Method and apparatus for obtaining combustion pages of high calorific value

Abstract

The present invention relates to a method for obtaining combustion gases of high calorific value, wherein carbonaceous materials are allothermically gasified in a fluidized layer containing solid particles, using a gaseous gasifying agent and by supply of heat, and the gases thus produced are separated from the solid particles and withdrawn. Said method is characterized in that the solid particles are indirectly heated in a first descending bed and supplied to a second ascending fluidized bed in which the fluidized layer is formed and gasification takes place for the greatest part. The method further relates to an apparatus for performing said method.

1 . A method for obtaining combustion gases of high calorific value, wherein carbonaceous materials are allothermically gasified in a fluidized layer containing solid particles, using a gaseous gasifying agent and by supply of heat, and the gases thus produced are separated from said solid particles and withdrawn, said solid particles being indirectly heated in a first descending bed ( 1 ) and supplied to a second ascending fluidized bed ( 2 ) in which said fluidized layer is formed and gasification takes place for the greatest part.  
     
     
         2 . The method according to  claim 1 , characterized in that said first descending bed ( 1 ) is loosened by injecting a gas.  
     
     
         3 . The method according to  claim 1 , characterized in that said first descending bed ( 1 ) is slightly fluidized.  
     
     
         4 . The method according to at least one of the preceding claims, characterized in that said first descending bed ( 1 ) is indirectly heated with the help of a heat exchanger having a heating medium flowing therethrough.  
     
     
         5 . The method according to  claim 4 , characterized in that said heating medium flows in pulsating fashion upon heat emission to said first descending bed ( 1 ).  
     
     
         6 . The method according to at least one of the preceding claims, characterized in that said gasification process is carried out under pressure.  
     
     
         7 . The method according to at least one of  claims 1  to  5 , characterized in that said gasification process takes place under atmospheric conditions.  
     
     
         8 . The method according to at least one of the preceding claims, characterized in that said carbonaceous materials consist of liquid, paste-like or solid materials in particular of coke, crude oil, biomass or waste materials.  
     
     
         9 . The method according to at least one of the preceding claims, characterized in that said gasifying agent is steam.  
     
     
         10 . An apparatus for performing the method according to  claim 1 , comprising: 
 a reaction zone ( 3 ) for gasifying said carbonaceous materials,    a means ( 4 ) for producing said ascending fluidized bed ( 2 ) in said reaction zone ( 3 ),    a means ( 5 ) for separating the gases produced during gasification from said solid particles and for discharging said gases,    a heating zone ( 6 ) for heating said solid particles in said descending bed ( 1 ), said heating zone ( 6 ) being substantially separated from said reaction zone ( 3 ),    a means ( 7 ) for transferring the heated solid particles from said heating zone ( 6 ) into said reaction zone ( 3 ), and    an indirect heat supply means ( 8 ) assigned to said heating zone ( 6 ).    
     
     
         11 . The apparatus according to  claim 10 , characterized in that said heating zone ( 6 ) and said reaction zone ( 3 ) are separated by different fluidization of said fluidized bed, said different fluidization effecting a circulation of the bed material about one or several substantially horizontal axes.  
     
     
         12 . The apparatus according to  claim 11 , characterized in that said substantially horizontal axes are closed in the form of a ring.  
     
     
         13 . The apparatus according to  claim 10 , characterized in that said heating zone ( 6 ) and said reaction zone ( 3 ) are separated by a wall ( 9 ).  
     
     
         14 . The apparatus according to  claim 10 , characterized in that said heating zone ( 6 ) and said reaction zone ( 3 ) are each formed in a separate reactor.  
     
     
         15 . The apparatus according to any one of claims  13  or  14 , characterized in that said means ( 7 ) for transferring said heated solid particles is a wall opening ( 10 ) or a pipe.  
     
     
         16 . The apparatus according to at least one of  claims 13  to  15 , characterized in that said means ( 7 ) for transferring said heated solid particles is provided in a lower portion of said heating zone ( 6 ).  
     
     
         17 . The apparatus according to at least one of  claims 10  to  16 , characterized in that said means ( 7 ) for transferring said heated solid particles comprises a nozzle bottom ( 11 ) for slightly fluidizing said solid particles.  
     
     
         18 . The apparatus according to at least one of  claims 10  to  17 , characterized in that said indirect heat supply means ( 8 ) is at least one heat exchanger ( 12 ) through which a heating medium can flow and which is provided in or on said heating zone ( 6 ).  
     
     
         19 . The apparatus according to  claim 18 , characterized in that said heat exchanger ( 12 ) comprises at least one resonant tube ( 13 ) in which said heating medium flows in pulsating fashion upon heat emission to said heating zone ( 6 ).  
     
     
         20 . The apparatus according to  claim 19 , characterized in that said resonant tube ( 13 ) is connected to a combustion chamber for generating resonance.  
     
     
         21 . The apparatus according to  claim 18 , characterized in that an acoustic resonator is provided for generating resonance, said resonator being separated from a combustion chamber.  
     
     
         22 . The apparatus according to at least one of  claims 10  to  21 , characterized in that said means for producing said ascending fluidized bed ( 2 ) is a nozzle bottom ( 15 ) provided in a lower portion of said reaction zone ( 3 ).  
     
     
         23 . The apparatus according to at least one of  claims 10  to  22 , characterized in that said means for separating the gases produced during gasification from said solid particles is a cyclone.  
     
     
         24 . The apparatus according to at least one of  claims 10  to  24 , characterized in that a vertical outflow of said gases produced in said ascending bed is blocked by baffles ( 18 ,  19 ) which effect a multiple deflection of the gas flow, and said multiple deflection results in a substantial separation of said solid particles from said gas flow.  
     
     
         25 . The apparatus according to at least one of  claims 10  to  24 , characterized in that for circulating said solid particles a means ( 16 ) is provided for transferring said solid particles from said reaction zone ( 3 ) into said heating zone ( 6 ).  
     
     
         26 . The apparatus according to  claim 25 , characterized in that said means ( 16 ) for transferring said solid particles from said reaction zone ( 3 ) into said heating zone ( 6 ) is a wall opening ( 17 ) or a pipe.  
     
     
         27 . The apparatus according to at least one of claims  25  and  26 , characterized in that said means ( 16 ) for transferring said solid particles is provided in an upper portion of said reaction zone ( 3 ).  
     
     
         28 . The apparatus according to at least one of  claims 10  to  22 , characterized in that a feed means ( 21 ) for said carbonaceous materials terminates in said heating zone ( 6 ).  
     
     
         29 . The apparatus according to at least one of  claims 10  to  28 , characterized in that a feed means for said carbonaceous materials terminates in said reaction zone ( 3 ).