碳封存受限介质中甲烷水合物的稳定性和生长,The Journal of Physical Chemistry C

当前位置： X-MOL 学术 › J. Phys. Chem. C › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

碳封存受限介质中甲烷水合物的稳定性和生长
The Journal of Physical Chemistry C ( IF 3.3 ) Pub Date : 2022-07-07 , DOI: 10.1021/acs.jpcc.2c02936
Shurraya Denning ₁ , Ahmad A. A. Majid ₁ , Carolyn A. Koh ₁

Affiliation

甲烷水合物既是一种能源资源，也是一种环境风险，因为地球上大量的碳被封存在深水多孔海洋沉积物中的天然气体水合物中。需要更多的研究来了解孔隙等受限空间中的热力学稳定性和动力学增长，以找到有效提取甲烷和防止不稳定的方法。尽管在文献中已经研究了孔径对甲烷水合物的影响，但对孔隙形状的影响知之甚少。本研究使用两种介孔二氧化硅材料：SBA-15（圆柱形通道）和 SBA-16（具有互连通道的立方孔）研究了孔的形状如何影响甲烷水合物和冰的稳定性和成核。两种 SBA 都破坏了甲烷水合物和冰的结构，相对于孔径，SBA-16 平均比 SBA-15 降低热力学平衡温度的程度更大，因为 SBA-16 的互连通道由于其更窄的尺寸而阻碍了生长. 孔隙形状也影响水合物的生长。SBA-15 有利于圆柱形通道内的水合物生长，而 SBA-16 表现出不同的行为，甲烷水合物在立方孔隙中生长，但在相互连接的通道中结冰。这两种 SBA 还显示出有趣的冰冻抑制作用，但促进了甲烷水合物的形成。与环境压力下的实验相比，添加 8 MPa 的甲烷导致 SBA-15 的液态水转化为水合物的转化率提高了 72 ± 14%，SBA-16 提高了 67 ± 19%。较高压力 (>1 MPa) 下的甲烷会破坏 SBA-15 和 SBA-16 的亲水二氧化硅表面上的水吸附，导致水活度增加。总体而言，这项研究发现，孔隙形状可能不会显着影响甲烷水合物的形成量，但会极大地影响甲烷水合物的稳定性和成核。

"点击查看英文标题和摘要"

Stability and Growth of Methane Hydrates in Confined Media for Carbon Sequestration

Methane hydrates pose potential as both an energy resource and an environmental risk, as a significant amount of the Earth’s carbon is sequestered in naturally occurring gas hydrates in deep-water porous oceanic sediments. More research into understanding the thermodynamic stability and kinetic growth in confined spaces like pores is needed to find ways to efficiently extract methane and prevent destabilization. Although effects of pore diameter on methane hydrates have been studied in the literature, very little is known about the effect of pore shape. This study investigated how the shape of a pore affected both stability and nucleation of methane hydrate and ice using two mesoporous silica materials: SBA-15 (cylindrical channels) and SBA-16 (cubic pores with interconnecting channels). Both SBAs destabilized the structure of methane hydrates and ice, with SBA-16 on average decreasing the thermodynamic equilibrium temperature to a greater extent than SBA-15 relative to pore size, as the interconnecting channels of SBA-16 choke growth due to its narrower size. The pore shape also affected hydrate growth. SBA-15 favored hydrate growth within the cylindrical channels, and SBA-16 showed differing behavior with methane hydrate growth in the cubic pore, yet ice freezing in the interconnecting channels. The two SBAs also showed interesting inhibition of ice freezing, yet promoting methane hydrate formation. In comparison to experiments at ambient pressure, the addition of 8 MPa of methane resulted in the liquid water to hydrate conversion increasing by 72 ± 14% for SBA-15 and 67 ± 19% for SBA-16. Methane at relatively high pressures (>1 MPa) disrupts the water adsorption on the hydrophilic silica surfaces of SBA-15 and SBA-16, leading to an increase in water activity. Overall, this study found that the pore shape may not significantly influence how much methane hydrate forms, yet greatly impacts methane hydrate stability and nucleation.

更新日期：2022-07-07

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南

全部期刊列表>>