多孔介质中SDBS对天然气水合物生成促进研究

Study on the Promotion of Natural Gas Hydrate Formation by SDBS in Porous Media

摘要: 自然界中大量水合物均赋存在海底和永冻区土壤的孔隙中，而非以块状水合物的形式存在。因此，研究多孔介质孔隙环境中水合物生成特点对于水合物资源的商业开采具有重要的意义。通过采用粒径为100，200和300目的氧化铝和二氧化硅颗粒，研究了该孔隙环境中水合物在纯水和表面活性剂十二烷基苯磺酸钠(SDBS)溶液中的生成特性，得到了如下结论：对于本实验采用的粒径尺度内，水合物在较大粒径的颗粒中生成时，有利于其储气能力的提升，并且生成速率较快；由表面具有微孔的氧化铝组成的水合物生成体系对于气体有着更好的吸附能力；表面活性剂SDBS的加入可以降低气液界面的表面张力，使气体分子更易向液相中溶解，促进水合物晶核的生成，进而可以较为显著地改善水合物的生成效果，提高水合物生成速率的同时增加其储气能力。该研究可为水合物的快速生成技术提供理论指导，进而促进水合物法的工业应用和自然界水合物资源的商业开采。

Abstract: A large number of hydrates in nature are present in the pores of the seabed and permafrost regions, rather than in the form of massive hydrates. Therefore, studying the characteristics of hydrate formation in the pore environment of porous media is of great significance for the commercial exploitation of hydrate resources. The formation characteristics of hydrates in pure water and surfactant sodium dodecyl benzene sulfonate (SDBS) solution were studied by using alumina and silica particles with particle sizes of 100, 200 and 300 mesh. The following conclusions were obtained: for the particle size scale adopted in this experiment, when the hydrate is formed in the particles of larger particle size, it is beneficial to the improvement of its gas storage capacity, and the formation rate is faster; a hydrate generating system composed of alumina having micropores on the surface has a better adsorption capacity for gas; the addition of surfactant SDBS can reduce the surface tension of the gas-liquid interface, make the gas molecules more soluble in the liquid phase, promote the formation of hydrate nucleus, and thus can significantly improve the formation of hydrates and increase the rate of hydrate formation and its gas storage capacity. This study provides theoretical guidance for the rapid generation of hydrates, which in turn promotes the industrial application of hydrate processes and the commercial exploitation of hydrate resources in nature.