Yan-Ping Chen
National Taiwan University, Taiwan
Title: Measurement for the Dissociation Conditions of Methane and Carbon Dioxide Hydrates in the Presence of Additive Materials
Biography
Biography: Yan-Ping Chen
Abstract
The target of this study is to find the appropriate materials as additives for the formation or dissociation of methane or carbon dioxide hydrate. These hydrates are used for either natural gas energy sources or for carbon dioxide sequestration. The dissociation conditions for gas hydrates in the presence of additives at various concentrations in aqueous solutions were experimentally measured in this study. These additives include alcohols, cyclic ethers, or cyclic ketones. Hydrate phase dissociation conditions were measured with an apparatus which was operated at high pressure and low temperature conditions. The liquid water-hydrate-vapor (Lw-H-V) three-phase dissociation temperatures and pressures for methane hydrate in the presence of additives were determined by employing the isochoric method. New experimental data were reported within the pressure range from 4 to 15 MPa. It is demonstrated that the addition of certain additives in gas hydrate system shifted the original hydrate phase boundaries to lower pressure and higher temperature. The hydrate stability region was broadened, therefore it has a promotion effect on the formation of gas hydrate. Other additives might show inhibition behavior. These promotion or inhibition effect is also investigated by the possible hydrate structures in cases of various additive materials. The determination of gas hydrate structures is calculated using the Clausius-Clapeyron equation and the experimental measured dissociation temperature and pressure data.