Gas-hydrates are crystalline form of water and methane that form at high pressure and low temperature. They have attracted the global attention due to their wide-spread occurrences in the permafrost and outer continental margins; potential as major energy resources; role in climate change etc. It is estimated that the carbon in gas-hydrates is two times the carbon content in fossil fuel reserve...

Sequestration of carbon dioxide (CO2) in the form of its hydrates in natural methane (CH4) hydrate reservoirs, via CO2/CH4 exchange, is an attractive pathway that also yields valuable CH4 gas as product. In this paper, we describe a macroscale experiment to form CO2 and CH4-CO2 hydrates, under seafloor-mimic conditions, in a vessel fitted with glass windows that provides visualization of hydrat...

Scientific knowledge of natural clathrate hydrates has grown enormously over the past decade, with spectacular new findings of large exposures of complex hydrates on the sea floor, the development of new tools for examining the solid phase in situ, significant progress in modeling natural hydrate systems, and the discovery of exotic hydrates associated with sea floor venting of liquid CO2. Majo...

It has long been known that crystalline hydrates are formed by many simple gases that do not interact strongly with water, and in most cases the gas molecules or atoms occupy 'cages' formed by a framework of water molecules. The majority of these gas hydrates adopt one of two cubic cage structures and are called clathrate hydrates. Notable exceptions are hydrogen and helium which form 'exotic' ...

Gas hydrates, low molecular weight gas molecules trapped in water-ice “cages,” have gained international attention over the last few years for energy, safety, and environmental reasons. In 2000 CODATA (Committee on Data for Science and Technology, International Council for Science) established a task group for Data on Natural Gas Hydrates, which aims to develop a comprehensive information syste...

Gas hydrates in sub-seabed sediments is an unexploited source of energy with estimated reserves larger than those of conventional oil. One of the methods for recovering methane from gas hydrates involves injection of Carbon Dioxide (CO2), causing the dissociation of methane and storing CO2. The occurrence of gas hydrates offshore Portugal is well known associated to mud volcanoes in the Gulf of...

Program Scope Clathrate hydrates are inclusion compounds in which guest molecules occupy the cages formed by a hydrogen-bonded water network [1]. Solid gas clathrate hydrates generally form at high pressures and temperatures near or even above the ice point. Pure hydrogen hydrates have been reported to form cubic structure II hydrates under extreme conditions (200 MPa at 280 K) [2]. We have rec...

Solid gas hydrates are a potentially huge resource of natural gas for the United States. The U.S. Geological Survey estimated that there are about 85 trillion cubic feet (TCF) of technically recoverable gas hydrates in northern Alaska. The Minerals Management Service estimated a mean value of 21,000 TCF of in-place gas hydrates in the Gulf of Mexico. By comparison, total U.S. natural gas consum...

The significance of clathrate hydrates lies in their ability to encapsulate a vast range of inert gases. Although the natural abundance of a few noble gases (Kr and Xe) is poor their hydrates are generally abundant. It has already been reported that HF doping enhances the stability of hydrogen hydrates and methane hydrates, which prompted us to perform a model study on helium, neon and argon hy...

The standard picture is that clathrate hydrates form when hydrophobic guest molecules are compressed with water under high pressure-low temperature conditions. In the ice-like hydrate framework, water molecules form molecule-sized cavities that encapsulate the guests and minimize water-hydrophobic guest interactions. This picture, however, must be modified by observations that many water solubl...