How do Kinetic Separations work? скачать в хорошем качестве

How do Kinetic Separations work?

The focus of this presentation is on mixture separations that are driven by differences in intra-crystalline diffusivities of guest molecules in micro-porous crystalline adsorbent materials. Such “kinetic” separations serve to over-ride, and reverse, the selectivities dictated by mixture adsorption equilibrium. The Maxwell-Stefan formulation for description of intra-crystalline fluxes shows that the fluxes of each species is coupled with that of partner species. For binary mixtures, the coupling is quantified by a two-dimensional matrix of thermodynamic correction factors; these elements can be determined from the model used to describe mixture adsorption equilibrium. If the thermodynamic coupling effects are essentially ignored, the M-S formulation degenerates to yield uncoupled flux relations. The significance of thermodynamic coupling is highlighted by detailed analysis of separations of three different mixtures: N2/CH4, N2/O2, and CO2/C2H6 using LTA-4A, and DDR zeolites. We demonstrate the strong influence of thermodynamic coupling on transient mixture uptakes. The transient overshoots in the uptake of the more mobile partner is traceable to thermodynamic coupling influences; such influences are signatures of kinetic separations. Thermodynamic coupling effects are also of importance in transient breakthroughs in fixed beds; ignoring thermodynamic coupling results in lower productivity of the desired purified product. For background details refer to my paper: Krishna, R. Fundamental Insights into Intra-Crystalline Diffusional Influences on Mixture Separations in Fixed Bed Adsorbers. Chem Bio Eng. 2024, 1, 53-66. https://doi.org/10.1021/cbe.3c00057. Watch also: What drives kinetic separations?, Nitrogen removal from Natural Gas, N2/CH4 Separations with Ba-ETS-4, N2/CH4 Separations with Ba-RPZ, N2/CH4 diffusion in LTA-4A, Kinetic C3H6/C3H8 Separations with CHA zeolite, Factors Influencing Kinetic Separation, Particle Size Effects in Kinetic Separations, Diffusional Time Constants and Contact Times, LDF vs Maxwell-Stefan in PSA, C2H4/C2H6 Separations with Co-gallate, The Need for Maxwell-Stefan Formulation in PSA Modelling, LDF Model for Intra-Particle Diffusion, Metrics for Evaluation of MOFs, Transient Breakthrough Simulations, that are available for viewing on my YouTube channel    / @rajamanikrishna250