Low-medium temperature application of selective catalytic reduction denitration in cement flue gas through a pilot plant

Yangyang Guo; Lei Luo; Yang Zheng; Jian Wang; Tingyu Zhu

doi:10.1016/j.chemosphere.2021.130182

Low-medium temperature application of selective catalytic reduction denitration in cement flue gas through a pilot plant

Chemosphere. 2021 Aug:276:130182. doi: 10.1016/j.chemosphere.2021.130182. Epub 2021 Mar 3.

Authors

Yangyang Guo¹, Lei Luo¹, Yang Zheng¹, Jian Wang¹, Tingyu Zhu²

Affiliations

¹ Key Laboratory of Green Process and Engineering, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing, 100190, China.
² Key Laboratory of Green Process and Engineering, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing, 100190, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China. Electronic address: tyzhu@ipe.ac.cn.

PMID: 34088084
DOI: 10.1016/j.chemosphere.2021.130182

Abstract

Low-medium temperature application of selective catalytic reduction (SCR) denitration in cement flue gas was established and investigated in this study. The 2000 h continuous operation shows the concentration of NO_x at the outlet can be maintained at 24 mg/Nm³ on average, while due to the increase of SO₂ in flue gas, the NO_x concentration increased to 57.5 mg/Nm³ after long time operation. The sulfur deposition is the main reason for catalyst deactivation, and SO₂ is still a big obstacle for low-medium temperature SCR application in cement flue gas. The denitration efficiency was tested as fluctuated from 73.5% to 86.2%, and ammonia concentration after SCR was as still as high as 22.5-60.0 mg/Nm³ due to the excessive ammonia injection from selective non-catalytic reduction (SNCR), shows serious ammonia escape problem for SNCR, and the potential application of hybrid SNCR-SCR technology. In order to maintain the denitration efficiency above 85.0%, the gaseous hourly space velocity (GHSV) should not be exceeded 2800 h^-1, the electrostatic precipitators (ESP) setting at 60 kV was relatively appropriate, the temperature of the flue gas should be kept at above 200 °C. The concentrations and toxic equivalent quantities (TEQs) of the PCDD/Fs congeners in the flue gas raised greatly after SCR reactor, indicating the PCDD/Fs concentration should be concerned during the application of low-medium temperature SCR, especially for the waste co-disposal processes.

Keywords: Low-medium temperature; Operation conditions; PCDD/Fs analysis; SCR application; Sulfur poisoning.

MeSH terms

Catalysis
Dibenzofurans
Gases
Polychlorinated Dibenzodioxins*
Temperature

Substances

Dibenzofurans
Gases
Polychlorinated Dibenzodioxins