Efficient CO2 capture by non-aqueous 2-amino-2-methyl-1-propanol (AMP) and low temperature solvent regeneration

An experimental study describes the reversible fixation of CO2 by non-aqueous solutions of 2-amino-2-methyl-1-propanol (AMP). The captured CO2 is stored in solution as AMP carbamate and alcohol carbonates in different relative amounts as a function of the CO2-AMP ratio. The identification and the quantification of the species in solution were obtained from C-13 NMR spectroscopic analysis. The bench-scale experiments of CO2 fixation and solvent regeneration have been carried out in a continuous cycle where the CO2-loaded and regenerated solutions are continuously circulated between the desorber and absorber. The carbonated solutions are decomposed in the desorber at 80-90 degrees C to regenerate the free amine for its reuse, affording CO2 absorption efficiency over 90%. The replacement of water with an organic solvent and the relatively low temperature of the desorption-regeneration step, could have the potential of reducing some disadvantages of aqueous absorbents, namely the amine loss by degradation and evaporation, equipment corrosion and energy cost of the regeneration step, yet preserving the high efficiency of aqueous amines.