Prospective Retrofit Assessment of an Existing Material Recovery Facility: Industrial-Scale Evaluation of Sensor-Based Sorting for Paper and Plastic Recovery from Mixed Municipal Solid Waste

Austria must increase its recycling rates for plastic packaging waste and address paper-paperboard-cardboard (PPC) challenges to meet EU 2030 targets. Urban areas like Vienna, which generate one-third of Austria's mixed municipal solid waste (mMSW), are key due to lower separate collection rates. This study investigates whether upgrading Vienna's material recovery facility (MRF) with near-infrared (NIR) sorting can enhance the recovery of plastic packaging waste and PPC before incineration. An industrial-scale trial using 100 t mMSW was conducted on the particle size fractions <80 mm, 80–125 mm, and 125–250 mm, where PPC, beverage cartons (BC), and plastics were recovered. Results show the highest recovery potential in the 125–250 mm fraction, especially for plastics and PPC. The 80–125 mm fraction showed good plastic recovery but poorer PPC recovery due to moisture and contamination. The <80 mm fraction was unsuitable for recovery, with over 80% impurities. Recovered plastics were mainly films and rigid packaging (PET, PP, HDPE, PS). Recovery efficiencies reached 67% for films, 69% for rigid packaging plastics, 52% for rigid non-packaging plastics, 82% for PPC, and 30% for BC. The simulated MRF upgrade would recover ~17,000 t/a (dry) of target materials concentrates. The residues after recovering plastics and paper still have a sufficiently lower heating value for incineration (LHVraw ~9100 kJ/kg). Upgrading Vienna's MRF with sensor-based sorting is technically feasible and would positively complement the existing waste management system in Vienna. Focus should be on larger particle sizes, while metal-depleted fractions <80 mm should be directly incinerated. • Vienna MRF upgrade tested for plastics and paper recovery from mMSW. • Best recovery of plastics and paper in 125–250 mm fraction. • 80–125 mm showed good plastics recovery, poor paper due to moisture. • <80 mm fraction had >80% impurities, not suitable for recovery. • Sorting residues still viable for incineration.