Energy demand and carbon footprint of cheddar cheese with energy recovery from cheese whey

This study evaluates the life cycle environmental sustainability of cheddar cheese with energy recovery from cheese whey via anaerobic digestion. Environmental hotspots and improvement opportunities along the supply chain are also identified. The cheddar cheese production process has been simulated by using Aspen Plus. The environmental impacts have been estimated through life cycle assessment (LCA) using the outputs from process simulation. The LCA data for the rest of the life cycle have been sourced from databases and literature. The results reveal that the total primary energy consumed in the whole life cycle of cheddar cheese is 347 MJ, with the carbon footprint equal to 14 kg CO₂ eq. per kg of cheddar. Energy recovered from anaerobic digestion of whey reduces the total life cycle primary energy demand and the carbon footprint by only 2%. Much greater reductions could be achieved by targeting milk production and storage of cheese. However, anaerobic digestion of whey makes the cheese production process energy self-sufficient and reduces the production costs. It also makes the production process carbon negative, reducing its carbon footprint from 0.12 to -0.12 kg CO₂ eq./kg due to the credits for electricity and heat produced from biogas.