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论文类型：期刊论文

发表时间：2016-04-22

发表刊物：CHEMICAL ENGINEERING SCIENCE

收录刊物：SCIE、EI、Scopus

卷号：144

页面范围：135-143

ISSN号：0009-2509

关键字：Hydrate; Depressurization range; Depressurization rate; Dissociation; Magnetic resonance imaging

摘要：Depressurization is considered to be the most promising method for exploitation of natural gas hydrate. To analyze the characteristics of hydrate dissociation during depressurization, methane hydrate (MH) dissociation was performed at different depressurizing ranges and rates, and the hydrate dissociation process was directly observed using magnetic resonance imaging (MRI). The experimental results indicate that with increased depressurizing rate from 0.01 MPa/min to 0.1 MPa/min, the average dissociation rate increases for a given depressurizing range. Meanwhile, with an increase in depressurizing range from 0.3 MPa to 1.1 MPa, the average dissociation rate increases for a given depressurizing rate. Moreover, the hydrate dissociation process can be divided into two main stages: hydrate saturation remains constant with little fluctuation for several minutes after back-pressure decreases, and then the hydrate dissociates continuously until dissociation completes. In addition, excessively high depressurizing range and rate result in hydrate reformation and ice generation, which slow the rate of hydrate dissociation. Furthermore, it was also determined that MH reformation and ice generation always occur at the higher depressurizing range and rate due to insufficient heat transfer. (C) 2016 Elsevier Ltd. All rights reserved.