Background to the problem

The growing demand for material recovery, a reduction in landfill disposal and increased resource circularity is transforming the way in which unsorted municipal waste is managed. Despite efforts made in selective collection, a proportion of recyclable materials and organic matter remains present in unsorted waste.

Experience in various European countries over recent decades shows that, even with well-established selective collection systems and ongoing awareness campaigns, a significant quantity of recyclable materials and organic matter remains present in unsorted waste. This situation stems from behavioural factors, practical limitations on source separation the characteristics of the waste itself, and the growing complexity of products placed on the market, making it necessary to implement complementary downstream recovery and valorisation solutions. There is a technical, economic and behavioural limit to source sorting; therefore, the most advanced and ambitious systems must combine separate collection with downstream material recovery technologies, through the pre-treatment of unsorted waste.

In this context, there is a need for flexible and adaptable solutions that will improve waste preparation prior to the treatment and recovery stages, thereby increasing resource recovery, improving the quality of the processed waste streams and reducing the quantities sent for final disposal.

Overview of the current context

Amarsul and Valorsul are urban waste management companies which, together, process around 154,000 tonnes of waste per year and serve approximately 2.44 million inhabitants across Greater Lisbon, the Western Region and the Setúbal Peninsula. 

Their activities include:

• Waste collection and transport;
• Sorting and recycling centres;
• Treatment of organic waste (food waste);
• Waste-to-energy plant;
• Bottom ash treatment;
• Sanitary landfills;
• Transfer stations;
• Ecocenters (collection centre for other types of household waste);
• Industrial maintenance operations;
• Environmental monitoring.

The challenge

We are seeking modular, flexible and adaptable systems for the pre-treatment of unsorted municipal waste, capable of improving the quality of waste streams sent for energy recovery or disposal in landfill, whilst at the same time contributing to maximise resource recovery and minimise the fraction destined for final disposal.

Solutions may operate at different stages of pre-treatment and combine mechanical, optical, biological, digital or other compatible technologies; the call remains open to innovative configurations that demonstrate technical, economic or environmental advantages.

Proposals may include operations such as:

• Waste characterisation and monitoring;
• Separation, sorting and intelligent routing of materials;
• Removal of contaminants and unwanted fractions;
• Recovery of recyclable materials;
• Recovery of organic matter for subsequent valorisation;
• Preparation, conditioning or homogenisation of waste;
• Stabilisation of the biodegradable organic fraction;
• Reduction of moisture content and improvement of waste characteristics for subsequent treatments;
• Intelligent control and optimisation of operating parameters.

The aim is to find solutions that can be implemented in phases, tested on a pilot scale and progressively scaled up, enabling Amarsul and Valorsul to evaluate different technological configurations before any larger-scale investments are made.

Particular value is placed on solutions that are modular, mobile, compact or easily integrable into existing infrastructure, and capable of adapting to different waste compositions, operational conditions and future treatment requirements.

The solutions may be integrated into existing treatment facilities, such as landfill sites or other outdoor operational areas. Proposals must therefore demonstrate robustness and the ability to operate under demanding environmental and operational conditions, including exposure to the elements, dust, humidity, leachate, seasonal variations in waste composition, and space or infrastructure constraints. The ability to implement the solution in a modular configuration, to relocate it and to expand it progressively will be valued.

The aim is to create greater flexibility in the management of unsorted waste, improve resource recovery and provide new options to address the growing challenges of circularity, operational efficiency and the reduction of landfill disposal.

Expected results and objectives

The proposed solutions must demonstrate the potential to contribute to one or more of the following objectives:

• To increase the recovery of valuable materials;
• To reduce the presence of contaminants and unwanted fractions;
• To improve the quality of the waste streams sent for treatment;
• To reduce the content of biodegradable organic matter sent for landfill disposal;
• Promote the stabilisation of the organic fraction present in unsorted waste;
• Improve the homogeneity and predictability of waste sent for treatment;
• Reduce the quantity of waste sent for final disposal;
• Increase flexibility in dealing with different waste compositions;
• Improve the system’s overall environmental performance;
• To allow for a gradual increase in installed capacity.

Non-exhaustive list of topics that may be addressed

• Modular pre-treatment lines;
• Compact containerised solutions;
• Mobile or semi-mobile units;
• Advanced mechanical sorting systems;
• Optical and sensor-based sorting;
• Sorting technologies supported by artificial intelligence;
• Recovery of recyclable materials from unsorted waste;
• Recovery of organic matter for biological recovery;
• Biodrying and biological stabilisation systems to prepare the material for the production of refuse-derived fuel (RDF);
• Equipment for stabilising or homogenising the material;
• Technologies for reducing moisture content and improving the calorific value of waste;
• Scalable systems for different treatment capacities;
• Solutions adaptable to different waste profiles and compositions.

Requirements to be met when submitting the solution

The proposal must include, where applicable:

• Expected mass balance;
• Projected material recovery rates;
• Quality of the products or fractions obtained;
• Energy and water requirements;
• Production of waste and associated treatment systems (where applicable);
• Area required for implementation;
• Operational and maintenance requirements;
• Implications for operational safety;
• Integration with existing infrastructure;
• Phased implementation model;
• Pathway for scalability and future expansion.
• Support during the commissioning phase.

The solutions must enable a pilot or demonstration to be carried out under conditions representative of actual operation and must provide indicators that allow for an objective assessment of technical, economic and environmental performance.

The solution to be implemented must comply with all applicable legislation and the environmental and safety requirements in force.