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Updated: Apr 20, 2026

Designed for Molecular Recycling: A Lignin-Derived Semi-aromatic Biobased Polymer
Published on: November 30, 2020
An innovative recycling process to obtain pure polyethylene and polypropylene from household waste
Silvia Serranti1, Valentina Luciani1, Giuseppe Bonifazi1
1DICMA, Department of Chemical Engineering, Materials and Environment, Sapienza University of Rome, Via Eudossiana 18, 00184 Rome, Italy.
Abstract:
An innovative recycling process, based on magnetic density separation (MDS) and hyperspectral imaging (HSI), to obtain high quality polypropylene and polyethylene as secondary raw materials, is presented. More in details, MDS was applied to two different polyolefin mixtures coming from household waste. The quality of the two separated PP and PE streams, in terms of purity, was evaluated by a classification procedure based on HSI working in the near infrared range (1000-1700 nm). The classification model was built using known PE and PP samples as training set. The results obtained by HSI were compared with those obtained by classical density analysis carried in laboratory on the same polymers. The results obtained by MDS and the quality assessment of the plastic products by HSI showed that the combined action of these two technologies is a valid solution that can be implemented at industrial level.
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