Autor: |
Jianing Liu, Peng Zheng, Zizhen Yan, Yuxin Wang, Zhanguo Zhang, Guangwen Xu, Jianjun Guo, Lei Shi |
Jazyk: |
angličtina |
Rok vydání: |
2024 |
Předmět: |
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Zdroj: |
Resources Chemicals and Materials, Vol 3, Iss 1, Pp 46-53 (2024) |
Druh dokumentu: |
article |
ISSN: |
2772-4433 |
DOI: |
10.1016/j.recm.2023.08.006 |
Popis: |
It is well known that calcium oxide (CaO) has better catalytic efficiency than most heterogeneous catalysts in many transesterification reactions. However, the gradual deactivation problem prevents its large-scale application in industry. In this paper, the deactivation mechanism of CaO in a fixed-bed reactor is investigated based on the transesterification reaction of propylene carbonate and methanol. The leaching amount of CaO during the reaction was estimated by the concentration of Ca in the products. The pretreated and recovered catalysts were characterized by FT-IR, XRD, TG-MS and SEM-EDS. It is evident from experiments and characterization that the deactivation process of CaO is accompanied by the leaching of calcium species and the generation of CaCO3, which are also verified by DFT calculations. At high temperature and high weight hourly space velocity, the deactivation was attributed to the formation of dense CaCO3 shell, which prevents the contact between the feedstock and the active species inside. |
Databáze: |
Directory of Open Access Journals |
Externí odkaz: |
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