Liquid hold-up correlations for trickle beds without gas flow

Dynamic and total liquid hold-up data required for trickle bed reactors without gas flow were gathered from the literature to generate an exhaustive database including over 1100 measurements. The slit model was satisfactorily representational of the evolution of the total liquid hold-up and yielded an average absolute relative error (AARE) of 21.3% for the gravity-driven liquid flow depicted in the database. Similarly, an alternate approach that combined artificial neural networks with dimensional analysis enabled derivation of an empirical dynamic liquid hold-up correlation hD=f(FrL, WeL, ReL, EoL) yielding an AARE=14%.