Laboratory study on high-temperature adsorption of HCl by dry-injection of Ca(OH)₂ in a dual-layer granular bed filter

Abstract

Combustion-generated hydrogen chloride (HCl) is considered to be a very hazardous acid gaseous pollutant. This paper presents a laboratory study on the dry adsorption of HCl. The experiments were conducted in a dual-layer granular bed filter, at gas temperatures of 500°C–700°C and n(Ca)/n(Cl)molar ratios of 1.0–5.0 using the silver nitrate titration method by dry adsorbent powders Ca(OH)₂. Mainly, the adsorption efficiency of HCl and utilization efficiency of Calcium were studied, by varying relevant factors including n(Ca)/n(Cl), temperature, feeding method, water vapor and CO₂. With a relatively higher HCl concentration of 1000 ppm, the experimental results revealed that 600°C may be the optimum temperature for HCl adsorption when optimum n(Ca)/n(Cl) was 2.5 in our tests. The results also demonstrated that the feeding at a constant pressure was more effective, and the HCl adsorption efficiency could rapidly reach over 90% with n(Ca)/n(Cl) = 2.5 at 600°C. Furthermore, the HCl adsorption efficiency was found to be slightly promoted by water vapor, while could be impeded by CO₂, and the utilization efficiency of calcium could be up to 74.4% without CO₂, while was only 36.8% with CO₂ when n(Ca)/n(Cl) was 2.5 at 600°C.

Keywords

acid gas HCl / Ca(OH)₂ / dry adsorption / high temperature / dual-layer granular bed filter

References

[1] Wey M Y, Liu K Y, Yu W J, Lin C L, Chang F Y. Influences of chlorine content on emission of HCl and organic compounds in waste incineration using fluidized beds. Waste management, 2008, 28(2): 406–415

[2] Addink R, Bakker W C M, Olie K. Influence of HCl and Cl₂ on the Formation of polychlorinated dibenzo-p-dioxins/dibenzofurans in a carbon/fly ash mixture. Environmental Science and Technology, 1995, 29(8): 2055–2058

[3] Moyeda D K, Seeker W R, England G C, Linz D G. The formation and control of PCDD/PCDF from RDF-fired combustion systems. Chemosphere, 1990, 20(10–12): 1817–1824

[4] Wunsch P, Leichsenring S, Schramm K W, Kettrup A. Temperature dependence of PCDD/F-formation in boiler ash. Chemosphere, 1994, 29(6): 1235–1243

[5] Stieglitz L, Bautz H, Roth W, Zwick G. Investigation of precursor reactions in the De-Novo-synthesis of PCDD/PCDF on fly ash. Chemosphere, 1997, 34(5–7): 1083–1090

[6] Shemwell B, Levendis Y A, Simons G A. Laboratory study on the high-temperature capture of HCl gas by dry-injection of calcium-based sorbents. Chemosphere, 2001, 42(5–7): 785–796PMID:11219704

[7] Weinell C E, Jensen P I, Johansen K D, Livbjerg H. Hydrogen chloride reaction with lime and limestone: kinetics and sorption capacity. Industrial and Engineering Chemistry Research, 1992, 31(1): 164–171

[8] Zhu H M, Jiang X G, Yan J H, Chi Y, Cen K F. TG-FTIR analysis of PVC thermal degradation and HCl removal. Journal of Analytical and Applied Pyrolysis, 2008, 82(1): 1–9

[9] Li S, Bie R. Modeling the reaction of gaseous HCl with CaO in fluidized bed. Chemical Engineering Science, 2006, 61(16): 5468–5475

[10] Wey M Y, Chen J C, Wu H Y, Yu W J, Tsai T. Formations and controls of HCl and PAHs by different additives during waste incineration. Fuel, 2006, 85(5–6): 755–763

[11] Yan R, Chin T, Liang D T, Laursen K, Ong W Y, Yao K, Tay J H. Kinetic study of hydrated lime reaction with HCl. Environmental Science and Technology, 2003, 37(11): 2556–2562

[12] Wey M Y, Liu K Y, Yu W J, Lin C L, Chang F Y. Influences of chlorine content on emission of HCl and organic compounds in waste incineration using fluidized beds. Waste Management, 2008, 28(2): 406–415

[13] Poggio A, Grieco E. Influence of flue gas cleaning system on the energetic efficiency and on the economic performance of a WTE plant. Waste Management, 2010, 30(7): 1355–1361

[14] Hsu C J, Hsiau S S. Experimental study of the gas flow behavior in the inlet of a granular bed filter. Advanced Powder Technology, 2011, 22(6): 741–752

[15] Jiang X G, Yan J H, Li X P, Liu B C, Lu S Y, Chi Y, Cen K F. Experimental study of HCl emission and removal on incinerating of typical MSW components in fluidized bed. In: Proceedings of the 18th International Conference on Fluidized Bed Combustion, Toronto, Canada, 2005, 867–872

[16] Fonseca A M, Órfão J J, Salcedo R L. Dry scrubbing of gaseous HCl with solid lime in a cyclone reactor at low temperatures. Industrial and Engineering Chemistry Research, 2001, 40(1): 304–313

[17] Chibante V G, Fonseca A M, Salcedo R R. Comparing the performance of recirculating cyclones applied to the dry scrubbing of gaseous HCl with Hydrated Lime. Industrial and Engineering Chemistry Research, 2009, 48(2): 1029–1035

[18] Chin T, Yan R, Liang D T. Study of the reaction of lime with HCl under simulated flue gas conditions using X-ray diffraction characterization and thermodynamic prediction. Industrial and Engineering Chemistry Research, 2005, 44(23): 8730–8738

[19] Chin T, Yan R, Liang D T, Tay J H. Hydrated lime reaction with HCl under simulated flue gas conditions. Industrial and Engineering Chemistry Research, 2005, 44(10): 3742–3748

[20] Yu J W, Yang G H, Tan J J, Huang S, Sheng W P, Chen Z S, Fei H J. Dechlorination Test of Modified Calcium-based Sorbent in a Dual-layer Granular Bed Filter. In: Proceedings of the International Conference on Materials for Renewable Energy and Environment, Shanghai, China, 2011, 1271–1274

[21] Fei H J, Yang G H. Hot gas desulphurization of red mud in the dual- layer granular bed filter. In: Proceedings of the Annual Conference on Electrical and Control Engineering, Yichang, China, 2011, 2355– 2358

[22] Mura G, Lallai A. On the kinetics of dry reaction between calcium oxide and gas hydrochloric acid. Chemical Engineering Science, 1992, 47(9–11): 2407–2411

[23] Partanen J, Backman P, Backman R, Hupa M. Absorption of HCl by limestone in hot flue gases. Part I: the effects of temperature, Gas atmosphere and adsorbent quality. Fuel, 2005, 84(12–13): 1664–1673

[24] Lawrence A D, Bu J. The reactions between Ca-based solids and gas representatives of those found in a fluidized-bed incinerator. Chemical Engineering Science, 2000, 55(24): 6129–6137

[25] Matsuda H, Ozawa S, Naruse K, Ito K, Kojima Y, Yanase T. Kinetics of HCl emission from inorganic chlorides in simulated municipal wastes incineration conditions. Chemical Engineering Science, 2005, 60(2): 545–552

[26] Bie R, Li S, Yang L. Reaction mechanism of CaO with HCl in incineration of wastewater in fluidized bed. Chemical Engineering Science, 2005, 60(3): 609–616

[27] Duo W, Kirkby N F, Seville J P K, Clift R. Alteration with reaction progress of the rate-limiting step for solid-gas reactions of Ca-compounds with HCl. Chemical Engineering Science, 1995, 50(13): 2017–2027

[28] Li S Y, Bie R S, Lu X R. Reaction kinetics of Ca-based sorbents with HCl in fluidized bed. Journal of Chemical Industry and Engineering, 2005, 56(2): 318–323 (in Chinese)

[29] Chyang C S, Han Y L, Zhong Z C. Study of HCl absorption by CaO at high temperature. Energy and Fuels, 2009, 23(8): 3948–3953

[30] Partanen J, Backman P, Backman R. Formation of calcium chloride and its interaction with the sand particles during fluidised bed combustion. In: Proceedings of the 17th International Conference on Fluidized Bed Combustion, Jacksonville, Florida, 2003, 579– 585

[31] Allal K M, Dolignier J C, Martin G. Reaction Mechanism of Calcium Hydroxide with Gaseous Hydrogen Chloride. Oil and Gas Science and Technology, 1998, 53(6): 871–880

[32] Partanen J, Backman P, Backman R, Hupa M. Absorption of HCl by limestone in hot flue gases. Part III: simultaneous absorption with SO₂. Fuel, 2005, 84(12–13): 1685–1694

[33] Wang R, Nie R, Deng J, Tian J G, Xu Y X, Sheng H Z. An experimental study of the effect of steam to HCl removal efficiency by CaO. Journal of Engineering Thermophysics, 2009, 30(5): 897–899(in Chinese)

[34] Zhu J Z, Hu Z H. Study on the effect of moisture on combustion and chlorine removal in solid waste incinerator. Techniques and Equipment for Environmental Pollution Control. 2006, 7(1): 41–44 (in Chinese)

[35] Wang R. The reaction mechanism of HCl removal by Cao dry process with humidification. Journal of Engineering Thermophysics, 2013, 34(3): 554–557(in Chinese)

[36] Lin Y, Wei D S, Chen D Z. Influence of CO₂ on HCl removal from high-temperature flue gas. Gas and Heat, 2006, 26(3): 19–22(in Chinese)

Acknowledgements

This work is supported by the National Basic Research Program of China (No. 2012CB417006), the National High Technology Research and Development Program of China (No. 2008AA05Z205) and the Program for Changjiang Scholars and Innovative Research Team in University (IRT1233).

RIGHTS & PERMISSIONS

2014 Higher Education Press and Springer-Verlag Berlin Heidelberg