Numerical research on mechanisms of the mercury capture by activated carbon injection within an electrostatic precipitator

doi:10.7523/j.issn.2095-6134.2021.02.005

Abstract

Abstract: Based on the Ansys Fluent platform along with its secondary development programs, this research developed a comprehensive numerical model for mercury capture by activated carbon injection and particle migration within an electrostatic precipitator (ESP). The multi-field model coupled sub-models such as flow field, electric field, mercury adsorption, particle charging, and particle motion. The mechanisms and crucial operation parameters of mercury adsorption by suspended activated carbon particles in electrostatic precipitators are fully discussed. The results show that both activated carbon particle size and ion wind effects have great impacts on combined removal efficiency of the mercury and particles. Reducing the size of sorbent particles (activated carbon) can promote mercury removal efficiency while decreasing the particle collection efficiency,the mercury removal efficiency will be 89.6% while the particle size is 5 μm. Additionally, the ion wind has distinct effects on the two mercury adsorption mechanisms in an ESP where the adsorption mechanism of mercury by suspended activated carbon particles is dominant, while the mercury capture efficiency near the wall is at a low level which is below 9%. The comparison between the experimental data and numerical results demonstrates that this model is able to predict the mercury removal efficiency by powdered sorbent injection with acceptable accuracy.

Key words: electrostatic precipitation, activated carbon, mercury removal, adsorption mechanism, numerical model

CLC Number:

TK123

FENG Yuxuan, LUO Kun, FAN Jianren. Numerical research on mechanisms of the mercury capture by activated carbon injection within an electrostatic precipitator[J]. Journal of University of Chinese Academy of Sciences, 2021, 38(2): 189-197.

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