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论文类型：期刊论文

发表时间：2013-04-01

发表刊物：SCIENCE CHINA-EARTH SCIENCES

收录刊物：SCIE、EI

卷号：56

期号：4

页面范围：611-617

ISSN号：1674-7313

关键字：magnetic resonance imaging; carbon dioxide hydrate; porous media; saturation; induction time; growth and dissociation rate

摘要：The study of formation and dissociation of CO2 hydrate in porous media was characterized by magnetic resonance imaging (MRI) system in in situ conditions. This work simulated porous media by using glass beads of uniform size. The growth and dissociation habit of CO2 hydrate was observed under different temperature and pressure conditions. The induction time and the hydrate saturation during the growth and dissociation process in different sizes of porous media were obtained by using the MRI signal intensity. The results indicate that hydrate growth rate and the induction time are affected by the size of porous media, pressure, and degree of supercooling. There are three hydrate growth stages, i.e., initial growth stage, rapid growth stage and steady stage. In this study, the CO2 hydrate forms preferentially at the surface of vessel and then gradually grows inward. The hydrate tends to cement the glass beads together and occupies the pore gradually. As the hydrate decomposes gradually, the dissociation rate increases to the maximum and then decreases to zero.