Abstract
A continuous-stirred microwave pyrolysis (CSMP) reactor was designed for linear low-density polyethylene (LLDPE) conversion. Its performance was compared with the batch microwave pyrolysis (BMP) under identical conditions. During the pyrolysis, the continuous-stirred system generated more condensate products with higher selectivity in long carbon chains (C14–C20), whereas the batch system was more selective for gas products with a higher proportion of methane. An ex-situ catalytic bed with HZSM-5 was assembled to upgrade pyrolysis vapors, corresponding to improved gasoline-range hydrocarbons and propylene production. The comparison of catalytic processes showed similar product yields for both configurations, with differences primarily on chemical species selectivity. For instance, the products from the continuous-stirred system had narrower carbon number distribution (C7–C10) and higher selectivity to mono-aromatics (72.3%). The proposed pathways for LLDPE conversion from the two systems showed slight differences in the thermal cracking process but similarities in the catalytic cracking process. During the catalytic processes, the potential net energy gain was 34.16 MJ/kg for CSMP and −38.86 MJ/kg for BMP, compared with the non-catalytic processes, when the figures were 9.85 MJ/kg and −42.86 MJ/kg, respectively.
Original language | English (US) |
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Article number | 120612 |
Journal | Energy |
Volume | 228 |
DOIs | |
State | Published - Aug 1 2021 |
Bibliographical note
Funding Information:This work was supported by National Natural Science Foundation of China (No. 51906096 ), National Key Research and Development Program of China ( 2019YFE011926 ), Postdoctoral Research Project of Jiangxi Province of China ( 2019KY21 ), and the Talent Program for Distinguished Young Scholars of Jiangxi Province of China ( 20171BCB23015 ). We would also like to thank the technical support from University of Minnesota Center for Biorefining.
Funding Information:
This work was supported by National Natural Science Foundation of China (No. 51906096), National Key Research and Development Program of China (2019YFE011926), Postdoctoral Research Project of Jiangxi Province of China (2019KY21), and the Talent Program for Distinguished Young Scholars of Jiangxi Province of China (20171BCB23015). We would also like to thank the technical support from University of Minnesota Center for Biorefining.
Publisher Copyright:
© 2021 Elsevier Ltd
Keywords
- Batch microwave pyrolysis
- Continuous-stirred microwave pyrolysis
- HZSM-5
- LLDPE
- Mechanism
- Net energy gain