| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of recovering methane gas from natural gas hydrate which includes: a step of adding a mixed gas containing both carbon dioxide and air to natural gas hydrate in the deep sea bottom; a step of replacing the mixed gas with methane gas; and a step of dissolution-dissociation step of methane hydrate.SOLUTION: When the temperature in a technique-applied region is low, a replacement reaction using a mixed gas of carbon dioxide plus air is induced, and, when the temperature in the technique-applied region is high, dissociation of solid methane hydrate with the mixed gas of carbon dioxide plus air is induced. The method is thus applicable as an all-weather-type technique for recovery of methane gas. The method eliminates the need of transportation of another injection gas, compared with conventional methods, and directly collects and compresses air over a region involving natural gas hydrate and then mixes air with carbon dioxide for injection. |
