Method for Generating or Recovering Materials through Smoldering Combustion

Abstract

Methods are provided for generating or recovering gaseous materials such as hydrogen and solids such as metals through the smoldering combustion of an organic material. The methods include admixing a porous matrix material with an organic material, and, in some embodiments a catalyst, to produce a porous mixture. The mixture is exposed to an oxidant, initiating a self-sustaining smoldering combustion of the mixture, and collecting the vapors and combustion products or processing the porous matrix following combustion to physically separate the porous matrix material from ash containing inorganic materials of value. Additional embodiments aggregate the organic material or catalyst or porous matrix material or mixture thereof in an impoundment such as a reaction vessel, lagoon or matrix pile. Further embodiments utilize at least one heater to initiate combustion and at least one air supply port to supply oxidant to initiate and maintain combustion.

What is claimed is: 
     
         1 . A method for producing and collecting a byproduct through smoldering combustion of an organic material, the method comprising:
 forming a porous mixture comprising an organic material and an inorganic material;   heating at least a portion of the mixture;   forcing an oxidant through the mixture so as to initiate a self-sustaining smoldering combustion of the organic material and to cause the production of the solid byproduct; and   collecting the byproduct.   
     
     
         2 . The method of  claim 1 , where the organic material is selected from the group consisting of a liquid, a slurry, a semi-solid, a solid, and mixtures thereof. 
     
     
         3 . The method of  claim 1 , where the porous mixture further comprises a porous matrix and the organic material is a liquid. 
     
     
         4 . The method of  claim 1 , further comprising causing propagation of the combustion away from a point of initiation of the smoldering combustion. 
     
     
         5 . The method of  claim 1 , where the components of the porous mixture are aggregated in one of a reaction vessel, a pile, or a lagoon. 
     
     
         6 . The method of  claim 1 , further comprising continuously feeding at least one of the components of the porous mixture into a zone of smoldering combustion. 
     
     
         7 . The method of  claim 1 , wherein forming the mixture comprises batch-feeding at least one the components of the porous mixture into a vessel. 
     
     
         8 . The method of  claim 1 , where the inorganic material includes an element selected from the group consisting of phosphorus, a metal, and combinations thereof. 
     
     
         9 . The method of  claim 1 , where the organic material and the inorganic material are in a biosolid. 
     
     
         10 . The method of  claim 1 , where the inorganic material comprises a nutrient. 
     
     
         11 . The method of  claim 1 , where the inorganic material includes phosphorous. 
     
     
         12 . The method of  claim 1 , where the inorganic material includes a chemical element that is a metal, wherein the metal is selected from the group consisting of precious metals, rare-earth and minor metals, platinum group elements, and combinations thereof. 
     
     
         13 . The method of  claim 1 , where the inorganic material includes a metal oxide. 
     
     
         14 . A method for producing and collecting hydrogen gas through smoldering combustion of an organic material, the method comprising:
 admixing an inert porous matrix material and the organic material to produce a mixture;   heating a portion of the mixture; and   exposing the mixture to at least one oxidant so as to initiate self-sustaining smoldering combustion of the mixture to cause the production of hydrogen gas; and   collecting hydrogen gas.   
     
     
         15 . The method of  claim 14 , wherein the inert porous matrix material is selected from the group consisting of sand, gravel, glass beads, zeolite, crushed stone, ceramic chips, ceramic beads, and combinations thereof. 
     
     
         16 . The method of  claim 14 , wherein the inert porous matrix material is a fixed porous material. 
     
     
         17 . The method of  claim 16 , wherein the fixed porous material is selected from the group consisting of steel mesh, porous plate, lava rock, coral, and combinations thereof. 
     
     
         18 . The method of  claim 14 , wherein the inert porous matrix material is a loose porous material. 
     
     
         19 . The method of  claim 18 , wherein the loose porous material is selected from the group consisting of steel shot, glass beads, gravel and sand. 
     
     
         20 . The method of  claim 14 , wherein admixing the porous matrix material and the organic material to produce the mixture includes admixing the mixture in a lagoon or a pile.