METHOD FOR OPERATING MONO-FUEL COMBUSTION BOILER HAVING FUEL OF HOT BLAST FURNACE GAS

摘要

PURPOSE:To enable a stable operation of a boiler to be performed only with a hot blast furnace gas (BFG) as a fuel by a method wherein a part of blast gas is fed together with water vapor into a reaction device in which a catalyst layer can exchange heat with a thermal medium, hydrogen is generated and a modified blast gas having the got hydrogen as its major constituent is used as a flame stabling fuel gas. CONSTITUTION:BFG gas generated in a blast furnace 1 is fed to a boiler 6 through BFG pipe 1a and a part of BFG gas is passed through a branch pipe 1b and then fed to a low quality steam fed from a steam pipe 2 to a reaction device 3. In this case, the modified BFG having a large amount of hydrogen is fed directly to the boiler 6 through a pipe 5 as a flame stabling fuel. Quality improved off-gas is returned back to a pipe 1a through a pipe 1c. Both BFG supplied from a catalyst layer inlet 12 of a reaction device 3a and low quality steam are processed such that CO in BFG is modified to H2 under a shift reaction with steam at the catalyst layer 13, this H2 is simultaneously passed and separated in porous material pipe 14, H2 is selectively removed to generate a modified BFG having a large amount of H2 and then passed through gas outlets 18 and 19 and guided to the boiler 6 under operation of a vacuum pump 21.