Abstract Abundant reserves of natural gas hydrates are hosted in the pores of sediment layers, and the hydrate-based technology could be widely used in industry. In this work, the formation kinetics of methane hydrate in a complex system containing silica sand and 300-ppm sodium dodecyl sulfate (SDS) solution were investigated at 275.15 K and 7 MPa. The hydrate was formed in different-saturated silica sand with particle sizes of 100, 150, 200, 300, and 400 mesh. The results indicated that in both the 50%- and 100%-saturated sand, a larger particle size exhibited a better methane storage capacity. In the complex system, the presence of SDS molecules significantly enhanced the hydrate formation process and weakened the effect of particle size on the hydrate formation rate. The difference in hydrate gas uptake formed in the differently saturated silica sand indicted that with an increase in saturation, the smaller-sized silica sands caused a more marked inhibitory effect. Finally, the different hydrate distributions in the 50%- and 100%-saturated silica sand revealed that a hydrate film formed quickly and preferentially on the surface of the silica sand, which was attributed to the adsorption of the SDS active groups and the presence of the silica sand surface. With the thickening of the hydrate film, the resulting volume expansion and stronger capillary force led to the migration of the liquid phase, which resulted in the hydrate distributions observed in the differently saturated silica sands.

中文翻译：

---

硅砂粒径和饱和度对SDS存在下甲烷水合物形成的影响

摘要 沉积层孔隙中蕴藏着丰富的天然气水合物储量，水合物基技术可广泛应用于工业领域。在这项工作中，研究了在 275.15 K 和 7 MPa 下，含有硅砂和 300 ppm 十二烷基硫酸钠 (SDS) 溶液的复杂系统中甲烷水合物的形成动力学。水合物在不同饱和度的硅砂中形成，粒径分别为 100、150、200、300 和 400 目。结果表明，在 50% 和 100% 饱和砂中，较大的粒径表现出更好的甲烷储存能力。在复杂体系中，SDS分子的存在显着增强了水合物形成过程，减弱了粒径对水合物形成速率的影响。不同饱和度硅砂中形成的水​​合物气体吸收量的差异表明，随着饱和度的增加，较小尺寸的硅砂抑制作用更明显。最后，50% 和 100% 饱和硅砂中不同的水合物分布表明，在硅砂表面快速且优先地形成了水合物膜，这归因于 SDS 活性基团的吸附和硅砂表面。随着水合物膜的增厚，由此产生的体积膨胀和更强的毛细管力导致液相的迁移，从而导致在不同饱和度的硅砂中观察到的水合物分布。最后，50% 和 100% 饱和硅砂中不同的水合物分布表明，在硅砂表面快速且优先地形成了水合物膜，这归因于 SDS 活性基团的吸附和硅砂表面。随着水合物膜的增厚，由此产生的体积膨胀和更强的毛细管力导致液相的迁移，从而导致在不同饱和度的硅砂中观察到的水合物分布。最后，50% 和 100% 饱和硅砂中不同的水合物分布表明，在硅砂表面快速且优先地形成了水合物膜，这归因于 SDS 活性基团的吸附和硅砂表面。随着水合物膜的增厚，由此产生的体积膨胀和更强的毛细管力导致液相迁移，从而导致在不同饱和度的硅砂中观察到水合物分布。