Automatization of membrane contactors and applications for the management of dissolved gases in wines

Abstract

Over the last decade, several distinct research groups tested possible uses of membrane contactors for the wine industry, notably for the management of dissolved gases in wines, adjustment of the CO2 concentration while reducing the O2 concentration at the same time. Other experiments were done with partial alcohol reduction and addition of N2 to wines. The contactor's heart is its Liqui-Cel™ membrane where the two separate circuits meet. The membrane's hydrophobic characteristics allows a liquid to get in contact with a gas, without dispersing into it. The directions that these gases take through the membrane depend on their partial pressure differences within the two circuits. However, other factors need to be considered to determine exact exchange rates for each target gas. The present article describes the new membrane contactor prototype that was co-developed by the University of applied Sciences and Arts, Viticulture and Enology at Changins, Switzerland, and the School of Engineering and Architecture at Fribourg, Switzerland. The prototype was designed for small scale operations. Flow rates, temperatures and internal pressures can be instantly measured and graphically visualized. Also, O2 concentrations are measured inside the liquid. CO2 concentrations in the liquid can be measured with a device that is connected to the liquid circuit through a bypass after the membranes.