Intercalation of Gas Hydrates in Clays

古根海姆EAR-0207770这个建议的工作假设是，粘土/甲烷-天然气水合物在低温和高气压下，在适当的水饱和条件下会形成复合体。在一系列的初步实验中，我们获得了在这些条件下确实可以形成这些络合物的证据。在这些实验中，我们使用了一个环境室，能够承受-100到200摄氏度的温度和75bar的气体压力。我们自己开发的这个小室，可以从0度到70度2度进行X射线扫描。我们建议在适当的条件下研究钠交换和钙交换的蒙脱石和甲烷形成粘土/甲烷-天然气水合物的复合体。此外，我们还将研究甲烷与NH4交换的蒙脱石之间可能存在的相互作用。我们的目的是确定允许天然气水合物插入粘土结构的粘土的成分范围。然后，我们将确定这些粘土/天然气水合物形成的P-T条件，以及粘土中包含的天然气水合物的数量。粘土/天然气-水合物复合体的发现引入了一类新的材料，这在矿物学、地球化学和材料科学中应该引起人们的兴趣。与天然气水合物一样，这些新的复合体：(1)可能出现在深海和极地地区(如永冻土、南极冰)，(2)可能与海底沉积物的稳定性有关，(3)可能存在于火星上。粘土/天然气水合物的稳定范围可能会扩大天然气水合物的稳定范围。此外，粘土/天然气-水合物复合体可能储存大量甲烷和其他碳氢化合物，因此，这些复合体可能在气候变化中发挥重要作用，就像人们对天然气水合物提出的那样。

GuggenheimEAR-0207770The working hypothesis of this proposal is that clay/methane-gas hydrate complexes will form under appropriate water-saturated conditions at low temperatures and high gas pressures. In a series of preliminary experiments, we obtained evidence that these complexes indeed can form at these conditions. In these experiments we used an environmental chamber, capable of temperatures from -100 to 200 oC and gas pressures to 75 bars. This chamber, which we developed in-house, allows X-ray scans from 0 to 70 degrees two theta.We propose to examine Na-exchanged and Ca-exchanged montmorillonite and methane under the appropriate conditions to form clay/methane-gas hydrate complexes. In addition, we will examine possible interactions between methane and NH4-exchanged montmorillonite. Our intent is to determine the compositional range of clays that allow gas hydrates to intercalate into clay structures. We will then determine the P-T conditions where these clay/gas-hydrate complexes form, as well as the amounts of gas hydrates that are incorporated in the clay. The discovery of clay/gas-hydrate complexes introduces a new class of materials, which should be of interest in mineralogy, geochemistry, and materials science. As with gas hydrates, these new complexes: (1) may be expected to occur in deep ocean and polar regions (e.g., permafrost, Antarctic ice), (2) may be involved in submarine sediment stability, and (3) may be present on Mars. It is probable that the stability range of clay/gas-hydrate complexes will extend the stability range of gas-hydrate compounds. Also, clay/gas-hydrate complexes may store significant quantities of methane and other hydrocarbons, and thus, these complexes may play an important role in climate changes, much like what has been proposed for gas hydrates.