A Novel Biphasic Absorbent for Liquid-Solid Phase Separation Induced by Nanoparticle Polarity Difference and...

Area of Science:

• Chemical Engineering
• Materials Science
• Environmental Science

Background:

• Liquid absorption is a mature technology for direct air capture (DAC) but suffers from high energy costs and poor stability.
• Biphasic solvent systems offer low-energy CO2 regeneration but are sensitive to humidity and degradation.

Purpose of the Study:

• To develop a stable nanoparticle-coupled biphasic ionic liquid system for direct air capture.
• To overcome the limitations of existing liquid absorption and biphasic solvent systems for DAC.

Main Methods:

• Development of a nanoparticle-coupled biphasic ionic liquid system ([AEP][1,2-DMI]-DMSO-H2O/MgO).
• Investigation of CO2 transport and phase transition kinetics.
• Evaluation of regeneration energy and cycling stability.

Main Results:

• The system achieved 79.5% CO2 concentration in a minimal solid phase with high loading capacity (0.65 mol·mol-1 total).
• Ultralow regeneration energy of 0.94 GJ·t-1CO2 was recorded.
• Exceptional cycling stability with >96.5% efficiency retention over 7 cycles was demonstrated.

Conclusions:

• The nanoparticle-enhanced biphasic ionic liquid system represents a significant advancement in liquid DAC technology.
• This breakthrough unifies ultralow energy consumption with excellent operational stability.
• The developed system pushes DAC technology towards a new stage of practical development.