Method for removing carbon dioxide and sulfur compounds in combustion exhaust gas

PURPOSE: To check the loss of expensive alkanolamine and to completely remove SOX in exhaust gas by performing desulfurization treatment of SOX contg. combustion exhaust gas to the SOX concentrations in the prescribed range before bringing the desulfurization treated gas come into contact with water solution of alkanolamine. CONSTITUTION: In a highly efficient desulfurization process, the circulated quantity of slurry needs increasing as the desulfurization level is increased and power required for operating a pump, etc., is increased, causing power consumption to be increased. On the other hand, when the desulfurization level is lowered, SOX remained in the desulfurization process is reacted with alkanolamine in a CO 2 removing process to increase the loss of the amine. Therefore, as the desulfurization level in the desulfurization process, the SOX concentration is set in the range of 5-10ppm. After combustion exhaust gas is desulfurization treated by the highly effective desulfurization process, it is brought into contact with the smallest possible quantity of water solution of alkanolamine in the CO 2 removing process to remove CO 2 , causing SOX in gas for CO 2 removing treatment to be removed to the concentration of ≤1ppm, permitting the loss of alkanolamine to be held to a minimum. COPYRIGHT: (C)1993,JPO&Japio