Servicios Personalizados
Revista
Articulo
Indicadores
Citado por SciELO
Accesos
Links relacionados
Similares en SciELO
Compartir
Revista de la Facultad de Ingeniería Universidad Central de Venezuela
versión impresa ISSN 0798-4065
Resumen
ZABALA, Damelys y LOPEZ DE RAMOS, Aura. Hydrocarbon mass transfer in capillary tubes: 1D transient model with moving boundaries. Rev. Fac. Ing. UCV [online]. 2013, vol.28, n.2, pp.123-134. ISSN 0798-4065.
The diffusion of CO2 was modeled on a glass capillary tube, with cylindrical and square cross sections, filled with liquid hydrocarbon. A mathematical model of transient one-dimensional diffusion with moving boundary was numerically solved. The model results were validated with experimental data of the rise of a liquid-gas interface, due to the injection of CO2 at the top of a capillary tube filled of liquid n-decane. The results show that the rate of ascent of the boundary is greater at the square capillary and that the model can be adjusted by defining a mass flux ratio parameter hidrocarbon/CO2 variable in time. For the square capillary case, it represents the contribution of the presence of a corner with a negative flux ratio, meaning that the liquid filaments formed in the corner of the square capillary induce the movement of the hydrocarbon in the opposite direction of CO2 movement. This finding was extended to the experiments performed by other author in n-heptane, n-octane and n-decane at different pressure and temperature. The convective effect induced by the corner is stronger for smaller hydrocarbon chains and in the case of specific pressure and temperature conditions that increase the saturation concentration of the solute, which reduces the contact angle and increases the wettability on the solid. The maximum deviations found in the position of the interface inside square capillary were 10.8% and 8.3% for CO2/n-octane to CO2/n-heptane, both at 25°C and 1000 kPa. The latter is in contrast with the deviation (33%) reported by other authors for the same experiment based on a model only for the liquid phase, with analytical solution and without moving boundary.
Palabras clave : CO2 Diffusion; Square capillaries; Moving boundary; Enhanced oil recovery; Wettability.