METHOD AND APPARATUS FOR DESULFURIZING COAL GAS

PURPOSE:To improve operating efficiency, by a method wherein crude gas produced in a coal gasifier oven is desulfurized with a fluid bed, dry desulfurizer and fed to a load, and when a load supply is increased, part of the crude gas is caused to by-pass the desulfurizer and fed to the load, while a desulfurizing agent is introduced into the coal gasifier oven. CONSTITUTION:Crude gas produced in a coal gasifier oven 1 is desulfurized by a fluid bed, dry desulfurizer 3 and fed to a load 8. When the flow rate of the gas fed to the load 8 is not higher than a predetermined value, the whole of the crude gas is fed to the desulfurizer 3. On the other hand, when the flow rate of the gas fed to the load 8 exceeds the predetermined value, the crude gas is fed to the desulfurizer 3 at a predetermined value of flow rate and the quantity of the crude gas exceeding the predetermined value of flow rate is fed to the load 8 through a by-pass line 4 which by-passes the desulfurizer 3. Simultaneously, a desulfurizing agent is fed to the coal gasifier oven 1 in accordance with the flow rate of by-passed gas so as to maintain the desulfurization rate of the gas fed to the load 8 at a predetermined value.