(222an) Measurements of the Dissociation Conditions of Gas Hydrates in the Presence of Hydrocarbon Additives

Measurements of the dissociation conditions of gas hydrates in the presence of hydrocarbon additives

Yan-Ping Chen^{*, (1)}, Li-Jen Chen⁽¹⁾, Shiang-Tai Lin⁽¹⁾, , Muoi Tang⁽²⁾

Department of Chemical Engineering

(1)   National Taiwan University, (2) Chinese Culture University

Taipei, Taiwan

Abstract

This study measured the dissociation temperatures and pressures of gas hydrates in the presence of hydrocarbon additives. The gases include methane and carbon dioxide. The hydrocarbon additives include alcohol compound like tetrt-butanol, ring compound like 1,3,5-trioxane and furan compounds. The gas hydrate dissociation conditions were measured with a static and well-mixed apparatus which was operated at high pressure and low temperature conditions. The liquid water-hydrate-vapor (L_w-H-V) three-phase dissociation temperatures and pressures for methane and carbon dioxide hydrates 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 some additives in gas hydrate systems shifted the original hydrate phase boundaries to lower pressure and higher temperature (the promotion effect). Some other additives showed the opposite inhibition effect. In addition, the liquid-hydrate-vapor (L-H-V) three-phase dissociation conditions for brine systems with 0.035 mass fraction of NaCl were also measured and reported in this study.

^*Corresponding author, email address: ypchen@ntu.edu.tw