Journal of Chemical Thermodynamics, Vol.117, 113-118, 2018
Bulk liquid and gas mole fraction measurements during hydrate growth for the CH4 + CO2 + H2O system
Gas and liquid mole fraction were experimentally obtained for the CH4 + CO2 + H2O system at four different time intervals during hydrate growth. In order to validate the procedure, equilibrium mole fractions were also obtained and satisfactorily compared to literature values. Using a 70.0% CH4 - 30.0% CO2 loading composition in combination with a 1.6 MPa driving force at 274 K, results showed that both the liquid and gas mole fraction of methane and carbon dioxide were independent of time during the early stages of growth. For comparison purposes, samples were also obtained during the induction period. After the nucleation event, methane liquid mole fractions dropped below induction values while no change was observed for carbon dioxide. It is therefore postulated that methane consumption is favored during the early stages of growth. The rates of crystal growth were acquired and in parallel with all other parameters obtained experimentally, were proven critical to understand multicomponent gas hydrate kinetics. (C) 2017 Elsevier Ltd.