Replacement of Methane from Quartz Sand-Bearing Hydrate with Carbon Dioxide-in-Water Emulsion

• Published in: Energy & fuels 2008-05, Vol.22 (3), p.1759-1764
• Main Authors: Zhou, Xitang, Fan, Shuanshi, Liang, Deqing, Du, Jianwei
• Format: Article
• Language: English
• Subjects: Applied sciences; Crude oil, natural gas and petroleum products; Crude oil, natural gas, oil shales producing equipements and methods; Energy; Exact sciences and technology; Fossil Fuels; Fuels; Prospecting and production of crude oil, natural gas, oil shales and tar sands
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/ef700705y

The replacement of CH4 from its hydrate in quartz sand with 90:10, 70:30, and 50:50 (w CO2 :w H2 O) carbon dioxide-in-water (C/W) emulsions and liquid CO2 has been performed in a cell with size of ϕ 36 × 200 mm. The above emulsions were formed in a new emulsifier, in which the temperature and pressure were 285.2 K and 30 MPa, respectively, and the emulsions were stable for 7–12 h. The results of replacing showed that 13.1–27.1%, 14.1–25.5%, and 14.6–24.3% of CH4 had been displaced from its hydrate with the above emulsions after 24–96 h of replacement, corresponding to about 1.5 times the CH4 replaced with high-pressure liquid CO2. The results also showed that the replacement rate of CH4 with the above emulsions and liquid CO2 decreased from 0.543, 0.587, 0.608, and 0.348 1/h to 0.083, 0.077, 0.069, and 0.063 1/h with the replacement time increased from 24 to 96 h. It has been indicated by this study that the use of CO2 emulsions is advantageous compared to the use of liquid CO2 in replacing CH4 from its hydrate.