A Spanish anaerobic digestion plant has become the first in the country to install an HRS Heat Exchangers Digestate Pasteurisation System (DPS), processing agricultural and livestock waste into 58 GWh of biomethane annually for grid injection. The facility, which commenced operations in 2025, supplies sufficient renewable gas for approximately 11,000 homes.
The plant processes a mixture of whey, olive pomace, chicken manure and pig slurry. The resulting digestate must be pasteurised to comply with European animal by-products regulations (EC 1069/2009) before use as agricultural fertiliser, enabling a circular economy model that displaces synthetic fertilisers in rural areas.
The HRS DPS pasteurises 200 tonnes of digestate daily using a corrugated double-tube heat exchanger that raises digestate temperature to 75°C. The system recovers approximately 50 per cent of thermal energy from hot pasteurised material to heat incoming feedstock, delivering annual savings of 1.75 million kilowatt-hours of thermal energy and reducing CO₂ emissions by 375 tonnes.
Spain's biomethane capacity is expanding rapidly: 12 operational sites in 2024 grew to 25 in 2025, with 46 facilities expected by end-2026 and 90 projected for 2027. According to HRS, efficient digestate management systems are critical as AD deployment accelerates across the region.
Spanish AD plant deploys thermal energy recovery for biomethane digestate pasteurisation
