As Green As It Gets: An Abundant Kinetic Hydrate Inhibitor from Nature

Abstract

We report the development of a kinetic hydrate inhibitor (KHI) based on a cheap, abundantly available natural product that is readily biodegradable and low in toxicity. The optimal product, called KHI530, was determined using KHI screening tests by the slow constant cooling method in multiple rocking cells. The performance was better than a low molecular weight poly(N-vinylpyrrolidone) for a synthetic natural gas mixture (SNG) forming primarily structure II hydrate and about the same performance for structure I methane hydrate. Isothermal tests using the SNG mixture indicate that an active dosage of 0.5 wt % can protect against hydrate formation for 48 h at a subcooling of 6–7 °C. KHI530 exhibits no cloud point up to 95 °C in deionized water or NaCl brines up to 7 wt %. KHI530 can be biostabilized in monoethylene glycol (MEG) or using a biocide such as tetrahydroxymethylphosphonium sulfate (THPS), which does not affect the KHI performance. KHI530 was found to be fully compatible at all ratios with thermod...