TY - JOUR
T1 - Aromatic hydrocarbon selectivity as a function of CaO basicity and aging during CaO-catalyzed PET pyrolysis using tandem µ-reactor-GC/MS
AU - Kumagai, Shogo
AU - Yamasaki, Ryota
AU - Kameda, Tomohito
AU - Saito, Yuko
AU - Watanabe, Atsushi
AU - Watanabe, Chuichi
AU - Teramae, Norio
AU - Yoshioka, Toshiaki
N1 - Funding Information:
This work was partially supported by JSPS KAKENHI (Grant No. 16H05893 ).
Publisher Copyright:
© 2017 Elsevier B.V.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2018/1/15
Y1 - 2018/1/15
N2 - During the tandem pyrolysis of poly(ethylene terephthalate) (PET) and catalytic conversion of the PET pyrolysates over calcium oxide (PET/CaO process), the relationship between catalyst deterioration and the aromatic hydrocarbon selectivity was elucidated. Using a tandem micro (µ)-reactor-gas chromatography/mass spectrometry (TR-GC/MS) system, PET was pyrolyzed at 450 °C in the 1st µ-reactor and the PET pyrolysates were refined over one of two CaO catalysts with different basicities at 700 °C in the 2nd µ-reactor. Strongly basic CaO enhanced benzene production via decarboxylation, resulting in 83.6% selectivity for aromatic hydrocarbon products. This selectivity decreased with repeated runs over the strongly basic CaO, while oxygen-containing compounds such as benzophenone and benzoic acid increased. The surface morphology changes observed by scanning electron microscopy indicated that CaO was thoroughly sintered with repeated use, which reduced its basicity. The less-basic CaO effected diminished carboxyl-unit surface adsorption and suffered deteriorated deoxygenation ability. Thus, this study clearly demonstrates that CaO deterioration (by sintering during repeated PET/CaO processing) and CaO basicity strongly influence reaction selectivity.
AB - During the tandem pyrolysis of poly(ethylene terephthalate) (PET) and catalytic conversion of the PET pyrolysates over calcium oxide (PET/CaO process), the relationship between catalyst deterioration and the aromatic hydrocarbon selectivity was elucidated. Using a tandem micro (µ)-reactor-gas chromatography/mass spectrometry (TR-GC/MS) system, PET was pyrolyzed at 450 °C in the 1st µ-reactor and the PET pyrolysates were refined over one of two CaO catalysts with different basicities at 700 °C in the 2nd µ-reactor. Strongly basic CaO enhanced benzene production via decarboxylation, resulting in 83.6% selectivity for aromatic hydrocarbon products. This selectivity decreased with repeated runs over the strongly basic CaO, while oxygen-containing compounds such as benzophenone and benzoic acid increased. The surface morphology changes observed by scanning electron microscopy indicated that CaO was thoroughly sintered with repeated use, which reduced its basicity. The less-basic CaO effected diminished carboxyl-unit surface adsorption and suffered deteriorated deoxygenation ability. Thus, this study clearly demonstrates that CaO deterioration (by sintering during repeated PET/CaO processing) and CaO basicity strongly influence reaction selectivity.
KW - Aromatic hydrocarbon
KW - CaO
KW - Catalytic pyrolysis
KW - Poly(ethylene terephthalate)
KW - Recycling
KW - Tandem micro-reactor
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U2 - 10.1016/j.cej.2017.09.077
DO - 10.1016/j.cej.2017.09.077
M3 - Article
AN - SCOPUS:85033703857
VL - 332
SP - 169
EP - 173
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
SN - 1385-8947
ER -