Simultaneous removal of NOX and SO2 from flue gas in an integrated FGD-CABR system by sulfur cycling-mediated Fe(II)EDTA regeneration

Xi-Jun Xu; Yi-Ning Wu; Qing-Yang Xiao; Peng Xie; Nan-Qi Ren; Yi-Xing Yuan; Duu-Jong Lee; Chuan Chen

doi:10.1016/j.envres.2021.112541

Simultaneous removal of NO_X and SO₂ from flue gas in an integrated FGD-CABR system by sulfur cycling-mediated Fe(II)EDTA regeneration

Environ Res. 2022 Apr 1:205:112541. doi: 10.1016/j.envres.2021.112541. Epub 2021 Dec 13.

Authors

Xi-Jun Xu¹, Yi-Ning Wu², Qing-Yang Xiao¹, Peng Xie¹, Nan-Qi Ren¹, Yi-Xing Yuan¹, Duu-Jong Lee³, Chuan Chen⁴

Affiliations

¹ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China.
² State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China. Electronic address: lien68@sina.com.
³ Department of Chemical Engineering, National Taiwan University, Taipei, 106, Taiwan; Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei, 106, Taiwan.
⁴ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China. Electronic address: echo110244@126.com.

PMID: 34915032
DOI: 10.1016/j.envres.2021.112541

Abstract

Chemical absorption-biological reduction (CABR) process is an attractive method for NO_X removal and Fe(II)EDTA regeneration is important to sustain high NO_X removal. In this study a sustainable and eco-friendly sulfur cycling-mediated Fe(II)EDTA regeneration method was incorporated in the integrated biological flue gas desulfurization (FGD)-CABR system. Here, we investigated the NO_X and SO₂ removal efficiency of the system under three different flue gas flows (100 mL/min, 500 mL/min, and 1000 mL/min) and evaluated the feasibility of chemical Fe(III)EDTA reduction by sulfide in series of batch tests. Our results showed that complete SO₂ removal was achieved at all the tested scenarios with sulfide, thiosulfate and S⁰ accumulation in the solution. Meanwhile, the total removal efficiency of NO_X achieved ∼100% in the system, of which 3.2%-23.3% was removed in spray scrubber and 76.7%-96.5% in EGSB reactor along with no N₂O emission. The optimal pH and S^2-/Fe(III)EDTA for Fe(II)EDTA regeneration and S⁰ recovery was 8.0 and 1:2. The microbial community analysis results showed that the cooperation of heterotrophic denitrifier (Saprospiraceae_uncultured and Dechloromonas) and iron-reducing bacteria (Klebsiella and Petrimonas) in EGSB reactor and sulfide-oxidizing, nitrate-reducing bacteria (Azoarcus and Pseudarcobacter) in spray scrubber contributed to the efficient removal of NO_X in flue gas.

Keywords: Fe(II)EDTA regeneration; Flue gas; NO(X); S(0) recovery; SO(2).

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bacteria
Edetic Acid
Nitric Oxide
Nitrogen Oxides*
Oxidation-Reduction
Sulfur Dioxide
Sulfur*

Substances

Nitrogen Oxides
Sulfur Dioxide
Nitric Oxide
Sulfur
Edetic Acid