TY - JOUR
T1 - Conversion of low-density polyethylene into monocyclic aromatic hydrocarbons through continuous microwave pyrolysis with ex-situ dual-catalyst beds
AU - Peng, Yujie
AU - Wang, Xiaofei
AU - Fan, Liangliang
AU - Zhang, Qi
AU - Cui, Xian
AU - Tian, Xiaojie
AU - Wu, Qiuhao
AU - Cobb, Kirk
AU - Ruan, Roger
AU - Tu, Heng
AU - Yang, Jing
AU - Wang, Yunpu
N1 - Publisher Copyright:
© 2023 Elsevier Ltd
PY - 2023/9/15
Y1 - 2023/9/15
N2 - The single-use of polyolefins-based individual protective equipment has led to the rapid generation of substantial plastic waste. This study aimed at cleaner disposal of the polyolefin waste, and carried out the continuous microwave pyrolysis (CMP) of low-density polyethylene (LDPE) over dual-catalyst beds of MCM-41 and HY. The dual-catalyzed trial was able to produce more condensate fractions with higher selectivity of monocyclic aromatic hydrocarbons (MAHs), compared with using only MCM-41 or HY zeolite. It was because the larger pore size of the MCM-41 catalyst (4.00 nm) could crack long-chain polyolefin intermediates into shorter chains. This alleviates steric and diffusional resistance while entering and exiting the micropores of the HY zeolite (0.74 × 0.74 nm). The maximum liquid yield (63.75 wt%) and MAHs selectivity (78.21%) were achieved at a catalysis temperature of 450 °C, feedstock to catalyst ratio of 8:3, and HY to MCM-41 ratio of 2:1. In addition, the performance of the CMP reactor was also compared favorably with the batch microwave pyrolysis (BMP) reactor under the same conditions. It has been found that the CMP reactor generated more MAHs products, whereas the BMP reactor was more selective for the generation of polycyclic aromatic hydrocarbons (PAHs) and gas products. The combination of CMP and the co-catalysis process offers new insight into sustainable management and value-added recovery of medical plastic waste.
AB - The single-use of polyolefins-based individual protective equipment has led to the rapid generation of substantial plastic waste. This study aimed at cleaner disposal of the polyolefin waste, and carried out the continuous microwave pyrolysis (CMP) of low-density polyethylene (LDPE) over dual-catalyst beds of MCM-41 and HY. The dual-catalyzed trial was able to produce more condensate fractions with higher selectivity of monocyclic aromatic hydrocarbons (MAHs), compared with using only MCM-41 or HY zeolite. It was because the larger pore size of the MCM-41 catalyst (4.00 nm) could crack long-chain polyolefin intermediates into shorter chains. This alleviates steric and diffusional resistance while entering and exiting the micropores of the HY zeolite (0.74 × 0.74 nm). The maximum liquid yield (63.75 wt%) and MAHs selectivity (78.21%) were achieved at a catalysis temperature of 450 °C, feedstock to catalyst ratio of 8:3, and HY to MCM-41 ratio of 2:1. In addition, the performance of the CMP reactor was also compared favorably with the batch microwave pyrolysis (BMP) reactor under the same conditions. It has been found that the CMP reactor generated more MAHs products, whereas the BMP reactor was more selective for the generation of polycyclic aromatic hydrocarbons (PAHs) and gas products. The combination of CMP and the co-catalysis process offers new insight into sustainable management and value-added recovery of medical plastic waste.
KW - Continuous microwave pyrolysis
KW - Dual-catalyst
KW - Low-density polyethylene
KW - Microwave-assisted pyrolysis
KW - Monocyclic aromatic hydrocarbons
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U2 - 10.1016/j.jclepro.2023.138039
DO - 10.1016/j.jclepro.2023.138039
M3 - Article
AN - SCOPUS:85165993147
SN - 0959-6526
VL - 418
JO - Journal of Cleaner Production
JF - Journal of Cleaner Production
M1 - 138039
ER -