Effective Inhibition of Unfavorable Hydrate Formation in Magnetic Nanoparticle (MNP)-Stabilized Pickering Emulsions

Undesirable hydrate formation at an offshore drilling could induce clogging in a subsea pipeline, which could result in a huge environmental and economic damage. To prevent the unfavorable hydrate formation, non-ionic surfactant (Span 20)-adsorbed magnetic nanoparticles (MNPs, Fe₃O₄) were introduced. Through UV-Vis spectroscopy and SEM analysis, it was confirmed that the surfactant-adsorbed MNPs were effectively stabilized w/o Pickering emulsions. The Pickering emulsion stabilized by 0.125 wt% of MNPs were exhibited maximum ability of inhibiting hydrate formation, by blocking contact between methane molecules and water. Also, these MNP-stabilized emulsions lowered relative torque after hydrate formation, indicating that MNP-stabilized emulsions could act as an anti-agglomerants (AA). The inhibiting ability of MNPs were declined with higher concentration, due to increase of effective surface area of water from the formation of water bridges. By vibrating sample magnetometer (VSM) analysis and recovery simulations, it was revealed that MNP-stabilized emulsions had superparamagnetic behavior and MNPs could be successfully recovered by boot-drum separator.¹ Therefore, it can be concluded that surfactant-adsorbed MNPs could be utilized as a low-dosage hydrate inhibitor (LDHI), by acting as both kinetic hydrate inhibitor (KHI) and anti-agglomerants (AA).

1. J. Min, D.W. Kang, Y.H. Ahn, W. Lee, M. Cha, J.W. Lee, Recoverable magnetic nanoparticles as hydrate inhibitors, Chem. Eng. J. 389 (2020), 124461.