Carbon dioxide recovery system and method of exhaust gas

Abstract

Disclosed is a method for recovering carbon dioxide from exhaust gas, more particularly, a method for recovering carbon dioxide from exhaust gas for saving the cost for recovery of carbon dioxide by decreasing energy required for recycling a carbon dioxide absorbent solution. In particular, a circulating solvent, whose heat of vaporization and/or sensible heat is lower than that of a solvent of an absorbent solution introduced to a recycling tower, is supplied to the lower portion of the recycling tower and mixed with the heated absorbent solution. As a result, the pressure inside the recycling tower is maintained so that carbon dioxide released from the absorbent solution is discharged to a storage tank/drum.

1 - 4 . (canceled) 
     
     
         5 . A system for recovering carbon dioxide from exhaust gas comprising:
 a recycling tower having an lower portion to which a circulating solvent, whose heat of vaporization and/or sensible heat is lower than that of a solvent of an absorbent solution introduced to the recycling tower, is introduced and mixed with the heated absorbent solution, to maintain the pressure inside the recycling tower wherein carbon dioxide released from the absorbent solution is separated and discharged to a storage tank.   
     
     
         6 . The system for recovering carbon dioxide from exhaust gas according to  claim 5 , wherein the circulating solvent is discharged out of the recycling tower together with the carbon dioxide released from the absorbent solution, separated from the carbon dioxide by being cooled/condensed by a cooler at a separation drum, and returned to the lower portion of the recycling tower. 
     
     
         7 . The system for recovering carbon dioxide from exhaust gas according to  claim 5 , further comprising a heater configured to heat the absorbent solution in the recycling tower to about 85-140° C. 
     
     
         8 . The method for recovering carbon dioxide from exhaust gas according to  claim 5 , wherein the circulating solvent is selected from a group consisting of n-propanol and isopropyl alcohol.