A study of guar gum derivatives as green kinetic hydrate inhibitors

Abstract

The research on green hydrate kinetic inhibitors has gained significant attention due to their commendable environmental compatibility. In this study, guar gum and its derivatives (hydroxypropyl guar gum, cationic guar gum, carboxymethyl guar gum) were chosen as potential kinetic inhibitors to investigate their effects on methane hydrate formation and dissociation in terms of different structures, ionic types and concentrations. It was found that the four guar gums were feasible as green hydrate kinetic inhibitors. Among them, carboxymethyl guar gum exhibited the best performance in nucleation and growth inhibition, with the induction time 2.7 times longer than that of PVP system and the maximum standardized growth rate 80% lower than pure water system, at the optimal concentration (1.0 wt%). The inhibition performance of hydroxypropyl guar gum was observed to be significant only at high concentrations, whereas cationic guar gum exhibited comparatively weaker performance compared to regular guar gum. In addition, the hydrate systems in presence of more effective guar gums were observed more difficult to dissociate, requiring higher dissociation temperature and displaying lower dissociation rates. These results provide guidance for the use of biopolymers in the field of natural gas flow assurance.