Computer Simulation for Adsorption of CO₂, N₂and Flue Gas in a Mimetic MCM-41

Abstract

Adsorption of pure and mixed CO 2 and N 2 is simulated in a mimetic MCM-41. The full-atom MCM-41 model is constructed by caving cylindrical pores from an amorphous silica matrix and energetically optimized. Dreiding force field is used for the dispersive interaction with the atomic charges estimated from the densityfunctional theory calculations. The optimized MCM-41 maintains a hexagonal array of the mesoscopic pores as evidenced by the three characteristic peaks in the XRD pattern. The pore surface of MCM-41 is corrugated and coated with hydroxyls and defects. The pore size exhibits a Gaussian distribution with an average radius of 14.38 Å close to the experimental value. Simulated adsorption isotherms and isosteric heats of CO 2 match well with the experimental data. CO 2 adsorbs preferentially at the active sites near the pore surface, while N 2 tends to adsorb homogeneously on the pore surface. In CO 2 and N 2 mixture as a flue gas, CO 2 is more adsorbed than N 2 . The selectivity of CO 2 over N 2 drops rapidly with increasing temperature and depends weakly on pressure. At temperatures higher than 400 K, the selectivity approaches a constant and pressure has no discernible effect.

Mesoporous silica nanoparticles as a new carrier methodology in the controlled release of the active components in a polypill

“…5 shows the model obtained by molecular modelling. Models of silica mesopores specifically for MCM-41, have been designed by our group (Doadrio et al, 2010;Doadrio et al, 2014) and other authors (Coasne and Ugliengo, 2012;He and Seaton, 2003;Ugliengo et al, 2008;Williams et al, 2016;Zhuo et al, 2008). However, these MCM-41 models were built with the purpose of introducing a single molecule into the matrix or without and has not been tested with four molecules at a time.…”

Monte Carlo Simulation on Adsorption Properties of Benzene, Toluene, and p-Xylene in MCM-41

“…In order to mimic the real MCM-41 structure, various pore sizes and/ or thicknesses of pore walls can be introduced in a model of MCM-41. For example, Zhuo et al 19 employed an MCM-41 structural model in which the pore radii had a Gaussian distribution based on an experimental radius. Puibasset 20 developed a large-scale porous material model with 1000 pores and a length of several micrometers, in which the heterogeneity of the pores was described by Gaussian and uniform distributions to characterize the disorder in a given pore and the disorder between the pores.…”

Atomistic simulations for adsorption and separation of flue gas in MFI zeolite and MFI/MCM-41 micro/mesoporous composite

“…The detail of construction has been described in our previous work [27]. In the model of MFI/MCM-41 shown in Fig.…”

“…The self-diffusivities of CO 2 are also compared in MFI and MFI/MCM-41. As a mesoporous material composed of silica [22,23], MCM-41 has been commonly studied for CO 2 adsorbent by both experimental [18,[24][25][26] and theoretical methods [27][28][29][30][31]. MCM-41 contains a hexagonal array of nearly uniform mesoscopic pores.…”