Production of hydrogen from a gaseous hydrocarbon and system used in said procedure

Abstract

Procedure and system for the production of hydrogen from methane or other gaseous hydrocarbon, in which the methane is decomposed at high temperature in the presence of a catalyst supplying hydrogen and carbon. The carbon which would pollute the catalyst is eliminated by means of a catalyst regeneration phase with steam, which generates a reaction gas that can be re-used as a source of energy

1 . Procedure for the production of hydrogen from a gaseous hydrocarbon, characterised in that it comprises a hydrogen generation phase in which the hydrocarbon is decomposed in the presence of a catalyst at high temperature, according to the following reaction:  
       C n H m   →n C+ m/ 2H 2    
       and a catalyst regeneration phase with steam or water with elimination of the carbon deposited on the catalyst, according to the reaction:  
       C+H 2 O→CO+H 2    
       in which the reaction gas (CO+H 2 ) from the catalyst regeneration phase is re-used as a source of energy.  
     
     
         2 . Procedure according to  claim 1 , characterised in that the reaction gas from the catalyst regeneration phase is re-used as a source of energy in the process itself.  
     
     
         3 . Procedure according to  claim 1  or  2 , characterised in that the two phases are performed, at least for a certain amount of time, parallel, in at least two retorts which operate alternatively generating hydrogen and regenerating the catalyst.  
     
     
         4 . Procedure according to  claim 1 ,  2  or  3 , characterised in that the temperature of the cracking phase is between 1000° C. and 1100° C.  
     
     
         5 . Procedure according to  claim 1 ,  2  or  3 , characterised in that the retort(s) are filled or coated with catalyst supported on a ceramic material.  
     
     
         6 . Procedure according to  claim 5 , characterised in that the catalyst is nickel-based.  
     
     
         7 . Procedure according to  claim 6 , in which the catalyst contains nickel at 4% or more.  
     
     
         8 . Procedure according to  claim 1 ,  2  or  3 , characterised in that the hydrogen obtained is cooled and stored or used in fuel cells.  
     
     
         9 . Procedure according to  claim 2 , characterised in that the reaction gas from the regeneration phase is used for generating steam and/or for heating the retort(s).  
     
     
         10 . System for the production of hydrogen from a gaseous hydrocarbon according to the procedure of  claim 1  or  2 , characterised in that it comprises: 
 a retort (A or B)  
 a hot chamber (C) enclosing the retort;  
 means for supplying the hydrocarbon (a 1 , a 2 ) to the retort;  
 means for supplying the steam (b 1 , b 2 ) to the retort;  
 means for supplying combustible gas (f 1 ) to a burner (g 1 ) of the hot chamber;  
 means for supplying the regeneration gas to an external heat generator and/or to a steam generator and/or to a burner (g 2 ) in the hot chamber.  
 
     
     
         11 . System for the production of hydrogen from a gaseous hydrocarbon according to the procedure of  claim 3 , characterised in that it comprises: 
 two retorts(A and B);    a hot chamber (C) enclosing the retorts;    means for supplying hydrocarbon (a 1 , a 2 ) alternatively to the retorts;    means for supplying steam alternatively (b 1 , b 2 ) to the retorts;    means for supplying combustible gas (f 1 ) to a burner (g 1 ) of the hot chamber;    means for supplying the regeneration gas to an external heat generator and/or to a steam generator and/or to a burner ( 92 ) in the hot chamber.    
     
     
         12 . System, according to  claim 10  or  11 , characterised in that the retort(s) use a catalyst supported on a ceramic material.  
     
     
         13 . System according to  claim 10  or  11 , characterised in that the hot chamber (C) is provided with a heat exchanger ( 11 ) connected to a steam generator ( 13 ).  
     
     
         14 . System according to  claim 10  or  11 , characterised in that it comprises, at the outlet of the retort(s), a heat exchanger ( 12 ) for cooling the gases produced.