For a reactive distillation column with a novel internal which is made of several structured porous passages, the models of pressure drop and liquid holdup are developed. The simulation from the models shows that the internal can make more than 70% gas contact liquid in cross-current instead of counter-current, so that excessive pressure drop is avoided. In addition, below the load point, only superficial liquid velocity and the volume fraction of the internals have evident effects on the liquid holdup; above the load point, both superficial gas and liquid velocities have great effects on the liquid holdup, and so do the parameters of the internal because they can affect gas flow behavior. (C) 2003 Elsevier B.V. All rights reserved.