Date of Publication:2020-01-01

Journal:Modern Chemical Industry

Volume:40

Issue:11

Page Number:87-91,97

ISSN:0253-4320

Key Words:"adsorption of CO_2; molecular sieve; ratio of silicon to aluminum; metal ion modification; Monte Carlo simulation"

CN:11-2172/TQ

Abstract:Molecular sieve models including Si_(96) O_(192),NaAlSi_(95) O_(192),Na_2Al_2 Si_(94) O_(192),Li_2Al_2 Si_(94) O_(192) and K_2Al_2 Si_(94) O_(192) are established by adjusting Si /Al ratio and adding metal ions. Adsorption of CO_2 and N_2 by these molecular sieves is simulated by Monte Carlo method. It is found that the decreasing Si /Al ratio and the increasing adding amount of metal ions both can provide more adsorption sites, therefore the adsorption amount of CO_2 by these molecular sieve increases gradually, and the selectivity of CO_2 /N_2 increases significantly. The adsorption sites for CO_2 concentrate mainly near Na~+ and in the pores. Under a low pressure, the adsorption capacity of molecular sieve is mainly determined by the interaction between different metal ions and CO_2 molecules. With the increase of pressure, the adsorption capacity depends mainly on the free volume of molecular sieve channels. The adsorption mechanism of CO_2 /N_2 is explored from molecular level, which is expected to provide theoretical basis and guidance for the development of high-efficiency adsorbents.

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