Conical spouted beds for waste valorization: Assessment of particle segregation in beds composed of sand and Tetra Pak residues

Pyrolysis is a sustainable, clean, and innovative technology to obtain high added value products. A conical spouted bed composed of binary mixtures can be used as a promising reactor for the pyrolysis of solids due to its high heat transfer rate. For the start-up of the plant, low levels of axial particle segregation in the bed are needed. As an innovative aspect, this research proposes to use a statistical method to investigate particle concentration uniformity along the conical bed. Results reveal conical spouted beds presents uniform axial composite concentration when dealing with sand and polyethylene/aluminum composite mixtures. The axial uniformity of composite in the bed enables the reactor application in the thermal recycling of carton packaging waste using a sustainable waste route. The experimental design shows both polyethylene/aluminum composite concentration and particle diameter ratio of sand and composite affect axial particle segregation in the bed. Model equations have a good adjustment to the experimental data and predict results with an error of <10%.

Automated summary

Pyrolysis is a sustainable and innovative technology that can produce high added value products, and a conical spouted bed composed of binary mixtures is a promising reactor for this purpose. Using a statistical method, this research investigated the uniformity of particle concentration along the conical bed, showing that uniform axial composite concentration enables the reactor to be applied in the thermal recycling of waste materials.