Thermodynamic and kinetic hydrate inhibition performance of aqueous ethylene glycol solutions for natural gas

• Hydrate formation characteristics have been investigated with natural gas.
• The hydrate onset is greatly delayed at the MEG concentration of 30 wt%.
• Crystal growth is also suppressed significantly at the MEG concentration of 30 wt%.
• We investigate the synergistic inhibition effect of two inhibitors.
• This study suggests feasible incorporation of MEG effects into hydrate inhibition.

Hydrate formation characteristics have been investigated with synthetic natural gas at different mono-ethylene glycol (MEG) concentrations by measuring hydrate onset time and subcooling temperature. MEG is well known thermodynamic hydrate inhibitor (THI), however there have been little works studying its effect on hydrate formation kinetics. In this paper, we report the hydrate onset is delayed and crystal growth is suppressed significantly at the MEG concentration of 30.0 wt%. We also investigate the hydrate formation in the presence of both MEG and poly-vinyl pyrrolidone (PVP). Hydrate onset time is further delayed due to synergistic inhibition effect of two inhibitors. These results suggest that it might be feasible to incorporate the kinetic inhibition performance of MEG into current hydrate inhibition strategy to manage the hydrate risk.