Efficient Adsorption-Based Direct Air Capture Via Triply Periodic Minimal Surface Architectures

Area of Science:

• Chemical Engineering
• Materials Science
• Environmental Science

Background:

• Direct air capture (DAC) is crucial for climate change mitigation but faces challenges with energy demands and process efficiency.
• Conventional DAC contactors exhibit a trade-off between adsorbent capacity and mass transfer kinetics, hindering optimal performance.
• The structure-function relationship in CO2 capture contactors requires further elucidation.

Purpose of the Study:

• To overcome the capacity-kinetics trade-off in adsorbent-based DAC systems.
• To design and evaluate architected contactors fabricated using additive manufacturing for improved CO2 capture.
• To elucidate the impact of flow topology on DAC contactor efficiency.

Main Methods:

• Utilizing 3D-printed triply periodic minimal surface (TPMS) structures as active hydrodynamic substrates for DAC.
• Comparing the performance of TPMS-based contactors with conventional square-channel monoliths.
• Analyzing the effects of TPMS architecture on mass transfer boundary layer and energy consumption.

Main Results:

• Achieved a 70%-75% increase in fast adsorption sites and a 114% enhancement in CO2 productivity compared to conventional monoliths.
• TPMS architecture induced chaotic advection and stable vortices, significantly thinning the mass-transfer boundary layer.
• Reduced energy consumption by 51.8% through optimized flow dynamics.

Conclusions:

• Architected contactors, specifically 3D-printed TPMS structures, effectively overcome the capacity-kinetics trade-off in DAC.
• The demonstrated design principle of architected flow topology offers a transferable strategy for enhancing DAC contactor efficiency.
• This approach presents a promising pathway for more efficient and cost-effective CO2 capture technologies.