METHOD FOR REMOVING CARBON DIOXIDE IN ACIDIC GAS AND APPARATUS THEREFOR

Provided is a method for removing carbon dioxide in acidic gas and an apparatus therefor. A method for removing carbon dioxide in acidic gas includes: purifying coke oven gas to prepare acidic gas; injecting ammonia into the acidic gas and adjusting a molar ratio of carbon dioxide to ammonia in an entire mixed stream to 0.5 or more; indirectly cooling the mixed stream to form a salt; removing the salt in a form of slurry; heating the salt in the removed slurry to decompose the salt into carbon dioxide gas, ammonia gas, and water; and recovering the decomposed ammonia gas. 1. A method for removing carbon dioxide in acidic gas , the method comprising:purifying coke oven gas to prepare acidic gas;injecting ammonia into the acidic gas and adjusting a molar ratio of carbon dioxide to ammonia in an entire mixed stream to 0.5 or more;indirectly cooling the mixed stream to form a salt;removing the salt in a form of slurry;heating the salt in the removed slurry to decompose the salt into carbon dioxide gas, ammonia gas, and water; andrecovering the decomposed ammonia gas.2. The method of claim 1 , wherein:in the injecting of the ammonia into the acidic gas and adjusting the molar ratio of ammonia to carbon dioxide in the entire mixed stream to 0.5 or more,when the molar ratio of ammonia to carbon dioxide is less than 0.5, ammonia is injected.3. The method of claim 2 , wherein:in the injecting of the ammonia into the acidic gas and adjusting the molar ratio of ammonia to carbon dioxide in the entire mixed stream to 0.5 or more,ammonia is injected in a form of a mixed gas of ammonia gas and steam.4. The method of claim 1 , wherein:in the heating of the salt in the removed slurry to decompose the salt into carbon dioxide gas, ammonia gas, and water,high-temperature nitrogen gas and steam are used.5. The method of claim 4 , wherein:the heating of the salt in the removed slurry to decompose the salt into carbon dioxide gas, ammonia gas, and wateris performed at 70° C. or more.6. ...