CO2 gas purification method and apparatus, and CO2 gas absorption liquid used for the purification

摘要

PPROBLEM TO BE SOLVED: To save circulation energy by separating and recovering acidic gas from mixed gas with high efficiency at low cost, increasing absorbing amount of the acidic gas per unit volume of an absorbing liquid, and reducing circulation amount of the absorbing liquid. PSOLUTION: The absorbing liquid having ionic liquid as a main component is supplied to the top of an absorption column 13 maintained at a given temperature and a pressure, and mixed gas containing acidic gas and non-acidic gas is supplied to the lower part of the column 13 to bring the mixed gas into contact with the absorbing liquid. Thus, the acidic gas is absorbed into the absorbing liquid to recover the non-acidic gas from the absorbing column 13 by separating it from the acidic gas. The absorbing liquid having absorbed the acidic gas is supplied to the top of a regeneration column 16 maintained at the same temperature of the absorbing column 13 or higher, and at a pressure lower than that of the absorbing column. Thus, the acidic gas is released, separated from the absorbing liquid, and recovered from the regeneration column 16 to regenerate the absorbing liquid. The regenerated liquid is supplied to the top of the absorbing column 13. PCOPYRIGHT: (C)2007,JPO&INPIT