System and method for absorbent seperation of acid gas

PURPOSE: An acid gas absorbing and separating system and a method thereof are provided to collect heat generated in a process of a system as a condenser heat-exchanges low temperature absorbent and process gas of a separation tower. CONSTITUTION: An acid gas absorbing and separating system(100) comprises an absorbent supply line, a processing gas supply line, and a vapor supply line. The absorbent absorbs the acidic gas in an absorption tower(130) and the absorbent supply line supplies absorbent to a separation tower. The processing gas supply line supplies the process gas exhausted from the separation tower to a reflux drum(160). The absorbent supply line and the processing gas supply line are crossed to each other. The steam supply line supplies steam from a boiler(110) to the absorption tower. The absorbent absorbs the heat of the steam vapor and process gas.