Breakthrough curve of CO2 capture using amino-functionalized silica

“After functionalization and new dynamic characterization, the solids were used for an adsorption test operated in the confined-fluidized bed configuration. For each sample, two values of the fluidization velocity were chosen in order to analyze the effect of the flow rate on the level of CO2 capture: 5.7 and 8.6 cm/s for APTES20 and 6.9 and 10.9 cm/s for APTES40. Both values correspond to a condition expansion of the adsorbent over its incipient fluidization velocity threshold. It has to be borne in mind that all the gas fed to the fluidized bed is in contact with the adsorbent; in a packed-fluidized bed the bypass effect in the gas–solid contact typical of the bubbling regime is avoided, so that the value of the gas velocity directly influences the contact time between gas and particles as well as the mass and heat transfer rates. Figure 12Figure 13Figure 14 and Figure 15 show the breakthrough curves (the ratio between the concentration downstream and upstream of the adsorption column versus time) and the temperature trends for both amino-functionalized samples at various values of the superficial velocity of the gas mixture. In order to compare the performance of adsorbents with a different concentration of APTES, a mixture with 12.5% of CO2 was used in all the adsorption tests and a mass of sorbent of 100 g.”


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