A Complete Set of Experimental Devices for the Determination of the Gas Separation Capacity of Adsorbents

Abstract

In this work, we present a complete experimental procedure which aims at measuring adsorption isotherms, selectivity curves and kinetics of air compounds on porous media in broad ranges of pressure and temperature. The experimental set-up and the experimental procedures are presented as well as a complete report on treatments of the rough experimental results to obtain the adsorption isotherms, selectivity and kinetics curves. Results are provided for nitrogen/LiLSX and oxygen/LiLSX systems (adsorption isotherms curves at 278 and 303 K in the pressure range 0-400 kPa), for a binary mixture nitrogen/oxygen/LiLSX system at 303 K and 400 kPa (selectivity curves). Kinetics curves are presented for nitrogen/LiLSX and oxygen/LiLSX systems at 303 K and 400 kPa.

Metal–organic frameworks for H2and CH4storage: insights on the pore geometry–sorption energetics relationship

“…The recorded uptakes for O 2 and N 2 in 1 were comparable. This is in contrast to commonly observed preferential N 2 uptake, compared with O 2 , in numerous examples of zeolites (Talu et al, 1996;Hutson et al, 1999;Agha et al, 2005). In the case of most MOFs and zeolites, preferential N 2 sorption is attributed to stronger interactions between N 2 molecules and the material surface due to a larger quadrupole moment of N 2 .…”

Tracing Experimentally Compatible Dynamical and Structural Behavior of Atmospheric N2/O2 Binary Mixtures within Nanoporous Li–LSX Zeolite: New Insights to Influence of Extra-Framework Cations by MD Simulations

“…This observation from Figure is in very good agreement with previous experimental adsorption reports ,, which showed only Li–III sites in the supercages of Li–LSX zeolite framework are available to interact with guest gases such as N 2 and H 2 . The accessible Li–III cationic sites are in a high energy, low coordination environment in the supercages, while other Li + cations further imbedded in the framework and are sterically inaccessible to guest molecules …”

“…The accessible Li−III cationic sites are in a high energy, low coordination environment in the supercages, while other Li + cations further imbedded in the framework and are sterically inaccessible to guest molecules. 35 Figure S11 shows the RDF curves between center of mass of N 2 or O 2 and oxygen, aluminum, and silicon atoms of the rigid framework of Li−LSX zeolite for "mix 16−4" at 400 K. Both guest molecules show similar behavior and do not have strong structural correlations with O, Al, and Si framework sites.…”

“…Li–LSX zeolite has been used for a long time in chemical industry for the effective separation of N 2 from air in dry conditions − by cyclic pressure or vacuum swing adsorption (PSA/VSA) processes, and particularly for ∼90% O 2 production from ambient air. Previous studies emphasize the selective adsorption of N 2 due to the larger permanent quadrupole moment of N 2 compared to that of O 2 .…”

High Pressure Excess Isotherms for Adsorption of Oxygen and Nitrogen in Zeolites

“…Adsorbents considered most commonly are inorganic materials, such as zeolites, which are not combustible in contrast to carbonaceous materials. Izumi and Suzuki 3,4 studied oxygen adsorption on NaX zeolite at a total pressure of 120 kPa and temperatures of 213, 243, 273, and 298 K. Isotherm data at pressures up to 30 bar have been reported for several zeolite-type materials, 5À10 including 5A, 5,6 LiLSX, 7 ETS-4 (a small pore titanium silicate), 8 AlPO 4 -5, 9 and SAPO-5. 9 Higher pressure oxygen isotherm data are found in the literature for only AX-21, a superactivated carbon, for pressures up to 100 bar and temperatures of 118À313 K. 11 These experimentally measured isotherms are exclusively represented as excess quantities adsorbed because it is impossible to differentiate between molecules confined in the adsorbed phase and molecules in the bulk fluid phase.…”