The Study on Thermal Stability of Hg and S Element in Semi-Dry Flue Gas Desulfurization Ash

Abstract:

The semi-dry flue gas desulfurization technology is widely used by coal-fired power plant. Desulfurization ash produced by semi-dry flue gas desulfurization, which consist CaSO₃, CaCO₃, Ca (OH) ₂, CaSO₄ and so on. It will bring new environment pollution if not been disposed properly. Building material industry is the main field in terms of the comprehensive utilization of desulfurization ash. While hazardous elements especial S and Hg may be released in the condition of temperature changes in the process of desulfurization ash utilization, causing second environment pollution. Combined with the research achievement of preparing autoclaved brick before, the content of S and Hg in raw materials and autoclaved brick were studied during the thermal utilization process in this article. The thermal stability of calcium sulfite was analyzed by the chemical reagent calcium sulfite. The results shown that calcium sulfite only lost crystal water whether in oxygen or air when the temperature is below 450°C, calcium sulfite was completely oxidized to calcium sulfate when the temperature is 475 °C in oxygen or 515°C in air. The contents of S and Hg which existed in desulfurization ash were 7.03%wt and 460μg/kg, respectively. The contents of S and Hg in autoclaved brick which made by desulfurization ash mainly were 5.16%wt and 450μg/kg, respectively. The results shown that the content of elements S and Hg in raw materials and autoclaved brick were roughly the same, which indicated that S and Hg no escape in the process of preparing autoclaved brick. The research provided a certain references for the comprehensive utilization of semi-dry flue gas desulfurization ash in the condition of heat and humid.

• Periodical: Applied Mechanics and Materials (Volume 768)
• Pages: 434-440
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.768.434
• Online since: June 2015
• Authors: Yu Shen, Li Sha Yang, Chao Jie Li, Chuan Min Chen, Song Tao Liu
• Keywords: Autoclaved Brick, Desulfurization Ash, Hg Releasing, S Releasing, Thermal Stability

References

[1] L.C. Yang. Semidry Flue Gas Desulfurization Technologies in China, J. Jiangxi Energy, 3(2005): 24~26.

[2] F. Wang, F. Zhang, H. G. Wang, et. Industrial Applications of Semi-dry Flue Gas Desulfurization Ash , J. Environmental Pollution & Control, 26 (2004): 209-211.

[3] L. Z. Liu, Ch. Zh. Zhang, X. M. Huang, et. Study on Comparability of Three Calcium desulfurizing agents for desulfurization of sinter gas on CFBA, J. Environmental Pollution & Control, 26(2004): 418-420.

[4] G. Tian, Fan Zhang, H.M. Wang. Systematically Utilization of Flue Gas Desulfurization Ash, J. Energy Environmental Protection, 6(2003): 8-12.

[5] Y. J. Xue, X. G. Li, X. Han, et. Application Status quo and Development for Resource Utilization of Flue Gas Desulfurization By product, J. Electric Power Environmental Protection, 4(2009): 47-49.

[6] L. S. Lesley Mercury-emissions and control, R. /IEA Clean Coal Centre Reports. USA: International Energy Agency，58(2002).

[7] X. C. Qiao, C. S. Poon，C. Cheeseman. Use of Flue Gas Desulfurization Waste and Rejected Fly Ash in Waste Stabilization/Solidification Systems, J. Waste Management，2(2006): 141-149.

DOI: 10.1016/j.wasman.2005.02.020

[8] H. Dang, H. Sh. Wang, H. Huang, et. Properties of CFB Ash and Slag and Its Applications, J. International Electric Power for China, 6 (2004): 55-58.

[9] F. Shi. The Research and Application of Desulfurization Slag in Semi-dry Flue Gas Desulfurization Ash, C. /Technical Series-Complete National flue gas desulfurization technology engineering analysis and application, (2001): 116-119.

DOI: 10.1002/9780470935446.ch1

[10] Y. F. Ge, X.C. Bao. Building Utilization to Coal-fired Power Plant Desulfurization Ash, J. Utilization of Fly Ash, 2 (1999): 54-56.

[11] D. G. Su, X. X. Yuan. The Study of dgypsum cement clinker ash and sulfur Yat, J. Cement, 11 (2007) : 21－22.

[12] Brad Buecker，Roger Blaine．Therogravimetry: A Great Tool for Flue Gas Desulfurization Solids Analysis［EB / OL］． http: / / www．tainstruments．com / library download．aspx file = TA318．pdf.

[13] C. Leiva, C. Gar Arenas, L. F. Vilches. Use of FGD gypsum in fire resistant panels, J. Waste Management，30（ 2010）：1123-1129.

DOI: 10.1016/j.wasman.2010.01.028

[14] P. Taerakul, P. Sun, H. Walker, et al. Variability of Inorganic and Organic Constituents in Lime Spray Dryer Ash, J. Fuel, 14-15(2006): 1820-1829.

DOI: 10.1016/j.fuel.2005.03.015

[15] S. V. Pisupati, R. S. WASCO, A. W. Scaroni. An Investigation on Polycyclic Aromatic Hydrocarbon Emissions from Pulverized Coal Combustion Systems, J. Hazardous Materials, 1-2, 74(2000): 91-107.

DOI: 10.1016/s0304-3894(99)00201-0

[16] Zh. F. Song, Y. Zhu, T. Zh. Zhang, et. Comprehensive Utilization of Slag in Dry and Semi-dry FGD Technology, J. Power System Engineering, 2(2002): 49-50.

[17] L. G. Zheng, G. J. Liu, C.C. Qi, et. Study on environmental geochemistry of mercury in Chinese coals, J. Journal of University of Science and Technology of China, 8(2007): 953-963.

[18] Sh. W. Pang, G. K. Qiu, J. F. Sun, et. Explore different forms of mercury in the sediment measured sequential chemical extraction, J. Environmental Sciences Journal, 3 (1991): 234-241.

[19] American Society for Testing and Materials. Standard test method for elemental, oxidized, par -ticle bound and total mercury in flue gas generated from coal-fired stationary source(Ontario hydro method), S. (2002).

DOI: 10.1520/d6784-02

[20] Us Environmental Protection Agency. Method 30B determination of total vapor phase mercury From coal fired combustion sources using carbon sorbent[EB/OL]. [2010-09-04]. http: /www. epa. gov/ttn/emc/promgat/Meth 30B. Pdf.