A simulation-based model studying monoethanolamine and aprotic heterocyclic anion ionic liquid (AHA-IL) mixtures for carbon capture

•Carbon capture with MEA/ionic liquid solvent was modeled using Aspen Plus.•Hybrid MEA AHA-IL solvent has ∼32 % lower CO₂ regeneration energy than aqueous MEA.•Hybrid MEA AHA-IL solvent has ∼ 64 % lower viscosity than pure ionic liquid.•Hybrid solvents promote a higher diffusivity of CO₂ than pure ionic liquid. Capturing of waste CO2, particularly from large industrial point sources, is necessary for either permanent storage or CO2 utilization. Amine solvents used for carbon capture have certain drawbacks, particularly the high energy required by the reboiler for solvent regeneration and degradation of the amine with absorption/regeneration cycling. These challenges may be overcome using ionic liquids (ILs) that can be tailored for operating under typical flue gas stream conditions (8–10 % CO2, 18–20 % H2O, 2–3 % O2, and 67–72 % N2). ILs, however, oftentimes suffer from high viscosities, leading to diffusion limitations when compared to amine solvents. This work models the combinations of aprotic heterocyclic anion ILs (AHA-IL) with monoethanolamine (MEA) and studies the carbon capture effectiveness of these mixtures. This study found that all AHA-IL/MEA mixtures exhibited 32 % lower enthalpy of reaction (compared to MEA) and 64 % lower viscosity (compared to AHA-IL), which are desirable characteristics for CO2 capture solvents.