Formation and decomposition of methane hydrate in pores of γ-Al2O3 и θ-Al2O3: The dependence of water to hydrate transformation degree on pressure and temperature

Abstract The formation and decomposition of methane hydrate in the mesopores of two polymorphous modifications of Al2O3 and the state of water adsorbed in the mesopores were studied in the work. It is demonstrated that adsorbed water may have several energy states differing from each other in the degree of interaction with pore walls. Methane hydrate may be formed from different types of water present in the sample, and the amount of water transformed into hydrate depends on the conditions of hydrate formation. A conceptual model explaining the observations is proposed.