膨润土中甲烷水合物生成特性的实验研究

Experimental Study of Methane Hydrate Formation in Bentonite

恒容条件下,实验研究了甲烷水合物在膨润土中的生成规律,考察了不同水浴温度(3℃、5℃、7℃和9℃)和不同初始压力(9 MPa、12 MPa和15 MPa)对甲烷水合物生成规律的影响。研究表明:水合物在膨润土中生成的诱导时间很短,生成速度快,初始压力为12 MPa、水浴温度为3℃时,诱导时间最短为16.5 min;当系统温度降低到设置温度时,水合物基本停止生成,水合物的生成受到传质过程控制;水合物停止生成后,最终压力均明显高于纯水体系甲烷水合物相平衡压力。水的最终转化率介于55.73%和61.93%之间,水的最终转化率随着水浴温度降低而增大,但是增大的幅度并不显著。

The formation behaviors of methane hydrate in bentonite were experimentally studied.The experiments werecarried out under conditions of bath temperatures of3oC,5oC,7oC and9oC,and initial pressures of9MPa,12MPa and15MPa.The experimental results indicate that the induction time of methane hydrate formation is very short and the methanehydrate formation rate is very fast.When the initial pressure is12MPa and the bath temperature is3oC,the induction timeis16.5min and it’s shorter than that of other experiments.When the temperature of the system is lower than the settingtemperature,the hydrate formation halted.The hydrate formation is controlled by the process of mass transfer.After thehydrate stops forming,the final pressure is significantly higher than the phase equilibrium pressure of bulk hydrate.Thefinal conversion of water ranges between55.73%and61.93%.The final water conversion decreases with the increase ofbath temperature,but lower bath temperature have no significant help to enhance the final conversion of water.