New Approach for Optimization of Construction and Demolition Waste Management: Application to the Lisbon Metropolitan Area

The growing concern regarding global sustainability is increasingly evident in the construction sector due to the large amounts of waste produced. This work aims to develop a new approach in order to plan an efficient recycling network for Construction and Demolition Waste (CDW). The approach is based on the methodology of Process Systems Engineering (PSE), allowing an appropriate problem systematization and the definition of flows of materials between the network nodes. The developed mixed-integer linear programming (MILP) model is a tool to support CDW management in assessing the recycling network from a regulatory perspective (minimizing the total cost). Various scenarios can be defined and sensitivity analyses performed, making the aforementioned assessment clear regarding location, types and capacities of the new processes to be installed. The model was applied to the 211 parishes that comprise the Lisbon Metropolitan Area (LMA), in Portugal, but due to its generic formulation can be applied elsewhere at regional or national level. Results show a preference for direct deposition in landfills and the fact that high quality recycling processes are not, at present, economically viable for the LMA.