Towards a Cradle‐to‐Cradle Polyolefin Lifecycle

Abstract

Achieving efficient chemical depolymerization of waste polyolefins to monomers remains an unsolved challenge, while it could be an effective means to avoid further waste accumulation in the environment and generate economic benefits. In a recent publication by Conk et al., polyethylene (PE) is converted to propylene, the second most used monomer in the polymer industry. The conversion is achieved via a tandem catalysis approach in which partially unsaturated PE chains react with ethylene to generate propylene with yields as high as 87 %. The study is a first proof of concept showcasing a selective chemical depolymerization of PE to a monomer. Future research is expected to focus on the catalyst optimization, process design, and compatibility with contaminated and multi-polymer waste streams.

Making Persistent Plastics Degradable

“…Although these materials can be considered as polymers with eco‐friendly properties, they cannot be considered as a sustainable alternative due to their fossil origin [18] . Recently, a synthetic process for the catalytic decomposition of long‐chain olefins from waste plastics or renewable origin to propylene by isomerization metathesis has been reported [26–29] . Building on this work, the conversion of propylene to allyl acetate is a well‐established chemical procedure [30,31] .…”

“…[18] Recently, a synthetic process for the catalytic decomposition of long-chain olefins from waste plastics or renewable origin to propylene by isomerization metathesis has been reported. [26][27][28][29] Building on this work, the conversion of propylene to allyl acetate is a wellestablished chemical procedure. [30,31] Allyl acetate can then be converted to 1,4-butanediol (9), the key precursor for PBS, PBAT and PBC production via self-metathesis [32] followed by hydrogenation.…”

Ni-based catalysts supported on Hbeta zeolite for the hydrocracking of waste polyolefins

“…12 Moreover, recycled plastics produced through mechanical recycling can only be downgraded for use due to polymer degradation, product contamination and other issues. 13 In contrast, chemical recycling, an ideal recycling or even upcycling process that can convert polyolen plastics into hydrocarbon fuels, lubricants or even monomer raw materials, has gained signicant attentions. [14][15][16] Currently, non-catalytic pyrolysis is the primary chemical recycling technique for polyolen plastics.…”