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A parametric study was carried out to improve the cyclic performance of the three-bed pressure−vacuum swing adsorption (PVSA) process, which consisted of two zeolite 10X beds for equilibrium separa...

To produce O2 with a high purity of 99+% and a high productivity from various oxygen-rich feeds, a parametric study was done on a six-step pressure swing adsorption (PSA) purifier using carbon molecular sieve (CMS). The cyclic performances of the PSA process such as purity, recovery, and productivity were compared under nonisothermal conditions. To study the effects of N2 amount on the PSA purifier, various feeds with 90% O2 or more were experimentally and theoretically applied for the PSA process. Since N2 plays a key role in product purity, the maximum purity of the PSA was 99% O2 with 51.5% recovery from a higher nitrogen feed (O2:Ar:N2; 90:4:6 vol %) and 99.8% O2 with 56.9% recovery from a lower nitrogen feed (O2:Ar:N2; 95:4:1 vol %) within the experimental range. The adsorption step time and feed flow rate served as key operating variables in the purification of the oxygen-rich feeds because the concentration wave fronts of minor impurities such as N2 and Ar were controlled by kinetic selectivity. To...

Adsorption characteristics in a layered bed packed with activated carbon and zeolite 5A were studied experimentally and theoretically through the breakthrough experiments of binary (H2/CO, H2/CH4, H2/CO2), ternary (H2/CH4/CO), and five-component (H2/CH4/CO/N2/CO2) systems. The effects of adsorption pressure, feed flow rate, and carbon-to-zeolite ratio on the breakthrough curve in a layered bed were observed. Breakthrough curves in all of the mixtures showed tailing due to temperature variance in the bed by the heat of adsorption. In the layered bed, each mixture showed the specific characteristics of concentration and temperature wave fronts in each layer. Although the amount of impurity in a ternary mixture is larger than that in a binary mixture, the breakthrough time and elongation depending on the adsorption pressure and flow rate showed an intermediate value between the results of the H2/CO and H2/CH4 mixtures, and the tailing was not much different from those in these binary systems. Also, the roll-...