Dissociation behavior of “dry water” C3H8 hydrate below ice point: Effect of phase state of unreacted residual water on a mechanism of gas hydrates dissociation

The results on a dissociation behavior of propane hydrates prepared from “dry water” and contained unreacted residual water in the form of ice inclusions or supercooled liquid water (water solution of gas) were presented for temperatures below 273 K. The temperature ramping or pressure release method was used for the dissociation of propane hydrate samples. It was found that the mechanism of gas hydrate dissociation at temperatures below 273 K depended on the phase state of unreacted water in the hydrate sample. Gas hydrates dissociated into ice and gas if the ice inclusions were in the hydrate sample. The samples of propane hydrates with inclusions of unreacted supercooled water only (without ice inclusions) dissociated into supercooled water and gas below the pressure of the supercooled water-hydrate-gas metastable equilibrium.

Gas hydrate samples contained inclusions of unreacted ice always decompose into ice and gas while the samples contained supercooled liquid water can decompose below the ice melting point into liquid water and gas.Figure optionsDownload full-size imageDownload as PowerPoint slide