Separation device for carbon dioxide gas

Abstract

The present invention reduces the consumption of a solute used for generating alkaline water while using the alkaline water for efficiently separating carbon dioxide gas from exhaust gas, so as to reduce running costs. A separation device for carbon dioxide gas according to the present invention comprises: a steam generation part that heats alkaline water to a boiling point or higher and generates alkaline water steam; a mixing part that mixes the alkaline water steam with exhaust gas to form steam-mixed exhaust gas; a cooling part that cools the steam-mixed exhaust gas to form mist-containing exhaust gas containing mist in which the carbon dioxide gas is absorbed and which is formed by condensation of the alkaline water steam having absorbed carbon dioxide gas; a recovered water separation part that recovers, as recovered water from the mist-containing exhaust gas, the mist in which the carbon dioxide gas is absorbed; a vaporization part that heats and vaporizes the recovered water to form mixed gas which contains the carbon dioxide gas and the alkaline water steam; a gas separation part that filters the mixed gas with a gas separation membrane to separate the carbon dioxide gas and solute gas of the alkaline water; and a solute mixing part that dissolves, in water, the solute gas of the alkaline water to form alkaline water.