title: The effects of Na/K additives and flyash on NO reduction in a SNCR process.
abstract: An experimental study of Na/K additives and flyash on NO reduction during the selective non-catalytic reduction (SNCR) process were carried out in an entrained flow reactor (EFR). The effects of reaction temperature (Tr), water vapor, Na/K additives (NaCl, KCl, Na2CO3) and flyash characteristics on NO reduction were analyzed. The results indicated that NO removal efficiency shows a pattern of increasing first and decreasing later with the increase of the temperature at Tr=850-1150°C. Water vapor can improve the performance of NO reduction, and the NO reduction of 70.5% was obtained while the flue gas containing 4% water vapor at 950°C. Na/K additives have a significant promoting effect on NO reduction and widen the SNCR temperature window, the promoting effect of the test additives is ordered as Na2CO3>KCl>NaCl. NO removal efficiency with 125ppm Na2CO3 and 4% water vapor can reach up to 84.9% at the optimal reaction temperature. The additive concentration has no significant effects on NO reduction while its concentration is above 50ppm. Addition of circulating fluidized combustion (CFB) flyash deteriorates NO reduction significantly. However, CFB flyash and Na/K additives will get a coupling effect on NO reduction during the SNCR process, and the best NO reduction can reach 72.3% while feeding Na2CO3-impregnated CFB flyash at 125ppm Na2CO3 and Tr=950°C.
authors.affiliation: Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, School of Energy & Mechanical Engineering, Nanjing Normal University, Nanjing 210042, PR China.
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Hao
authors.affiliation: Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, School of Energy & Mechanical Engineering, Nanjing Normal University, Nanjing 210042, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yu
authors.affiliation: Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, School of Energy & Mechanical Engineering, Nanjing Normal University, Nanjing 210042, PR China. Electronic address: luping@njnu.edu.cn.
authors.forename: Ping
authors.initials: P
authors.lastname: Lu
authors.affiliation: Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, School of Energy & Mechanical Engineering, Nanjing Normal University, Nanjing 210042, PR China.
authors.forename: Yufei
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, School of Energy & Mechanical Engineering, Nanjing Normal University, Nanjing 210042, PR China.
authors.forename: Xiuming
authors.initials: X
authors.lastname: Zhu
mesh_terms: D000393:Air Pollutants / Q000737:chemistry*; D002254:Carbonates / Q000737:chemistry*; D060729:Coal Ash / Q000737:chemistry*; D009569:Nitric Oxide / Q000737:chemistry*; D010084:Oxidation-Reduction; D011189:Potassium Chloride / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry*; D013696:Temperature
chemical_list: D000393:Air Pollutants; D002254:Carbonates; D060729:Coal Ash; D009569:Nitric Oxide; D012965:Sodium Chloride; C005686:sodium carbonate; D011189:Potassium Chloride
keywords: NO reduction; Na/K additives; SNCR; flyash