Smart Waste Sorting : Stockholm sets new standard with high-performance automated waste sorting facility

The waste management industry continues to evolve as municipalities seek more efficient solutions to support their circular economy goals. Stockholm's new Resursutvinning plant, delivered by STADLER Anlagenbau GmbH, exemplifies how cutting-edge technology can transform municipal solid waste processing while reducing environmental impact.

Designed to process 50 tons of waste per hour, the new facility represents a significant advancement in municipal waste management. The plant features two parallel sorting lines equipped with state-of-the-art technology that operates with minimal manual intervention. Commissioning was completed in August 2024, with the official inauguration taking place in October.

The facility's primary function centers on recovering organic waste from household garbage, along with plastics and metals that accidentally end up in residual waste streams. This approach directly reduces the volume of materials destined for incineration, consequently lowering CO₂ emissions.
"The Resursutvinning Stockholm plant is a leap forward towards ambitious environmental goals while ensuring reliable, high-quality waste management," says Lars Nyquist project manager at SVOA. "It is important that packaging is sorted at home, but plastic and metal packaging can accidentally end up in the residual waste. With STADLER's expertise, we now have the technology and infrastructure to improve resource recovery, reduce emissions, and move closer to closing the loop on waste in Stockholm."

At the facility's core lies a sophisticated sorting process that separates materials with high precision. Incoming municipal waste enters through five walking floors equipped with hydraulic covers, ensuring seamless reception. The material transfers to dosing conveyors that create uniformly distributed waste streams to feed the plant.

Following initial manual pre-sorting to remove bulky or hazardous items, the material undergoes particle size separation through STADLER's screening drums. The plant's standout feature is its proven Coloured Bag Sorting System, which combines five Near-Infrared (NIR) and visual spectrometers (VIS) to accurately identify and extract green bags containing food waste without opening them.

The remaining material moves through NIR sorting systems that recover plastics by polymer and color, while magnetic and eddy current separators extract ferrous and non-ferrous metals. An innovative system of movable conveyors beneath the screening drums allows rapid adaptation to changes in waste composition without interrupting operations.

Operational excellence drove the facility's design philosophy. Equipment positioning across multiple levels maximizes the compact footprint while ensuring accessibility and safety. All drives and maintenance points remain accessible via walkways and dedicated platforms, enabling quick and safe servicing.

"We at SVOA are impressed with STADLER's work ethic in both the design and construction phase," says Lars Nyquist. "Their diligence and attention to detail have been crucial in achieving a great result also in terms of HSEQ (Health Safety Environment and Quality). They have shown admirable attention to client satisfaction when optimising the plant, both in regards of delivering better waste treatment and HSEQ."

The facility incorporates several engineering innovations. A residual fraction buffer weighing system with two weighing bunkers provides accurate weight data while maintaining continuous material flow. The movable conveyors under drum screens accommodate changes in input composition or seasonal variations without stopping operations. A central vacuum system and distributed cleaning points throughout the plant facilitate maintenance and contribute to a safer work environment.

Plant automation remains central to operations, with the facility running entirely through a centralized control system. Manual input is required primarily for routine maintenance and cleaning tasks.

"With our design, we were able to deliver a facility that combines performance, precision and adaptability within a highly compact layout," explains Uroš Tintor, Project Manager at STADLER.

"What stands out in this plant is its adaptability," adds Nejc Božič, Project Manager at STADLER. "Everything from the parallel line design to the movable conveyors under the screens gives SVOA the flexibility to handle seasonal variations, keep the line running and optimise performance with minimal manual intervention."

Stockholm Vatten och Avfall serves 1.5 million residents and businesses in the Stockholm area as Sweden's leading water and waste management company. The Resursutvinning Stockholm plant supports SVOA's goal of increasing material recovery while reducing environmental impact in the region.

The facility enables separation and recovery of valuable materials that would otherwise undergo incineration for energy. By isolating organic waste for bioprocessing and capturing plastics and metals accidentally included in residual waste for recycling, the plant helps reduce the city's carbon footprint while transforming waste into resources.

The dual parallel sorting line design ensures continued operation during maintenance or partial outages, providing uninterrupted service and long-term reliability. Advanced sorting technology enables adaptation to changing waste streams and future requirements, establishing new benchmarks in municipal waste recovery and circular economy progression.