Direct Measurement of the Four-Phase Equilibrium Coexistence Vapor-Aqueous Solution-Ice-Gas Hydrate in Water-Carbon Dioxide System.

Precise data on the non-variant equilibrium of the four phases (vapor-aqueous solution-ice-gas hydrate) in - coordinates are highly desired for developing accurate thermodynamic models and can be used as reference points (similar to the triple point of water). Using the two-component hydrate-forming system CO-HO, we have proposed and validated a new express procedure for determining the temperature and pressure of the lower quadruple point Q. The essence of the method is the direct measurement of these parameters after the successive formation of the gas hydrate and ice phases in the initial two-phase gas-water solution system under intense agitation of the fluids.

Three-Dimensional-Printed Polymeric Cores for Methane Hydrate Enhanced Growth.

Polymeric models of the core prepared with a Raise3D Pro2 3D printer were employed for methane hydrate formation. Polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), carbon fiber reinforced polyamide-6 (UltraX), thermoplastic polyurethane (PolyFlex), and polycarbonate (ePC) were used for printing. Each plastic core was rescanned using X-ray tomography to identify the effective porosity volumes.