Gas Recovery Through the Injection of Carbon Dioxide or Concentrated Flue Gas in a Natural Gas Hydrate Reservoir

Because CO₂ hydrate is stable at pressures lower than those required to stabilize hydrates of CH₄ when compared at the same temperature the injection of CO₂ into gas hydrate reservoirs was proposed a while ago as a method to recover methane. The added advantage of such a technology is the simultaneous sequestering/storage of CO₂ captured from fossil fuel power plants or other significant point sources of CO₂. Recent reviews on the subject have provided an account of the laboratory and theoretical work on this topic. The reviews highlighted the need to further elucidate the dynamics of the exchange process and provide information needed for the design of industrial scale facilities. In this work, the kinetics of the CO₂/CH₄ exchange process are investigated in a 5.3 L laboratory crystallizer (reservoir) equipped with ahorizontal injection tube with 24 exits into the packed bed of silica sand particles. Preliminary experiments conducted using this apparatus and also with a high pressure calorimeter indicate that in lab experiments there is some residual water and that the extent of the exchange process is limited. Even if the CH₄ recovery is optimized there is aneed for a CH4/CO2 separation plant to enable a complete cyclic sequence of CO₂ capture, injection and CH₄ recovery.