Optimization of the integrated system for the differentiated collection of plastics, evaluated through a LCA analysis

Quintavalla Alberto*, Melloni Riccardo**, Bergonzoni Marco***

* Managing Engineer - University of Parma
** University in Modena and Reggio - Faculty of Engineering (associated professor)
*** University of Parma - Faculty of Engineering (contract professor)

Abstract

Target
The target of this study has been to evaluate the economic advantage and the environmental impact of the differentiated collection of plastics, through a LCA analysis. In particular it has been meant to draw up a useful survey to support the decisions of the bodies acting on the territory both from a planning and a managing point of view as regards the waste service.

Methods
The first part of the study takes under examination the present outlook of the differentiated collection of plastics in Italy. Afterwards an analysis has been carried out relating to the Italian law panorama, besides estimation on the present state of the art concerning the recovery and the recycling (mechanical, chemical), the heat regeneration and the disposal in garbage dumps. The second part of the study takes under examination the system of collection, transport, recovery and removal of plastics by the LCA method, using the real data of the province of Reggio Emilia. In this field some considerations and comparisons have been made among possible alternative sceneries to point out the one with the less prominent impact. In particular, for each scenery treated, it has been meant to know the economic/environmental impact of the transport phase from the drawing at the rubbish container to the plant chosen for the recovery activity without, however, neglecting the pre-selection before the conferment. As regards this aspect it has been taken as a reference the pre-selection plant existing in Reggio Emilia managed by RePlast.

Results
The target to optimize costs-benefits, both environmental and economic, has been achieved simulating different situations, in particular varying the type and the number of collection and transport means, the coefficient of stuffing of road rubbish containers, the energetic consumption, the number of the shifts a week, the number of people in charge, the average of kilometers done by the vehicles, the capacities and the coefficients of stuffing in collection vehicles, maintenance costs, depreciations and the wages of the people in charge. Also the collection area (rural or urban) and the types of collection (on the road or at home) have been varied to better estimate their influence on the final results.

Conclusions
The LCA analysis of the differentiated collection system of plastics allowed to point out the extreme importance of accurate and precise estimations in order to identify input parameters in the starting of the decision process, to be able to really achieve low environmental impact but economically favorable targets.