Chemsuschem Chemistry And Sustainability, Energy & Materials 2012-09-01

Improved solvent formulations for efficient CO₂ absorption and low-temperature desorption.

Francesco Barzagli, Massimo Di Vaira, Fabrizio Mani, Maurizio Peruzzini

Index: ChemSusChem 5(9) , 1724-31, (2012)

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Abstract

This experimental study describes efficient CO₂ capture by 2-amino-2-methyl-1-propanol (AMP)/piperazine (PZ) in ethylene glycol monoethyl ether (EGMEE, 2-ethoxyethanol) containing approximately 15 wt % of water. In these experiments, the solvent is continuously circulated between the absorber (packed-bed reactor at 30, 40, or 45 °C) and the desorber (at 80, 85, or 90 °C). The CO₂ -solvent reaction equilibria have been investigated by using ¹³C NMR spectroscopy, which provides confirmatory evidence that the formation of mono- and biscarbamate derivatives of PZ accounts for most of the CO₂ absorbed by the AMP/PZ/EGMEE/H₂O blend. The solid-state structures of AMP carbamate and of the carbonate salt of protonated AMP have been determined by using XRD. Both AMPCO₂(-) and CO(3)(2-) species completely convert to the monoalkyl carbonates on dissolving the respective salts in methanol, ethanol, or ethylene glycol.Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.