Highly efficient carbon dioxide capture by a novel amine solvent containing multiple amino groups

BACKGROUNDAqueous solutions of amine are considered to be effective absorbents for CO2 capture. Special attention is increasingly being given to developing efficient solvents with both high absorption rate and absorption loading for CO2 capture. RESULTSA novel amine 2-[(3-aminopropyl)methylamino]ethanol (HMPDA) containing a primary amino group and a tertiary amino group was screened to improve the CO2 absorption performance. The equilibrium loading of CO2 in aqueous HMPDA solution was found to be 1.65mol CO2 mol(-1) HMPDA at 313K and 1 MPa, which is larger than those of conventional amines like monoethanolamine (MEA, 0.75mol CO2 mol(-1) MEA) and N-methyldiethanolamine (MDEA, 1.05mol CO2 mol(-1) MDEA) at 313K and 1 MPa. Moreover, the HMPDA solution demonstrated a faster absorption rate of CO2 than those of MEA and MDEA solutions. The viscosity of HMPDA solution increases by around 66% after CO2 absorption, which is smaller than the 88% increase of MEA solution. CONCLUSIONSEfficient results for CO2 absorption using HMPDA were obtained through assessing the absorption rate, absorption loading of CO2 and related physical properties. This novel amine shows both fast absorption rate and high absorption loading due to the multiple-site reaction elaborated by the zwitterion and single-step termolecular mechanism. (c) 2015 Society of Chemical Industry