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Abstract
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In the present study, two adsorbents of zeolite 13X as a pure adsorbent and a
composite form of carbon- zeolite are synthesized in a hydrothermal method and then
characterized using a variety of conventional analyzing apparatuses including XRD,
XRF, BET, PSA, and SEM. After that, both adsorbents are used in CO2/ N2
separation system for an adsorption process. The mixture of these gases, are studied
as a representative of flue gas to remove CO2. For this reason, pure adsorption data of
CO2 and N2 were determined experimentally at three temperatures of (283, 303, and
323) K and pressures up to 1.6 bar in a volumetric method on the adsorbents both to
have the isotherms plot. The results reveal a clear tendency of both adsorbent in CO2
adsorption in contrast to N2. The increase of adsorbed amounts with pressure increase
and temperature decrease has also seen. Comparing the carbon-zeolite composite with
the zeolite 13X, it can be reached higher adsorption capacity of carbon- zeolite in all
three temperatures. The experimental results have been fitted on Langmuir-Frendlich
as the most proper isotherm for these data. Furthermore, the binary adsorption data of
the system have been also measured on both adsorbents and evaluated by ideal
adsorbed solution theory. Using the results of that theory, it can be possible to predict
the equilibrium selectivity values.
After adsorption equilibrium study, adsorption kinetics behavior of CO2, N2 and their
mixture on both adsorbents have been also studied at two temperatures of 303 and
323 K and constant flow rate and pressure in a fixed bed to have breakthrough plots.
In both temperatures for both adsorbents the breakthrough time of CO2 take places
after a long time compared to N2 showing that capability of these adsorbent in CO2/
N2 separation.
Along with the results of adsorption equilibrium, the pure and binary breakthrough
tests again showed that the separation of CO2/ N2 can be well done using carbonzeolite
composite comparing to
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