2004 Fiscal Year Final Research Report Summary
Study of High Performance Methane Hydrate Recovery System by Air Lift system
| Project/Area Number |
15560147
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Fluid engineering
|
|---|
| Research Institution | Kyushu University |
|---|
Principal Investigator |
MINEMOTO Masaki Kyushu University, Chemical Engineering, Professor, 大学院・工学研究院, 教授 (10315103)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MIYAIRI Yoshio Kyushu Kyoritu University, Mechanical Engineering, Professor, 工学部・機械工学科, 教授 (10309734)
MATSUKUMA Yosuke Kyushu University, Chemical Engineering, Associate Professor, 大学院・工学研究院, 助教授 (70282241)
INOUE Gen Kyushu University, Chemical Engineering, Research Assistant, 大学院・工学研究院, 助手 (40336003)
|
|---|
| Project Period (FY) |
2003 – 2004
|
| Keywords | Methane Hydrate / Gas lift system / HCFC141b / Decomposition rate / Lattice Gas automata / three-phase model / three-phase flow |
|---|
| Research Abstract |
The research includes two main themes
1.Fluid Dynamic Study on Recovery System of Methane Hydrate
As one of the recovery system of methane hydrate, gas-lift system is applied and investigated. The height 5m, diameter 0.1m, gas-lift system is experimented. The relationship between injected gas quantity and pumped water quantity is obtained. Unsteady one-dimensional two-phase flow in vertical pipe is calculated by compressible one-dimensional two-fluid model, as analysis of flow in recovery pipe of methane hydrate from the deep ocean floor. From the calculation result, it is shown that the power requirement of the gas-lift system is 0.5 to 4% of power generated from recovered methane gas and the optimal gas injection depths exist. Next, the decomposition ratio of gas hydrate is measured using R-141b hydrate instead of methane hydrate. And it is suggested that the methane gas generated from decomposition of hydrate influences enough to decrease the injected gas flow rate. Thus, it is suggested that the gas-lift system can be economically effective recovery system of methane hydrate from the deep ocean floor.
2.Gas Hydrate Decomposition Rate in Flowing Water
The gas hydrate decomposition rate in flowing water was measured using HCFC141b hydrate as a substitute for MH. When the water temperature was higher than the boiling point of the decomposition gas, it was observed that the decomposition gas increased the decomposition rate. Moreover, the decomposition phenomenon was simulated by the Lattice Gas Automaton method in order to establish the technique which analytically estimates the decomposition rate. The validity of the simulation method was shown by comparing the experiments. Furthermore, the formula between Reynolds number and Nusselt number was obtained, which express the heat transfer around the gas hydrate lump.
|
