在高达 373 MPa 的压力下，结构-H 甲烷与 1,1,2,2,3,3,4-七氟环戊烷混合水合物。

Structure-H methane + 1,1,2,2,3,3,4-heptafluorocyclopentane mixed hydrate at pressures up to 373 MPa.

机构信息

Division of Chemical Engineering, Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan.

出版信息

J Phys Chem A. 2013 May 23;117(20):4338-41. doi: 10.1021/jp402777a. Epub 2013 May 9.

DOI:10.1021/jp402777a

PMID:23621777

Abstract

Thermodynamic stability boundary of structure-H hydrates with large guest species and methane (CH4) at extremely high pressures has been almost unclear. In the present study, the four-phase equilibrium relations in the structure-H CH4 + 1,1,2,2,3,3,4-heptafluorocyclopentane (1,1,2,2,3,3,4-HFCP) mixed hydrate system were investigated in a temperature range of (281.05 to 330.12) K and a pressure range up to 373 MPa. The difference between equilibrium pressures in the structure-H CH4 + 1,1,2,2,3,3,4-HFCP mixed hydrate system and the structure-I simple CH4 hydrate system gets larger with increase in temperature. The structure-H CH4 + 1,1,2,2,3,3,4-HFCP mixed hydrate survives even at 330 K and 373 MPa without any structural phase transition. The maximum temperature where the structure-H CH4 + 1,1,2,2,3,3,4-HFCP mixed hydrate is thermodynamically stable is likely to be beyond that of the structure-H simple CH4 hydrate.

摘要

结构-H 水合物与大型客体分子以及甲烷（CH4）在极高压力下的热力学稳定边界几乎不明确。在本研究中，在温度范围为 (281.05 至 330.12) K 和压力范围高达 373 MPa 的条件下，研究了结构-H CH4 + 1,1,2,2,3,3,4-七氟环戊烷（1,1,2,2,3,3,4-HFCP）混合水合物体系中的四相平衡关系。结构-H CH4 + 1,1,2,2,3,3,4-HFCP 混合水合物体系中的平衡压力与结构-I 简单 CH4 水合物体系中的平衡压力之差随温度升高而增大。结构-H CH4 + 1,1,2,2,3,3,4-HFCP 混合水合物即使在 330 K 和 373 MPa 下也能稳定存在，而不会发生任何结构相变。结构-H CH4 + 1,1,2,2,3,3,4-HFCP 混合水合物在热力学上稳定的最高温度可能高于结构-H 简单 CH4 水合物。