Temperature and CO₂ responsive polyethylenimine for highly efficient carbon dioxide release

Post combustion carbon dioxide capture with aqueous polymer solutions is a field of major interest. Via acylation of commercially available polyethylenimine (b-PEI) with butyric anhydride, lower critical solution temperature (LCST) behaviour together with a reversible pH shift was found in water as well as in CO₂ containing aqueous solutions. As expected, a low CO₂ absorption capability of the acylated thermosensitive b-PEI was measured in a stirred tank reactor. However, the observed improved CO₂ release in the desorption process associated with the LCST behaviour of the polymer is a "green" tool to face high efficiency loss in standard CO₂ capturing processes.