Methane hydrate film growth kinetics

Kinetic parameters for methane hydrate formation were obtained from film growth measurements at the methane-water interface. Experimental data were collected for methane hydrate formation over the pressure and temperature ranges of 3.55-9.06 MPa and 1.0-4.0 degreesC, respectively. The growth rate was found to be proportional to the supercooling, which indicates that crystallization proceeds by a continuous growth mechanism. A model for hydrate formation was proposed which accounts for both heat transfer and kinetics. Molecular attachment kinetics were assumed to follow Arrhenius behavior, and the heat transfer coefficient was assumed constant. The heat transfer assumption was verified using a thin wire approximation which was considered a geometric analog. The resulting parameters were regressed and an activation energy of 171 kJ/mol, a pre-exponential factor of 1.605 x 10(36) W/m(2) K, and a heat transfer coefficient of 42,325 W/m(2) K were found. (C) 2001 Elsevier Science B.V. All rights reserved.