Role of Adsorption-Induced Deformation on Gas Self-Diffusivity in a Flexible Microporous Coal Matrix

Langmuir, Journal Year: 2025, Volume and Issue: unknown

Published: April 22, 2025

Adsorption-induced deformation has long been underappreciated in gas transport studies of microporous coal, yet it strongly influences pore configurations and diffusive pathways. Here, a hybrid grand canonical Monte Carlo (GCMC)/molecular dynamics (MD) approach equilibrium MD (EMD) simulations are employed to investigate how matrix flexibility reshapes structures and, turn, impacts CH4 CO2 self-diffusion connected networks under various loadings. The results show that coal enhances adsorption, with exhibiting greater uptake volumetric strain than CH4. A universal linear relationship emerges among loading, free volume ratio, coefficients for both rigid flexible matrices. In matrices, this linearity features gentler slope, indicating reduced diffusion sensitivity diminishing By comparing geometrical effective tortuosity, is revealed adsorbing induces significant swelling complex local rearrangements at elevated loadings, pushing tortuosity far beyond rigid-matrix levels, whereas CH4─with weaker adsorption─drives smaller, more uniform structural adjustments only mildly increase tortuosity. These differences directly reflect changes path complexity, which turn governs behavior. Collectively, the findings clarify dynamic coupling between deformation, self-diffusivity offering critical guidance enhanced recovery sequestration strategies rely on accurate modeling deformable media.

Language: Английский

Simulation of Water Vapor Sorption Profiles on Activated Carbons in the Context of the Nuclear Industry

Separations, Journal Year: 2025, Volume and Issue: 12(5), P. 126 - 126

Published: May 14, 2025

Activated carbons (ACs) are employed in the nuclear industry to mitigate emission of potential radioactive iodine species. Their retention performances towards mainly dependent on relative humidity due competitive effect induced by adsorbed water molecules. Thus, this work will focus prediction AC behavior toward capture vapor better assess poisoning radiotoxic removal. For first time, H2O breakthrough curves (BTCs) grade ACs predicted through a specific methodology based combination transport phenomena with adsorption kinetics and equilibrium. Three ACs, similar those deployed context, considered within present study. Our model is Linear Driving Force Model (LDF), governed an intraparticle diffusion mechanism, notably surface Knudsen diffusions. In addition, type V isotherms obtained for investigated carbon supports were described Klotz equation, taking into account formation progressive growth clusters internal porosity. This allowed us successfully simulate non-impregnated AC, where only physisorption involved. promising results highlighted when extrapolating two other impregnated (AC 5KI Nuclear).

Language: Английский

Acoustic response of molecular adsorption and sound propagation in nanoporous materials

Physical Review Materials, Journal Year: 2025, Volume and Issue: 9(5)

Published: May 7, 2025

Language: Английский