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Adsorption Kinetics of CO2 Under Rotation
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DOI:10.3390/chemengineering10050064.png)
Abstract
En 中文
The effect of high-gravity fields, generated by rapid rotation, on CO2 adsorption in activated carbon beds is examined. Adsorption-desorption kinetics is monitored before, during, and after short rotation periods at up to 5000 rpm. Rotation induced a reproducible transient bump in headspace pressure, quantitatively attributed to a centrifugal free energy shift (~12.2 J/mol) that overfilled weak adsorption sites beyond their static equilibrium. The bump mechanism is described by fold catastrophe theory, with a critical angular velocity (ωc = 3500 rpm) triggering a sudden transition to a high-occupancy branch. Post-rotation, constant-rate zero-order desorption from shallow sites overlapped with a slower pseudo-first-order adsorption process as deep, previously inaccessible pores became available, increasing CO2 capacity by 2.5%. Kinetic modeling produced an apparent diffusivity of 1.2 × 10−5 m2/s and a structural accessibility time constant of ~25 h. Thermodynamic analysis showed that rotation improved the overall free energy of adsorption and altered entropy in a manner consistent with the observed adsorption-desorption sequence. These results demonstrate that rotational fields can enhance CO2 uptake, modify kinetic pathways, and trigger threshold phenomena in porous adsorbents.
Keywords:
direct air capture
rotation
CO<sub>2</sub> adsorption
activated carbon
Journal
IF:
3.4
Papers:
328
Citations:
1.6K
