Abstract:

Improving seawater hydration storage rate and storage density is crucial for the large-scale application of hydrate technology. A certain concentration of NaCl solution was dispersed with hydrophobic fumed nano-silica by high-speed stirring into micrometer-sized saline droplets. Under the conditions of 8.0 MPa and 274.15 K, methane hydrate storage experiments were conducted by using saline droplets with different silicon contents to study the kinetic characteristics of methane hydrate formation. With a gas storage capacity of 141.01 cm³·cm^-3 and a gas storage rate of 7.37 cm³·cm^-3·min^-1, saline droplets with a silicon content of 2.5 %(mass) demonstrated the best dispersibility and gas storage performance, according to the data. The silicon-containing brine droplets are further filled into the open-pore copper foam to construct a saline droplet/copper foam composite hydration gas storage system. It is discovered that the three-dimensional nested metal framework of copper foam can significantly accelerate the transfer of hydration reaction heat and improve the gas storage performance of saline droplets hydration. At 5.0—8.0 MPa, compared to the saline droplets single system, the hydration gas storage capacity of the composite system is increased by 4.72%—21.70%, and the maximum gas storage rate is increased by 38.25%—110.58%.

Key words: saline droplets, copper foam, methane hydrate, formation kinetics, promotion

摘要：

提高海水水合储气速率和储气密度对水合物技术规模化应用至关重要。将一定浓度的NaCl溶液与疏水性气相纳米二氧化硅高速搅拌分散成微米级盐水微滴。8.0 MPa、274.15 K条件下，利用不同硅含量的盐水微滴进行水合储甲烷实验，研究甲烷水合物生成动力学特性。结果表明，硅含量2.5%（质量分数）的盐水微滴分散性和储气性能最佳，储气量达141.01 cm³·cm^-3，储气速率达7.37 cm³·cm^-3·min^-1。进一步将该硅含量盐水微滴填充至开孔泡沫铜中，构建盐水微滴/泡沫铜复合水合储气体系。研究发现，泡沫铜三维巢状金属骨架能显著加速水合反应热的转移，提高微滴水合储气性能。5.0~8.0 MPa下，相较于盐水微滴单一体系，复合体系水合储气量提高4.72%~21.70%，最大储气速率提高38.25%~110.58%。

关键词: 盐水微滴, 泡沫铜, 甲烷水合物, 生成动力学, 促进