbent removes the nitric oxide from the gas stream by sorption. 
     
     
         8 . The method of  claim 6 , wherein the activated carbon sorbent catalyzes the reaction of nitric oxide to N 2  and O 2  and/or to NO 2 . 
     
     
         9 . The method of  claim 6 , wherein a majority of the pores of the activated carbon sorbent have a size of from about 5 Å to about 10 Å. 
     
     
         10 . The method of  claim 6 , wherein the activated carbon sorbent has a BET surface area of from about 1000 m 2 /g to about 3,000 m 2 /g. 
     
     
         11 . A method of treating a gas stream containing nitric oxide, comprising:
 passing a gas stream containing nitric oxide through an activated carbon sorbent to remove nitric oxide from the gas stream, wherein the activated carbon sorbent is produced by heating a porous carbon material in an oxygen-containing environment under conditions effective to enhance the capability of the carbon material to remove nitric oxide from mainstream tobacco smoke by sorption, wherein the activated carbon sorbent contains pores having a pore size of from about 5 Å to about 10 Å and has a BET surface area of from about 1000 m 2 /g to about 2,000 m 2 /g.   
     
     
         12 . The method of  claim 11 , wherein the activated carbon sorbent removes the nitric oxide from the gas stream by sorption. 
     
     
         13 . The method of  claim 6 , wherein the activated carbon sorbent catalyzes the reaction of nitric oxide to N 2  and O 2  and/or to NO 2 .