Análisis comparativo del consumo de recursos en procesos que siguen una ruta tradicional o biotecnológica : Análisis comparativo del consumo de recursos entre dos procesos tradicionales y uno biotecnológico empleados para la remoción de la capa de celulosa en envases asépticos Tetra Pak reciclados.

Abstract

Tetra Pak aseptic packaging is widely used, mainly by its materials properties, but its complex structure has been a challenge at the moment to define recycling guidelines. Thus, in 2020, just the 26 % of the 4 million tons of Tetra Pak packaging produced were recycled. Generally, prior to the PEAl transformation process, the cellulose layer is the first to be removed from the package. The aim of this work was to calculate an approximation of the material and energy requirements needed to process 1 kg of Tetra Pak by three different recycling alternatives that serves this purpose. For hydropulping, in the presence of water, Tetra Pak are subjected to vigorous centrifugal forces to hydrate and remove cardboard layer. Solvent delamination allows separately recovers the three constituent materials by the dissolution of LDPE in boiling xylene, and the separation of aluminum from cellulose in the presence of CCl4. The third method involves the enzymatic hydrolysis of cellulose by direct action of T. reesei in a liquid fermentation system. Hydropulping reclaimed 70 % of cellulose, was the fastest and less resource consuming method. Delamination recovered 90 % of the homopolymer, that was 20 % more than hydropulping and 5 % more than the biotechnological alternative but required more polluting reagents. The biotechnological procedure achieved 85 % of cellulose recovery but demanded 38 % and 35 % more water than hydropulping and solvent delamination, respectively; it also took more time and energy