Environmental performance assessment of a decentralized network of recyclable waste sorting facilities: Case study in Montreal

The generation of waste grows yearly. In a centralized approach, more trucks
are dispatched to collect the growing demand, with a higher pressure on the road network
and greenhouse gas emissions. In contrast, a decentralized approach creates a network
of distributed facilities. This study analyzes the impact of a decentralized approach for
recyclable waste sorting facilities. It models waste generation, collection, and location of
recyclable waste sorting facilities. This approach is applied to a case study in Montreal for
polyethylene terephthalate. The case study computes two performance indicators: costs
and CO2 emissions. Six scenarios were developed and compared to a baseline scenario.
The results show that decentralization reduces greenhouse gas emissions by 20.3% and
operation costs by 8.04%. However, investment costs for the new facilities remain an
obstacle. These costs can represent up to 89.7% of the expenses in a decentralized context.
Nonetheless, decentralization increases the flexibility of waste collection under growing demand,
since the distance to collect one ton has reduced by 35.3% and the average truck load
per trip has reduced by 12.8%. To apply the model to the real world, further improvements
are required. They span technical, economic, and social acceptability constraints.