Abstract
Biogas production in Norway is expected to increase substantially, driven mainly by expanded use of livestock manure, food waste, fish sludge, and fish ensilage. While this supports climate mitigation and circular bioeconomy objectives, it will also lead to a significant rise in digestate generation, requiring efficient management. This study quantifies current and future digestate volumes, nutrient content, and energy requirements for downstream processing within the Norwegian food system. Results show that feedstock and digestate volumes are projected to increase more than fourteenfold, with nitrogen and phosphorus contents rising by approximately nineteen times. Future digestate could supply up to 40 % of Norway’s agricultural phosphorus demand and about 25 % of nitrogen demand, highlighting its potential as a key nutrient recycling resource. However, energy analysis reveals that digestate drying dominates processing energy demand, accounting for over 99 % of total energy use. These findings underline the need for integrated digestate management strategies that prioritize nutrient recovery while minimizing energy use through enhanced dewatering, partial drying, direct land application, and utilization of surplus heat.
