Hydrate Equilibrium Conditions of CO₂ Containing Natural Gas in Methanol/Ethylene Glycol/Sodium Chloride Aqueous Solutions

The development of carbon dioxide (CO2) containing a gas field in deep water makes it necessary to measure the hydrate equilibrium conditions. In this work, the hydrate equilibrium conditions of two CO2 containing natural gas samples in 10 wt % methanol, ethylene glycol, and sodium chloride aqueous solutions were measured by using the isochoric pressure searching method. The concentrations of CO2 in each of the two samples are 21.3 and 25.5 mol %. The temperature and pressure ranges are 4.80–15.10 °C and 1.00–6.77 MPa, respectively. Comparison of the measured data with Multiflash predictions shows a good agreement. The thermodynamic consistency of the measured data was checked by the Clausius–Clapeyron equation, with a max (1 – R2) × 100% value of 0.72%.