Field: Technical waste treatment
Global Technical function: Burning, Collecting, Gasifying, Managing, Purifying, Recovering, Separating, Storing, Substituting
Technical Function Unit: Abrasing, Cleaning, Combusting, Cooling, Data analysing, High temperature, Pyrolysing, Software tool
Techniques: Scanning electron microscopy (SEM), X Ray Diffraction (XRD)
Geographic Area: Italy

TyGRE

In recent years, the quantity of Solid Waste collecting has increased significantly in the EU and other industrialized countries. The problem of managing waste strongly affects not only the environment protection but also resource savings. The storing of waste tyres represents a problem within the waste management strategy of the European Community: the world production amounts to 7 million tons (according to the European Tyre Recycling Association, Report 2008), of which 3 million are generated in Europe which corresponds to 2% of the total solid waste production. Even today the final destination of nearly 23% of such an amount is the landfill, with the consequent loss of high added value materials and the adverse environmental impact.

Most of the current recycling methods for waste tyres are not environmental friendly and produce low value products. These methods deal with production of steam, electricity, cement, lime, paper, steel and the incineration of garbage (burning). It is well known that tyres possess high volatile and low ash contents with a heating value greater than coal and biomass. These properties make them an ideal material for a thermal technical waste treatment like pyrolysing and high temperature gasifying (combusting processes), that are promising ways for alternative high-efficiency materials and energy production.

“High added value materials from waste tyre gasification residues” (TyGRE) is a collaborative project composed of 9 partners. It has involved several European institutions, companies and technological centres, and was led by the Centro Ricerche ENEA Portici, located in Italy. The project is funded under the Seventh Framework Programme (FP7_ENV), started in 2011 and will finish in 2013.

This project focuses on recycling waste from tyres using a thermal process for producing, in a sustainable way, high added value ceramic materials. The project includes also a data analysing approach by using a software tool for LCA (Life cycle assessment) and a Life Cycle Costing study, which both help to carry out the eco-friendly production of ceramics from waste tyres.

In the framework of this wide research program for recovering waste tyres via a thermal process, particular efforts have been made to use elements from tyres waste as precursors for ceramic materials (high carbon and silica content). The exploitation of this peculiarity has entailed a series of experimental activities through high temperature carbothermal synthesis reactions following cooling, separating, cleaning and purifying processes. The products have been characterized by X Ray Diffraction (XRD) and scanning electron microscopy (SEM), to confirm the resulting presence of ceramic silicon carbide (SiC) at high yield and purity, with the process parameters that have been adopted. After a series of successful results at laboratory scale, the project has reached the prototype phase. So, the project is estimated to be 5 on the TRL scale. The process has been thoroughly explained in proceedings concerning the Synthesis of Ceramic Materials from Waste Residues.

The market in the field of ceramics is in constant growth. Silicon carbide (SiC) is one of the most important non-oxide ceramic materials; it has a wide industrial application due to its excellent properties, and can be used for substituting natural silicon carbide in high wear applications, metallurgy, abrasing applications, electronics, etc. Tyres recyclers, Waste managers, Ceramics users (electronic and metallurgic sector) and public bodies are the main target audiences of this result.