Kinetic mechanism of hydrophilic amino acid inhibiting the formation of tetrahydrofuran (THF) hydrate

Abstract

Hydrophilic amino acid, as a new kind of hydrate inhibitor, is the hot spot of domestic and foreign relevant studies. At present, however, its intrinsic mechanism influencing the formation of hydrate is not figured out, and the understandings on its synergistic inhibition mechanism with other kinetic hydrate inhibitors (KHIs) are still controversial. In this paper, the influence laws of glycine, l-arginine and its combination with polyvinylpyrrolidone (PVP) on the formation of hydrate were clarified by experimentally simulating the formation of tetrahydrofuran (THF) hydrate, and the intrinsic mechanism was revealed by virtue of various experimental methods. And the following research results were obtained. First, glycine has such a strong disturbance action on water molecules that it has stronger inhibition on the formation of hydrate. And when its dosage is 1.0%, its inhibition effect is the best. Second, l-arginine has a stronger binding action on water molecules, so it has stronger inhibition on the formation of hydrate. And in the range of lower dosages, its inhibition on the formation of hydrate increases gradually with the increase of its dosage. Third, the combination of hydrophilic amino acid and PVP has synergistic inhibition on the formation of hydrate. And the synergistic inhibition ability of combined glycine and PVP K90 is stronger when the total dosage of inhibitors is 1.0%. In conclusion, the research results provide experimental data and a theoretical basis for the research and development of new hydrate inhibitors. Keywords: Hydrate inhibitor, Hydrophilic amino acid, Glycine, l-arginine, Polyvinylpyrrolidone, Tetrahydrofuran hydrate, Mechanism