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Hydroxyl sodalite (Na8Al6Si6O24(OH)2) and hydrogrossular (Ca3Al2(SiO4)0.8(OH)8.8) were investigated for the purpose of developing new ecofunctional ceramics with removal performance for toxic substances present in waste combustion gas. It was found that these materials had functions of chlorine fixation, copper fixation and the control of dioxin formation. Hydroxyl sodalite had nanometer-sized micropores (β-cage) in the structure, and the chloride ions were fixed in the pores above 400◦C. The amount of chlorine that was fixed increased with increasing reaction temperature and was greatest, 7.3wt%, at 800◦C. The fixation of the copper progressed by the substitution with sodium ion, and the substitution quantity increased with increasing reaction temperature. The amount of copper fixed as CuO at 900◦C was 10.5wt%. On the other hand, hydrogrossular changed to the mayenite phase (Ca12Al10Si4O35) after heating to above 700◦C. Mayenite had micropores in the structure, which were fixed by the chloride ions. A drastic decrease in the concentration of dioxins was confirmed by introducing the ecofunctional ceramics, hydroxyl sodalite and hydrogrossular, in the municipal solid waste incineration.
chlorine, copper fixation, dioxin, hydrogrossular, hydroxyl sodalite, oxidative catalyst, waste combustion gas
[1] Choudhry, G., Olie, K. & Hutzinger, O., Chlorinated Dioxins and Related Compounds-Impact on the Environment, Pergamon Press: New York, pp. 275–301, 1982.
[2] Addink, R. & Olie, K., Mechanisms of formation and destruction of polychlorinated dibenzop-dioxins and dibenzofurans in heterogeneous systems. Environmental Science & Technology, 29, pp. 1425–1435, 1995.
[3] Gordon, M., Dioxin characterisation, formation and minimisation during municipal solid waste (MSW) incineration: review. Chemical Engineering Journal, 86, pp. 343–368, 2002.
[4] Stanmore, B.R., The formation of dioxins in combustion systems. Combustion and Flame, 136, pp. 398–427, 2004.
[5] Daoudi, M. & Walters, J.K.,Athermogravimetric study of the reaction of hydrogen chloride gas with calcined limestone: determination of kinetic parameters. Chemical Engineering Journal, 47, pp. 1–9, 1991.
[6] Daoudi, M. & Walters, J.K., The reaction of HCl gas with calcined commercial limestone particles: the effect of particle size. Chemical Engineering Journal, 47, pp. 11–16, 1991.
[7] Mura, G. & Lallai, A., On the kinetics of dry reaction between calcium oxide and gas hydrochloric acid. Chemical Engineering Science, 47, pp. 2407–2411, 1992.
[8] Uchida, T., Itoh, I. & Harada, K., Immobilization of heavy metals contained in incinerator fly ash by application of soluble phosphate – treatment and disposal cost reduction by combined use of ‘high specific surface area lime’. Waste Management, 16, pp. 475–481, 1996.
[9] Bodénan, F. & Deniard, Ph., Characterization of flue gas cleaning residues from European solid waste incinerators: assessment of various Ca-based sorbent processes. Chemosphere, 51, pp. 335–347, 2003.
[10] Tejima, H., Nakagawa, I., Shinoda, T. & Maeda, I., PCCDs/PCDFs reduction by good combustion technology and fabric filter with/without activated carbon injection. Chemosphere, 32, pp. 169–175, 1996.
[11] Furubayashi, M., Shinohara, R. & Nagai, K., Study of dioxin removal by activated carbon. Kagaku Kogaku Ronbunshu, 27, pp. 236–242, 2001 (in Japanese, with English abstract).
[12] Okajima, S., Kojima, T., Ueoka, S. & Ozaki, H., Fixed-bed adsorption of polychlorinated dibenzo-p-dioxins and dibenzofurans from the flue gas of a municipal solid waste incinerator. Organohalogen Compounds, 54, pp. 193–196, 2001.
[13] Furubayashi, M. & Nagai, K., Estimation of dioxins removal efficiency by activated carbon. Kagaku Kogaku Ronbunshu, 30, pp. 54–64, 2004 (in Japanese, with English abstract).
[14] Everaert, K. & Baeyens, J., Removal of PCDD/F from flue gases in fixed or moving bed adsorbers. Waste Management, 24, pp. 37–42, 2004.
[15] Ok, G., Hanai, Y. & Katou, T., Decomposition of chlorinated dioxins, odorous compounds and NOx from MSW incineration plant by oxidizing catalyst. Chemosphere, 26, pp. 2167–2172, 1993.
[16] Fujii, T., Murakawa, T., Maeda, N., Kondo, M., Nagai, K., Hama, T. & Ota, K., Removal technology of PCDDs/PCDFs in flue gas from MSW incinerators by fabric bag filter and SCR system. Chemosphere, 29, pp. 2067–2070, 1994.
[17] Ide, Y., Kashiwabara, K., Okada, S., Mori, T. & Hara, M., Catalytic decomposition of dioxin from MSW incinerator flue gas. Chemosphere, 32, pp. 189–198, 1996.
[18] Weber, R., Sakurai, T. & Hagenmaier, H., Low temperature decomposition of PCDD/ PCDF, chlorobenzenes and PAHs by TiO2-based V2O5–WO3 catalysts. Applied Catalysis B: Environmental, 20, pp. 249–256, 1999.
[19] Liu, Y., Luo, M., Wei, Z., Xin, Q., Ying, P. & Li, C., Catalytic oxidation of chlorobenzene on supported manganese oxide catalysts.AppliedCatalysisB:Environmental, 29, pp. 61–67, 2001.
[20] Yim, S.D., Koh, D.J. & Nam, I.S., A pilot plant study for catalytic decomposition of PCDDs/ PCDFs over supported chromium oxide catalysts. Catalysis Today, 75, pp. 269–276, 2002.
[21] Ukisu, Y. & Miyadera, T., Dechlorination of polychlorinated dibenzo-p-dioxins catalyzed by noble metal catalysts under mild conditions. Chemosphere, 46, pp. 507–510, 2002.
[22] Okumura, M., Akita, T., Haruta, M., Wang, X., Kajikawa, O. & Okada, O., Multi-component noblemetalcatalystspreparedbysequentialdepositionprecipitationforlowtemperaturedecomposition of dioxin. Applied Catalysis B: Environmental, 41, pp. 43–52, 2003.
[23] Suzuki,K.,Shibasaki,Y.,Fujita,S.,Yamasaki,T.,Ogawa,N.,Fukuda,T.&Sataka,S.,Hydrogen chloride removal by hydroxyl sodalite or hydrogrossular at high temperature. Advances in Science and Technology, 34, pp. 345–356, 2003.
[24] Fujita, S., Suzuki, K., Ohkawa, M., Shibasaki, Y. & Mori, T., Reaction of hydrogrossular with hydrogen chloride gas at high temperature. Chemistry of Materials, 13, pp. 2523–2527, 2001.
[25] Fujita, S., Suzuki, K., Mori, T. & Shibasaki, Y., A new technique to remove hydrogen chloride gas at high temperature using hydrogrossular. Industrial & Engineering Chemistry Research, 42, pp. 1023–1027, 2003.
[26] Brian, K.G., Wojciech, J. & Leonard, A.S., Reaction kinetics of Ca-based sorbents with HCl. Industrial & Engineering Chemistry Research, 31, pp. 2437–2446, 1992.
[27] Barin,I.,Sauert,F.,Shultze-Rhonhof,E.&Wang,S.,ThermochemicalDataofPureSubstances, VCH Publishers: Weinheim, Germany, 1989.
[28] Duo, W., Sevill, J.P.K., Kirkby, N.F. & Clift, R., Formation of product layers in solid-gas reactions for removal of acid gases. Chemistry of Engineering Science, 49, pp. 4429–4442, 1994.
[29] Gullett, B.K., Bruce, K.R., Beach, L.O. & Drago, A.M., Mechanistic steps in the production of PCDD during waste combustion. Chemosphere, 25, pp. 1387–1392, 1992.
[30] Ismo, H., Kari, T. & Juhani, R., Formation of aromatic chlorinated compounds catalyzed by copper and iron. Chemosphere, 34, pp. 2649–2662, 1997.
[31] Hatanaka,T.,Kitajima,A.&Takeuchi,M.,Roleofcopperchlorideintheformationofpolychlorinated dibenzo-p-dioxins and dibenzofurans during incineration. Chemosphere, 57, pp. 73–79, 2004.
[32] Fujita, S., Suzuki, K., Ohkawa, M., Mori, T., Iida, Y., Miwa, Y., Masuda, H., & Shimada, S., Oxidative destruction of hydrocarbons over a new zeolite-like Ca12Al10Si4O35 crystal including O−2 and O22− radicals. Chemistry of Materials, 15, pp. 255–263, 2003.
[33] Fujita, S., Ohkawa, M., Suzuki, K., Nakano, H., Mori,T. & Masuda, H., Controlling the quantity of radical oxygen occluded in a new aluminum silicate with nanopores. Chemistry of Materials, 15, pp. 4879–4881, 2003.