Determination of multicomponent sorption equilibria using perturbation gas chromatography

Abstract

efficient method for obtaining sorption equilibria for systems with up to two vapor phase components at finite concentration. The objective of this work was to obtain a theoretical result that could be used for experimeptal determinations of sorption of multiple interfering species at finite concentration. Results obtained are applicable for both non-stoichiometric and stoichiometric situations for systems that may have flowing phase velocity and volume changes associated with interphase transport and also may have interactions among the sorbed components. The dependence of each effluent peak characteristic velocity upon all of the component equilibrium isotherms requires that the equilibria be considered as a whole by simultaneously fitting a set of composition grid perturbation response data to appropriate isotherm surface equations.

Adsorption of Off‐Gases from Steam Methane Reforming (H2, CO2, CH4, CO and N2) on Activated Carbon

“…If ZLC experiments are performed in the samples and analyzed using the long time response, only the resistance in the smaller micropores will be accounted and then results of ZLC and breakthrough curves may give large differences (38). For this reason we have employed perturbation chromatography methods (39). Due to the hazardous nature of carbon monoxide we have employed only pulses.…”

Integral Mass Balance (IMB) Method for Measuring Multicomponent Gas Adsorption Equilibria in Nanoporous Materials

“…Only differential adsorbed quantities can be determined, so a mathematical isotherm equation must be assumed in order to relate retention time to the amount of each component adsorbed. 42,43,45,46,53,55 Finally, one very different approach to measuring binary adsorption equilibrium is isotope exchange, which uses isotopic tracers. 57,58 Rynders et al, 57 for example, described a closed loop cycle method, in which a gas mixture is circulated through an adsorbent bed, before an isotope is switched into the flow.…”

“…Mathematically, these are differential equations, and some of the partial derivatives can be measured directly. Other multicomponent measurement methods, mostly based on gas chromatography, − therefore exploit this approach.…”

Gas adsorption isotherms from composition and flow-rate transient times in chromatographic columns I. Basic theory and a binary experimental test

“…Hyun & Danner (1985) have used a hybrid method in which the retention of a radioactive tracer is measured in addition to the chromatographic transient. The extra measurement may be avoided by assuming a form for the isotherms and thereby parametrizing the problem (van der Vlist & van der Meijden 1973;Ruthven & Kumar 1980), but there is no guarantee th at the assumed form is appropriate (see also Glover & Lau 1983).…”