Catalytic Pyrolysis of Polypropylene Waste for Production of Aromatics and Light Hydrocarbons in a Reactive Distillation System
Year: 2025
Type: article
Abstract: Compared to traditional mechanical recycling, plastic waste pyrolysis is a promising method to produce value-added chemical products. In particular, polyolefins are interesting feedstocks for the production of light olefins and monoaromatics. However, the broad distribution of pyrolysis liquid products, whose carbon numbers may range from 5 to 60, hinders the downstream conversion to specific chemicals. To obtain a narrower product distribution, polypropylene (PP) pyrolysis was conducted in a novel batch reactive distillation system with the catalytic pyrolysis reaction taking place in the reboiler. A partial reflux system was used to recirculate heavier fractions into the reactor and enhance their cracking. The use of a modified commercial ZSM-5 catalyst in the reaction zone enabled the production of aromatics. The effect of catalyst-to-PP ratio and reaction temperature on product distribution was investigated. With the use of this configuration and a suitable content of zeolite catalyst, the monocyclic aromatic hydrocarbons (MAHs) concentration in the liquid product reached over 50 wt.% at 400 °C and higher. Around 95 wt.% of products had a carbon number less than 12 in all catalytic reactions. Online mass spectrometry equipment was used to analyse the gaseous product composition, yielding a significant concentration of H2 along with light olefins and paraffins. Overall, the catalytic reactive distillation system in this work shows great promise in targeting aromatics and light hydrocarbons, in particular olefins, as pyrolysis products.
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4416114640