Inhibited Gas Hydrate Formation at Activated Carbon Particle-Laden Oil-Water Interfaces

This study showed that the formation of cyclopentane (CP)-propane mixed hydrate is inhibited by activated carbon particles in the non-hydrate forming oil phase (isooctane) having a nonionic surfactant (sorbitan monooleate, Span 80). Due to the hydrophobicity, the activated carbon layer is formed at the oil (CP)-water interface. The inhibition effects of activated carbon layer come from preventing the contact between water molecules and hydrate formers. First, the formation of cyclopentane-propane mixed hydrate was confirmed using Raman spectroscopy; the results of Raman spectra showed that cyclopentane and propane mixed hydrate is structure II. Using high pressure micro differential scanning calorimetry (HP micro-DSC), the inhibition efficiency of activated carbon was analyzed by measuring the dissociation enthalpy. The dissociation enthalpy of mixed hydrate was reduced sharply until 0.5 wt% of activated carbon. When the activated carbon is 1.0 wt%, because the oil-water interface is covered entirely by the particle layer, and thus, hydrate growth was not observed over 6 hours. These results indicate that activated carbon particles can be used as a kinetic hydrate inhibitor.