Method for continuously separating CH4/CO2 by using fluidized bed

A method for continuously separating CH4/CO2 by using a fluidized bed is achieved by a significant difference among pressures needed by different guest molecules to form hydrates at the same temperature. The mixed gas forms a hydrate in a fluidized bed reactor, the increasing mass and the arrangement of a variable diameter conduit for changing the flow rate push hydrate particles to move upwards,the temperature of the fluidized bed reactor is controlled to make CO2 in the mixed gas continuously form hydrate, and CH4 is enriched in the gas phase and flows out from the top of the fluidized bedto achieve the separation purpose. A heat pump technology is combined with the formation and decomposition of the hydrate to increase the energy utilization efficiency. A cold source is provided for the fluidized bed reactor to form the hydrate and produce a CH4-rich gas; and a heat source is provided for the cyclone separator to decompose the hydrate and produce a CO2-rich gas. The method forms aclean, efficient and envir