Seo Yongwon, Lee Seungmin, Cha Inuk, Lee Ju Dong, Lee Huen
Department of Chemical Engineering, Changwon National University, 9 Sarim-dong, Changwon, Gyeongnam 641-773, Republic of Korea.
J Phys Chem B. 2009 Apr 23;113(16):5487-92. doi: 10.1021/jp810453t.
In the present study, we examined the active role of porous silica gels when used as natural gas storage and transportation media. We adopted the dispersed water in silica gel pores to substantially enhance active surface for contacting and encaging gas molecules. We measured the three-phase hydrate (H)-water-rich liquid (L(W))-vapor (V) equilibria of C(2)H(6) and C(3)H(8) hydrates in 6.0, 15.0, 30.0, and 100.0 nm silica gel pores to investigate the effect of geometrical constraints on gas hydrate phase equilibria. At specified temperatures, the hydrate stability region is shifted to a higher pressure region depending on pore size when compared with those of bulk hydrates. Through application of the Gibbs-Thomson relationship to the experimental data, we determined the values for the C(2)H(6) hydrate-water and C(3)H(8) hydrate-water interfacial tensions to be 39 +/- 2 and 45 +/- 1 mJ/m(2), respectively. By using these values, the calculation values were in good agreement with the experimental ones. The overall results given in this study could also be quite useful in various fields, such as exploitation of natural gas hydrate in marine sediments and sequestration of carbon dioxide into the deep ocean.
在本研究中，我们考察了多孔硅胶作为天然气储存和运输介质时的活性作用。我们利用硅胶孔隙中的分散水大幅增加用于接触和包裹气体分子的活性表面。我们测量了6.0、15.0、30.0和100.0纳米硅胶孔隙中乙烷和丙烷水合物的三相水合物（H）-富水液体（L（W））-蒸汽（V）平衡，以研究几何约束对气体水合物相平衡的影响。在特定温度下，与大块水合物相比，水合物稳定区域根据孔径大小向更高压力区域移动。通过将吉布斯-汤姆逊关系应用于实验数据，我们确定乙烷水合物-水和丙烷水合物-水的界面张力值分别为39±2和45±1 mJ/m²。使用这些值时，计算值与实验值吻合良好。本研究给出的总体结果在诸如海洋沉积物中天然气水合物的开采以及将二氧化碳封存到深海等各个领域也可能非常有用。
