Pyrazine Analogues on Clathrate Hydrates in Methane?Water Systems
Pyrazine Analogues on Clathrate Hydrates in Methane?Water Systems
复制标题
甲烷水系统中笼形水合物的吡嗪类似物
DOI：
10.1021/acs.jced.0c00528
复制
发表时间：
2020
影响因子：
--
通讯作者：
Nagao Jiro
中科院分区：
文献类型：
--
作者：
Jin Yusuke;Oshima Motoi;Nagao Jiro
本文报告了通过添加三种吡嗪类似物：2-甲基吡嗪、2,3-二甲基吡嗪和 2,3,5-三甲基吡嗪，甲烷 (CH4)-水系统中平衡压力-温度 (pT) 边界的变化。通过拉曼光谱分析，2-甲基吡嗪、2,3-二甲基吡嗪和2,3,5-三甲基吡嗪对CH4-水体系中形成的笼形水合物结构没有影响。拉曼光谱表明，CH4-吡嗪类似物-水体系中形成的笼形晶体具有I型结构的CH4水合物。与不含添加剂的 CH4-水系统相比，三个 CH4-吡嗪类似物-水系统的相平衡 pT 边界转移到更高和更低的条件。高p/低Tshift证实2-甲基吡嗪、2,3-二甲基吡嗪和2,3,5-三甲基吡嗪充当水合物形成的热力学抑制剂。 ΔT（来自 CH4-水系统的较低 T 位移）的顺序如下：2-甲基吡嗪-水 > 2,3-二甲基吡嗪 > 2,3,5-三甲基吡嗪。该顺序与分子中-CH3基团的数量一致。
This paper reports the change in equilibrium pressure–temperature (pT) boundaries in a methane (CH4)–water system by adding three pyrazine analogues: 2-methylpyrazine, 2,3-dimethylpyrazine, and 2,3,5-trimethylpyrazine. The 2-methylpyrazine, 2,3-dimethylpyrazine, and 2,3,5-trimethylpyrazine showed no effect on the clathrate hydrate structure that formed in the CH4–water system upon analysis via Raman spectroscopy. Raman spectra revealed that clathrate crystals that formed in the CH4–pyrazine analogue–water system were of a structure-I CH4hydrate. Phase equilibriumpTboundaries in the three CH4–pyrazine analogue–water systems shifted to a higherpand lowerTcondition than that for the CH4–water system with no additive. The higherp/lowerTshift confirmed that 2-methylpyrazine, 2,3-dimethylpyrazine, and 2,3,5-trimethylpyrazine act as thermodynamic inhibitors for hydrate formation. The order of ΔT, a lowerTshift from the CH4–water system, was as follows: 2-methylpyrazine–water > 2,3-dimethylpyrazine > 2,3,5-trimethylpyrazine. This order is in agreement with the number of −CH3groups in the molecules.