Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Molten-Phase Unsaturation Enhanced Pyrolytic Upcycling of Polyolefins

Journal Article · · Energy and Fuels
Fast pyrolysis is a robust deconstruction technology for chemically upcycling waste plastics without losing significant carbon to noncondensable gases. However, fast pyrolysis of polyolefins often produces hydrocarbons with broad molecular weight distributions, mainly waxes, which can also negatively affect the commercial reactor operation and downstream upgrading of the products. We discovered that combining molten-phase thermal treatment with subsequent fast pyrolysis offers a facile method to enhance polyolefin pyrolysis and catalytic upgrading. The molten-phase thermal treatment increased unsaturated C–C bonds in the treated polyolefins. During subsequent pyrolysis, the preheated polyolefins significantly reduced wax range hydrocarbons in the condensable products without an increase in gas formation. Here, the wax yields from pyrolysis of high-density polyethylene (HDPE) preheated to 295 °C and low-density polyethylene (LDPE) preheated to 275 °C were 20.5% and 26.5%, respectively, compared to 38.6% and 46% produced from pyrolyzing untreated polyolefins. When catalytically pyrolyzed using a zeolite catalyst, the preheated polyolefins promoted higher yields of olefins during ex-situ catalytic pyrolysis and higher yields of aromatic hydrocarbons during in-situ catalytic pyrolysis. During ex-situ catalytic pyrolysis, ethylene yields were 23.3% and 24.7% for the preheated HDPE and LDPE compared to 16.7% and 9.3% for untreated HDPE and LDPE, respectively.
Research Organization:
Iowa State University, Ames, IA (United States); University of Wisconsin, Madison, WI (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Office of Sustainable Transportation. Bioenergy Technologies Office (BETO)
Grant/Contract Number:
EE0009285
OSTI ID:
3020474
Journal Information:
Energy and Fuels, Journal Name: Energy and Fuels Journal Issue: 17 Vol. 38; ISSN 1520-5029; ISSN 0887-0624
Publisher:
American Chemical Society (ACS)Copyright Statement
Country of Publication:
United States
Language:
English

References (50)

Feedstock Recycling and Pyrolysis of Waste Plastics: Converting Waste Plastics into Diesel and Other Fuels book March 2006
Polyethylene Incorporating Diels–Alder Comonomers: A “Trojan Horse” Strategy for Chemically Recyclable Polyolefins journal June 2023
Thermal degradation of polyethylene in a nitrogen atmosphere of low oxygen content. II. Structural changes occuring in low-density polyethylene at an oxygen content less than 0.0005% journal March 1974
The Chemistry and Kinetics of Polyethylene Pyrolysis: A Process to Produce Fuels and Chemicals journal February 2020
The Effect of Polymer Structures on Complete Degradation: A First‐Principles Study journal June 2018
Pyrolysis of polyolefins journal June 1960
Calculation of activation energy from fraction of bonds broken for thermal degradation of polyethylene journal January 2003
Thermal decomposition of cross-linked polybutadiene and its copolymers journal September 1999
Fluidised bed pyrolysis of low density polyethylene to produce petrochemical feedstock journal July 1999
Effect of the temperature in the nature and extension of the primary and secondary reactions in the thermal and HZSM-5 catalytic pyrolysis of HDPE journal February 2007
Thermal and catalytic pyrolysis of polyethylene over HZSM5 and HUSY zeolites in a batch reactor under dynamic conditions journal February 2009
Catalytic conversion of model compounds of plastic pyrolysis oil over ZSM-5 journal May 2023
Modelling plastic heating and melting in a semi-batch pyrolysis reactor journal February 2021
Influence of time and temperature on pyrolysis of plastic wastes in a semi-batch reactor journal September 2011
A review on pyrolysis of plastic wastes journal May 2016
Parametric study on catalytic cracking of LDPE to liquid fuel over ZSM-5 zeolite journal August 2016
Effect of catalyst contact mode and gas atmosphere during catalytic pyrolysis of waste plastics journal June 2017
Pyrolysis of plastic wastes in a fountain confined conical spouted bed reactor: Determination of stable operating conditions journal February 2021
The effect of thermal aging on the composition of pyrolysis oil fuel derived from typical waste plastics journal July 2021
Thermal and catalytic pyrolysis of crosslinked polyethylene journal June 2006
Catalytical and thermal pyrolysis of polyolefins journal May 2007
Characterization of the waxes obtained by the pyrolysis of polyolefin plastics in a conical spouted bed reactor journal March 2012
Pyrolysis of plastic waste: Opportunities and challenges journal November 2020
Gaseous products from primary reactions of fast plastic pyrolysis journal September 2021
Liquid-fed waste plastic pyrolysis pilot plant: Effect of reactor volume on product yields journal September 2022
Pyrolysis of waste high density polyethylene (HDPE) and low density polyethylene (LDPE) plastics and production of epoxy composites with their pyrolysis chars journal November 2017
Conversion of low-density polyethylene into monocyclic aromatic hydrocarbons by catalytic pyrolysis: Comparison of HZSM-5, Hβ, HY and MCM-41 journal July 2022
A review on thermal and catalytic pyrolysis of plastic solid waste (PSW) journal July 2017
Challenges and opportunities of light olefin production via thermal and catalytic pyrolysis of end-of-life polyolefins: Towards full recyclability journal May 2023
Changes during the weathering of polyolefins journal November 2020
The influence of the recycling stress history on LDPE waste pyrolysis journal June 2020
Catalytic pyrolysis of plastic waste: A review journal July 2016
Thermochemical routes for the valorization of waste polyolefinic plastics to produce fuels and chemicals. A review journal June 2017
Morphological characteristics of waste polyethylene/polypropylene plastics during pyrolysis and representative morphological signal characterizing pyrolysis stages journal February 2013
Wax Recovery from the Pyrolysis of Virgin and Waste Plastics journal May 2021
Evaluation of Pyrolysis Wax as a Solvent in Polyolefin Pyrolysis Processing journal July 2022
Effect of Temperature and Vapor Residence Time on the Micropyrolysis Products of Waste High Density Polyethylene journal February 2018
Homogeneous Catalysis in Plastic Waste Upcycling: A DFT Study on the Role of Imperfections in Polymer Chains journal October 2023
Study of the Viscosity and Thermal Characteristics of Polyolefins/Solvent Mixtures: Applications for Plastic Pyrolysis journal November 2021
Micropyrolysis of Polyethylene and Polypropylene Prior to Bioconversion: The Effect of Reactor Temperature and Vapor Residence Time on Product Distribution journal October 2021
Melt Processing Pretreatment Effects on Enzymatic Depolymerization of Poly(ethylene terephthalate) journal October 2022
Wax Formation in the Pyrolysis of Polyolefins in a Conical Spouted Bed Reactor journal November 2002
Product Yields and Compositions in the Continuous Pyrolysis of High-Density Polyethylene in a Conical Spouted Bed Reactor journal April 2011
Cracking of High Density Polyethylene Pyrolysis Waxes on HZSM-5 Catalysts of Different Acidity journal July 2013
Chemically Recyclable Ester-Linked Polypropylene journal July 2022
Monomer recovery through advanced pyrolysis of waste high density polyethylene (HDPE) journal January 2018
Expanding plastics recycling technologies: chemical aspects, technology status and challenges journal January 2022
Applications and societal benefits of plastics journal July 2009
Production, use, and fate of all plastics ever made journal July 2017
Plastic waste inputs from land into the ocean journal February 2015


Similar Records

Catalytic Upgrading of Pyrolysis Condensables from Postconsumer Polyolefins Using HZSM-5
Journal Article · Mon Oct 14 20:00:00 EDT 2024 · Energy and Fuels · OSTI ID:2510458

The Effects of Polyolefin Structure and Source on Pyrolysis-Derived Plastic Oil Composition
Journal Article · Tue Oct 29 20:00:00 EDT 2024 · Green Chemistry · OSTI ID:2475641

Catalytic co-pyrolysis of LDPE and PET with HZSM-5, H-beta, and HY: experiments and kinetic modelling
Journal Article · Wed Jun 29 20:00:00 EDT 2022 · Reaction Chemistry & Engineering · OSTI ID:1978907