Adsorption equilibria of binary gas mixtures on rigid solid adsorbents like activated carbons (AC) and molecular sieves (MS) can be measured “on line” by combining the (well known) gravimetric and the volumetric method. The resulting volume‐gravimetric method is described. Also the basic equations necessary to calculate the masses of each of the two adsorbed components are formulated. Explicit solutions for binary ideal gas adsorptives are given. The experimental device used for measurement is outlined. Data for coadsorption equilibria of a N2/CH4 mixture on activated carbon AK WS IV‐G 20575 at T = 298 K in the pressure range 1–20 bar are reported and discussed to a certain extend.
Adsorption equilibria of He, Ar, N2, CH4 on several types of activated carbon (AC) and molecular sieves (MS) have been measured at ambient temperature in the pressure range 0 MPa-15 MPa using a microbalance (Sartorius 4104 S). The resulting experimental data on principle only allow to calculate the difference (m-pfVds) between the net mass adsorbed m, and the buoyancy related volume Vas of the adsorbent/ adsorbate system multiplied by the density of the (fluid) adsorptive pf. To determine simultaneously m and Vus, the data are fitted to an analytic adsorption isotherm in = in (pf,T) of generalized Langmuir-Freundlich type and/or Dubinin-Radushkeviz type, and to one of four different models for the volume V"', including the so-called helium volume, this quantity considered to be constant. -The two times four adsorption isotherms (AI) resulting in this way do not differ much for low pressures (p < 1 MPa), however tend to differ considerably at higher pressures, the helium volume related A1 leading to thermodynamic inconsistencies! As a result it can be stated that the buoyancy related apparent volume VaS of a porous adsorbent/adsorbate system strongly depends on the adsorptive used, i.e. on the size of its molecules, and also, to lesser extend, on the amount of mass adsorbed. Consequently, Vas should not simply be identified with the helium volume but instead specified for different adsorptives and pressure ranges used in industrial adsorption processes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.