OS6B-8:NEW MATERIAL FOR RAPID METHANE HYDRATE FORMATION

Pinnelli S.R. PRASAD
Gas Hydrate Group, National Geophysical Research Institute (CSIR-NGRI), Council of Scientific and Industrial Research, Hyderabad – 500 007 (India)

    Gas hydrates, fiery ice, have the ability to store large volumes of naturally occurring fuel gas molecules, like methane, as guests in its vacant water cages, and they exist in some moderately high pressure and low temperature zones across the permafrost and ocean bottom sedimentary strata. Earlier research on these materials was largely for academic curiosity; however, recent estimates reveal that the total energy contained in them will suffice ever increasing requirements. Challenges for its commercialization are many, like optimization of gas content with pressure and temperature, developing means of controlled gas liberation upon command and means of confining larger volumes of hydrates rapidly in a lighter (cheaper) medium. Accordingly, we carried out systematic studies, aiming to rapidly enhance the methane gas storage capacity in methane hydrates formed in the presence of hollow silica matrix. We observed over 90% of hydrate conversion in capillary-water in silica-water-methane system at moderately high pressure (5.0MPa) and 278K. Methane hydrate conversion in such system is extremely fast and the material is apt for multiple freezing-thawing cycles without noticeable reduction in storage capacity. The volume storage capacity increased from 128 to 206v (STP)/v by decreasing the combined weight of water and silica from 100 and 18g in a fixed volume non-stirred reactor, at pressures higher than 5.0MPa.