表面活性剂在瓦斯水合中的作用机理

The influence mechanism of surfactant on the process of gas hydration

运用自制的可视化实验设备,进行了表面活性剂吐温(T40,1×10-3mol/L;T40,2×10-3mol/L;T40/T80(1∶1),1×10-3mol/L)在瓦斯水合过程中的影响研究,结合煤层高压注水中添加表面活性剂R1-89的现场研究,分析了表面活性剂在瓦斯水合3阶段的主要作用.认为在煤层注水阶段表面活性剂的加入降低了液体表面张力和注水压力,使注水速度加快,煤体得到均匀润湿;在水合物诱导阶段表面活性剂的胶束化增加了瓦斯气体的溶解度,促进了气体在溶液中过饱和,推动了水合物晶核生长,缩短了诱导时间;在水合物生长阶段,表面活性剂胶束对溶于其中的气体分子和吸附于其周围的水分子的束缚作用,相当于降低了体系的温度,改变了水合物生成热力学条件.

Using self-developed visible experimental installation, the influences of surfactant Tween （T40, 1 × 10^-3 tool/L; T40, 2 × 10^-3 mol/L; T40/T80 （1：1 ） , 1 × 10%-3 mol/L） on the process of gas hydration were studied. Combined with the field study of adding surfactant R1 - 89 for coal seam water infusion with high pressure, the essential roles of surfactant in three stages of gas hydration were analyzed. The results indicate that in the stage of coal seam water infusion, the surfaetant decreases the surface tension of liquid and the pressure of water infusion, quickens the rate of water infusion, and coal is dabbled uniformly. In the stage of gas hydrate induction, the micelle agglomeration of surfactant can increase the solubility of gas, accelerate the supersaturation of gas in solution, prompt the formation of crystal nucleus of gas hydrate, and the induction time is shortened. In the stage of gas hydrate growth, the binding effect of surfactant micelle on gas molecule dissolved in it and water molecule absorbed around it is equivalent to the reduction of systems ＇ temperature, so the thermodynamic conditions of gas hydrate formation are changed.