Assessing the impacts of feedstock and process control on pyrolysis outputs for tyre recycling
File(s)
Published version
Author(s)
Bowles, AJ
Fowler, GD
Type
Journal Article
Abstract
Tyres are a problematic waste stream which are associated with low recycling rates; most are dumped or incinerated, offering poor value return from this material-rich and energy intensive waste. Pyrolysis offers the potential for ~30% of a tyre to be directly recyclable as ‘recovered carbon black’ (RCb), potentiating tyre-to-tyre recycling. However, most attempts to exploit the process have failed to produce consistent, high quality RCb on a commercially viable scale. Current consensus implies that RCb quality can only be improved by expensive post-processing, such as demineralisation using chemical solvents. Here it is shown that the quality (ash and volatile matter content) and consistency of RCb can be improved significantly by careful application of feedstock and process control during pyrolysis. This was achieved via the analysis of peer reviewed data from 31 waste tyres and yields from 161 runs in 37 pyrolysis reactors. A statistical bootstrapping regime showed that by selective exclusion of high ash tyres, and mixing the remainder thoroughly, RCb ash content could be reduced from 49% (upper 99% CI) to 14%. By utilising a unique reactor classification, it was found that fixed beds performed inconsistently, whilst rotary kilns and conical spouted beds produced high quality RCb and a high oil yield, even at lower pyrolysis temperatures. Due to their higher throughput, this work therefore suggests that application of rotary kilns with feedstock control are the best mechanisms to produce consistent high-quality products from pyrolysis, increasing the recyclability of automotive tyres.
Date Issued
2022-07
Date Acceptance
2022-03-04
Citation
Resources, Conservation and Recycling, 2022, 182
ISSN
0921-3449
Publisher
Elsevier
Journal / Book Title
Resources, Conservation and Recycling
Volume
182
Copyright Statement
© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000793392400005&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=a2bf6146997ec60c407a63945d4e92bb
Subjects
ALTERNATIVE FUEL
BIOMASS GASIFICATION
BUBBLING FLUIDIZED-BED
CARBON-BLACK
CATALYTIC PYROLYSIS
Engineering
Engineering, Environmental
Environmental Sciences
Environmental Sciences & Ecology
FAST CO-PYROLYSIS
Life Sciences & Biomedicine
LIFE TIRES
Pyrolysis
Recovered carbon black
Recycling
Science & Technology
SCRAP TIRES
Technology
Tyre pyrolysis oil
Tyres
VACUUM PYROLYSIS
Waste
WASTE TIRE PYROLYSIS
Publication Status
Published
Article Number
106277
Date Publish Online
2022-04-08