Improvement of the reduction of condensable particulate matter in flue gas scrubbing process

Tailin Chen; Lejun Deng; Yuzhong Li; Jingwei Li; Zhuping Zhang

doi:10.1016/j.envres.2023.116945

Improvement of the reduction of condensable particulate matter in flue gas scrubbing process

Environ Res. 2023 Nov 15;237(Pt 1):116945. doi: 10.1016/j.envres.2023.116945. Epub 2023 Aug 25.

Authors

Tailin Chen¹, Lejun Deng¹, Yuzhong Li², Jingwei Li¹, Zhuping Zhang¹

Affiliations

¹ National Engineering Laboratory for Reducing Emissions from Coal Combustion, Engineering Research Center of Environmental Thermal Technology of Ministry of Education, Shandong Key Laboratory of Energy Carbon Reduction and Resource Utilization, School of Energy and Power Engineering, Shandong University, Jinan, Shandong, 250061, China.
² National Engineering Laboratory for Reducing Emissions from Coal Combustion, Engineering Research Center of Environmental Thermal Technology of Ministry of Education, Shandong Key Laboratory of Energy Carbon Reduction and Resource Utilization, School of Energy and Power Engineering, Shandong University, Jinan, Shandong, 250061, China. Electronic address: lyz@sdu.edu.cn.

PMID: 37633633
DOI: 10.1016/j.envres.2023.116945

Abstract

Condensable particulate matter (CPM) is characterized by complex composition, non-negligible emission concentration, and fine or ultrafine in size after conversion to particles, which is difficult to remove. Current methods to control CPM are not fully developed and mainly focus on synergistic removal of CPM in existing air pollution control devices, such as CPM reduction through scrubbing processes in wet flue gas desulfurization (WFGD) systems. In this work, an experimental system including a simulated WFGD scrubber, also referred to as the primary scrubber (PS), and a secondary scrubber (SS) was built to explore measures to improve the CPM reduction performance during scrubbing. The operating parameters of the liquid-to-gas (L/G) ratio and the spray temperature in the two scrubbers were tuned in the experiments. The results indicated that CPM could be reduced in the PS by conversion to filterable particulate matter (FPM), and captured by the spray droplets through the effects of dissolution and condensation, but the reduction was not very efficient. In the SS, the reduction performance of CPM could be further improved due to increased dissolution of CPM caused by increased opportunities for gas-liquid contact, and increased condensation of CPM due to lower spray temperature. The FPM transformed from the CPM in the PS could also be reduced in the SS by the effects of diffusiophoresis and thermophoresis contributed by water vapor condensation. An increase in the L/G ratio could improve the CPM reduction.

Keywords: Condensable particulate matter; Condensation scrubbing; Filterable particulate matter; Synergistic removal; Wet flue gas desulfurization.