(285c) Gas-Liquid Flow Modeling in Columns Equipped With Structured Packing Seen As Bi-Structured Porous Media

Gas-liquid flow modeling in columns equipped with structured packing seen as bi-structured porous media

Structured packing play a large role in chemical engineering processes involving gas-liquid. The packings are made of an assembly of corrugated sheets where two adjacent sheets are respectively inclined by an angle and the opposite of this angle from the vertical axis. Each group of oriented sheets may force the flow in its preferential direction, hence the naming of such media as bi-structured porous media. In addition, such a device features the classical porous medium two-scales characteristics: the pore-scale and the packing scale or macro-scale. Due to this peculiar structured geometry, the flow modeling from a macroscopic point of view remains a challenging problem that has to be overcome to design enhanced devices. In particular, the macroscopic phenomena that leads to the spreading of a liquid point source at the top of a packing are still misunderstood, and the classical two-phase flow models in porous media failed to properly catch the liquid distribution within the column.

We have developed a mathematical model based on a multi-scale analysis to simulate gas-liquid flow through distillation columns. This model is partly inspired by the work of [1] and our recent research on single phase flow through bi-structured porous media [2]. The effective properties that appears in this model are evaluated from either simulations or analytical solutions of the flow at the pore-scale. Simulation results have been successfully compared to laboratory-scale experiments and industrial-scale measurements.

[1] CFD Modelling and Calculation of Dynamic Two-Phase Flow in Columns Equipped with Structured Packing Chemical Engineering Research and Design, Volume 85, Issue 8, 2007, Pages 1112-1122 B. Mahr, D. Mewes

[2] A two-pressure model for slightly compressible single phase flow in bi-structured porous media Chemical Engineering Science, Volume 96, 7 June 2013, Pages 55-70 Cyprien Soulaine, Yohan Davit, Michel Quintard