Continuous separation of oxygen from air has received a wide range of attention because of its industrial application.
The novel way of separating oxygen from air was found via the selective adsorption of oxygen on supported metal crystallites.
The air heated with exhausted gases from furnace can be enriched with oxygen by supported metal crystallites which has a capability of adsorbing oxygen only from air.
The adsorbed oxygen can be desorbed with air at temperatures slightly higher than adsorption temperatures.
Various metals (Pt,Fe,Cu,Zn and Co) were tested to find the best adsorbent for economic separation process which has a large adsorption capacity for oxygen and small difference in the temperature between adsorption and desorption cycle allow more cycle per unit time.
Co, Zn, Fe and Cu could adsorb oxygen from air at low temperatures (25-200℃), but their temperatures for maximum desorption rate was too high (400-550℃), which causes the time for each thermal swing cycle to be large.
Platinum was the best candidate for the economic separation of oxygen from air. The amount of oxygen desorbed is the largest among the metals.
The rates of adsorption and desorption were fast. Furthermore, the platinum crystallite sintered during the desoption process can be redispersed in the atmosphere of air at the high temperature (450-530℃).
But the slowest step was found to be the redispersion process, which remains to be improved for the commercial applications.
