Semiconducting group 14 clathrates are inorganic host-guest materials with a close structural relationship to gas hydrates. Here we utilize this inherent structural relationship to derive a new class of porous semiconductor materials: noble gas filled group 14 clathrates (Ngx[M136], Ng = Ar, Kr, Xe and M = Si, Ge, Sn). We have carried out highlevel quantum chemical studies using periodic Local-...

Recent observations have evidenced traces of methane (CH4) heterogeneously distributed in the martian atmosphere. However, because the lifetime of CH4 in the atmosphere of Mars is estimated to be around 300–600 years on the basis of photochemistry, its release from a subsurface reservoir or an active primary source of methane have been invoked in the recent literature. Among the existing scenar...

This paper introduces the research advances on replacement of CH4 in Natural Gas Hydrates (NGHs) by use of CO2 and discusses the advantages and disadvantages of the method on the natural gas production from such hydrates. Firstly, the feasibility of replacement is proven from the points of view of kinetics and thermodynamics, and confirmed by experiments. Then, the latest progress in CH4 replac...

This work was performed to improve the storage and transportation technology of gas hydrates in nonequilibrium conditions. At atmospheric pressure positive ambient temperature, they gradually dissociate into water. Simulation hydrate dissociation will determine optimal conditions for their storage, as well minimize loss. Thermodynamic parameters adiabatic processes forced preservation pre-coole...

The unique nature of the molecular structures of gas hydrates results in curious acoustic properties which have yet to be adequately characterized. Understanding the acoustic behavior of hydrates in liquids, in bubbly liquids, and in sediments containing liquids and/or gas is vital for surveying their location using seismic or echosounding techniques and may become a key tool for monitoring hyd...

The kinetics of film growth of hydrates of methane, ethane, and methane-ethane mixtures were studied by exposing a single gas bubble to water. The morphologies, lateral growth rates, and thicknesses of the hydrate films were measured for various gas compositions and degrees of subcooling. A variety of hydrate film textures was revealed. The kinetics of two-dimensional film growth was inferred f...

INTRODUCTION The most unique physical property of gas hydrate is the anomalous low and unexpected glassy-like thermal conductivity [ I ,2]. This interesting behaviour has both significant practical and scientific consequences. Thermal conductivity is a vital parameter required for the computer modelling of the recovery of natural gas from the hydrate [3]. A knowledge on the variation of the the...