Synthesis and Evaluation of a New Kind of Kinetic Hydrate Inhibitor

A new kind of kinetic hydrate inhibitor (KHI) named KL-1 as the ramification of poly (N-vinyl caprolactam) (PVCap), was synthesized successfully by use of precipitation polymerization. The hydrate inhibition performance of KL-1 was assessed in a high pressure sapphire cell, and the onset time of hydrate formation and maximum subcooling were determined by the visual observation method and compared with the commercial KHIs, including Inhibex 501 and VC-713. Meanwhile, the synergic effect between ethanol and KL-1 developed was also studied in this work. The experimental results show that the onset time of KL-1 measured increases with the increase of the dosage and decrease of subcooling. Compared with the system without kinetic hydrate inhibitor, the morphological behavior of hydrate crystals in the systems containing KL-1 is different, and the hydrate crystals only grow to the gas phase with the hydrate formation. Additionally, based on the measurement of inhibition time, the inhibition performance of KL-1 is superior to Inhibex 501 and VC-713, and shows higher maximum subcooling at the similar conditions. Finally, we also demonstrated that ethanol can be used as synergist to improve the performance of KL-1 remarkably at suitable dosage.