Characterization and prediction of adsorption in heterogeneous microporous materials.
Isotherms, activated carbon, SO2, γ-alumina, N2, Monte Carlo.
Molecular simulation is a powerful tool to predict gas adsorption and to characterize microporous materials. The isotherms were calculated by applying the Monte Carlo method in the grand canonical ensemble. A new kernel of N2 isotherms in γ-alumina and SO2 isotherms in activated carbons were present with different pores sizes, dedicated to the characterization of the micropore range of γ-alumina and to predict SO2 adsorption in carbonaceous materials. The representative pore size distribution of γ-alumina and activated carbons samples were calculated with N2 isotherms at 77 K. A complementary characterization of C141 and WV1050 carbons were obtained with CO2 isotherms at 273 K. N2 kernel in slit-pore of γ-alumina presented a better performance in the description of the experimental N2 isotherm than the models based on cylindrical pores, confirming experimental evidence of γ-alumina morphology. Two γ-alumina samples are investigated, and we observe that 12 to 22% of the total volume consists of micropores that are not adequately characterized with approximate cylindrical kernels. For the first time in the literature, the rMD model is used to predict gas adsorption isotherms. The simulated isotherms obtained for the heterogeneous pore model agree with the experimental data and satisfactorily reproduced the adsorption of SO2 at 298 K C141 and WV1050 activated carbons. The enhancement of the characterization prediction should improve the design of suitable microporous materials for different catalysis and adsorption applications and the prediction of toxic gas adsorption isotherms, like SO2, in amorphous carbon through molecular simulation techniques should help researchers who work with adsorption under critical operational conditions to design suitable adsorbent materials for different processes without the need to carry out laborious experimental tests.