Exploitation of methane in the hydrate by use of carbon dioxide in the presence of sodium chloride

• 作 者: Li Zunzhao Guo Xuqiang Yang Lanying Ma Xiaona
• 机 构: State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China
• 出 处: 石油科学（英文版）
• 发表日期: 2009年4期
• 关键词: CO2 hydrate CH4 hydrate guest molecule replacement kinetic model

The replacement process of CH4 from CH4 hydrate formed in NaCI solution by using pressurized CO2 was investigated with a self-designed device at temperatures of 271.05, 273.15 and 275.05 K and a constant pressure of 3.30 MPa. The mass fraction of the NaCI solution was either 0.5 wt% or 1.0 wt%. The effects of temperature and concentration of NaCI solution on the replacement process were investigated. Experimental results showed that high temperature was favorable to the replacement reaction but high NaCI concentration had a negative effect on the replacement process.Based on the experimental data, kinetic models of CH4 hydrate decomposition and CO2 hydrate formation in NaCI solution were established. The calculated activation energies suggested that both CH4 hydrate decomposition and CO2 hydrate formation are dominated by diffusion in the hydrate phase.