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Desulfurization characteristics of waste cement particles as a sorbent in dry desulfurization / Jiawei Wu ; Atsushi Iizuka ; Kazukiyo Kumagai in Industrial & engineering chemistry research, Vol. 47 n°24 (Décembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°24 (Décembre 2008) . - p. 9871–9877 Titre : Desulfurization characteristics of waste cement particles as a sorbent in dry desulfurization Type de document : texte imprimé Auteurs : Jiawei Wu, Auteur ; Atsushi Iizuka, Auteur ; Kazukiyo Kumagai, Auteur Année de publication : 2009 Article en page(s) : p. 9871–9877 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Sulfur--Characteristics--Desulfurization Résumé : Dry desulfurization characteristics of waste cement particles were examined with laboratory-scale experimental apparatus based on the weight change of the sample exposed to a gas flow containing SO2. The waste cement particles, a byproduct of recycling aggregates from waste concrete, are fine particles with diameters ranging from 10 to 200 μm and an average diameter of 105 μm. The effects of the operation parameters, i.e., the reaction temperature (650−950 °C), SO2 concentration (61−1543 ppm), oxygen concentration (0−10%), NO2 concentration (0−500 ppm), absolute humidity (0−15000 ppm), and particle size (10−200 μm), on the desulfurization performance were investigated. The desulfurization rates were found to depend on the 1.26th order of the SO2 concentration and to slightly depend on the absolute humidity and the particle size, but they were almost independent of the concentrations of oxygen and NO2 in the gas flow. Arrhenius type temperature dependence was observed up to 850 °C with activation energy of 12 kJ/mol. The observed dry desulfurization rates of the waste cement particle were almost equivalent to those of the conventional sorbents such as limestone and calcium hydroxide. Therefore, it is confirmed that the waste cement particles could be applicable in dry desulfurization as an inexpensive sorbent derived from wastes. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8009654#afn1 [article] Desulfurization characteristics of waste cement particles as a sorbent in dry desulfurization [texte imprimé] / Jiawei Wu, Auteur ; Atsushi Iizuka, Auteur ; Kazukiyo Kumagai, Auteur . - 2009 . - p. 9871–9877. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°24 (Décembre 2008) . - p. 9871–9877 Mots-clés : Sulfur--Characteristics--Desulfurization Résumé : Dry desulfurization characteristics of waste cement particles were examined with laboratory-scale experimental apparatus based on the weight change of the sample exposed to a gas flow containing SO2. The waste cement particles, a byproduct of recycling aggregates from waste concrete, are fine particles with diameters ranging from 10 to 200 μm and an average diameter of 105 μm. The effects of the operation parameters, i.e., the reaction temperature (650−950 °C), SO2 concentration (61−1543 ppm), oxygen concentration (0−10%), NO2 concentration (0−500 ppm), absolute humidity (0−15000 ppm), and particle size (10−200 μm), on the desulfurization performance were investigated. The desulfurization rates were found to depend on the 1.26th order of the SO2 concentration and to slightly depend on the absolute humidity and the particle size, but they were almost independent of the concentrations of oxygen and NO2 in the gas flow. Arrhenius type temperature dependence was observed up to 850 °C with activation energy of 12 kJ/mol. The observed dry desulfurization rates of the waste cement particle were almost equivalent to those of the conventional sorbents such as limestone and calcium hydroxide. Therefore, it is confirmed that the waste cement particles could be applicable in dry desulfurization as an inexpensive sorbent derived from wastes. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8009654#afn1

Improvement of desulfurization performances of waste cement particles by acid treatment / Jiawei Wu in Industrial & engineering chemistry research, Vol. 48 N° 7 (Avril 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 7 (Avril 2009) . - pp. 3303–3307 Titre : Improvement of desulfurization performances of waste cement particles by acid treatment Type de document : texte imprimé Auteurs : Jiawei Wu, Auteur ; Atsushi Iizuka, Auteur ; Kazukiyo Kumagai, Auteur Année de publication : 2009 Article en page(s) : pp. 3303–3307 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Waste  cement  Desulfurization  rate  Acid  treatments Résumé : We studied the effect of acid treatments on the desulfurization rate of waste cement, a byproduct in the recycling of aggregates from waste concrete. Calcium components in the waste cement were partially extracted by treatment with carbonic acid (aqueous solution of high-pressure CO2), hydrochloric acid, or acetic acid. The desulfurization rate was examined using a thermogravimetric method. The desulfurization rates in the initial stage of the reaction (<5 min) were almost unaffected by the treatments with acetic acid and hydrochloric acid, provided the degree of calcium extraction was lower than about 30%. However, the desulfurization rates at a later stage were lower than that of the original waste cement. The desulfurization rates of the waste cement treated with carbonic acid were higher than those of the original sample for all reaction times studied when the degree of calcium extraction was in the range of 4.13−8.54%. The desulfurization rate normalized by the amount of calcium remaining in the waste cement was higher for all samples with acid treatment than for the original sample when the degree of calcium extraction was lower than 60%. The desulfurization rates of the acid-treated waste cements were significantly higher than that of limestone, a conventional sorbent used in dry desulfurization. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801312b [article] Improvement of desulfurization performances of waste cement particles by acid treatment [texte imprimé] / Jiawei Wu, Auteur ; Atsushi Iizuka, Auteur ; Kazukiyo Kumagai, Auteur . - 2009 . - pp. 3303–3307. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 7 (Avril 2009) . - pp. 3303–3307 Mots-clés : Waste  cement  Desulfurization  rate  Acid  treatments Résumé : We studied the effect of acid treatments on the desulfurization rate of waste cement, a byproduct in the recycling of aggregates from waste concrete. Calcium components in the waste cement were partially extracted by treatment with carbonic acid (aqueous solution of high-pressure CO2), hydrochloric acid, or acetic acid. The desulfurization rate was examined using a thermogravimetric method. The desulfurization rates in the initial stage of the reaction (<5 min) were almost unaffected by the treatments with acetic acid and hydrochloric acid, provided the degree of calcium extraction was lower than about 30%. However, the desulfurization rates at a later stage were lower than that of the original waste cement. The desulfurization rates of the waste cement treated with carbonic acid were higher than those of the original sample for all reaction times studied when the degree of calcium extraction was in the range of 4.13−8.54%. The desulfurization rate normalized by the amount of calcium remaining in the waste cement was higher for all samples with acid treatment than for the original sample when the degree of calcium extraction was lower than 60%. The desulfurization rates of the acid-treated waste cements were significantly higher than that of limestone, a conventional sorbent used in dry desulfurization. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801312b