TOWARD A CIRCULAR ECONOMY: WASTE VALORIZATION FOR THE PRODUCTION OF BIODIESEL AND ENRICHED PELLETS

The most common model of linear economy is currently unsustainable, from the economic, energy and ecological aspects. The enormous increase in human needs for various products and energy has led to a reduction in raw material reserves, on the one hand, and the accumulation of waste, on the other. Therefore, it is necessary to widely adopt the circular economy model, where waste is treated as a raw material, with the idea of achieving zero waste production without use of virgin raw materials. In that sense, in this work food and agricultural waste was used to obtain liquid and solid biofuels. Used cooking oil was used as a raw material in the production of biodiesel, while the waste shell of a hen's egg served as the source of a catalyst for the reaction. Glycerine, as a side product of the chemical reaction, was mixed with agricultural and woody biomass in the production of enriched pellets. The fuels obtained in this way were thermodynamically characterized. For biodiesel and glycerine, the density and viscosity at atmospheric pressure and temperatures were measured, while for the mixtures of crude glycerine and biomass, the calorific value was determined. The obtained products show promising characteristics as potential energy source.