Some considerations on the use of steam in industrial wine-making processes

Industrial wine production, a key EU-sector, exhibits significant energy consumption, whose reduction is crucial to achieve the 2050 climate goals. The main energy source in wineries is electricity, while steam is still commonly used as heat carrier, even if its convenience in winemaking has never really been explored in the literature. Thus, the objective of this study is to investigate whether steam as energy carrier is really the ideal solution in wineries. After a detailed characterization of process thermal requirements and related equipment, an energetic model of a winery was developed. Different possible plant configurations in terms of combinations of thermal power generation technologies were identified and their energy performance analysed, including both gas-fired steam and hot water boilers. The developed model was validated thanks to a case study constituted by a winery in north eastern Italy, specialized in sparkling wines. Results show that a very common solution, involving a steam boiler serving all different process utilities, entails significant energy inefficiencies. Indeed, only very few low energy demanding utilities require thermal energy in this form. The more energy efficient solution is, instead, supplying thermal needs through hot water at different temperatures, able also to minimize production costs from a life-cycle perspective. Other interesting benefits lie in the adoption of heat recovery systems e.g. from air compression units, to meet part of the loads related to heating needs. These research findings, pursuing efficiency and sustainability performance improvement, are applicable when designing new wine production plants or replacing existing steam boilers at the end of their technical life.