Co2 recovery unit

A CO2 recovery unit comprising:

• a CO2 absorber in which a CO2-containing gas comes into contact with a CO2 absorbent to remove CO2;
• and
• an absorbent regenerator in which a CO2-absorbed rich solution is regenerated by a regenerating heater, thereby reusing a lean solution in which CO2 has been removed in the absorbent regenerator, in the CO2 absorber as the CO2 absorbent, wherein
• the absorbent regenerator is divided into at least two parts and includes:
• a rich solution supply line through which the rich solution is supplied to the absorbent regenerator from the CO2 absorber;
• a lean solution supply line through which the lean solution is supplied to the CO2 absorber from the absorbent regenerator;
• a lean-rich solution heat exchanger that is provided at an intersection of the lean solution supply line and the rich solution supply line to exchange heat between the lean solution and the rich solution;
• a branch portion that branches some of the rich solution at a downstream side of the lean-rich solution heat exchanger on the rich solution supply line;
• and
• a mixing portion that mixes the some of the rich solution branched at the branch portion with a semi-lean solution in which CO2 has been partially removed from the rich solution in the absorbent regenerator, wherein a front end of a branch line through which the some of the branched rich solution is supplied is connected to a solution storage portion of the semi-lean solution which is located at an upper stage side of the absorbent regenerator divided into pails to mix the some of the branched rich solution with the semi-lean solution.

A CO2 recovery unit comprising:

• a CO2 absorber in which a CO2-containing gas comes into contact with a CO2 absorbent to remove CO2;
• and
• an absorbent regenerator in which a CO2-absorbed rich solution is regenerated by a regenerating heater, thereby reusing a lean solution in which CO2 has been removed in the absorbent regenerator, in the CO2 absorber as the CO2 absorbent, wherein
• the absorbent regenerator is divided into at least two parts and includes:
• a rich solution supply line through which the rich solution is supplied to the absorbent regenerator from the CO2 absorber;
• a lean solution supply line through which the lean solution is supplied to the CO2 absorber from the absorbent regenerator;
• a lean-rich solution heat exchanger that is provided at an intersection of the lean solution supply line and the rich solution supply line to exchange heat between the lean solution and the rich solution;
• a branch portion that branches some of the rich solution at a downstream side of the lean-rich solution heat exchanger on the rich solution supply line;
• and
• a mixing portion that mixes the some of the rich solution branched at the branch portion with a semi-lean solution in which CO2 has been partially removed from the rich solution in the absorbent regenerator, wherein
• the mixing portion is provided with a semi-lean solution extracting line through which the semi-lean solution is extracted from a solution storage portion located at an upper stage side of the absorbent regenerator divided into parts and the extracted semi-lean solution is supplied to a lower stage side of the absorbent regenerator, and
• a front end of a branch line through which the some of the branched rich solution is supplied is connected to the semi-lean solution extracting line to form a mixing portion in which the some of the branched rich solution is mixed with the semi-lean solution.