Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Experimental determination of methane diffusivity in water and brine under hydrate formation conditions
Submission Author:
Thales Sirino , PR , Brazil
Co-Authors:
Thales Sirino, Celina Kakitani, Luiz Fernando Santos De Vasconcelos, Joao Vitor Mendes Rocha, Dalton Bertoldi, Rigoberto Morales, Moisés Marcelino Neto
Presenter: Thales Sirino
doi://10.26678/ABCM.COBEM2023.COB2023-0521
Abstract
The objective of this study is to experimentally determine the diffusivity of methane in water and brine under hydrate formation conditions using the pressure decay method. To reduce the simplifications necessary for determining mass transfer parameters, which may lead to potential errors or limit its applicability, a numerical model that considers diffusivity dependent on solute concentration and liquid phase swelling was developed. Quasi-equilibrium and mass balance based boundary conditions were used at the gas-liquid interface, with the saturation concentration of the solute obtained through a flash calculation using the Cubic-Plus-Association equation of state (CPA). The equation of state also provided the mixture density and gas fugacity coefficient, enabling the use of a thermodynamic correction factor for refining diffusivity. Experiments were conducted at 277.15 K and pressures ranging from 45 bar to 50 bar, with salt concentrations up to 3.5% in mass fraction.
Keywords
Diffusivity, Pressure Decay, hydrate, Concentration-dependent diffusivity, swelling, Cubic-Plus_Association
