Experimental Investigation of Methane Gas Production from Methane Hydrate

• Published in: Industrial & engineering chemistry research 2009-03, Vol.48 (6), p.3142-3149
• Main Authors: Zhou, Yue, Castaldi, Marco J, Yegulalp, Tuncel M
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemical engineering; Exact sciences and technology; General Research
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie801004z

A 72 L large-scale reactor vessel was designed, manufactured, and built to investigate the gas production from methane gas hydrates. Methane hydrates were successfully formed within the reactor using pure methane gas and deionized water in a sand matrix with grain sizes between 100 and 500 μm. Hydrate formation tests resulted in formation at 2.2 °C around 600 psi. Mass balance calculations show that 11% of the pore space volume was occupied by hydrate. Measurements and simulations suggest that hydrate was initially formed at the top section of the reactor followed by formation within the lower part of the sediment. A cooling effect was observed during the dissociation via depressurization experiments, caused by the endothermic dissociation reaction. The observed temperature decrease of the system was between 4.0 and 0.8 °C. During the hydrate dissociation tests, a transition regime showing an increased gas production from 9.5 to 13 L/min within a very narrow range of temperature between −1.6 and −1.2 °C and pressure between 310 and 360 psi was recorded. In addition, the temperature was observed to jump to 0 °C in an extremely short time period. The interpretation of this phenomenon is ice formation in the transition regime where hydrate decomposes to gas and ice instead of gas and liquid. This is the first experimental observation of this phenomenon.