Impacts of CeO2 oxygen carriers on the conversion of mercury in chemical looping combustion of coal

被引：0
|
作者：
Wang X. [1 ,2 ]
Liu D. [1 ,2 ]
Xu K. [1 ,2 ]
Liu Q. [1 ,2 ]
Fan Y. [1 ,2 ]
Jin J. [1 ,2 ]
机构：
[1] School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai
[2] Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering, Shanghai
来源：
Huagong Jinzhan/Chemical Industry and Engineering Progress | 2024年 / 43卷 / 04期
关键词：
cerium dioxide; chemical looping combustion; coal; mercury; oxygen carrier;
D O I：
10.16085/j.issn.1000-6613.2023-0521
中图分类号：
学科分类号：
摘要：
Mercury pollution has attracted increasing attention due to serious harm to the human beings and ecosystem. This study aims to analyze the effects of CeO2 oxygen carriers on the conversion of mercury during coal chemical looping combustion. The combustion characteristics of “CeO2+coal”, “SiO2+coal” and “coal” in the fluidized bed reactor were investigated experimentally. In gasification atmosphere, the reaction between oxygen carrier and coal was mainly converted to CO2 and a small amount of compositions including CO, CH4, and H2 . “CeO2+coal” system consumed the largest amount of O2 and produced the largest amount of CO2, indicating that the CeO2 oxygen carriers contributed to the fully combustion of the coal. Mercury was mainly released as Hg0 in the gasification atmosphere, and the Hg0 release from “CeO2 + coal” accounted for 49.75% of the total mercury, which was significantly lower than that of the system without oxygen carriers. In air atmosphere, mercury was released in the form of Hg2+ with a small amount. The Hg0 and Hg2+ release from “CeO2 + coal” system were both lower than those of the “coal” system. By changing the different locations between CeO2 oxygen carriers and coal in experiments, it was shown that under gasification atmosphere, CeO2 oxygen carriers had weak adsorption capacity for Hg0, and their catalytic and oxygen release properties were the key factors in removing Hg0, and the catalytic activity played a major role. Under gasification atmosphere, CO2 could replenish the lattice oxygen consumed in CeO2, thus improving its catalytic and regenerative performances. XPS analysis of the CeO2 oxygen carriers after reduction and oxidation showed the peak position for Ce3+ in Ce 3d disappeared and all of them were converted to Ce4+, which indicated that the CeO2 oxygen carrier had good cyclic performance. © 2024 Chemical Industry Press Co., Ltd.. All rights reserved.
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页码：2191 / 2200
页数：9
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