Development of a new nanofiltration membrane for removal of kinetic hydrate inhibitor from water

Abstract

Abstract Kinetic Hydrate Inhibitors (KHIs) are added to the produced fluids in natural gas fields to prevent hydrate formation. Because KHI dissolved into produced water may have a negative impact on the environment, an effective treatment method is needed to remove KHI. A novel thin film nanocomposite (TFN) nanofiltration (NF) membrane was prepared with polyphenylsulfone (PPSU)/graphene oxide (GO) blended support membrane fabricated by the phase inversion method and with a polyamide (PA) selective layer formed by interfacial polymerization over the surface of the PPSU (TFC) and PPPSU/GO supports. The performance of the NF membranes was investigated in terms of the pure water flux (PWF), MgSO4 rejection and KHI rejection under different operating pressures and feed concentrations. The TFN membrane embedded with 0.1 wt.% GO exhibited higher permeate flux than the TFC membrane, with no significant change in KHI rejection. The KHI rejection of 99% and permeation flux of 32.7 L/m2 h (at 9 bar and feed concentration of 0.5 wt.% KHI) were achieved, suggesting that the TFN membrane has potential as an application for KHI removal from water. The prepared TFN membrane also showed a significant antifouling property due to the improved smoothness of the membrane surface.