ANALYSIS OF PRODUCTS FROM THE PYROLYSIS OF PLASTICS WASTE FROM A PRINTING PLANT: A PILOT SCALE STUDY

Abstract

As plastic production increases, new waste management methods are required. Chemical recycling, such as pyrolysis, has the potential to raise recycling rates taking into account that it can use more waste plastics than standard mechanical recycling. Four types of bits of plastic: polyethylene (PE), polypropylene (PP), polystyrene (PS), and biaxial-oriented polypropylene (BOPP) fractions from the printing plant were collected; the possibility of recycling them by batch pyrolysis was investigated. Characterization of the obtained pyrolysis oils was carried out by gas chromatography-mass spectrometry (GC-MS), the analysis showed a mixture of aliphatic (saturated and unsaturated) compounds, in the case of PE and PP, while in the case of PS, aromatics and low quantities of other hydrocarbons were detected. In the case of BOPP the distribution of the pyrolysis products is not as uniform as in the case of PE, PP, or PS plastic samples. The FT-IR results showed clear peaks of aliphatic compounds in two liquid oil samples of PE, and PP that further confirmed the GC-MS results. More than 60% monomer (styrene) can be recovered from the PS pyrolysis, besides other aromatic compounds in low concentration. The pyrolysis oils have a reasonable heating value (calorific value) in the range of 36–45 KJ/g, close to conventional diesel. Therefore, the pyrolysis oils has the potential to be used as an alternative source of energy as fuel, after blending with conventional fuel, or heating combustion products. The research results will contribute to the development of waste valorization via plastic upcycling from a printing press, without using an expensive catalyst or reactor system.