Surface-Modified Carbon and Sorbents for Improved Efficiency in Removal of Gaseous Contaminants

Abstract

A material, and filters and other structures exposed to flowing gas that have the material therein, which removes VOCs, such as formaldehyde, from the gas. The material is a porous sorbent impregnated by a metal oxide, such as manganese oxide (MnOx) nano particles. The sorbent may be activated carbon, and the manganese oxide may catalyze formaldehyde to water and carbon dioxide while the carbon may adsorb formaldehyde, both mechanisms of which remove the VOC from the air to prevent or reduce inhalation of the same by humans. The material may be combined with an untreated sorbent or sorbent treated with ionic alkaline salts.

1 . A material for reacting with volatile organic compounds in a flow of gas, the material comprising a porous sorbent impregnated with metal oxide particles in at least pores formed on an outer surface of the porous sorbent. 
     
     
         2 . The material in accordance with  claim 1 , wherein the porous sorbent further comprises zeolite and the metal oxide particles further comprise manganese oxide (MnOx). 
     
     
         3 . The material in accordance with  claim 2 , wherein the manganese oxide particles are in a range of 0.5-2.0% by weight of the zeolite. 
     
     
         4 . The material in accordance with  claim 1 , wherein the porous sorbent further comprises activated carbon and the metal oxide particles further comprise manganese oxide (MnOx). 
     
     
         5 . The material in accordance with  claim 4 , wherein the manganese oxide particles are within a size range of about 100 to about 400 nanometers. 
     
     
         6 . The material in accordance with  claim 4 , wherein the activated carbon has a surface area per unit mass of between about 800 to about 1,300 square meters per gram. 
     
     
         7 . The material in accordance with  claim 4 , wherein the activated carbon size is within a range of between about 10 microns and about 4.0 millimeters. 
     
     
         8 . The material in accordance with  claim 4 , wherein the manganese oxide particles are in a range of 0.5-5.0% by weight of the carbon. 
     
     
         9 . A material for reacting with volatile organic compounds in a flow of gas, the material comprising:
 (a) a first porous sorbent impregnated with metal oxide particles in at least pores formed on an outer surface of the first porous sorbent; and   (b) a second porous sorbent impregnated with ionic alkaline salts in at least pores formed on an outer surface of the second porous sorbent.   
     
     
         10 . The material in accordance with  claim 9 , wherein the first porous sorbent further comprises zeolite, the metal oxide particles further comprise manganese oxide (MnOx), the second porous sorbent further comprises zeolite and the ionic alkaline salts further comprise a potassium ion. 
     
     
         11 . The material in accordance with  claim 10 , wherein the first porous sorbent constitutes about 40-50% by weight and the second porous sorbent constitutes about 50-60% by weight. 
     
     
         12 . The material in accordance with  claim 9 , wherein the first porous sorbent further comprises activated carbon, the metal oxide particles further comprise manganese oxide (MnOx), the second porous sorbent further comprises activated carbon and the ionic alkaline salts further comprise a potassium ion. 
     
     
         13 . The material in accordance with  claim 12 , wherein the first porous sorbent constitutes about 40-50% by weight and the second porous sorbent constitutes about 50-60% by weight. 
     
     
         14 . A filter media for removing at least volatile organic compounds from a flow of gas in which the filter media is placed, the filter media comprising a first porous sorbent impregnated with metal oxide particles in at least pores formed on an outer surface of the first porous sorbent. 
     
     
         15 . The material in accordance with  claim 14 , wherein the first porous sorbent further comprises zeolite and the metal oxide particles further comprise manganese oxide (MnOx). 
     
     
         16 . The material in accordance with  claim 14 , wherein the first porous sorbent further comprises activated carbon and the metal oxide particles further comprise manganese oxide (MnOx). 
     
     
         17 . The filter media in accordance with  claim 16 , wherein the first porous sorbent is mounted to a gas-permeable panel. 
     
     
         18 . The filter media in accordance with  claim 17 , wherein the gas-permeable panel is adjacent a fibrous web. 
     
     
         19 . The filter media in accordance with  claim 16 , wherein the first porous sorbent is mounted to a fibrous web. 
     
     
         20 . The filter media in accordance with  claim 19 , further comprising a second porous sorbent impregnated with ionic alkaline salts in at least pores formed on an outer surface of the porous sorbent. 
     
     
         21 . The filter media in accordance with  claim 20 , wherein the ionic alkaline salts further comprise potassium ions. 
     
     
         22 . The filter media in accordance with  claim 21 , wherein the first porous sorbent constitutes about 40-50% by weight and the second porous sorbent constitutes about 50-60% by weight.