Bioproducts and biofuels from sheep cheese whey: environmental benefits

Cheese whey (CW), namely the liquid obtained by the milk casein removal during the cheese-making process, is one of the main agro-industrial waste streams of several Mediterranean countries. In this study, the environmental impacts of two CW valorization options were considered and were compared by Life Cycle Assessment (LCA): anaerobic digestion, characterized by TRL8-9, and dark fermentation combined with biopolymers production, characterized by TRL3-5. The LCA results show that the anaerobic digestion scenario is still characterised by higher environmental performance as compared to dark fermentation associated with biopolymers production, mainly because avoided impacts - as electricity and thermal energy recovery - are higher. Additionally, the consumptions of energy, water and chemicals that affect the dark fermentation associated with biopolymers production are higher than for the anaerobic digestion case. The preliminary results of this study suggested to introduce some modifications in the dark fermentation associated with biopolymers production process, that can improve the overall environmental balance.