Trickle bed mechanistic model for (non-)Newtonian power-law foaming liquids

Abstract

Physical models for the description of the hydrodynamics of trickle-bed reactors for foaming Newtonian and power-law liquids are virtually inexistent in the literature. An attempt is made in this work to develop a hydrodynamic model for cocurrent gas–liquid downflow involving foaming (non-)Newtonian power-law liquids through packed beds at non-ambient temperatures and moderate pressures. The model was an extension of the well-trodden slit model variants proposed for (non-)Newtonian power-law coalescing-liquid systems. Its validation using recently published experimental data [Aydin, B., and Larachi, F., 2008. Trickle bed hydrodynamics for (non-)Newtonian foaming liquids in non-ambient conditions. Chem. Eng. J. 143, 236–243.] allowed a quantitative representation of foaming flow hydrodynamics in terms of the two-phase pressure gradient and the liquid holdup up to 90 °C and 0.7 MPa. The model, requiring no arbitrary adjustable parameters, in addition related foam stability to quantitative descriptors such as the liquid-film-borne bubble holdup and diameter, and free (or headspace)-gas holdup. The model also exhibited logical and fully interpretable trends with regard to foam stability, reactor temperature and pressure, liquid and gas superficial velocities.