Method for the production of a methane-containing gas

Abstract

A method and apparatus for the conversion of a hydrocarbon-bearing feedstock to a valuable product gas such as methane (CH 4 ). The feedstock can advantageously be a low-cost or negative net cost feedstock such as municipal waste or low-grade coal. The method advantageously includes the step of forming large volumes of hydrogen gas and contacting the hydrogen gas with the feedstock to produce methane. The methane can be combusted to produce electricity, such as in a combined cycle generator.

What is claimed is:  
     
         1 . A method for the conversion of a hydrocarbon-bearing feedstock to a gas product containing methane, comprising contacting said hydrocarbon-bearing feedstock with a hydrogen-containing gas comprising at least about 40 weight percent H 2  at a reaction temperature of at least about 600° C. for a time sufficient to convert at least about 90 weight percent of the hydrocarbons in the feedstock to methane.  
     
     
         2 . A method as recited in  claim 1 , wherein said hydrocarbon-bearing feedstock comprises municipal waste.  
     
     
         3 . A method as recited in  claim 1 , wherein said hydrocarbon-bearing feedstock comprises separated municipal waste having not greater than about 5 weight percent cellulose-based materials.  
     
     
         4 . A method as recited in  claim 1 , wherein said hydrocarbon-bearing feedstock comprises automobile shredder refuse.  
     
     
         5 . A method as recited in  claim 1 , wherein said hydrocarbon-bearing feedstock comprises coal.  
     
     
         6 . A method as recited in  claim 1 , wherein said hydrocarbon-bearing feedstock comprises tar sand.  
     
     
         7 . A method as recited in  claim 1 , wherein said hydrocarbon-bearing feedstock comprises crude oil.  
     
     
         8 . A method as recited in  claim 1 , wherein said hydrogen-containing gas comprises at least about 99 weight percent H 2 .  
     
     
         9 . A method as recited in  claim 1 , wherein said hydrogen-containing gas is formed by the reduction of steam with a metal.  
     
     
         10 . A method as recited in  claim 1 , wherein said hydrogen-containing gas comprises H 2  and CO.  
     
     
         11 . A method as recited in  claim 1 , wherein said hydrogen-containing gas is formed by partial oxidation of carbon.  
     
     
         12 . A method as recited in  claim 1 , wherein said reaction temperature is from about 700° C. to about 900° C.  
     
     
         13 . A method as recited in  claim 1 , further comprising the step of cycling a portion of said methane to create process heat.  
     
     
         14 . A method as recited in  claim 1 , further comprising the step of combusting said methane to generate electricity.  
     
     
         15 . A method as recited in  claim 1 , further comprising the step of combusting said methane in a combined cycle generator to generate electricity.  
     
     
         16 . A method as recited in  claim 1 , wherein said hydrogen-containing gas comprises at least about 99 weight percent H 2  and further comprising the step of removing a portion of said hydrogen-containing gas and combusting said removed portion with said methane.  
     
     
         17 . A method for the conversion of a hydrocarbon-bearing feedstock to a gas product containing methane, comprising the steps of: 
 a) generating a hydrogen-containing gas by contacting steam with a metal under conditions sufficient to form a hydrogen-containing gas stream and convert said metal to a metal oxide;    b) contacting said hydrocarbon-bearing feedstock with said hydrogen-containing gas at a reaction temperature of at least about 600° C. for a time sufficient to convert at least a portion of said hydrocarbon-bearing feedstock to methane.    
     
     
         18 . A method as recited in  claim 17 , wherein said metal is iron.  
     
     
         19 . A method as recited in  claim 17 , wherein said metal is tin.  
     
     
         20 . A method as recited in  claim 17 , wherein said hydrocarbon-bearing feedstock comprises municipal waste.  
     
     
         21 . A method as recited in  claim 17 , wherein said hydrocarbon-bearing feedstock comprises automobile shredder refuse.  
     
     
         22 . A method as recited in  claim 17 , wherein said hydrocarbon-bearing feedstock comprises coal.  
     
     
         23 . A method as recited in  claim 17 , wherein said contacting step comprises contacting said hydrocarbon-bearing feedstock with said hydrogen containing gas at a pressure of not greater than about 5 psi.  
     
     
         24 . A method as recited in  claim 17 , wherein said reaction temperature is from about 700° C. to about 900° C.  
     
     
         25 . A method as recited in  claim 17 , further comprising the step of combusting at least a portion of said methane in a combined cycle generator to generate electricity.