(284e) Physicochemical Properties, Equilibrium and Kinetic Adsorption Performance, Manufacturability, and Stability of Tifsix-3-Ni for Direct Air Capture
AIChE Annual Meeting
2024
2024 AIChE Annual Meeting
Separations Division
Adsorption for Negative Emissions I
Tuesday, October 29, 2024 - 9:12am to 9:30am
The use of adsorbents for direct air capture (DAC) is regarded as a promising and essential carbon dioxide removal technology to help meet the goals outlined by the 2015 Paris Agreement. It is a challenging process due to the ultra-dilute concentration of CO2 in the air (~0.04%vol or 0.4 mbar) and varying ambient conditions (i.e. temperature and relative humidity), but it offers a route towards long-term carbon storage and allows the amount of CO2 captured to be quantitatively measured.
Ultramicroporous metal organic frameworks (MOFs) have gained significant attention for this application. To properly assess these adsorbents at scale, adsorbent screening should be conducted using key performance indicators determined from process modelling and optimization (i.e. purity, recovery, productivity, energy consumption). To facilitate such process scale evaluation, various adsorbent properties are required such as: equilibrium isotherms of all relevant species, heat and mass transfer coefficients, porosity, density (skeletal, particle, bed), heat capacity, and heat of adsorption. However, this data is not currently available for many promising ultramicroporous MOFs.
In this work, we assessed the potential of using TIFSIX-3-Ni, a previously reported ultramicroporous MOF [1], as a DAC adsorbent by measuring the physicochemical, equilibrium sorption, and kinetic sorption properties needed for, or relevant to, process scale evaluation [2]. We confirmed the successful synthesis of TIFSIX-3-Ni powder and reported its textural properties, thermal stability, and specific heat capacity. We also measured volumetric equilibrium adsorption isotherms of CO2, N2, Ar, O2, and H2O, and reported isotherm model fitting parameters and heats of adsorption for CO2, N2, and H2O (Figure 1). We easily scaled up the synthesis procedure of TIFSIX-3-Ni powder 4-fold but observed large variations in the textural properties and CO2 adsorption capacity between different batches. We also successfully pelletized TIFSIX-3-Ni powder with minimal loss in CO2 adsorption at 0.4 mbar, and we reported the skeletal, pellet, and bed density, total pore volume, and pellet porosity. For a particular batch of TIFSIX-3-Ni, the gravimetric and volumetric CO2 adsorption capacities at 0.4 mbar and 25 °C were 1.07 mmol g-1 and 0.62 mmol cm-3bed, respectively. Both adsorption capacities are higher than those previously reported for Lewatit VP OC 1065, a benchmark adsorbent for DAC [3]. TIFSIX-3-Ni also displayed faster adsorption kinetics than Lewatit VP OC 1065 when CO2 uptake experiments were fitted to a temperature-dependent linear driving force model. When subjected to humidity, TIFSIX-3-Ni is relatively stable at mild temperatures such as 25 °C, but it suffers a reduction in crystallinity, porosity, and CO2 adsorption at higher temperatures such as 40 °C. TIFSIX-3-Ni also has a relatively short lifetime and suffered decreased performance after 50 adsorption-desorption cycles in ambient air, or even storage in ambient air for 6 months.
Overall, our data enable initial process modelling and optimization studies to evaluate TIFSIX-3-Ni for DAC, which can help process this technology. They also highlight the possibility to pelletize TIFSIX-3-Ni without binder and the limited stability of the MOF under humid and oxidative conditions as well as upon multiple adsorption-desorption cycles.
Figure 1. a) CO2, b) N2, Ar, and O2, and c) H2O equilibrium adsorption isotherms for TIFSIX-3-Ni. Filled symbols represent the measured experimental data and solid lines represent the isotherm model fitting results. Adapted from Low et al., Physicochemical properties, equilibrium adsorption performance, manufacturability, and stability of TIFSIX-3-Ni for direct air capture, ChemRxiv, 2024 [2].
References:
Ultramicroporous metal organic frameworks (MOFs) have gained significant attention for this application. To properly assess these adsorbents at scale, adsorbent screening should be conducted using key performance indicators determined from process modelling and optimization (i.e. purity, recovery, productivity, energy consumption). To facilitate such process scale evaluation, various adsorbent properties are required such as: equilibrium isotherms of all relevant species, heat and mass transfer coefficients, porosity, density (skeletal, particle, bed), heat capacity, and heat of adsorption. However, this data is not currently available for many promising ultramicroporous MOFs.
In this work, we assessed the potential of using TIFSIX-3-Ni, a previously reported ultramicroporous MOF [1], as a DAC adsorbent by measuring the physicochemical, equilibrium sorption, and kinetic sorption properties needed for, or relevant to, process scale evaluation [2]. We confirmed the successful synthesis of TIFSIX-3-Ni powder and reported its textural properties, thermal stability, and specific heat capacity. We also measured volumetric equilibrium adsorption isotherms of CO2, N2, Ar, O2, and H2O, and reported isotherm model fitting parameters and heats of adsorption for CO2, N2, and H2O (Figure 1). We easily scaled up the synthesis procedure of TIFSIX-3-Ni powder 4-fold but observed large variations in the textural properties and CO2 adsorption capacity between different batches. We also successfully pelletized TIFSIX-3-Ni powder with minimal loss in CO2 adsorption at 0.4 mbar, and we reported the skeletal, pellet, and bed density, total pore volume, and pellet porosity. For a particular batch of TIFSIX-3-Ni, the gravimetric and volumetric CO2 adsorption capacities at 0.4 mbar and 25 °C were 1.07 mmol g-1 and 0.62 mmol cm-3bed, respectively. Both adsorption capacities are higher than those previously reported for Lewatit VP OC 1065, a benchmark adsorbent for DAC [3]. TIFSIX-3-Ni also displayed faster adsorption kinetics than Lewatit VP OC 1065 when CO2 uptake experiments were fitted to a temperature-dependent linear driving force model. When subjected to humidity, TIFSIX-3-Ni is relatively stable at mild temperatures such as 25 °C, but it suffers a reduction in crystallinity, porosity, and CO2 adsorption at higher temperatures such as 40 °C. TIFSIX-3-Ni also has a relatively short lifetime and suffered decreased performance after 50 adsorption-desorption cycles in ambient air, or even storage in ambient air for 6 months.
Overall, our data enable initial process modelling and optimization studies to evaluate TIFSIX-3-Ni for DAC, which can help process this technology. They also highlight the possibility to pelletize TIFSIX-3-Ni without binder and the limited stability of the MOF under humid and oxidative conditions as well as upon multiple adsorption-desorption cycles.
Figure 1. a) CO2, b) N2, Ar, and O2, and c) H2O equilibrium adsorption isotherms for TIFSIX-3-Ni. Filled symbols represent the measured experimental data and solid lines represent the isotherm model fitting results. Adapted from Low et al., Physicochemical properties, equilibrium adsorption performance, manufacturability, and stability of TIFSIX-3-Ni for direct air capture, ChemRxiv, 2024 [2].
References:
- Kumar et al., "Hybrid ultramicroporous materials (HUMs) with enhanced stability and trace carbon capture performance," Chem Commun (Camb), vol. 53, no. 44, pp. 5946-5949, May 30 2017, doi: 10.1039/c7cc02289a.
- M.-Y. Low et al., "Physicochemical properties, equilibrium adsorption performance, manufacturability, and stability of TIFSIX-3-Ni for direct air capture," ChemRxiv, 2024, doi: 10.26434/chemrxiv-2024-r5qsk.
- M.-Y. Low, D. Danaci, H. Azzan, R. T. Woodward, and C. Petit, "Measurement of Physicochemical Properties and CO2, N2, Ar, O2, and H2O Unary Adsorption Isotherms of Purolite A110 and Lewatit VP OC 1065 for Application in Direct Air Capture," J Chem Eng Data, vol. 68, no. 12, pp. 3499-3511, Dec 14 2023, doi: 10.1021/acs.jced.3c00401.
