Ethane Hydrate Phase Equilibria in WATER, MEG, and TMAB Semiclathrate System

Abstract

The oil and gas industries can benefit from the potential of storing clathrate hydrate gas by managing it with precise knowledge of thermodynamic conditions or preventing its formation in gas transmission lines. In this study, despite the assurance of the thermodynamic inhibition property of MEG on the formation of ethane hydrate, the effect of TMAB on the stability or decomposition of ethane hydrate in the presence of water and MEG was investigated for the first time across six different experimental systems with combinations of 1, 2, 3, and 5 wt % of TMAB from the group of quaternary ammonium salts. The reactor pressure in each system ranged from 0.5 to 3.5 MPa. The minimum temperature of the experiments for maximum clathrate hydrate formation was determined to be 272 K. According to the obtained data, the shift of the equilibrium diagram of ethane hydrate from 1 to 5 wt % changes in favor of the inhibition of stability and inhibition performance. The maximum inhibition of TMAB on ethane hydrate was observed in the presence of MEG and water in combinations close to stoichiometric ratios.