甲烷水合物在冰粉和铁粉混合物中的生成过程

Methane Hydrate Formation in a Mixed System of Ice Powder and Iron Powder

在自行搭建的实验台上利用恒压预冷法研究了不同压力(5.92 MPa、5.63 MPa)、恒定温度(267.5 K)下甲烷水合物在冰粉(154～300μm)与铁粉(108μm)混合物中的生成过程。实验发现:甲烷水合物在此混合物中聚集生长;一定压力下,流量时间曲线可以分为三个阶段,总体为双曲线型;在较大压力5.92 MPa下冰粉转化速度较小,而最终冰粉转化率较大;铁粉存在下,最终冰粉转化率最大为62.3%;基于冰粉中水合物生成的敛核模型或原位偏离模型,不能很好地解释本实验条件下的实验现象。

The formation of methane hydrate in a mixed system of ice powder and iron powder was studied at 267.5 K and at different pressure(5.92 MPa, 5.63 MPa). The results showed that the formation of methane hydrate is in the shape of aggregation;the velocity of the reaction increases exponentially and the hydrate mole fraction can reached 80 %, the sand increased the velocity of the formation of methane hydrate and the hydrate mole fraction. Both the shrinking model and the swelling model based on the condition of pure ice powders are not suitable for the condition of mixture of ice powders and sand.