The Granby Ecocentre in Québec Optimizes Polystyrene (PS) Recycling through Densification

A Partnership with Soprema in Sherbrooke (QC)

SOPREMA (Canada) has been recycling polystyrene (PS) since 2018. This recycled material, a type of plastic with the number 6 recycling symbol, is used to manufacture extruded polystyrene (XPS) thermal insulation at their Sherbrooke plant in Québec. To meet growing demand from the construction and renovation industry, the company recycled over 10,000 tonnes of PS in 2023. It is expecting an increase in demand to meet growing needs over the next few years [1].

In order to contribute to circular economy initiatives and thereby increase its supply of recycled raw materials, SOPREMA supports several companies and municipalities wishing to recycle their PS locally. A case in point is the Granby Ecocentre in Québec, which since March 2023 has been using hot densification equipment to optimize the recycling of approximately 20 tonnes of PS per year.

This case study outlines the key elements of this innovative project. It presents the main results of a comparative analysis between the recycling of non-conditioned PS at the Ecocentre (without densification) and the recycling of conditioned PS (with densification). Other aspects of the project examined include the impact on energy consumption, time (labour), costs, the carbon footprint and storage space. Environmental and occupational health and safety (OHS) compliance issues are also discussed.

The aim of the project is to collect and condition post-consumer PS from the Granby Ecocentre using a plastic densification process to optimize the processes leading to the recycling of this material, particularly in terms of ecocentre operations and transportation of materials to SOPREMA’s plant.

Project Partnership

Partner: Granby Ecocentre

Collaborator (City of Granby): Daniel Baril, general manager at the Corporation de gestion des matières résiduelles de La Haute-Yamaska

Recycler: SOPREMA plant in Sherbrooke

Collaborator (SOPREMA): Martin Olivier, recycled materials specialist at SOPREMA

Supplier (equipment): Foam Cycle and RecycleTech

Geographic and Demographic Context

Service cities: Granby (QC) and Waterloo (QC)

Region: Estrie

Population and density: 

• Granby: 66,222 people (442/km²) [2]
• Waterloo: 4,410 people (370/km²) [3]

TOTAL: 70,632 people (416,9/km²)

Area:

• Granby: 15,610 ha (⇔ 156.1 km²) [2]
• Waterloo: 1,330 ha (⇔ 13.3 km²) [3]

TOTAL: 16,940 ha (⇔ 169.4 km²)

Opening hours (Ecocentre): 4 days a week (January to April) and 5 days a week (May to December), for a total of 32 weeks or 224 days a year

Traffic (Ecocentre): 100,000 visitors per year (2024)

Distance (from the Ecocentre to SOPREMA): 78 km (55 min) [4]

Targeted Recyclable Material

Accepted materials: Polystyrene bearing the No. 6 recycling symbol, such as the following products:

• Thermal insulation,
• Food containers,
• Storage containers,
• Foam flower pots (white),
• Food trays (all colours).

Refused materials: All other plastics as well as certain PS materials containing other plastics with the #6 recycling symbol, such as the following products:

• Yogurt containers,
• Rigid flower pots (black),
• Soft objects (e.g. pool floats),
• CD covers,
• Objects soiled by any of the contaminants listed below.

Current volume (recycled PS): 20 Mt/year

Potential volume (recyclable PS): 40 Mt/year

Current contamination rate: 3% on average

Acceptable contamination level: 5% max

Observed contaminants: Inorganic materials from storage (e.g. dust, sand, earth and stone)

Contaminants to avoid: Concrete, cement, earth, metals, wood, cardboard, hazardous substances and other types of plastic

Examples of accepted PS materials

Examples of refused PS materials

Conditioning Equipment (Densification)

Commissioning date: March 2023

Delivery lead time: The machine delivery lead time is 3 to 5 months

Conditioning equipment: RecycleTech EPS Densifier XT200

PS material densification equipment

PS material densification equipment control panel

Two scenarios were developed to analyze the impact of the project, comparing the Granby Ecocentre’s plan to recycle conditioned PS (with densification) with the recycling of non-conditioned polystyrene (without densification). The various scenario parameters are also described in relation to ecocentre operations and the transportation of materials to SOPREMA’s facilities.

In both cases, residents as well as eligible industries, businesses and institutions (ICI) bring their PS materials to the Ecocentre, which manages the collection and processing of the materials. SOPREMA handles the transportation logistics and then recycles the materials at its Sherbrooke plant for the manufacture of XPS thermal insulation.

Non-Conditioned Polystyrene
(Without Densification)

The “non-conditioned polystyrene” scenario corresponds to ecocentre activities solely involving the collection and transportation of materials, without any processing or conditioning.

Conditioned Polystyrene
(With Densification)

The “conditioned polystyrene” scenario corresponds to ecocentre activities involving the collection, conditioning and transportation of materials, including densification for further processing.

Bags with non-conditioned PS materials

Pallets with conditioned PS materials

Various parameters, such as energy consumption, labour time, costs, carbon footprint and storage space, are used to compare the two scenarios. In order to better understand the differences between the scenarios, these parameters are explained first in terms of ecocentre operations and then in terms of transportation to SOPREMA’s facilities. The analysis period is based on a full year, from June 2023 to June 2024.

Stages and Participants

The participants and stages presented below apply to both scenarios, with the exception of the PS conditioning stage, which applies only to the “conditioned polystyrene” scenario.

1. Polystyrene collection: Residents and eligible ICI organizations are invited to voluntarily bring their PS materials to the Ecocentre during opening hours. The materials will then be directed to the sorting station by ecocentre employees who can also advise visitors and answer any questions they may have.
2. Sorting of materials: Residents and ICI organizations must ensure that only accepted materials are dropped off. They must also ensure that materials are properly sorted according to the instructions on the signs on the recycling bins. As a general rule, sorting is done according to colour. Ecocentre employees then check that the sorting has been done correctly, and make any necessary sorting adjustments, if necessary. Refused materials are placed in the waste container.
3. Material conditioning: Ecocentre employees take the accepted materials and feed them into the densifier for conditioning. No resident or ICI individual has access to the PS densification area. Conditioned materials are then put into a large bag, which is then placed on a standard pallet for easy handling.
4. Transportation of materials: Ecocentre employees load a truck to transport conditioned materials to SOPREMA’s facilities. The company then handles the logistics and transportation of the materials from the Ecocentre to its plant in Sherbrooke.
5. Material recycling: SOPREMA crushes and processes materials at its Sherbrooke plant. This first step involves extruding the plastic beads. These are then mixed into the recipes used to manufacture XPS insulation panels. 

Ecocentre Operations

For the collection and management of PS materials, the various scenarios relating to the operations of the Granby Ecocentre take into account that the materials in question were collected and handled under the following conditions:

^{1, 2, 3, 4} For methodology and calculation parameters, ask for the full case study available on request.

Transportation to SOPREMA’s Facilities

For the transportation of PS, the various scenarios relating to transportation from the Granby Ecocentre to SOPREMA’s facilities take into account that the materials in question were transported under the following conditions:

^{5, 6, 7, 8} For methodology and calculation parameters, ask for the full case study available on request.

The results of the analysis show the impact of the different scenarios in terms of energy consumption, labour time, costs, carbon footprint and storage space. It’s worth remembering that the volume of recycled PS is 20 tonnes for the period in question.

Energy Consumption

The table below compares the energy consumption of the two scenarios on an annual basis. Overall, conditioned PS requires 8,886 kWh less than non-conditioned PS, corresponding to a reduction of around 66%. This represents savings of 88,865 kWh over 10 years. The difference is mainly due to the fact that the amount of energy required to transport conditioned PS to SOPREMA’s facilities is much lower.

Labour Time

The table below compares the time and labour required for the two scenarios on an annual basis. For the Ecocentre, conditioned PS requires 124 hours more than non-conditioned PS, corresponding to an increase of around 182%. The use of the densification equipment explains this increase. Nonetheless, time is saved in terms of material handling and preparation for transportation of materials.

Cost

The table below compares the costs of the two scenarios on an annual basis. For the Ecocentre, conditioned PS requires $26,000 less than non-conditioned PS, corresponding to a reduction of around 78%. This represents savings of $260,000 over 10 years. The difference is mainly due to the fact that transportation costs for conditioned materials are reduced and entirely borne by SOPREMA. Nevertheless, the labour cost of conditioned PS is greater than that of non-conditioned PS, reducing potential savings.

Carbon Footprint

The table below compares the carbon footprint of the two scenarios on an annual basis. Overall, conditioned PS accounts for 4,446 kgCO₂eq. less than non-conditioned PS, corresponding to a reduction of around 92%. This represents around 44,446 kgCO₂eq. avoided over 10 years. The difference is mainly due to the fact that the carbon footprint of transporting conditioned materials is much lower.

Storage Space

The table below compares the storage space required in the two scenarios on an annual basis. Overall, conditioned PS requires 1,695 m² (⇔ 18,240 ft²) less than non-conditioned PS, corresponding to a reduction of around 91%. The difference is mainly due to the much smaller space required for conditioned materials storage and handling.

Québec’s legislation includes a number of laws and regulations that apply to ecocentre operations. It is important that polystyrene (PS) collection and conditioning activities comply with the relevant requirements. For these reasons, the relevant environmental and occupational health and safety (OHS) compliance aspects are addressed in this section.

Occupational Health and Safety

With regard to OHS compliance, certain conditions may apply to ecocentres carrying out PS densification activities on their site. In the interest of OHS risk prevention, SOPREMA requested an expert opinion from the Commission des normes, de l’équité, de la santé et de la sécurité du travail (CNESST) concerning the requirements to be met, more specifically with regard to the following provisions:

• Act Respecting Occupational Health and Safety, RLRQ, S-2.1
• Regulation Respecting Occupational Health and Safety, RLRQ, S-2.1, r. 13

This opinion is based on the CNESST visit carried out in June 2024 and deals with densification equipment operated at the Granby Ecocentre [7]. This section presents the main findings of the CNESST report, and includes some of SOPREMA’s recommendations.

Aspects: Odour

Findings of the CNESST Report

At the time of the visit, the operation of the machine did not give off any particular odours, and the operator did not seem to feel any discomfort. Exposure time was short, and good air circulation was ensured. The ventilation system seemed adequate.

SOPREMA’s Recommendations

Some materials may give off odours during densification. Therefore, when using a machine indoors, it is recommended to include a ventilation system to ensure a constant change of air in the area while the machine is in use.⁹

Aspects: Smoke and fumes

Findings of the CNESST Report

At the time of the visit, the machine was emitting smoke and fumes from the heating of the materials. These were captured by mechanical suction directly at the source of the machine and vented to the outside.

SOPREMA’s Recommendations

During densification, it is normal to generate light smoke and fumes resulting from the heating of the materials. Therefore, when using a machine indoors, it is recommended to include a mechanical extraction system directly at the source of the machine to discharge smoke and fumes outside.

Aspects: Personal protective equipment (PPE)

Findings of the CNESST Report

At the time of the visit, an operating procedure was displayed next to the machine. It showed that the employee operating the machine must use certain PPE, such as safety glasses, cut-resistant gloves and ear muffs.⁸

SOPREMA’s Recommendations

The use of PPE, such as safety glasses¹⁰, cut-resistant gloves¹¹ and ear muffs¹², is recommended as an additional means of protection. It is imperative to post the procedure and train employees handling the materials and operating the machine.

^{8, 9, 10, 11, 12} For compliance information, ask for the full case study available on request.

Examples of PPE to be used by ecocentre employees operating the densification equipment

Example of a ventilation system inside the container housing the densification equipment

Environmental

With regard to environmental compliance, certain conditions may apply to ecocentres carrying out PS densification activities on their site. In order to clarify this issue, SOPREMA requested a legal opinion from the Sodavex law firm concerning the requirements to be met, more specifically with regard to the following provisions [8]:

• Environment Quality Act, RLRQ, c Q-2 (hereinafter the EQA)
• Regulation Respecting the Regulatory Scheme Applying to Activities on the Basis of Their Environmental Impact, RLRQ, c Q-2, r 17.1 (hereinafter REAFIE)
• Regulation Respecting the Reclamation of Residual Materials, RLRQ, c Q-2, r 49 (hereinafter RVMR)
• Regulation Respecting the Landfilling and Incineration of Residual Materials, RLRQ, c Q-2, r 19 (hereinafter REIMR)

As a general rule, it’s important to understand that requirements may vary depending on the status and history of each ecocentre. Given that the environmental authorization regime changed in 2018 and again in 2021, we need to take into account the requirements that prevailed before 2018, between 2018 and 2021 and since 2021 in order to cover the different situations that apply to ecocentres wishing to operate PS densification equipment¹³.

For the sake of simplicity, the above is a summary of the key facts contained in the legal opinion provided by the Sodavex law firm. To take into account the reality and specificities of each ecocentre, SOPREMA recommends always verifying and ensuring the environmental compliance of the site before installing PS densification equipment. The same logic also applies during the operating phase. Details of the opinion are available on request¹⁴.

^{13, 14} For compliance information, ask for the full case study available on request.

[1] SOPREMA Canada. (2024). Collection and Recycling of Residual Materials – Discover Our SOPRALOOP Process

[2] Google Maps. (2024). Directions: 1080 Rue André-Liné, Granby, QC to 5255 Rue Robert-Boyd, Sherbrooke, QC.

[3] City of Granby, Québec. (2024). General information about the city of Granby.

[4] City of Waterloo, Québec. (2024). General information about the city of Waterloo.

[5] Environment and Climate Change Canada. (2024). National Inventory Report, 1990–2022: Greenhouse Gas Sources and Sinks in Canada – Part 3.

[6] Environment and Climate Change Canada. (2024). National Inventory Report, 1990–2022: Greenhouse Gas Sources and Sinks in Canada – Part 2.

[7] CNESST. (2024). Rapport d’intervention en santé et sécurité du travail [RAP1473243] – June 21, 2024 visit to COGEMRHY: 1080, rue André-Liné, Granby, Québec.

[8] Sodavex. (2021). Legal opinion on the need to obtain ministerial authorization under the Environment Quality Act in order to carry out polystyrene densification.

Val-Saint-François Regional County Municipality

Expanded polystyrene collection points in the Val-Saint-François regional county municipality, Québec

City of Sherbrooke

Recycling expanded polystyrene at the ecocentres of the City of Sherbrooke, Québec