Addressing the data gap in adsorption materials for direct air capture - an investigation of physicochemical, equilibrium sorption, and kinetic sorption properties
File(s)
Author(s)
Low, May-Yin
Type
Thesis
Abstract
Using adsorbents for direct air capture (DAC) is a promising and necessary carbon dioxide removal technology for climate change mitigation. However, the deployment of adsorption-based DAC technologies at scale still needs to be greatly accelerated. One area of focus is the development of new adsorbent materials for DAC, which subsequently need to be screened via process modelling and optimisation to assess their process scale performance. Yet, the adsorbent data needed to conduct this evaluation is rarely available.
This thesis aims to address this gap by measuring the physicochemical, equilibrium sorption, and kinetic sorption properties needed to facilitate the process scale evaluation of select adsorbents that represent three distinct classes of materials: polymeric resins, metal organic frameworks (MOFs), and zeolites. Polymeric resins are commercially available, and their amine functionality imparts high CO2 adsorption. Here, I conducted the first assessment of Purolite A110 for DAC and found that it often surpasses the adsorption performance of a benchmark DAC adsorbent, Lewatit VP OC 1065. Amongst MOFs, ultramicroporous MOFs exhibit high CO2 affinity and relatively low heat of adsorption. Here, I investigated TIFSIX-3-Ni and showed it could be a promising DAC adsorbent in terms of its CO2 uptake and manufacturability, but with limited stability under certain process conditions. Finally, zeolites are an industrially established class of adsorbents, though their hydrophilicity and relatively low CO2 adsorption at low pressure can be an obstacle for DAC. Here, I functionalised a commercially available “hydrophobic” zeolite with amine groups to combine hydrophobicity and CO2-philicity. Yet, the results showed that functionalisation caused poor CO2 adsorption kinetics and/or increased H2O adsorption.
Overall, this thesis increases the synergy between adsorbent and process development for DAC. The new adsorbent data provided can now facilitate process scale evaluation of these adsorbents, which can help advance the deployment of adsorption-based DAC technologies.
This thesis aims to address this gap by measuring the physicochemical, equilibrium sorption, and kinetic sorption properties needed to facilitate the process scale evaluation of select adsorbents that represent three distinct classes of materials: polymeric resins, metal organic frameworks (MOFs), and zeolites. Polymeric resins are commercially available, and their amine functionality imparts high CO2 adsorption. Here, I conducted the first assessment of Purolite A110 for DAC and found that it often surpasses the adsorption performance of a benchmark DAC adsorbent, Lewatit VP OC 1065. Amongst MOFs, ultramicroporous MOFs exhibit high CO2 affinity and relatively low heat of adsorption. Here, I investigated TIFSIX-3-Ni and showed it could be a promising DAC adsorbent in terms of its CO2 uptake and manufacturability, but with limited stability under certain process conditions. Finally, zeolites are an industrially established class of adsorbents, though their hydrophilicity and relatively low CO2 adsorption at low pressure can be an obstacle for DAC. Here, I functionalised a commercially available “hydrophobic” zeolite with amine groups to combine hydrophobicity and CO2-philicity. Yet, the results showed that functionalisation caused poor CO2 adsorption kinetics and/or increased H2O adsorption.
Overall, this thesis increases the synergy between adsorbent and process development for DAC. The new adsorbent data provided can now facilitate process scale evaluation of these adsorbents, which can help advance the deployment of adsorption-based DAC technologies.
Version
Open Access
Date Issued
2024-04-12
Date Awarded
01/08/2024
License URL
Advisor
Petit, Camille
Sponsor
Imperial College London
Publisher Department
Chemical Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)