十二烷基硫酸钠对甲烷水合物生成过程影响研究

Effect of Sodium Dodecyl Sulfate on the Process of Methane Hydrate Formation

根据甲烷水合物含气率高、分解速度慢等特性，提出利用高压注水技术和表面活性剂促进作用促使矿井瓦斯水合化以预防煤与瓦斯突出的思路。进行了3．6～12℃、7．82～12．26MPa条件下两种浓度体系（10mmol／L和0．3mmol／L）中十二烷基硫酸钠（SDS）对甲烷水合物作用效果的实验研究，结合水合物诱导时间、生成速度及含气率等计算对实验数据进行了分析，并运用表面张力法测得8℃时SDS溶液的临界胶束浓度（CMC）为2．5mmol／L。结果表明，高浓度体系对水合物生成速度、含气率的影响较之低浓度体系的更强，但是低浓度体系中水合物生成的诱导时间却较短，表面活性剂溶液浓度超过其CMC后对水合物的生成影响显著。

Based on the characteristics of high volumetric proportion and slow decomposition rate for methane hydrate, the method of water injection under high pressure and the present of surfactant for accelerating the hydrate formation of mine gas was put forward to prevent coal and gas outburst in this paper. The effects of sodium dodecyl sulfate （SDS） on methane hydrate formation in two concentration systems （10mmol/L; 0.3mmol/L） were investigated at 3.6- 12℃, 7.82 12.26MPa, and the experimental data were analyzed based on the theories of induction time, formation rate and volumetric proportion. Furthermore, the critical micelle concentration （CMC） of SDS solution is 2.5mmol/L at 8℃ which was measured by means of surface tension. The results indicated that the influence of high concentration SDS solution on formation rate and volumetric proportion is more intense than that of low concentration solution, but the induction time of methane hydrate formation in low concentration SDS solution is shorter. The concentration of surfactant solution has a notable effect on the gas hydrate formation while it is larger than CMC.