Bahman. ZareNezhad - School of Chemical, Petroleum and Gas Engineering, Semnan University, P.O. Box ۳۵۱۹۵-۳۶۳, Semnan, Iran
Mona Mottahedin - School of Chemical, Petroleum and Gas Engineering, Semnan University, P.O. Box ۳۵۱۹۵-۳۶۳, Semnan, Iran
Farshad Varaminian - School of Chemical, Petroleum and Gas Engineering, Semnan University, P.O. Box ۳۵۱۹۵-۳۶۳, Semnan, Iran

Nucleation is one of the most important steps in the process of crystallization of gas hydrates. In the present work the nucleation mechanism of gas hydrate formation process using the propane as a sII gas hydrate former is investigated at isothermal operating conditions. Effects of variations of supersaturation and impeller speed on the kinetics of hydrate nucleation are also presented. Differente expressions for dependence of induction time with degree of supersaturation are employed. The accuracy of the predicted induction times for the case of progressive nucleation are always much higher than those obtained through instantaneous nucleation assumption at all ranges of impeller speeds. It is found that the heterogeneous progressive nucleation is the most probable nucleation mechanism at the early stages of gas hydrate formation processes.

gas hydrate, formation, nucleation, mechanism, crystallization, kinetics