Pulverized coal pressurized gasifier system

Abstract

A gasifier system includes a gasifier chamber, a plurality of nozzles or burners injecting and combusting a mixture including coal and oxygen within the gasifier chamber, and an ash bed disposed proximate a bottom of the gasifier chamber. Concurrent flow is generated within the gasifier such that gas and bi-products generated by the combustion of the mixture flow through the ash bed. The ash bed serves as a filter and reducing volume for the trace carbon not gasified during the combustion process. The hot gases exit the gasifier and enter a gas cooler and then a hot gas filter. Ash is unloaded from the gasifier chamber and is transferred into a quench tank, where ash settles and is removed to atmospheric conditions by a progressive pitched dewatering screw press. The dewatering screw press also serves as a seal to prevent excessive water escaping from the high pressure of gasifier operation.

The invention claimed is:  
     
         1 . A method of combusting carbonaceous material comprising the acts of: 
 combining carbonaceous material with an oxygen and water source to create a mixture;    injecting said mixture into a gasifier such that a concurrent flow is generated within said gasifier;    gasifying said mixture within said gasifier to generate a gas and bi-products; and    passing said gas and said bi-products through an ash bed.    
     
     
         2 . The method as claimed in  claim 1  wherein said ash bed is disposed within said gasifier.  
     
     
         3 . The method as claimed in  claim 1  wherein said ash bed is in fluid communication with said gasifier.  
     
     
         4 . The method as claimed in  claim 1  wherein said act of passing said gas through said ash bed filters at least some of said bi-products from said gas.  
     
     
         5 . The method as claimed in  claim 1  wherein said act of passing said gas through said ash bed reacts at least some of said bi-products from said gas to form other materials.  
     
     
         6 . The method as claimed in  claim 1  further comprising the act of controlling said ash bed's porosity such that said gas can flow through said ash bed.  
     
     
         7 . The method as claimed in  claim 6  further comprising adding an inert material to said ash bed to maintain said ash bed's porosity.  
     
     
         8 . The method as claimed in  claim 1  further comprising the act of maintaining said ash bed's height.  
     
     
         9 . The method as claimed in  claim 8  further comprising the acts of removing material from said ash bed and recapturing a portion of the heat energy from said material.  
     
     
         10 . The method as claimed in  claim 9  wherein said act of recapturing heat energy from said material includes quenching said material in a quench tank.  
     
     
         11 . The method as claimed in  claim 10  further comprising the act of removing substantially all of said liquid from liquid-soaked material and removing said material from said gasifier.  
     
     
         12 . The method as claimed in  claim 11  wherein said act of removing said liquid from said liquid-soaked material and removing said material from said gasifier includes using a screw-dewater.  
     
     
         13 . The method as claimed in  claim 1  wherein said act of injecting said mixture into said gasifier further includes distributing said mixture into a plurality of nozzles using a distributor.  
     
     
         14 . The method as claimed in  claim 1  further comprising powering a turbine with said gas.  
     
     
         15 . The method as claimed in  claim 14  further including the act of removing substantially all of said remaining bi-products from said gas before said act of powering said turbine in a filter.  
     
     
         16 . The method as claimed in  claim 15  wherein further comprising cooling said gas prior to said act of filtering said filtering said gas.  
     
     
         17 . The method as claimed in  claim 16  wherein said act of removing substantially all of said remaining bi-products from said gas includes cooling said bi-products in a quench tank.  
     
     
         18 . The method as claimed in  claim 17  further comprising the act of removing substantially all of said liquid from liquid-soaked bi-products and removing said cooled bi-products from said filter.  
     
     
         19 . The method as claimed in  claim 18  wherein said act of removing said liquid from said liquid-soaked bi-products and removing said bi-products from said filter includes using a screw-dewater.  
     
     
         20 . A gasifier comprising: 
 a gasifier chamber;    a plurality of nozzles, said plurality of nozzles injecting and combusting a mixture including carbonaceous mixture and an oxygen and water source within said gasifier chamber to cause gasification; and    an ash bed region in fluid communication with said gasifier chamber, said ash bed region adapted to contain an ash bed wherein said a concurrent flow is generated within said gasifier such that gas and bi-products generated by said gasification of said mixture flow through said ash bed.    
     
     
         21 . The gasifier as claimed in  claim 20  wherein said ash bed region is disposed proximate a bottom region of said gasifier chamber.  
     
     
         22 . The gasifier as claimed in  claim 20  wherein said ash bed region is disposed in a second chamber.  
     
     
         23 . The gasifier as claimed in  claim 20  further including a distributor, said distributor distributing said mixture to said plurality of nozzles.  
     
     
         24 . The gasifier as claimed in  claim 20  further comprising an unloader to remove material from said ash bed.  
     
     
         25 . The gasifier as claimed in  claim 24  further comprising a quench tank to recapture a portion of the energy contained in said material removed from said ash bed region.  
     
     
         26 . The gasifier as claimed in  claim 25  further including a dewatering screw to remove substantially all of said liquid from said liquid-soaked material and to remove said material from said ash bed region.  
     
     
         27 . The gasifier as claimed in  claim 20  further including a mixer disposed within said ash bed region.  
     
     
         28 . The gasifier as claimed in  claim 20  further comprising a heat exchanger in fluid communication with said ash bed region, said heat exchanger reducing the temperature of said gas generated by said gasifier.  
     
     
         29 . The gasifier as claimed in  claim 28  further comprising a filter in fluid communication with said heat exchanger for removing any particulates in said gas.  
     
     
         30 . The gasifier as claimed in  claim 29  further comprising a quench tank in fluid communication with said filter.  
     
     
         31 . The gasifier as claimed in  claim 30  further including a second dewatering screw to remove substantially all of said liquid from said liquid-soaked particulates and to remove said particulates from said filter.  
     
     
         32 . The gasifier as claimed in  claim 20  further comprising a turbine in fluid communication with said gasifier wherein said gas generated by said gasifier rotates said turbine.