Equilibrium conditions for hydrate formation from binary mixtures of methane and carbon dioxide in the presence of electrolytes, methanol and ethylene glycol

Abstract

Ethylene glycol, methanol and electrolytes inhibit hydrate formation. Computation of the inhibition effects of these additives is necessary for the design of industrial operations where it is desired to avoid hydrate formation. Development of thermodynamic methods to calculate the hydrate equilibria conditions requires accurate experimental data. In the present work experimental three phase (aqueous liquid solution, vapor and incipient solid hydrate) equilibrium data for two mixtures of methane and CO₂ in the presence of methanol, ethylene glycol and electrolytes were obtained. The experiments were carried out in the temperature range of 264–282 K and pressure range of 1.5–10.4 MPa. A ‘full view’ fixed volume sapphire cell used earlier to gather data on CO₂ by the authors was converted into a variable volume cell with the help of a movable piston to perform the experiments.