title: Oxidation inhibition of sulfite in dual alkali flue gas desulfurization system.
abstract: A laboratory-scale well-mixed thermostatic reactor with continuously blasting air was used to investigate the oxidation inhibition of sulfite in dual alkali flue gas desulfurization (FGD) system. The effects of operating parameters such as pH value and catalyst concentration on the oxidation were studied. Sodium thiosulfate was used in the system, and was found that it significantly inhabited the sulfite oxidation. In the absence of catalyst, sodium thiosulfate at 12.67 mmol/L had an inhibition efficiency of approximately 98%. While in the presence of catalyst, sodium thiosulfate at 26.72 mmol/L had an inhibition efficiency less than 85.0%. The oxidation reaction order of sulfite in the sodium thiosulfate was determined to be -1.90 and -0.55 in the absence and presence of the catalyst, respectively. Apparent activation energy of oxidation inhibition was calculated to be 53.9 kJ/mol. Pilot tests showed that the consumption rate of thiosulfate agreed well with the laboratory-scale experimental results.
authors.affiliation: Department of Environmental Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Jian-song
authors.initials: JS
authors.lastname: Mo
authors.forename: Zhong-biao
authors.initials: ZB
authors.lastname: Wu
authors.forename: Chang-jie
authors.initials: CJ
authors.lastname: Cheng
authors.forename: Bao-hong
authors.initials: BH
authors.lastname: Guan
authors.forename: Wei-rong
authors.initials: WR
authors.lastname: Zhao
mesh_terms: D000393:Air Pollutants / Q000737:chemistry*; D000397:Air Pollution / Q000517:prevention & control*; D000468:Alkalies; D002384:Catalysis; D006863:Hydrogen-Ion Concentration; D008278:Magnesium Sulfate / Q000737:chemistry; D010084:Oxidation-Reduction; D013447:Sulfites / Q000737:chemistry*; D013455:Sulfur; D013885:Thiosulfates / Q000737:chemistry*; D018505:Waste Management / Q000379:methods
chemical_list: D000393:Air Pollutants; D000468:Alkalies; D013447:Sulfites; D013885:Thiosulfates; D013455:Sulfur; D008278:Magnesium Sulfate; C017717:sodium thiosulfate; C025026:sodium sulfite