Method for treating combustible wastes

Abstract

A method for treating combustible wastes comprises the steps of: carbonizing combustible wastes to produce carbonized products and a combustible gas; contacting an exhaust gas from a process with said carbonized products to purify the exhaust gas; and recovering the carbonized products in the exhaust gas. The carbonizing is carried out at a temperature of 400° C. or higher.

What is claimed is:  
     
         1 . A method for treating combustible wastes, comprising the steps of: 
 carbonizing combustible wastes to obtain carbonized products and combustible gas; and    using said carbonized products to purify exhaust gas from a process.    
     
     
         2 . The method of  claim 1 , wherein said combustible wastes contain at least one selected from the group consisting of paper and plastics.  
     
     
         3 . The method of  claim 2 , wherein said combustible wastes further contain at least one selected from the group consisting of coal, coal tar, pitch, activated sludge, and oil-based residue.  
     
     
         4 . The method of  claim 2 , wherein said combustible wastes further contain at least one selected from the group consisting of mill scales and dust of an electric dust collector.  
     
     
         5 . The method of  claim 1 , wherein said step of carbonizing comprises carbonizing said combustible wastes at a carbonization temperature of 400° C. or more.  
     
     
         6 . The method of  claim 5 , wherein said step of carbonizing comprises carbonizing said combustible wastes at a carbonization temperature of 600° C. or more.  
     
     
         7 . The method of  claim 6 , wherein said step of carbonizing comprises carbonizing said combustible wastes at a carbonization temperature of 1000 to 1300° C.  
     
     
         8 . The method of  claim 1 , wherein said step of carbonizing comprises carbonizing said combustible wastes in an inert atmosphere.  
     
     
         9 . The method of  claim 1 , wherein said step of carbonizing comprises: 
 carbonizing said combustible wastes to obtain carbonized products and combustible gas; and    activating said carbonized products.    
     
     
         10 . The method of  claim 1 , further comprising the step of grinding said carbonized products so as to have a particle size of 5 mm or smaller.  
     
     
         11 . The method of  claim 1 , wherein said carbonized products have a volatile matter of 5 wt % or less.  
     
     
         12 . The method of  claim 11 , wherein said carbonized products have a volatile matter of 1 wt % or less.  
     
     
         13 . The method of  claim 1 , wherein said exhaust gas from a process is exhaust gas from one process selected from the group consisting of a refuse incinerator, electric power plant, steel-making electric furnace, scrap melting furnace, and sintering machine for manufacturing iron.  
     
     
         14 . The method of  claim 1 , further comprising the step of using the recovered carbonized products as a fuel or a raw material.  
     
     
         15 . The method of  claim 13 , wherein said fuel is a fuel used for manufacturing sintered ore in a sintering machine for iron making.  
     
     
         16 . The method of  claim 1 , further comprising the step of using said combustible gas as a heat source for carbonization or iron-manufacturing process.  
     
     
         17 . The method of  claim 1 , wherein said combustible wastes are a refuse derived fuel (RDF).  
     
     
         18 . The method  claim 1 , wherein 
 said combustible wastes contain at least one selected from the group consisting of paper and plastics;    said combustible wastes further contain at least one selected from a group consisting of mill scales and dust of an electric dust collector; and    said step of carbonizing comprises carbonizing combustible wastes at a carbonization temperature of 1000 to 1300° C.    
     
     
         19 . A method for treating combustible wastes, comprising the steps of: 
 preliminarily carbonizing said combustible wastes to produce preliminarily carbonized products;    molding said preliminarily carbonized products to produce molded products; and    carbonizing said molded products to produce carbonized products.    
     
     
         20 . The method of  claim 19 , wherein said step of preliminarily carbonizing comprises preliminarily carbonizing combustible wastes at a temperature of 300 to 800° C.  
     
     
         21 . The method of  claim 19 , wherein said step of molding comprises molding said preliminarily carbonized products by a briquetting machine to produce briquettes.  
     
     
         22 . The method of  claim 19 , wherein said step of carbonizing comprises carbonizing said molded products to at a temperature of 600 to 1000° C.  
     
     
         23 . The method of  claim 19 , wherein said step of carbonizing comprises carbonizing said molded products in the presence of water vapor.  
     
     
         24 . The method of  claim 19 , wherein said step of carbonizing comprises carbonizing said molded products by using carbonization gas as a heat source.  
     
     
         25 . The method of  claim 19 , wherein said combustible wastes are combustible wastes containing a refuse derived fuel.  
     
     
         26 . The method of  claim 19 , wherein said combustible wastes are a refuse derived fuel.  
     
     
         27 . The method of  claim 19 , wherein said combustible wastes have an O/C atomicity ratio of 0.2 to 0.8 and an H/C atomicity ratio of 0.5 to 2.3.  
     
     
         28 . The method of  claim 19 , further comprising the steps of: 
 disintegrating said preliminarily carbonized products; and    removing iron and nonferrous metals from the disintegrated preliminarily carbonized products.    
     
     
         29 . The method of  claim 19 , further comprising the step of adding coal or coke to said preliminarily carbonized products.  
     
     
         30 . The method of  claim 19 , further comprising the step of adding and mixing a binder to and with said preliminarily carbonized products.  
     
     
         31 . The method of  claim 19 , further comprising the step of using said carbonized products as an agent for treating exhaust gas.  
     
     
         32 . The method of  claim 19 , further comprising the steps of: 
 removing granular carbonized products from said carbonized products; and    returning said granular carbonized products to said step of molding the preliminarily carbonized products.    
     
     
         33 . The method of  claim 19 , further comprising the steps of: 
 removing granular carbonized products from said carbonized products; and    using said granular carbonized products as a raw material blown as a fuel.    
     
     
         34 . Activated charcoal manufactured by the method for treating combustible wastes according to  claim 19 .  
     
     
         35 . The carbonized products of  claim 34 , wherein said activated charcoal has a Roga's strength of 88% or higher and a specific surface area of 148 m 2 /g or larger.  
     
     
         36 . A method for treating combustible wastes, comprising the steps of: 
 carbonizing said combustible wastes at a temperature of 500 to 1000° C.; and    obtaining carbonized products and carbonization gas after the carbonization.    
     
     
         37 . The method of  claim 36 , wherein said carbonizing is carried out under a pressure of 0.5 to 50 MPa.  
     
     
         38 . The method of  claim 36 , wherein said combustible wastes are a solid fuel in which refuse is solidified.  
     
     
         39 . The method of  claim 36 , wherein said combustible wastes comprises a solid fuel in which refuse is solidified and coal or high-carbon refuse.  
     
     
         40 . The method of  claim 36 , wherein the residue obtained by carbonization is ground to separate a carbon matter and ash.  
     
     
         41 . The method of  claim 36 , further comprising the step of using said carbonization gas as a heat source for carbonization.  
     
     
         42 . A method for treating combustible wastes, comprising the steps of: 
 preparing a refuse derived fuel;    carbonizing said refuse derived fuel at a temperature of 500 to 1000° C.; and    obtaining carbonized products and carbonization gas after the carbonizing.    
     
     
         43 . The method of  claim 42 , wherein said step of preparing the refuse derived fuel comprises impregnating said refuse derived fuel with a binder.  
     
     
         44 . The method of  claim 42 , wherein said step of preparing the refuse derived fuel comprises impregnating said refuse derived fuel with a binder and compression molding said refuse derived fuel.  
     
     
         45 . The method of  claim 42 , wherein said step of carbonizing comprises carbonizing said refuse derived fuel in the presence of water vapor.  
     
     
         46 . The method of  claim 42 , further comprising the step of activating said carbonized products.  
     
     
         47 . The method of  claim 42 , further comprising the step of using said carbonization gas as a heat source for carbonizing.  
     
     
         48 . Activated charcoal manufactured by the method for treating combustible wastes according to  claim 42.