Catalytic pyrolysis of plastic materials using natural zeolite catalysts synthesized from volcanic ash

Abstract

Plastic waste and its inadequate final disposal are a serious problem of environmental pollution, which has increased considerably in this time of pandemic due to the use of masks, gloves, food packaging or others, which will eventually reach the oceans, increasing the problem of the islands that are made up of plastic waste. Since the final disposal techniques of plastic waste are insufficient, in this research the catalytic pyrolysis has been evaluated using zeolites synthesized from volcanic ash of the Ubinas volcano (Peru), as catalysts. For this, two catalysts were synthesized, Z1 and Z2 zeolite, made at 150 and 180 °C in a 5 M NaOH solution, respectively. The pyrolysis was carried out at a catalyst/polymer ratio of 10 and 20 % and it was compared with a synthetic zeolite (ZSM-5) and without catalyst at a reaction temperature of 450 °C. The essays were carried out with PP virgin and plastic waste. It was determined that catalytic pyrolysis using natural zeolites synthesized from volcanic ash are appropriate for the treatment of plastic materials and that they tend to generate a higher proportion of pyrolytic gases and do not generate carbonaceous residues.