Desulfurization characteristics of slaked lime and regulation optimization of circulating fluidized bed flue gas desulfurization process—A combined experimental and numerical simulation study

doi:10.1016/j.cjche.2024.05.017

中国化学工程学报 ›› 2024, Vol. 73 ›› Issue (9): 163-175.DOI: 10.1016/j.cjche.2024.05.017

Desulfurization characteristics of slaked lime and regulation optimization of circulating fluidized bed flue gas desulfurization process—A combined experimental and numerical simulation study

Jing Chen¹, Wenqi Zhong¹, Guanwen Zhou¹, Jinming Li², Shasha Ding²

1. Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China;
2. Nanjing Iron and Steel United Co., Ltd., Nanjing 210035, China

收稿日期:2024-03-12 修回日期:2024-05-24 接受日期:2024-05-28 出版日期:2024-11-21 发布日期:2024-06-15
通讯作者: Wenqi Zhong,E-mail:wqzhong@seu.edu.cn
基金资助:
The work was supported by National Natural Science Foundation of China (52336005 and 52106133).

Desulfurization characteristics of slaked lime and regulation optimization of circulating fluidized bed flue gas desulfurization process—A combined experimental and numerical simulation study

Jing Chen¹, Wenqi Zhong¹, Guanwen Zhou¹, Jinming Li², Shasha Ding²

1. Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China;
2. Nanjing Iron and Steel United Co., Ltd., Nanjing 210035, China

Received:2024-03-12 Revised:2024-05-24 Accepted:2024-05-28 Online:2024-11-21 Published:2024-06-15
Contact: Wenqi Zhong,E-mail:wqzhong@seu.edu.cn
Supported by:
The work was supported by National Natural Science Foundation of China (52336005 and 52106133).

摘要/Abstract

摘要： Circulating fluidized bed flue gas desulfurization (CFB-FGD) process has been widely applied in recent years. However, high cost caused by the use of high-quality slaked lime and difficult operation due to the complex flow field are two issues which have received great attention. Accordingly, a laboratory-scale fluidized bed reactor was constructed to investigate the effects of physical properties and external conditions on desulfurization performance of slaked lime, and the conclusions were tried out in an industrial-scale CFB-FGD tower. After that, a numerical model of the tower was established based on computational particle fluid dynamics (CPFD) and two-film theory. After comparison and validation with actual operation data, the effects of operating parameters on gas-solid distribution and desulfurization characteristics were investigated. The results of experiments and industrial trials showed that the use of slaked lime with a calcium hydroxide content of approximately 80% and particle size greater than 40 μm could significantly reduce the cost of desulfurizer. Simulation results showed that the flow field in the desulfurization tower was skewed under the influence of circulating ash. We obtained optimal operating conditions of 7.5 kg·s^-1 for the atomized water flow, 70 kg·s^-1 for circulating ash flow, and 0.56 kg·s^-1 for slaked lime flow, with desulfurization efficiency reaching 98.19% and the exit flue gas meeting the ultraclean emission and safety requirements. All parameters selected in the simulation were based on engineering examples and had certain application reference significance.

关键词: Circulating fluidized bed flue gas desulfurization (CFB-FGD), Desulfurization characteristics, Computational particle fluid dynamics (CPFD) numerical simulation, Operational optimization, Gas-solid flow

Abstract: Circulating fluidized bed flue gas desulfurization (CFB-FGD) process has been widely applied in recent years. However, high cost caused by the use of high-quality slaked lime and difficult operation due to the complex flow field are two issues which have received great attention. Accordingly, a laboratory-scale fluidized bed reactor was constructed to investigate the effects of physical properties and external conditions on desulfurization performance of slaked lime, and the conclusions were tried out in an industrial-scale CFB-FGD tower. After that, a numerical model of the tower was established based on computational particle fluid dynamics (CPFD) and two-film theory. After comparison and validation with actual operation data, the effects of operating parameters on gas-solid distribution and desulfurization characteristics were investigated. The results of experiments and industrial trials showed that the use of slaked lime with a calcium hydroxide content of approximately 80% and particle size greater than 40 μm could significantly reduce the cost of desulfurizer. Simulation results showed that the flow field in the desulfurization tower was skewed under the influence of circulating ash. We obtained optimal operating conditions of 7.5 kg·s^-1 for the atomized water flow, 70 kg·s^-1 for circulating ash flow, and 0.56 kg·s^-1 for slaked lime flow, with desulfurization efficiency reaching 98.19% and the exit flue gas meeting the ultraclean emission and safety requirements. All parameters selected in the simulation were based on engineering examples and had certain application reference significance.

Key words: Circulating fluidized bed flue gas desulfurization (CFB-FGD), Desulfurization characteristics, Computational particle fluid dynamics (CPFD) numerical simulation, Operational optimization, Gas-solid flow

Jing Chen, Wenqi Zhong, Guanwen Zhou, Jinming Li, Shasha Ding. Desulfurization characteristics of slaked lime and regulation optimization of circulating fluidized bed flue gas desulfurization process—A combined experimental and numerical simulation study[J]. 中国化学工程学报, 2024, 73(9): 163-175.

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Desulfurization characteristics of slaked lime and regulation optimization of circulating fluidized bed flue gas desulfurization process—A combined experimental and numerical simulation study

Desulfurization characteristics of slaked lime and regulation optimization of circulating fluidized bed flue gas desulfurization process—A combined experimental and numerical simulation study

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