Selective deconstruction of polyethylene to propylene via isomerization/metathesis and 1-hexene isomerization studies

Polyethylene (PE), the world’s most produced single-use plastic, poses a significant environmental challenge due to its chemical inertness and resistance to degradation. Traditional recycling approaches—mechanical recycling and incineration—fail to offer selective, and circular solutions for effective PE waste management. This thesis explores an alternative strategy rooted in chemical upcycling, where PE is selectively converted into propylene, a high-value monomer, via a tandem catalytic process combining dehydrogenation, isomerization and metathesis. Chapter 1 outlines the limitations of current recycling strategies and introduces chemical recycling as a promising route toward closed-loop, polymer-to-polymer reuse. Chapter 2 highlights a tandem isomerization-metathesis (ISOMET) process that enables highly selective PE deconstruction to propylene in the presence of ethylene with both homogeneous and heterogenous catalysts in a continuously stirred tank reactor (CSTR). Chapter 3 focuses on the development of a kinetic understanding of 1-hexene isomerization, serving as a model PE system to capture the thermodynamic behavior of internal olefin redistribution. Finally, Chapter 4 reflects on the author’s experience as a Research Group Leader in the Summer Predoctoral Institute (SPI), highlighting the program’s role in fostering community and early graduate student success.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemical Engineering

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• DaSilva, Vanessa

Contributors dc:contributor

• Guironnet, Damien
• Kenis, Paul J. A.
• Kuenstler, Alexa
• Olshansky, Lisa

• Polyethylene
• Deconstruction
• Chemical Recycling
• ISOMET
• Ethenolysis
• Propylene Selectivity
• Catalysis
• Polymer to Polymer Recycling Strategy

Statement dc:rights

• Copyright 2025 Vanessa DaSilva

Language dc:language

en

Handle dc:identifier

https://hdl.handle.net/2142/132720

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/132720