Study of the adsorption and desorption of multiple adsorbates in a fixed bed

Abstract

An experimental and theoretical study was made of the adsorption of ethanelpropane mixtures from nitrogen or helium. The study also covered the desorption of the mixtures using a purge of hot nitrogen or helium. The adsorbent was Witco JXC activated carbon. A nonequilibrium, mechanistic model was developed and was shown to represent both adsorption and desorption processes. The model utilized mixture isotherm data predicted by the Flory Huggins form of the vacancy solution model. Both adsorption and hot purge regeneration were found to be intraparticle rate controlled processes, with surface diffusion dominating the intraparticle mass transfer mechanism. The dynamic model can be used for the simulation of a variety of commercial adsorption and desorption conditions.

Adsorption dynamics of a layered bed PSA for H2recovery from coke oven gas

“…The well-known roll-up phenomenon results from the Adsorption bed wd\ initidlly LatUrdted with H 2 at 299 15 K and 10 dtm fact that weakly adsorbed components lose their adsorption sites due t o the competitive adsorption of more strongly adsorbed components that follow the preceding wavefronts of weakly adsorbed components. The desorbed adsorbates join the bulk stream and increase the concentration more than feed concentration (Huang and Fair, 1988;Chlendi et al, 1995).…”

“…The stoichiometric breakthrough times are comparable to the experimental and predicted breakthrough times. Because of the preferential and competitive adsorption among the adsorbates, the kinetic effects of the adsorption rate, and temperature variations in the adsorption bed, the stoichiometric breakthrough times of a PSA process may shift to the left or right of the experimental breakthrough times (Huang and Fair, 1988).…”

Adsorption dynamics and effects of carbon to zeolite ratio of layered beds for multicomponent gas adsorption

“…The well-known roll-up phenomenon results from the fact that weakly adsorbed components lose their adsorption sites due to the competitive adsorption of the stronger adsorbed components that follow the preceding wavefronts of weakly adsorbed components. The desorbed adsorbates join the bulk stream and increase the concentration more than the feed concentration [8,23]. These breakthrough curve phenomena were reflected in the temperature profile.…”

Steam Regeneration of Adsorbents: An Experimental and Technical Review

“…Regeneration is expected to be complete when effluent gas temperature reaches to regeneration temperature 26 , however this is not applicable to adiabatic systems. Regeneration time is also defined as time at which effluent gas concentration reaches 1% of feed gas concentration 25,27 . Urano et al 28 reported following five elementary processes taking place during steam regeneration of spent granulated activated carbon (GAC) from waste water treatment plant.…”