Intensified biogas purification in a stirred tank
Résumé
The present study aims at intensifying the absorption of carbon dioxide in aqueous phases. For this purpose, a second immiscible liquid phase is used to improve the mass transfer of carbon dioxide in water. Absorption measurements are carried out in a stirred cell by online infrared monitoring of the output carbon dioxide concentration. As dispersed phase, 1-octanol shows an improvement in mass transfer whereas colza oil retards it. Toluene has no significant effect in the range of concentrations investigated. Mass transfer coefficients are determined using a chemical method. Nevertheless, the variety of behaviors could not be explained simply by solubility or variation of mass transfer coefficients. In order to understand the complex gas-liquid-liquid interactions and deduce the mass transfer mechanism between these three phases, surface and interface tension measurements and direct observation of bubbles and droplets are also carried out.