混合ガスにおける二酸化炭素濃度の影響 二酸化炭素ハイドレートの生成解離に関する基礎的研究 Ｉ

Abstract

The disposal of carbon dioxide to the marine and sea bed sediments as CO2 gas hydrate is an innovative technique for solving the global environment issue. Experiments on the formation and dissociation of gas hydrate have been carried out using a pressure vessel to investigate the effect of carbon dioxide concentration in the gas phase. From the experiment results, the following are clarified: 1 There is a strong relationship between the partial pressure of carbon dioxide concentration and the temperature of formation and dissociation of gas hydrate. Therefore, the use of this relation enables the estimation of equilibrium conditions of mixture gas. 2 The initial formation speed varies from 0.1 to 0.5 ml / (min. g). Considering, the average values of the initial formation speed, the initial formation speed increases as the carbon dioxide concentration of the initial mixture gas also increases. 3 From the analysis of component gas of gas hydrate and space gas, it can be assumed that nitrogen and oxygen are also incorporated into the cage of hydrate structure as guest molecules. Moreover, it can be seen that the carbon dioxide concentration in the initial space gas is of higher level than the carbon dioxide concentration in the space gas at the time when the gas hydrate grew up. Therefore, this hydrate technology applies in the concentration of carbon dioxide. In the near future, we will attempt to carry out tests on the formation and dissociation of CO2 hydrate under a low concentration of CO2. Furthermore, we will analyze the structure of gas hydrate using the Raman spectroscopy to clarify that nitrogen and oxygen are incorporated into the cage of gas hydrate structure as guest molecules.