Carbon dioxide absorber and carbon dioxide separation/recovery method using the absorber
AssigneeAsahi Kasei Kabushiki Kaisha
InventorsNorikazu Fujimoto, Kyouhei Hattori, Fumihiko Yamaguchi
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Abstract
The present invention provides a carbon dioxide absorber capable of efficiently and stably removing carbon dioxide in a gas or solution. This carbon dioxide absorber contains an amine compound, a weakly acidic compound and water, the pKb value of the amine compound in an aqueous solution at 30° C. is 4.0 to 7.0, the pKa value of the weakly acidic compound in an aqueous solution at 30° C. is 7.0 to 10.0, and the weakly acidic compound is present in an amount within the range of 0.01 equivalents to 1.50 equivalents with respect to amino groups of the amine compound.
Claims21
A carbon dioxide absorber containing an amine compound, a weakly acidic compound and water;
- wherein, the amine compound at least includes an amine compound represented by the following general formula (I):
- wherein, R1 and R2 represent hydrogen atoms or alkyl groups having 1 to 4 carbon atoms,
- the weakly acidic compound is a boric acid or a borate ester having a pKa value of 7.0 to 10.0 in an aqueous solution at 30° C., and
- the weakly acidic compound is present in an amount within the range of 0.01equivalents to 1.50 equivalents with respect to amino groups of the amine compound.
A carbon dioxide absorber containing water and an amine that at least includes an amine compound represented by the following general formula (I):
- (wherein, R1 and R2 represent hydrogen atoms or alkyl groups having 1 to 4 carbon atoms).
A carbon dioxide absorber containing an amine compound, a weakly acidic compound and water;
- wherein,
- the amine compound at least includes an amine compound represented by the following general formula (I):
- wherein, R1 and R2 represent hydrogen atoms or alkyl groups having 1 to 4carbon atoms,
- the weakly acidic compound is a boric acid or a borate ester,
- the weakly acidic compound is present in an amount within the range of 0.05equivalents to 0.30 equivalents with respect to amino groups of the amine compound, and
- wherein a compound having a pKb value in an aqueous solution at 30° C. of less than 4.0 is not contained.
Dependencies are inferred from the claim text.