Methane Hydrate Uptake of MCM-41 Mesoporous Molecular Sieves with Preadsorbed Water

Ordered meosoporous molecular sieves of MCM-41 were prepared by adjusting the pH with acetic acid. The synthesized samples were evaluated by 77 K nitrogen-adsorption data. The sample synthesized by a one-time pH adjustment has the same good characters as that synthesized by a three-times pH adjustment. The morphology and crystal structure of the calcined MCM-41 materials were examined with XRD and TEM, in which the ordered channel structure was confirmed. The sorption equilibrium isotherms of wet samples showed a sharp rise, because the large amount methane hydrate had been formed in the MCM-41 samples’ porous space. The methane sorption amount of the mesoporous MCM-41 sample with preadsorbed water reached 10.87 mmol at Rw = 2.0, which was 2.97 times that of the dry mesoporous MCM-41 sample. The comparative methane sorption capacities of the three ordered mesoporous materials (MCM-41, SBA-15, and large-pore MCM-41) by preadsorbtion of the same water mass (Rw = 2.0) are almost identical, and no previous ar...