A quantitive microscale dynamic column breakthrough apparatus for measurement of unary and binary adsorption equilibrium on milligram quantities of adsorbent

Abstract

A 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 μDCB is a low cost system that can be constructed through minor modifications of a commercial gas chromatograph and uses a thermal conductivity detector. The small scale of the apparatus allows for the rapid collection of dynamic column breakthrough experiments. The mass balances for adsorption and desorption experiments were derived along with a description of the blank. 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 measured equilibrium data agreed well with volumetrically collected data. These measurements are both accurate and precise. Multicomponent adsorption was also studied on zeolite 13X and activated carbon for CH4/N2 and CO2/CH4 mixtures. This data was compared with ideal and adsorbed solution theory, extended dual-site Langmuir calculations and the literature.

Simultaneous Estimation of Gas Adsorption Equilibria and Kinetics of Individual Shaped Adsorbents

“…We can circumvent this issue by either employing a more sensitive gas detector or by performing a simple mass balance forgoing the full curve fit, to obtain the adsorption capacity at high partial pressures. 38 Finally, note that we cannot quantitatively validate the estimated kinetic rate constants due to the unavailability of an independent commercial measurement technique.…”

“…Some of these techniques also enable studying multicomponent systems. 30,32,38,53,54 Driven by this momentum, we have developed the material characterization pipeline presented in this work to use less than 100 mg of a given adsorbent to obtain both the textural and adsorption properties.…”

“…Despite the large quantity of sample required, these setups enable studying competitive adsorption, adsorption kinetics and complex mass, momentum and heat transfer dynamics in a packed bed column. 7,[33][34][35][36][37][38] The third approach, referred to as zero length column (ZLC) technique, involves performing dynamic gas sorption experiments in an purpose-built adsorption column with a few milligrams of the sample. [39][40][41] This technique facilitates a reliable extraction of information on adsorption equilibrium, and diffusion behavior, particularly for strongly adsorbing gases.…”