LOW ENERGY-TYPE ACID GAS CAPTURE SYSTEM AND METHOD USING RECIRCULATION OF ABSORBENT

摘要

The present invention relates to a system and a method therefor capable of reducing the amount of heat which must be supplied to a regeneration tower for regenerating an absorbent in an acid gas capture process for such acid gas as carbon dioxide and provides a low energy-type acid gas capture system and method using recirculation of an absorbent capable of reducing energy consumption by recirculating the absorbent, from which acid gas has been pre-separated, to an absorption tower before supplying the absorbent to the regeneration tower in an acid gas capture system.

主权项

1. A low energy-type acid gas capture system using recirculation of an acid gas-absorbed absorbent in liquid form including a large amount of acid gas, the system comprising:
an absorption tower that absorbs the acid gas with an absorbent; a regeneration tower that isolates a processed gas free of the absorbent; an exhaust gas supply line through which an acid gas-included exhaust gas passed through a first heat exchanger and a water separator is supplied to an absorption tower; an absorbent supply line through which the acid gas-absorbed absorbent discharged from the absorption tower is supplied to a separation valve via a second heat exchanger and then a second condenser; a processed gas line through which the processed gas discharged from the regeneration tower is supplied to a first condenser via a third heat exchanger; and a condensate supply line through which condensate water discharged from the first condenser is supplied to regeneration tower, wherein the absorbent supply line comprises: a first absorbent transfer line through which the acid gas-absorbed absorbent in liquid form separated by the separation valve is supplied from the separation valve to the regeneration tower; a second absorbent transfer line through which an acid gas-free absorbent separated from the acid gas-absorbed absorbent in liquid form by the separation valve is supplied from the separation valve to a third condenser via an expansion valve; a third absorbent transfer line through which a recondensed absorbent in liquid form from the third condenser is supplied to the absorption tower via a fourth heat exchanger; a first acid gas transfer line through which the acid gas isolated in the second condenser is supplied to an upper part of the regeneration tower; and a second acid gas transfer line through which the remaining acid gas isolated in the third condenser is supplied to an upper part of the regeneration tower via a condenser.