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

Abstract

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%.