Coal gasifier

Abstract

Provided is a coal gasifier enabling a reduction in size of a shift reactor by generating hydrogen-rich gasified coal gas. In a coal gasifier generating gasified coal gas by a gasification reaction proceeding in a furnace fed with a gasifiable raw material, such as coal, and a gasifying agent, at least one of water and steam is fed to the furnace as a material accelerating a hydrogen-generating reaction that proceeds simultaneously with the gasification reaction.

1 . A coal gasifier generating gasified coal gas by a gasification reaction that proceeds in a furnace fed with a gasifiable raw material, such as coal, and a gasifying agent, wherein
 at least one of water and steam is fed to the furnace as a material accelerating a hydrogen-generating reaction proceeding together with the gasification reaction.   
     
     
         2 . The coal gasifier according to  claim 1 , wherein
 the coal gasifier is a two-stage entrained-bed gasifier having a combustion chamber and a reduction chamber, and   the combustion chamber is fed with the steam together with the gasifiable material and the gasifying agent, and the reduction chamber is fed with the gasifiable material only.   
     
     
         3 . The coal gasifier according to  claim 1 , wherein
 the coal gasifier is a two-stage entrained-bed gasifier having a combustion chamber and a reduction chamber, and   the combustion chamber is fed with the gasifiable material and the gasifying agent, and the reduction chamber is fed with at least one of water and steam together with the gasifiable material.   
     
     
         4 . The coal gasifier according to  claim 1 , wherein the amount of the water or steam to be fed is 0.1 to 0.8 (mass basis) relative to the amount of the gasifiable raw material to be fed. 
     
     
         5 . The coal gasifier according to  claim 1 , wherein a gas-cooling heat exchanger cooling the gasified coal gas is provided so as to be connected to an outlet of the coal gasifier, and the amount of carbon (C) remaining in char (unreacted coal) passing through the gas-cooling heat exchanger together with the gasified coal gas is set to 30% or more. 
     
     
         6 . The coal gasifier according to  claim 1 , wherein the steam is introduced from a water cooling system flowing in a water cooling wall cooling the periphery of the gasifier and/or the gas-cooling heat exchanger.