Carbon dioxide capture system and method of operating carbon dioxide capture system

A carbon dioxide capture system according to the embodiment includes: a carbon dioxide capturer configured to cause a carbon dioxide contained in a combustion exhaust gas into an absorbing liquid containing an amine; a first washer configured to wash the combustion exhaust gas from the carbon dioxide capturer with a mist of a first cleaning liquid sprayed by a spray to capture the amine contained in the combustion exhaust gas; and a cleaning liquid mist capturer configured to capture the mist of the first cleaning liquid contained in the combustion exhaust gas from the first washer. The first washer has a receiver arranged below the spray, and a washing-capturing space arranged between the spray and the receiver. In the washing-capturing space, the mist of the first cleaning liquid comes into gas-liquid contact with the combustion exhaust gas while freely dropping.