Efficient Upcycling of Polyolefin Waste to Light Aromatics via Coupling C─C Scission and Carbonylation

Abstract

The upcycling of waste polyolefins into light aromatics has great potential to generate hundreds of millions of tons of valuable aromatic carbon feedstock. However, the conventional high-temperature radical cracking method for aromatizing polyolefins on zeolites faces challenges in aromaticity control and rapid deactivation due to coke. Here, we present a unique strategy that integrates the traditional cracking-aromatization process of PE with CO insertion, a key step of Fischer–Tropsch synthesis, achieving a rise of yield of light aromatics by four times, with an absolute value up to 67% by weight at only 280 °C. The insertion of CO into the Ru-alkyl intermediates formed during polyolefin cracking facilitates the generation of active oxygenate species, guarantees an ideal C─C chain length range, and smooths the way for subsequent efficient aromatization on Hol-ZSM-5@S1 with a short b axis. According to the technical economic analysis, this low-carbon-footprint and economic approach can reduce approximately 1/3 of carbon emissions compared to traditional naphtha cracking technologies and holds promise for reshaping the global aromatic hydrocarbon cycle of the petrochemical industry through polyolefin degradation.