As an emerging green and sustainable
solvent, a deep eutectic solvent
(DES) applied to the carbon capture process is considered to be a
promising absorbent. This work aims to comprehensively evaluate the
potential and effectiveness of DESs for CO2 capture. First,
a hydrophobic DES, which is composed of tetrabutylammonium bromide
as the hydrogen bond acceptor (HBA) and decanoic acid as the hydrogen
bond donor (HBD) with a molar ratio of 1:2, was screened out from
280 DESs by the conductor-like screening models–segment activity
coefficient (COSMO-SAC) model. Then, quantum chemistry methods were
used to investigate the interaction mechanism between the DES and
CO2. The results show that the interactions between CO2 and the DES are mainly weak hydrogen bonds and van der Waals
dispersion attraction forces. Next, gas–liquid equilibrium
experiments were performed to investigate the effects of temperature
and pressure, the types of HBAs and HBDs, and the molar ratios of
HBA to HBD on the solubility of CO2. The results show that
the process of DES absorbing CO2 obeys Henry’s law
and confirm the reliability of the COSMO-SAC model prediction. Finally,
a rigorous rate-based model for the DES-based postcombustion CO2 capture process was simulated, and the life cycle environmental
sustainability was evaluated and compared with that of the traditional
solvent monoethanolamine, confirming the advantages of the negligible
vapor pressure, thermal stability, and low ecological toxicity of
the DES. This study provides a technical reference for applying new
solvents developed in the laboratory to practical industrial processes.