A CO 2 recovery device includes: a CO 2 absorption tower in which CO 2 included in an exhaust gas is absorbed by a CO 2 absorption liquid; and a CO 2 absorption liquid regeneration tower that heats and regenerates the CO 2 absorption liquid that has absorbed CO 2 . The CO 2 absorption liquid regeneration tower includes: a main body part in which the CO 2 absorption liquid is temporarily stored; a boot part provided downward from a tank end of the main body part, having a relatively smaller capacity than the main body part; a flowmeter provided to the boot part, and measuring the liquid surface level of the CO 2 absorption liquid that changes between the main body part and the boot part; and a control device controlling the liquid surface level of the CO 2 absorption liquid between the main body part and the boot part on the basis of the measurement result of the flowmeter.
1. A CO 2 recovery method comprising:
a CO 2 absorption process of bringing a gas to be treated into contact with a CO 2 absorption liquid, thereby causing CO 2 contained in the gas to be treated to be absorbed by the CO 2 absorption liquid; and
a CO 2 absorption liquid regeneration process of heating the CO 2 absorption liquid, which has absorbed CO 2 , in a CO 2 absorption liquid regeneration tower, to release CO 2 from the CO 2 absorption liquid to regenerate the CO 2 absorption liquid,
wherein the CO 2 absorption liquid regeneration process includes measuring a liquid surface level of the CO 2 absorption liquid in a second storage part which is to be supplied from the CO 2 absorption liquid regeneration tower to the CO 2 absorption tower, and controlling the liquid surface level of the CO 2 absorption liquid between a first storage part and the second storage part on the basis of the measured liquid surface level.
2. The CO 2 recovery method according to claim 1 ,
wherein an internal diameter d2 of the second storage part is relatively smaller than an internal diameter d1 of the first storage part.
3. The CO 2 recovery method according to claim 1 ,
wherein a ratio (d2:d1) of the internal diameter d2 of the second storage part to the internal diameter d1 of the first storage part is within a range of 1:10 to 1:2.
4. The CO 2 recovery method according to claim 1 ,
wherein the second storage part is a cylindrical member provided at a bottom part of the CO 2 absorption liquid regeneration tower.
5. The CO 2 recovery method according to claim 1 ,
wherein a liquid flow speed of the CO 2 absorption liquid to be fed from the inside of the second storage part to the CO 2 absorption tower is equal to or lower than 0.3 m/s.