Please wait a minute...

Frontiers of Environmental Science & Engineering

Front. Environ. Sci. Eng.    2015, Vol. 9 Issue (2) : 222-229     https://doi.org/10.1007/s11783-014-0636-2
RESEARCH ARTICLE |
Activity and characteristics of “Oxygen-enriched” highly reactive absorbent for simultaneous flue gas desulfurization and denitrification
Yi ZHAO(),Tianxiang GUO,Zili ZANG
School of Environmental Science & Engineering, North China Electric Power University, Baoding 071003, China
Download: PDF(654 KB)   HTML
Export: BibTeX | EndNote | Reference Manager | ProCite | RefWorks
Abstract

An “Oxygen-enriched” highly reactive absorbent was prepared by mixing fly ash, lime and a small quantity of KMnO4 for simultaneous desulfurization and denitrification. Removal of SO2 and NO simultaneously was carried out using this absorbent in a flue gas circulating fluidized bed (CFB). The highest simultaneous removal efficiency, 94.5% of SO2 and 64.2% of NO, was achieved under the optimal experiment conditions. Scanning Electron Microscope (SEM) and Accessory X-ray Energy Spectrometer (EDX) were used to observe the surface characteristics of fly ash, lime, “Oxygen-enriched” highly reactive absorbent and the spent absorbent. An ion chromatograph (IC) and chemical analysis methods were used to determine the contents of sulfate, sulfite, nitrate and nitrite in the spent absorbents, the results showed that sulfate and nitrite were the main products for desulfurization and denitrification respectively. The mechanism of removing SO2 and NO simultaneously was proposed based on the analysis results of SEM, EDX, IC and the chemical analysis methods.

Keywords “Oxygen-enriched” highly reactive absorbent      Surface characteristics      Flue gas circulating fluidized bed      Simultaneous desulfurization and denitrification     
Corresponding Authors: Yi ZHAO   
Online First Date: 18 February 2014    Issue Date: 13 February 2015
 Cite this article:   
Yi ZHAO,Tianxiang GUO,Zili ZANG. Activity and characteristics of “Oxygen-enriched” highly reactive absorbent for simultaneous flue gas desulfurization and denitrification[J]. Front. Environ. Sci. Eng., 2015, 9(2): 222-229.
 URL:  
http://journal.hep.com.cn/fese/EN/10.1007/s11783-014-0636-2
http://journal.hep.com.cn/fese/EN/Y2015/V9/I2/222
Service
E-mail this article
E-mail Alert
RSS
Articles by authors
Yi ZHAO
Tianxiang GUO
Zili ZANG
substances fly ash industrial lime “oxygen-enriched” highly reactive absorbent
specific surface area/(m2·g-1) 5.6 12.1 55.1
Tab.1  Surface properties of fly ash, industrial lime and “oxygen-enriched” highly reactive absorbent
Fig.1  The experimental apparatus of flue gas CFB system
Fig.2  The effect of contents of KMnO4 on the efficiencies of desulfurization and denitrification
items efficiencies 1 2 3 4 5 average sample variance, S2
SO2 % 94.1 95.4 94.8 93.5 94.7 94.5 0.42
NO % 64.9 64.5 63.1 63.8 64.7 64.2 0.44
Tab.2  Parallel experimental results of desulphurization and denitrification
Fig.3  Surface of fly ash particle (3000X)
Fig.4  Surface of Industrial lime particles (3000X)
Fig.5  Surface of “Oxygen-enriched” highly reactive absorbent (700X) (A,B,C are for the part of erosive traces)
Fig.6  Surface of the spent absorbent (980X)
samples relative contents of the main elements
Al Si K Ca Ti Fe Mn
fly ash 18.15 27.91 0.82 0.70 0.54 2.19
“oxygen-enriched” highly reactive absorbent 18.71 30.48 2.16 40.24 0.79 4.44 3.19
Tab.3  Relative contents of the main elements on the surface of fly ash and “Oxygen-enriched” highly reactive absorbent
Fig.7  Average energy spectrum on the surface of the “Oxygen-enriched ”highly reactive absorbent
Fig.8  Average energy spectrum on the surface of the spent absorbent
the contents of sulfur and nitrogen species in unreacted absorbent the contents of sulfur and nitrogen species in spent absorbent
[SO42-] [SO32-] [NO] [NO3] [SO42-] [SO32-] [NO2] [NO3]
0.002 0 0 0 0.999 0.538 0.555 0.186
Tab.4  Contents of sulfur and nitrogen species in unreacted absorbent and spent absorbent (mmol·g-1)
Fig.9  Ion chromatogram of the spent absorbent
1 Tsai C K. Removal of SO2 from industrial waste gases. Dissertation for the Doctoral Degree. Lubbock: Texas Tech University, 1996
2 Reed G D, R, Davis W T, Pudelek R E. Analysis of coal fly ash properties of importance to sulfur dioxide reactivity potential. Environmental Science and Technology, 1984, 18(7): 548–552
https://doi.org/10.1021/es00125a013
3 Petersen Tom, Karlsson H T. Significance of fly ash in wet-dry scrubbing of SO2. Chemical Engineering and Technology, 1988, 11(5): 298–305
4 Izquierdo J F, Cunill F, Martinez J C, Tejero J, Garcia A. Fly ash reactivation for the desulfurization of coal-fired utility station’s flue gas. Separation Science and Technology, 1992, 27(1): 61–72
https://doi.org/10.1080/01496399208018865
5 Peterson J R., Rochelle G T. Aqueous reaction of fly ash and Calcium hydroxide to produce calcium silicate absorbent for flue gas desulfurization. Environmental Science and Technology, 1988, 22(11): 1299–1304
https://doi.org/10.1021/es00176a009
6 Ho C S, Shih S M. Calcium hydroxide/fly ash sorbents for SO2 removal. Industrial and Engineering Chemistry Research, 1992, 31(4): 1130–1135
https://doi.org/10.1021/ie00004a023
7 Davini P. Investigation of flue gas desulphurization by fly ash and calcium hydroxide mixtures. Resources, Conservation and Recycling, 1995, 15(3–4): 193–201
8 Davini P. Investigation of the SO2 adsorption properties of Ca(OH)2-fly ash systems. Fuel, 1996, 75(6): 713–716
https://doi.org/10.1016/0016-2361(95)00303-7
9 Fernández J, Renedo J, Garea A, Viguri J, Irabien J A. Preparation and characterization of fly ash / hydrated lime sorbents for SO2 removal. Powder Technology, 1997, 94(2): 133–139
https://doi.org/10.1016/S0032-5910(97)03302-0
10 Li Y,Nishioka, Sadakata M. High calcium utilization and gypsum formation for dry desulfurization process. Energy Fuels, 1999, 13(5): 1015–1020
https://doi.org/10.1021/ef9802781
11 Renedo M J, Fernández J, Garea A, Ayerbe A, Irabien J A. Microstructural changes in the desulfurization reaction at low temperature. Industrial and Engineering Chemistry Research, 1999, 38(4): 1384–1390
https://doi.org/10.1021/ie980016m
12 Shi L M, Xu X C. Study of the effect of fly ash on desulfurization by lime. Fuel, 2001, 80(13): 1969–1973
https://doi.org/10.1016/S0016-2361(01)00072-2
13 Liu C F, Shih S M, Lin R B. Kinetics of the reaction of Ca(OH)2/fly ash sorbent with SO2 at low temperatures. Chemical Engineering Science, 2002, 57(1): 93–104
https://doi.org/10.1016/S0009-2509(01)00354-2
14 Lin R B, Shih S M, Liu C F.Structural properties and reactivities of Ca(OH)2/fly ash sorbents for flue gas desulfurization. Industrial and Engineering Chemistry Research, 2003, 42(7): 1350–1356
https://doi.org/10.1021/ie020289o
15 Liu C F, Shih S M, Lin R B. Kinetic model for the reaction of Ca(OH)2/fly ash sorbents with SO2 at Low Temperatures. Industrial and Engineering Chemistry Research, 2004, 43(15): 4112–4117
https://doi.org/10.1021/ie030840x
16 Liu C F, Shih S M, Lin R B. Effect of Ca(OH)2/fly ash weight ratio on the kinetics of the reaction of Ca(OH)2/fly ash sorbents with SO2 at Low temperatures. Chemical Engineering Science, 2004, 59(21): 4653–4655
https://doi.org/10.1016/j.ces.2004.06.031
17 Renedo M J, Fernández J. Preparation, characterization, and calcium utilization of fly ash/Ca(OH)2 sorbents for dry desulfurization at low temperature. Industrial and Engineering Chemistry Research, 2002, 41(10): 2412–2417
https://doi.org/10.1021/ie010938g
18 Ho C S, Shih S M. Characteristics and SO2 capture capacities of sorbents prepared from products of spray-drying flue gas desulfurization. Canadian Journal of Chemical Engineering, 1993, 71(6): 934–939
https://doi.org/10.1002/cjce.5450710615
19 Kind K K, Wasserman P D, Rochelle G T. Effects of salts on preparation and use of calcium silicates for flue gas desulfurization. Environmental Science and Technology, 1994, 28(2): 277–283
https://doi.org/10.1021/es00051a014 pmid: 22176173
20 Tsuchiai H, Ishizuka T, Ueno T, Hattori H, Kita H. Highly active absorbent for SO2 removal prepared from coal fly ash. Industrial and Engineering Chemistry Research, 1995, 34(4): 1404–1411
https://doi.org/10.1021/ie00043a048
21 Ishizuka T, Tsuchiai H, Murayama T, Tanaka T, Hattori H. Preparation of active absorbent for dry-type flue gas desulfurization from calcium oxide, coal fly ash, and gypsum. Industrial and Engineering Chemistry Research, 2000, 39(5): 1390–1396
https://doi.org/10.1021/ie990699l
22 Ishizuka T, Yamamoto T, Murayama T, Tanaka T, Hattori H. Effect of calcium sulfate addition on the activity of the absorbent for dry flue gas desulfurization. Energy Fuels, 2001, 15(2): 438–443
https://doi.org/10.1021/ef000186n
23 Fernández J, Renedo M J. Study of the influence of calcium sulfate on fly ash/Ca(OH)2 sorbents for flue gas desulfurization. Energy and Fuels, 2003, 17(5): 1330–1337
https://doi.org/10.1021/ef020291s
24 Renedo M J, Fernández J. Kinetic modeling of the hydrothermal reaction of fly ash, Ca(OH)2 and CaSO4 in the preparation of desulfurant sorbents. Fuel, 2004, 83(4–5): 525–532
https://doi.org/10.1016/j.fuel.2003.09.016
25 Zhao Y, Ma S C, Huang J J, Xu P Y, Wang L D, Hua W. Experimental study on SO2 and NOx removal and mechanism by highly reactive sorbent. Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering. 2003, 23(10): 236–240(in Chinese)
26 Zhao Y, Fu Y C, Ma S C, Huang J J. Experimental study on the simultaneous desulfurization and denitrification by duct injection. Journal of Environmental Sciences (China), 2004, 16(4): 674– 677
pmid: 15495979
27 Zhao Y, Han Y H, Ma T Z, Guo T X. Simultaneous desulfurization and denitrification from flue gas by Ferrate(VI). Environmental Science and Technology, 2011, 45(9): 4060–4065
https://doi.org/10.1021/es103857g
28 Su C Y, Ran X, Hu J L, Shao C L. Photocatalytic process of simultaneous desulfurization and denitrification of flue gas by TiO2–polyacrylonitrile nanofibers. Environmental Science and Technology, 2013, 47(20): 11562–11568
https://doi.org/10.1021/es4025595
29 Zhao Y, Han Y H, Chen C. Simultaneous removal of SO2 and NO from flue gas using multicomposite active absorbent. Industrial and Engineering Chemistry Research, 2012, 51(1): 480–486
https://doi.org/10.1021/ie202617h
30 Bai M D, Zhang Z T, Bai M D. Simultaneous desulfurization and denitrification of flue gas by ·OH radicals produced from O2+and water vapor in a duct. Environmental Science and Technology, 2012, 46(18): 10161–10168
https://doi.org/10.1021/es3013886
31 Zhao Y, Guo T X, Chen Z Y, Du Y R. Simultaneous removal of SO2 and NO using M/NaClO2 complex absorbent. Chemical Engineering Journal, 2010, 160(1): 42–47
https://doi.org/10.1016/j.cej.2010.02.060
32 Hao X W, Ma C Y, Dong Y, Yang J G. Composite fluidization in a circulating fluidized bed for flue gas desulfurization. Powder Technology, 2012, 215–216: 46–53
https://doi.org/10.1016/j.powtec.2011.09.004
33 Sakai M, Su C L, Sasaoka E. Simultaneous removal of SOx and NOx using slaked lime at low temperature. Industrial and Engineering Chemistry Research, 2002, 41(20): 5029–5033
https://doi.org/10.1021/ie010914+
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed