Methane Hydrates in Spherical Silica Matrix: Optimization of Capillary Water

• Published in: Energy & fuels Vol. 27; no. 7; pp. 3679 - 3684
• Main Authors: Chari, V. Dhanunjana, Raju, B, Prasad, P. S. R, Rao, D. Narayana
• Format: Journal Article
• Language: English
• Published: American Chemical Society 18.07.2013
• Subjects: Conversion; Formations; Hydrates; Methane; Methane hydrates; Moisture content; Optimization; Silicon dioxide
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/ef400397x

Methane hydrate formation/dissociation behavior in the presence of a fixed amount (10 g) of silica grains with a mean diameter of 30–70 μm has been examined in a non-stirred reactor vessel. We systematically varied the amount of water from 10 to 200 g in steps and probed the methane hydrate formation kinetics and the overall hydrate conversion in a silica–water–methane system. Our results showed that the overall methane conversion monotonically increased from 6.14 to 67.82% by reducing the water content from 20 to 1 g/g of SiO2, while under similar experimental conditions, the hydrate conversion in a pure water system was 4.1%. Interestingly, the time taken for 90% of methane gas consumption in hydrate, in a silica–water–methane system, decreased from 450 to 100 min by reducing the total water content from 20 to 4 g/g of SiO2. Our results also indicated that the methane hydrates in the SiO2 matrix are useful for gas storage upon optimizing capillary water. Moreover, we observed that the water-optimized system shows faster formation kinetics and better hydrate conversion, which are critical for methane storage/transportation.