A system for the recovery of carbon dioxide from a gas which contains it, said system including: - pressurizing means for pressurizing the gas - an absorption tank for absorbing into water the carbon dioxide contained in a gas pressurized with the pressurizing means - a desorption tank for desorbing from water the carbon dioxide absorbed in water - means for circulating water from the absorption tank into the desorption tank and from the desorption tank back into the absorption tank - recovering means for the recovery of carbon dioxide to be desorbed from the water, characterized in that - the absorption tank and the desorption tank houses an agitator (30, 30') which comprises a motor (31, 31'), a drive shaft (34, 34'), and at least one propeller (32, 32') located close to the water surface at a depth where the hydrostatic pressure of water is nonexistent or almost nonexistent, - the agitator (30, 30') has its shaft (34, 34') and at least one propeller (32, 32') surrounded by a guide pipe (33, 33') which conducts the water (35, 35') upwards above the water surface, - the drive shaft (34, 34') of said at least one propeller (32, 32') is provided above the water surface with a guard (39, 39') for spreading the water ejected upward by said at least one propeller over an extensive area in the air space (36, 36') as the water strikes against the guard (39, 39'), the agitator having a function of enabling water to circulate in the absorption tank and the desorption tank by ejecting it into an air space of the absorption tank and the desorption tank and by spreading it in the absorption tank's and desorption tank's air space over an area as extensive as possible. - pressurizing means for pressurizing the gas - an absorption tank for absorbing into water the carbon dioxide contained in a gas pressurized with the pressurizing means - a desorption tank for desorbing from water the carbon dioxide absorbed in water - means for circulating water from the absorption tank into the desorption tank and from the desorption tank back into the absorption tank - recovering means for the recovery of carbon dioxide to be desorbed from the water, - the absorption tank and the desorption tank houses an agitator (30, 30') which comprises a motor (31, 31'), a drive shaft (34, 34'), and at least one propeller (32, 32') located close to the water surface at a depth where the hydrostatic pressure of water is nonexistent or almost nonexistent, - the agitator (30, 30') has its shaft (34, 34') and at least one propeller (32, 32') surrounded by a guide pipe (33, 33') which conducts the water (35, 35') upwards above the water surface, - the drive shaft (34, 34') of said at least one propeller (32, 32') is provided above the water surface with a guard (39, 39') for spreading the water ejected upward by said at least one propeller over an extensive area in the air space (36, 36') as the water strikes against the guard (39, 39'), the agitator having a function of enabling water to circulate in the absorption tank and the desorption tank by ejecting it into an air space of the absorption tank and the desorption tank and by spreading it in the absorption tank's and desorption tank's air space over an area as extensive as possible.