Sulfur scavenging materials

Abstract

Materials which react with (“scavenge”) sulfur compounds, such as hydrogen sulfide and mercaptans, are useful for limiting sulfur-induced corrosion. Surface-modified particles incorporating a hexahydrotriazine moiety are disclosed and used as sulfur scavengers. These surface-modified particles are used a filter media in fixed filter systems and as additives to fluids including sulfur compounds. The hexahydrotriazine moiety can react with sulfur compounds in such a manner as to bind sulfur atoms to the surface-modified particles, thus allowing removal of the sulfur atoms from fluids such as crude oil, natural gas, hydrocarbon combustion exhaust gases, sulfur polluted air and water. The surface-modified particles may, in general, be sized to allow separation of the particles from the process fluid by sedimentation, size-exclusion filtration or the like.

What is claimed is: 
     
         1 . A method of making a surface-modified particle, comprising:
 exposing a particle having a hydroxyl reaction site thereon to a silane including a primary amine group; and   exposing the particle to an aniline compound.   
     
     
         2 . The method of  claim 1 , wherein the particle is a silica particle. 
     
     
         3 . The method of  claim 1 , wherein the silane is (3-aminopropyl)triethoxysilane. 
     
     
         4 . The method of  claim 1 , wherein the particle is a spherical particle. 
     
     
         5 . A method of removing a sulfur compound from a fluid, comprising:
 placing a fluid including a sulfur compound in contact with a particle having a hexahydrotriazine moiety linked via covalent bonds thereto.   
     
     
         6 . The method of  claim 5 , wherein placing the fluid including the sulfur in contact with the particle having the hexahydrotriazine moiety linked via covalent bonds thereto includes passing the fluid through a filter. 
     
     
         7 . The method of  claim 5  wherein placing the fluid including the sulfur in contact with the particle having the hexahydrotriazine moiety linked via covalent bonds thereto includes mixing the particle and the fluid. 
     
     
         8 . The method of  claim 5 , further comprising:
 separating the particle from the fluid.   
     
     
         9 . The method of  claim 8 , wherein separating the particle from the fluid includes a size-exclusion filtration process. 
     
     
         10 . The method of  claim 8 , wherein separating the particle from the fluid includes a sedimentation process.