Improving Lime’s Reactivity Towards Flue Gas Desulfurization by using Fly Ash, Bottom Ash and Waste Activated Sludge
DOI:
https://doi.org/10.18034/abcjar.v2i1.14Keywords:
Lime, Pozzolan, Reactivity, Surface areaAbstract
Lime reactivity was improved by blending it with either fly ash, bottom ash or waste activated sludge (W.A.S). The reactivity was tested using a pH-stat apparatus which simulates wet flue gas desulfurization (FGD). Temperature, solid to liquid ratio and stirring speed were varied in addition to lime to additive ratio in optimization tests. Design expert’s central cubic design was used in the design of experiments to aid with regression analysis. Temperature had the highest effect whereas W.A.S was the best additive then fly ash and finally bottom ash. The results were confirmed by the use of fixed bed apparatus where the best sorbents from each additive was tested in dry FGD. In a bid to explain the results, BET surface area analysis was used where the sorbent from the blend of lime and W.A.S had the highest improvement in surface area.
Metrics
Downloads
References
Aphane, M.E., The Hydration of Magnesium Oxide with Different Reactivities by Water and Magnesium Acetate, in Department of Chemistry. 2007, University of South Africa: Pretoria. p. 160.
Aydogan, S., et al., Dissolution kinetics of celestite (SrSO4) in HCl solution with BaCl2. Hydrometallurgy, 2006. 84(3-4): p. 239-246. DOI: https://doi.org/10.1016/j.hydromet.2006.06.001
DemirkIran, N., Dissolution kinetics of ulexite in ammonium nitrate solutions. Hydrometallurgy, 2009. 95(3-4): p. 198-202. DOI: https://doi.org/10.1016/j.hydromet.2008.05.041
Dintchev, O.D., A.S. Meyer, and D.O. Dintchev, South Africa’s electrical energy economy: environmental impacts, future developments and constraints. Engineering Science and Education Journal, 1998: p. 227-312. DOI: https://doi.org/10.1049/esej:19980508
Ekmekyapar, A., N. DemirkIran, and A. Künkül, Dissolution kinetics of ulexite in acetic acid solutions. Chemical Engineering Research and Design, 2008. 86(9): p. 1011-1016. DOI: https://doi.org/10.1016/j.cherd.2008.04.005
Energy, International Energy Outlook, U.S.D.o. Energy, Editor. 2008: Washington, DC. p. 260.
Energy, South Africa Energy Data,, D.o. Energy, Editor. 2010. p. 8.
Environmental, Affairs, and Tourism, How Energy Generation Causes Environmental Change in South Africa, D.o.E.A.a. Tourism, Editor. 2001: Pretoria.
Ghosh-Dastidar, A., et al., Ultrafast calcination and sintering of Ca(OH)2 powder: Experimental and modeling. Chemical Engineering Science, 1995. 50(13): p. 2029-2040. DOI: https://doi.org/10.1016/0009-2509(95)00043-5
Hu, G., et al., Review of the direct sulfation reaction of limestone. Progress in Energy and Combustion Science, 2006. 32(4): p. 386-407. DOI: https://doi.org/10.1016/j.pecs.2006.03.001
Lee, K.T., et al., Optimum conditions for preparation of flue gas desulfurization absorbent from rice husk ash. Fuel, 2005. 84(2-3): p. 143-151. DOI: https://doi.org/10.1016/j.fuel.2004.08.018
Levenspiel, O., Chemical reaction engineering. Third ed. 1999, Oregon: John Wiley and Sons. 668.
Maina, P. and M. Mbarawa, Investigating Effects of Zeolites As an Agent to Improve Limestone Reactivity toward Flue Gas Desulfurization. Energy & Fuels, 2011. 25(5): p. 2028-2038. DOI: https://doi.org/10.1021/ef200156c
Marta, B.M., Reactivity of Acid Gas Pollutants with Ca(OH)2 at Low Temperature in the Presence of Water Vapor, in Departament d’Enginyeria Química i Metal•lúrgia. 2005, Universitat de Barcelona: Barcelona. p. 172.
Ogenga, D.O., Performance of South African Calcium/Siliceous-Based Materials as Sorbents For SO2 Removal From Flue Gas, in Department of Mechanical Engineering. 2009, Tshwane University of Technology: Pretoria. p. 159.
Siagi, O.Z., Flue Gas Desulphurization Under South African Conditions, in Department of Mechanical Engineering. 2008, Tshwane University of Technology: Pretoria. p. 232.
Siagi, Z.O. and M. Mbarawa, Dissolution rate of South African calcium-based materials at constant pH. Journal of Hazardous Materials, 2009. 163(2-3): p. 678-682. DOI: https://doi.org/10.1016/j.jhazmat.2008.07.014
Xiang, G., et al., Dissolution rate of limestone for wet flue gas desulfurization in the presence of sulfite. Journal of Hazardous Materials, 2009. 168(2-3): p. 1059-1064. DOI: https://doi.org/10.1016/j.jhazmat.2009.02.156
Zainudin, N.F., et al., Study of adsorbent prepared from oil palm ash (OPA) for flue gas desulfurization. Separation and Purification Technology, 2005. 45(1): p. 50-60. DOI: https://doi.org/10.1016/j.seppur.2005.02.008
--0--
Downloads
Published
Issue
Section
License
