A New Approach to Evaluate the Sustainability of Raw Materials Substitution

Abstract

Despite that the resource depletion problem affects the European society, insufficient measures to preserve natural resources are proposed by recent developed policies. In particular few attentions are devoted to wastes and by-products recovery strategies and incentives. More legislative efforts must be devoted to promote raw materials substitution and support industries that are working in this direction, to achieve a circular Europe. The aim of this chapter is to introduce a simplified route to quantify the environmental sustainability of raw materials substitution. A SUB-RAW index is defined, based on the use of two parameters accounting the energies and the emissions involved in the formation of a material (i.e. embodied energy and CO2 footprint). The proposed index is used in three practical examples to evaluate the possibility of some raw materials substitution. It concerns the partial substitution of Portland cement with coal fly ash (CFA), the reuse of CFA to replace activated carbon in some adsorption processes and the use of a new stabilized filler (COSMOS) instead of natural fillers in polypropylene plastic composites. The SUB-RAW index represents a simplified and valuable approach for the quantification of the sustainability of a material substitution. The simplicity of the chosen parameters makes this evaluation method very simple and low onerous; then it can be used by industries to select suitable materials for future investments in the green economy. A knowledge-based decision support system can increase the capability and flexibility in the materials selection. Additionally it is demonstrated that SUB-RAW index can be used to design new materials, based on wastes and by-products, with increased sustainability in respect to the corresponding natural resources. This can be considered an additional strategy to incentivate materials eco-design.