Abstract

This study presents two methods for measuring the Soret coefficient of water-alcohol mixtures . These methods performed with porous packing are particularly adapted for apparent negative Soret coefficient determination . The first method uses a flat-packed Soret cell operated under a downwards vertical thermal gradient; the second method uses a packed cylindrical thermodiffusion column and thermogravitation. The porous packing is made of inert balls . The porosity is about 38% and the intrinsic permeability 1.01 2 10 m 10 m 2 or even 1.31 2 10 m 10 m 2 . For each experiment, the time evolution of the alcohol fraction sampled at the top and bottom of the cells is checked against the numerical outputs of a thermodiffusion model: the METSOR code