Deactivation mechanism of CaO in a flow type dimethyl carbonate synthesis process  

作　　者：Jianing Liu Peng Zheng Zizhen Yan Yuxin Wang Zhanguo Zhang Guangwen Xu Jianjun Guo Lei Shi 

机构地区：[1]Key Laboratory on Resources Chemicals and Materials of Ministry of Education,Shenyang University of Chemical Technology,Shenyang 110142,China [2]Shinghwa Advanced Material Group Co.,ltd,Dongying 257000,China [3]Institute of Industrial Chemistry and Energy Technology,Shenyang University of Chemical Technology,Shenyang 110142,China

出　　处：《Resources Chemicals and Materials》2024年第1期46-53,共8页资源化工与材料（英文）

基　　金：supported by the Liaoning Provincial Natural Science Foundation Joint Fund for Innovation Capability Improvement(2021-NLTS-12-02);Key Research and Local Service Projects of the Liaoning Provincial Department of Education(LDB2019005).

摘　　要：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.

关 键 词：Calcium oxide Dimethyl carbonate Deactivation mechanism Fixed-bed reactor TRANSESTERIFICATION 

分 类 号：O64[理学—物理化学]