Separation of the Chlorofluorocarbon (CFC) CClF from N in NaY Zeolite, in MIL-127(Fe) and in the two Carbon Nanotubes CNT (9,9) and CNT (11,11).

Four well-suited porous materials for the selective adsorption of the most prominent CFC, which is CClF, from the air are carbon nanotubes CNT (9,9) and CNT (11,11), NaY zeolite, and the Metal Organic Framework MIL-125(Fe). The adsorption has been investigated through molecular simulations. Simulation results and theoretical considerations show that reasons for the extraordinarily high selectivity in all four cases were found to be the differences in the enthalpy of adsorption for the various adsorbed gases rather than steric reasons.

Exceptionally high selectivity in the separation of light hydrocarbons by adsorption on MIL-127(Fe) and on a (9,9) carbon nanotube.

Porous solids with channel sizes that are not much above the size of small hydrocarbons can yield extremely large adsorption selectivity. Our Grand Canonical Monte-Carlo simulations indicate exceptionally high selectivity for the separation of methane, ethane and propane from natural gas. At 250 K the CH/CH separation on MIL-127 at low pressure has a selectivity of more than 1000 and the CH/CH separation on CNT (9,9) is even above 2000.

Adsorption and the Chemical Reaction NO ↔ 2NO in the Presence of N in a Gas Phase Connected with a Carbon Nanotube.

The paper shows, by molecular simulations, that a CNT (9,9) carbon nanotube allows very efficient separation of nitrogen oxides (NO ) from N, that has in good approximation properties of the complete air mixture. Gibbs ensemble Monte Carlo simulations are used to describe the adsorption. The permanent chemical reaction between NO and NO, which occurs simultaneously to adsorption, is treated by the reactive Monte Carlo simulation.

Combined Adsorption and Reaction in the Ternary Mixture N, NO, NO on MIL-127 Examined by Computer Simulations.

A high selectivity of NO over N (simulating air) is found in silico when studying the adsorption of the ternary mixture NO/NO/N on the metal-organic framework MIL-127(Fe) by molecular simulations under consideration of the recombination reaction NO ↔ 2NO. The number of N atoms in nitrogen oxides NO and that in N is used to define a selectivity of the combined adsorption and chemical recombination that can reach values of about 1000.

The permeation of methane molecules through silicalite-1 surfaces.

The permeation of methane molecules through the silicalite-1 surfaces with and without silanol groups has been studied by nonequilibrium molecular dynamics computer simulations. A newly fitted intermolecular potential between the methane molecules and the silanol is used. A control volume provides a nearly stationary gas phase close to the membrane.

Influence of boundaries of nanoporous crystals on molecular exchange under the conditions of single-file diffusion.

We study the tracer exchange of molecules between the phase adsorbed in one-dimensional channels and the surrounding gas phase by molecular dynamics simulations. Under the conditions of single-file diffusion, a novel boundary effect is observed. The shape of the tracer-exchange concentration profiles deviates from those obtained under the conditions of normal diffusion.

Single-file diffusion near channel boundaries.

Molecular transport under the conditions of single-file diffusion was investigated near the channel boundaries by using dynamic Monte Carlo and molecular dynamics simulations of tracer exchange between single-file channels and their surroundings. The boundary effect reported in our recent papers (Vasenkov S.; Kärger, J.