Synthesis and application of magnetically recyclable nanoparticles as hydrate inhibitors

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2022-03, Vol.431, p.133966, Article 133966
• Main Authors: Zhao, Yang, Liu, Yanzhen, Dong, Hongsheng, Chen, Chong, Zhang, Tianxiang, Yang, Lei, Zhang, Lunxiang, Liu, Yu, Song, Yongchen, Zhao, Jiafei
• Format: Article
• Language: English
• Subjects: Gas hydrate; Kinetic hydrate inhibitor; Magnetic nanoparticle; PVCap; Recoverable hydrate inhibitor
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2021.133966

[Display omitted] •A magnetically recoverable nanoparticle inhibitor was synthesized.•The induction time with inhibitors was 3 times longer than pure water case.•The inhibitors exhibit good cycling performance and magnetic separation efficiency.•The inhibition mechanism based on in-situ Raman was proposed. Current schemes dealing with hydrate blockage problems in gas pipelines suffer a high dosage of inhibitors and thus are associated with a significant risk of environmental damage. Overcoming these issues requires the development of novel recoverable inhibitors with persistent cycle performance. In this work, a new approach involving coating poly(vinylcaprolactam) (PVCap) and poly(vinylpyrrolidone) (PVP) onto the surface of γ-methacryloxypropyltrimethoxy silane (MPS)-modified Fe3O4 nanoparticles was proposed; this procedure enables the magnetic recovery of the inhibitory particles. It was found that the onset time of hydrate formation was extended 3 times compared to pure water with the help of the synthesized inhibitors showing better performance than commercial inhibitors. Excellent magnetic separation from sandy matrices in solution was achieved with a recovery efficiency of 86%. This was followed by a good cycle performance: the induction time remained still over 2 times longer than the pure water case after 5 cycles of recovery. The in-situ Raman spectra revealed that the recyclable inhibitors functioned through disturbing the construction of the large cages; a resulting mechanism was proposed with nanoparticles isolating the early hydrate patches preventing their further explosive bulk growth. In addition, the simple synthesis method makes it possible to coat various polymer inhibitors onto recovery particles. The results indicate that magnetically recovering the inhibitory particles and reusing them to hinder hydrate generation could be an alternative method to tackle the environmental and economic problems associated with current flow assurance procedures.