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Flow assurance treatment with chemical have become more common as new natural polymers are being develop and are viable for inhibiting hydrate formation in production systems due to its eco-friendly and economical properties. Using high-pressure micro-differential scanning calorimetry (HP-µDSC), the influence of kinetic inhibition on methane gas hydrate formation from synthetic polymer; polycaprolactam (PVCap) and organic polymers (low- and high-methoxylated pectin) was investigated. HP-µDSC was combined with the use of open-ended capillary tubes to counter the stochasticity of hydrate formation which often results in an inconclusive data set without numerous repetitions. By adding the capillary tubes within the cell, more data points on the performance of the inhibitors. Generally, the addition of these inhibitors increased the delay in formation of hydrates compared to the control sample which contained deionized water at 25˚C subcooling and 10 MPa pressure. However, the two types of organic inhibitors, which are distinguished primarily by the functional group ratios (carboxyl and ester), performed in contrast to one another. The results suggest that the presence of higher carboxyl functional groups is affecting the overall polarity (i.e., low-methoxylated pectin) significantly improved the hydrate inhibition at optimum concentration where both high-methoxylated pectin and PVCap; a commercial inhibitor, performed relatively weaker. In comparison with PVCap, high-methoxylated pectin showed comparable trend and slightly better performances at most concentrations; however, the peak structures indicate discernible difference in the formation mechanism. The use of low-methoxylated pectin at optimum concentration may offer inhibition performance up to three times to that of PVCap at high subcooling.

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In an offshore system, hydrocarbon fluids are produced at deeper depths in the oceans, and extended pipelines delivering fluids over long distances are common. Subsequently, these practices increase the tendency of unprocessed water-containing hydrocarbon fluid to be exposed to lower temperatures and higher pressures conditions where hydrate formation is favourable. One of the solutions to resolve this problem is by introducing hydrate inhibitors preferably low dosage hydrate inhibitors (LDHIs). The more versatile LDHIs; Kinetic Hydrate Inhibitors (KHIs) could further be optimised in cost and its biodegradation properties. The current study used an ionic, neutral, hydrophilic, mucoadhesive and highly branched Tamarindus indica L. polysaccharide (TSP). TSP as a new natural kinetic hydrate inhibitor due to its high methoxyl content. In this study, the polysaccharides were extracted using water-based extraction method which resulted in 61.3% yield. The performance of TSP in delaying the clathrate hydrates formation was evaluated based on the induction time recorded from the thermogram generated by a high pressure micro-differential scanning calorimeter device (HP-μDSC) at pressure of 5 MPa with subcooling degree of 17.3 °C. Three TSP concentrations (0.10 wt%, 0.25 wt%, and 0.50 wt%) were tested to determine the optimal concentration used to increase the delay time at the prescribed conditions while comparing it to a condition when there is no addition of TSP. The outcomes shows that TSP is able to delay hydrates formation at high degree of subcooling. The TSP works well at low concentration at high degree of subcooling while remain relatively economical and biodegradable.

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