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题名	甲烷水合物在冰粉石英砂混合物中的生成; Methane Hydrate Formation in a Mixed System of Ice Powders and Sand
作者	黄雯
学位类别	硕士
答辩日期	2007-06-09
授予单位	中国科学院广州能源研究所
授予地点	广州能源研究所
导师	樊栓狮
关键词	甲烷水合物 冰粉 石英砂 冰粉转化率 动力学模型
其他题名	Methane Hydrate Formation in a Mixed System of Ice Powders and Sand
中文摘要	The natural gas hydrate attracts much concern from the countries all over the world as one of potential energy with large amounts of storage, however, the present researches are focused on hydrate in the sea, not involving the hydrate frozen soil hydrate.Through the researches lasting many years, experts on the frozen soil in our country predicts that the frozen soil area in the Qiangtang basin in Qinghai-Tibet Plain possesses the temperature and the pressure condition for the formation of natural gas hydrate, possibly contains large amount of natural gas hydrate resoures. In order to study the formation and the evolution rule for natural gas hydrate in frozen soil and to appraise the resource quantity of natural gas hydrate in the Qinghai-Tibet Plain, the hyrate formation kinetics in the frozen soil is need to be investigated.The frozen soil is the mixed system, contains the porous medium and the ice. In order to simplify the research process and the analysis, the single porous media such as the quartz sand is generally used to study on the formation process of natural gas hydrate in this work. In this thesis, a new equipment for the methane hydrate formation in high pressure was built, and the preliminary experimental investigation on the formation of methane hydrate in the mixture of ice powders and quartz sand was carried. The influence of the temperature, the pressure, the surface area ratio of ice powders to quartz sand on the formation of methane hydrate and the hydration rate of ice were investigated by the constant pressure and precooling method . The results shows that: (1) There is no induction period of nucleation in the formation of methane hydrate in a mixed system of ice powders and sand ,moreover the hydrate sample with good dispersion is obtained ; (2)The hydration velocity of the ice powders increases exponentially with increasing pressure in the middle period of reaction , the influence of pressure on the velocity of the ice powders reaction and the final hydration rate of ice is small in the earlier and later period of reaction, the final hydration rate of ice reaches about 60%; (3) The lasting reaction time increases with increasing the temperature.The reaction lasts about 100 minutes at 263 K, about 150 minutes at 269 K, and about 250 minutes at 273 K. The hydration rate of ice increases with increasing the temperature, the value is 42% at 263 K, 51% at 269 K, and 60% at 273 K; (4) The hydration rate of ice increases with increasing the surface area ratio of ice powders to quartz sand Ks in the initial period of reaction,however, Ks has no influence on the lasting time of the initial period of reaction, the lasting time is about 30 minutes.In the middle period of reaction, the lasting time ncreases with increasing Ks,however, the hydration rate of ice increases formerly and dereases later. In the later period of reaction, Ks has nearly no influence on the hydration rate of ice.However, the final hydration rate of ice increases with increasing the surface area ratio of ice powders to quartz sand Ks. When the Ks is 0.00, the hydration rate of ice is only 32%; When the Ks is 0.33, the hydration rate of ice is 38%; When the Ks is 0.66, the hydration rate of ice is 44%; When the Ks is 1.32, the hydration rate of ice can reach 51%; (5) The existence of quartz sand can enhance the velocity of the ice powders reaction, but reduce the final hydration rate of ice;(6)The formation mechanism of methane hydrate in a mixed system of ice powders and sand was discussed.The formation process can be divided into two stages: (I) quartz sand absorption and transfer stage, （II）methane diffusion-control stage;(7) In the formation process of methane hydrate in a mixed system of ice powders and sand under constant pressure the surface area ratio of ice powders to quartz sand, the first stage of reaction can be described by the mathematical expression: （1－ ）1/3＝ 1/2.1＋1,and the second stage of reaction can be described as: （1－ ）1/3＝ （t－t*）1/2＋（1－ *）1/3, where *＝34％. The activation energy of the formation of methane hydrate can be calculated, the value is about 70.1 KJ•mol-1.
语种	中文
公开日期	2011-07-10 ; 2011-07-15
页码	77
内容类型	学位论文
源URL	[http://ir.giec.ac.cn/handle/344007/4021]
专题	中国科学院广州能源研究所
推荐引用方式 GB/T 7714	黄雯. 甲烷水合物在冰粉石英砂混合物中的生成, Methane Hydrate Formation in a Mixed System of Ice Powders and Sand[D]. 广州能源研究所. 中国科学院广州能源研究所. 2007.

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