Strategic phosphorus recovery clusters in Europe: Linking geospatial resource availability with thermochemical recovery potential

Phosphorus (P) is an essential, non-substitutional resource, yet Europe's supply of elemental P (P 4 ) - classified as critical raw material – remains highly vulnerable. This study assesses whether Europe's secondary organic P resources can support centralized P 4 recovery by linking demand, resource availability, spatial distribution and thermochemical recovery potential. European P 4 demand was estimated at 34.7 kt(P 4 )/a from foreign trade statistics for 2017–2022. Sewage sludge alone contains an estimated 190.9–220 kt(P)/a across the EU-27 and the United Kingdom, demonstrating that resource availability exceeds current demand but is spatially distributed. Geospatial clustering identified nine phosphorus resource centers (PRCs) containing 19.5% of the European sewage-sludge-derived P 4 potential, while 80.5% remains distributed outside these hotspots. The PRCs differed substantially in plant size and feedstock distribution, highlighting spatial aggregation, not P availability, as a key constraint for centralized recovery. Highest P-flux Ruhr-area PRC was subsequently evaluated using a METSIM-based FlashPhos digital twin. Co-processing sewage sludge with Category 1 meat-and-bone meal (MBM) reduced the Fe:P ratio and increased the modeled P 4 recovery from 73.42% to 78.09%, corresponding to a potential output of up to 5350 t(P 4 )/a, or 16.5% of European demand. MBM co-processing provided an additional gross economic contribution of 4.02–5.25 million€/a through increased P 4 production and avoided CaO expenditure. The results demonstrate that Europe possesses sufficient secondary P resources to substantially exceed current P 4 demand, but their decentralized distribution makes spatial aggregation a principal constraint. High-density PRCs combined with complementary feedstocks therefore represent promising targets for future site-specific logistical, techno-economic and experimental assessment of centralized P 4 recovery.