A carbon dioxide absorbent of an embodiment includes a heterocyclic amine expressed by Formula (1), and the heterocyclic amine having a pKa of any one amino group included in a heterocyclic ring in Formula (1) in a range of 7.0 or more to 8.6 or less and an organic solvent having a boiling point of 150° C. or more at 1 atm. A total mass of the heterocyclic amine and the organic solvent is 70 mass % or more to 100 mass % or less of the carbon dioxide absorbent. Each of R1 to R4 in Formula (1) is H, oxygen double-bonded with carbon of the heterocyclic ring, CH3, OH, or an alkyl chain optionally including a functional group. X1 in Formula (1) is H, CH3, CO, C(O)OC2H5, C(O)OC3H7, C(O)OCH(CH3)2, C(O)OC(CH3)3, C(O)OCH3, C(O)CH3, or C(O)C2H5.
一个实施方案中的
二氧化碳吸收剂包括由式(1)表示的杂环胺,该杂环胺在式(1)中杂环所包含的任何一个
氨基的 pKa 在 7.0 或以上至 8.6 或以下的范围内,以及在 1 atm 下沸点为 150° C 或以上的有机溶剂。杂环胺和有机溶剂的总质量占
二氧化碳吸收剂的 70 质量%或以上至 100 质量%或以下。式(1)中的 R1 至 R4 分别为 H、与杂环碳双键的氧、
CH3、OH 或任选包括一个官能团的烷基链。式(1)中的 X1 是 H、 、CO、C(O)O 、C(O)OC3H7、C(O)OCH( )2、C(O)OC( )3、C(O)O 、C(O) 或 C(O)
C2H5。