Optimising sustainability: circular pathways for Scotch Whisky distillery co-products

The use of co-products for animal feed can potentially have a higher greenhouse gas (GHG) emission and water scarcity offset compared to bio-energy (bio-electricity/fuel) production. We cluster 136 Scotch Whisky distilleries and evaluate the co-product pathways for the production of animal-feed and/or bio-energy at centralised processing facilities. Production of animal feed, and the subsequent displacement of imported animal feed, offered the most significant GHG offset, which was between a factor of c.a. 2.5 to 8 times greater than the bio-electricity/fuel and bio-energy/feed scenarios. This offers significant potential from a global net-zero carbon emissions perspective. However, this comes at a cost to local energy security potential. Bio-electricity produced in the electricity intensive scenarios was 481 GWh per year. This would significantly increase Scotland's bio-energy production and equates to c.a. 5% of Scotland's non-commercial electricity needs.