Fully exchanged Cu-Rho remains in an open form upon dehydration, the d8r windows remain nearly circular and the occupancy of window sites is low, so that it adsorbs CO 2 rapidly at room temperature. EPR spectroscopy reveals Cu 2+ cations are present in the dehydrated forms and Rietveld refinement shows these prefer S6R sites, away from the d8r windows that control diffusion. The fully copper-exchanged form of Rho and mixed Cu,H- and Cu,Na-forms have been prepared. The flexibility of the zeolite Rho framework offers great potential for tunable molecular sieving. This data was compared with ideal and adsorbed solution theory, extended dual-site Langmuir calculations and the literature. Multicomponent adsorption was also studied on zeolite 13X and activated carbon for CH4/N2 and CO2/CH4 mixtures. These measurements are both accurate and precise. The measured equilibrium data agreed well with volumetrically collected data. The μDCB apparatus was tested with 238.9 mg of zeolite 13X and 180.2 mg of activated carbon with single-component N2/He and CH4/He adsorption and desorption measurements. The mass balances for adsorption and desorption experiments were derived along with a description of the blank. The small scale of the apparatus allows for the rapid collection of dynamic column breakthrough experiments.
The μDCB is a low cost system that can be constructed through minor modifications of a commercial gas chromatograph and uses a thermal conductivity detector. A number of case studies is finally presented exemplifying the effect of applying accurate blank corrections, demonstrating also the application to a nonlinear adsorption system.Ī microscale dynamic column breakthrough (μDCB) apparatus with the ability to measure unary and binary adsorption equilibrium on a milligram-scale quantity of adsorbent is described. The inverse procedure of deconvolution can in turn be applied to experimental data with adsorbent, to yield corrected data which can readily be modelled using standard tools for equilibrium and kinetic analysis. The methodology is firstly validated through fitting to experimental experiments without adsorbent present. It is shown that the model parameters are closely related to the physical characteristics of the setup components and as such they remain valid over a range of process conditions. The composite effect of the individual contributions is subsequently described through the method of convolution.
#Stiles chemical aquadine series#
The methodology considers the experimental setup as a series of mixing volumes with diffusive pockets whose contributions to the overall measured signal can be accurately described by simple model functions. In this study we present a new methodology for correcting experimental Zero Length Column data, to account for contributions to the measured signal arising from extra-column volumes and the detector.
0 kommentar(er)
