Abstract:

The decomposition of type I ethane hydrate and type II propane hydrate stimulated by 2.45 GHz microwave (MW) were experimentally investigated. The decomposition characteristics of the hydrates under MW heating were analyzed based on the two-step dissociation mechanism accompanied by heat and mass transfer at the crystal surface. Results show that the decomposition behavior of the gas hydrate during MW heating is coupled with the real-time electromagnetic field. Volumetric heating enhances the heat and mass transfer process at the surface layer of the hydrate particles. The time-accumulated thermal effect of MWheating promotes the destruction of the clathrate host lattice. The average decomposition rates of ethane hydrate and propane hydrate obtained in this work range from 0.109 to 0.400 mol·min-1·L-1 and from 0.090 to 0.222 mol·min-1·L-1, respectively, under incident MW power that ranges from 120 to 540 W. We conclude that the average decomposition rates of ethane hydrate and propane hydrate are faster as the MW power increases within a certain range. The decomposition rates of ethane hydrate are mainly controlled by the MWpower. In contrast, the decomposition rates of propane hydrate are controlled by both the MW power and the kinetic mechanismunder relatively higher power.

Key words: Hydrate, Ethane, Propane, Microwave, Decomposition