Abstract:

Increasing hydrate formation rate and gas storage density is very important for the application of natural gas hydrate storage and transportation technology. Three pieces of copper foam (CF) with different pore density herein were immersed in sodium dodecyl sulfate (SDS) solution to build a gas storage enhancement system, and to study on the kinetic characteristics of the formation of methane hydrate by metal foam in a high-pressure static reactor. The research results showed that the copper foam framework can provide sufficient crystallization points for the formation of hydrates, at the same time, it can be used as a “highway” for hydration heat transfer during hydrate growth. Methane hydrate can be quickly formed in SDS/CF system, the maximum hydration gas storage rate is between 19.24—21.04 mmol·mol^-1·min^-1, the gas storage capacity of the SDS solution with 15 PPI copper foam was the highest (139 mmol·mol^-1), and it takes the shortest time to reach 90% of the maximum gas storage capacity (10.1 min). Under the pressure of 6.0—8.0 MPa, compared with SDS solution, the gas storage capacity of SDS solution with 15 PPI CF increased by 8.8%—35.6%, and the gas storage rates increased by 4.7%—40.4%. When the pressure is 5.0 MPa, the gas storage capacity of the pore density SDS/CF system is even increased by 13 times than that of the SDS solution, and the gas storage rate is increased by 16 times.

Key words: copper foam, methane hydrate, formation, kinetics, enhancement

摘要：

提高水合物生成速率和储气密度对天然气水合物技术应用非常重要。将三种孔密度的泡沫铜（CF）分别浸入十二烷基硫酸钠（SDS）溶液中构建水合储气强化体系，在高压静态反应釜中研究泡沫金属对甲烷水合物生成动力学特性。实验结果表明，泡沫铜骨架能为水合物生成提供充足的结晶点，同时可作为水合物生长过程水合热迁移的“高速公路”。甲烷水合物在SDS/CF体系中可快速生成，最大水合储气速率分布在19.24~21.04 mmol·mol^-1·min^-1之间，其中添加15 PPI泡沫铜的SDS溶液储气量最高（139 mmol·mol^-1），且达到最大储气量90%所用时间最短（10.1 min）。在6.0~8.0 MPa压力下，相比SDS溶液，添加15 PPI泡沫铜的SDS溶液储气量提高了8.8%~35.6%，储气速率提高了4.7%~40.4%；特别在压力为5.0 MPa时，该孔密度SDS/CF体系储气量甚至比SDS溶液增加13倍，储气速率增加16倍。

关键词: 泡沫铜, 甲烷水合物, 生成, 动力学, 强化