On the Potential of Two Hindered Amines 2,2,6,6‐Tetramethylpiperidine and 2,2,6,6‐Tetramethyl‐4‐Piperidinol for CO ₂ Capture

ABSTRACT

Amine‐based reactive absorption is most widely applied for post‐combustion CO ₂ capture. Hindered amines are considered as promising solvents because they are moderately reactive and easily regenerable and load much CO ₂ . In this work, two hitherto unreported hindered amines 2,2,6,6‐tetramethylpiperidine (TMP) and 2,2,6,6‐tetramethyl‐4‐piperidinol (TMP‐OH) were explored. Solution properties such as density, viscosity, Henry's law constant, N ₂ O diffusivity, absorption rate, equilibrium CO ₂ solubility, cyclic loading capacity, desorption rate and efficiency were measured and reported. The outcomes for the TMP‐OH application were especially encouraging, viz. a reaction rate constant of 1057 M ⁻¹ s ⁻¹ at 308 K, loading capacity in the 0.82–1.02 mol/mol range and desorption efficiency of 78.1%. This study will kindle more interest in these candidate solvents in future.