Biodegradable Organics as a Multisystem-Compatible Low-Dose Green Kinetic Hydrate Inhibitor

Kinetic hydrate inhibitors (KHIs) are applied to oil and gas transportation pipelines to prevent hydrate blockage. However, the slow degradation of conventional macromolecule polymeric inhibitors under natural conditions exhibits significant environmental concerns; their bioaccumulation and ecotoxicity also remain poorly evaluated. In this work, nisin was found to function as a low-dose natural green KHI with good biocompatibility and biodegradability. The results showed that a dose of 0.5 wt % nisin could reduce hydrate formation by 37.81%, with the induction time extended by approximately five times at a high subcooling temperature of 10.13 ?. Applying the same low dose of conventional KHIs, such as polyvinylpyrrolidone (PVP), at such a subcooling temperature would initiate an inhibition failure, with even slight enhancement in water conversion. The inhibitory effect of nisin could largely remain under the simulated high temperature and low pH acid-alcohol coupling production conditions; this finding demonstrated the great potential of nisin as a green KHI in field applications. The proposed inhibitory mechanism was that both the adsorption of KHI molecules on the hydrate crystal surface and the interaction of hydrogen bonds formed between polar functional groups and water molecules enabled the nisin kinetic inhibitory effect. Our research extends the existing knowledge in the field and provides guidance for developing a novel green KHI; this peptide abundant in polar functional group side chains could be more preferentially applied than polymeric KHIs due to its environmental friendliness and high performance.

Automated summary

This study discovered the potential of nisin as a low-dose natural green hydrate inhibitor (KHI) with good biocompatibility and biodegradability. Compared to conventional polymeric inhibitors, nisin showed inhibitory effects under high temperature and low pH conditions, demonstrating its potential for practical applications.