Charting the CO2 capture performance of a phase-change metal-organic framework in a pressure-vacuum swing adsorption process

13 June 2023, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Metal-organic frameworks (MOFs) that display step-shaped adsorption isotherms, i.e., phase-change MOFs, represent a relatively small subset of all known MOFs. Yet, they are rapidly emerging as promising sorbents to achieve excellent gas separation performances with little energy demand. In this work, we assessed F4_MIL-140A(Ce), a recently discovered phase-change MOF adsorbent for CO2 capture in two scenarios using a pressure-vacuum swing adsorption process, namely a coal-fired power plant flue gas (12.5 %mol CO2), and a steel plant flue gas (25.5 %mol CO2). Four CO2 and three N2 adsorption isotherms were collected on F4_MIL-140A(Ce) over a range of temperatures and modelled using a bespoke equation for step-shaped isotherms. We accurately measured the heat capacity of F4_MIL-140A(Ce), a key thermodynamic property for a sorbent, using a method based on differential scanning calorimetry that overcomes the issues associated with the poor thermal conductivity of MOF powders. We then used these experimental data as input in a process optimisation framework and we compared the CO2 capture performance of F4_MIL-140A(Ce) to that of other “canonical” sorbents, including, zeolite 13X, activated carbon and three MOFs (i.e., HKUST-1, UTSA-16 and CALF-20). We found that F4_MIL-140A(Ce) outranks other sorbents, in terms of recovery and purity, in most of the simulated process conditions. We attribute such promising performance to the non-hysteretic step-shaped isotherm, the low uptake capacity for N2 and the mild heat of CO2 adsorption displayed by F4_MIL-140A(Ce).


Metal-organic frameworks
Gas separation
Carbon capture

Supplementary materials

Electronic Supplementary Information
Supplementary figures - Adsorbent isotherm parameters and properties - Simulated adsorption isotherms - Update to adiabatic index


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.