Effect of Cod Gelatin and Sodium Alginate on the Nucleation of Gas Hydrates

The effect of mixtures of fish gelatin (protein) from Atlantic cod skin and sodium alginate (polysaccharide) from brown algae on the nucleation of methane-propane hydrate with cubic structure II was studied. The rocking cell method with cooling at a constant rate was used to determine the supercooling required for the formation of hydrates both from solutions of the individual polymers and from their mixtures. It was shown that sodium alginate has practically no effect on the formation of the gas hydrates in contrast to gelatin, the inhibiting activity of which had an intermediate value between polyvinylpyrrolidone and polyvinylcaprolactam (commercial kinetic hydrate inhibitors). In the case of blends of the polymers, an insignificant effectiveness reduction was observed with a decrease in the sodium alginate concentration at a fixed gelatin content. The results indicate antagonism in the kinetic inhibition of methane-propane hydrate by mixtures of polyelectrolytes of biological origin. Intermolecular interactions in the polysaccharide-gelatin complexes inevitably affect the ability of the polymers to retard the nucleation process. A more detailed investigation of the hydrate formation kinetics in relation to the ratio of the polymers in the solution will make it possible to reveal the mechanism of their effect and propose mixed reagents to control the hydrate formation process.

Automated summary

The study examined the effect of fish gelatin and sodium alginate on the nucleation of methane-propane hydrate. It was found that sodium alginate had no significant impact on hydrate formation, while gelatin showed inhibiting activity. The results also indicated antagonism in the kinetic inhibition of methane-propane hydrate by mixtures of the two polymers. Further investigation is needed to understand the mechanism and develop mixed reagents for hydrate formation control.