Caracterização e previsão de adsorção em materiais microporosos heterogêneos

Abstract

The microporous surface of heterogeneous materials is a challenge for the characterization of pore-size distribution by adsorption, which is still performed by phenomenological methods or approximate kernels. Molecular simulation using the Monte Carlo method in the Grand Canonical ensemble (GCMC) was combined with experimental gas adsorption to characterize and predict adsorption in γ-alumina and activated carbon. A new N2 kernel in γ-alumina slit-pore was proposed and presented a better performance in the description of the experimental N2 than models based on cylindrical pores. Two samples of γ-alumina were investigated and showed 12 to 22% of the total micropore volume, confirming experimental evidence of the γ- alumina morphological nature. For the first time in the literature, the heterogeneous pore model obtained by reactive molecular dynamics (rMD) was used to predict SO2 adsorption isotherms in activated carbon. The simulated isotherms obtained using heterogeneous model agree with the experimental data and satisfactorily reproduced SO2 adsorption at 298 K in C141 and WV1050 activated carbons. Improved characterization of heterogeneous materials should improve the microporous materials design suitable for different adsorption applications. The prediction of toxic gases adsorption isotherms such as SO2 in amorphous carbon using molecular simulation techniques will support researchers working with adsorption under critical operating conditions to design suitable adsorbent materials for different processes without laborious experiments