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

Abstract

Abstract BACKGROUND Aqueous solutions of amine are considered to be effective absorbents for CO 2 capture. Special attention is increasingly being given to developing efficient solvents with both high absorption rate and absorption loading for CO 2 capture. RESULTS A novel amine 2‐[(3‐aminopropyl)methylamino]ethanol ( HMPDA ) containing a primary amino group and a tertiary amino group was screened to improve the CO 2 absorption performance. The equilibrium loading of CO 2 in aqueous HMPDA solution was found to be 1.65 mol CO 2 mol −1 HMPDA at 313 K and 1 MPa , which is larger than those of conventional amines like monoethanolamine ( MEA , 0.75 mol CO 2 mol −1 MEA ) and N‐methyldiethanolamine ( MDEA , 1.05 mol CO 2 mol −1 MDEA ) at 313 K and 1 MPa . Moreover, the HMPDA solution demonstrated a faster absorption rate of CO 2 than those of MEA and MDEA solutions. The viscosity of HMPDA solution increases by around 66% after CO 2 absorption, which is smaller than the 88% increase of MEA solution. CONCLUSIONS Efficient results for CO 2 absorption using HMPDA were obtained through assessing the absorption rate, absorption loading of CO 2 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. © 2015 Society of Chemical Industry