CARBON DIOXIDE ABSORPTION METHOD AND CARBON DIOXIDE ADSORBENT AND PRODUCTION OF THE SAME

摘要

PROBLEM TO BE SOLVED: To efficiently carry out pressure-swing adsorption(PSA) at a high temperature within a range in which the carbon dioxide adsorption capacity of an adsorbent is small and regeneration by desorption is difficult by bringing a gas flow containing carbon dioxide into contact with a magnesium oxide- containing adsorbent having a specified chemical formula at a high temperature within the specified range. SOLUTION: A gas flow containing carbon dioxide is brought into contact with a magnesium oxide adsorbed having the general formula; (M2CO3)m(2 MHCO3)(1-m)}n(MgCO3)p(MgO)(1-p)-xH2o; at a high temperature within a range from 300 to 500 deg.C to make carbon dioxide adsorbed and removed from the gas flow. In the formula, M denotes an alkali metal; 0<=m<=1; 0<=n<=1.30; 0<=p<1; x denotes the degree of the hydration. If n is 0, MgO is produced by dehydration of (MgCO3)y[Mg(OH)2)(1-y)-xH2O (wherein 0.1<=y<=0.9; and x denotes the degree of the hydration) and CO2 removal.