Documents disponibles écrits par cet auteur

Effect of internal structure on flue gas mesulfurization with rapidly hydrated sorbent in a circulating fluidized bed at moderate temperatures / Jie Zhang in Industrial & engineering chemistry research, Vol. 49 N° 22 (Novembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 22 (Novembre 2010) . - pp. 11464–11470 Titre : Effect of internal structure on flue gas mesulfurization with rapidly hydrated sorbent in a circulating fluidized bed at moderate temperatures Type de document : texte imprimé Auteurs : Jie Zhang, Auteur ; Changfu You, Auteur ; Changhe Chen, Auteur Année de publication : 2011 Article en page(s) : pp. 11464–11470 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Gas  desulfurization  Sorbent Résumé : A moderate-temperature desulfurization process at 600−800 °C was studied in a pilot-scale circulating fluidized bed flue gas desulfurization (CFB-FGD) experimental facility with the addition of the internal structure. The rapidly hydrated sorbent and the desulfurization products were analyzed to clarify the influence mechanism of the internal structure on the moderate-temperature desulfurization process. The results show that the desulfurization efficiency with the internal structure at 600−800 °C was 74−93% for the calcium to sulfur (Ca/S) molar ratio of 2.0, which was higher than the desulfurization efficiency without the internal structure of 67−83%. As for the calcium-containing compositions, the desulfurization products included about 70% cyclone recirculation sample and about 30% bag filter sample. The cyclone recirculation sample was mainly composed of CaSO4 and CaO. The bag filter sample not only contained high contents of CaSO4 and CaO but also contained a considerable amount of CaCO3 and even some unreacted Ca(OH)2. With the addition of the internal structure, the calcium conversion rate of the cyclone recirculation sample greatly increased from 42.8 to 47.4% while that of the bag filter sample just increased from 29.4 to 30.7%. It demonstrated that the main contributor for the improved desulfurization efficiency was the cyclone recirculation sample due to the improved solids concentration distribution and the enhanced gas−solid contact efficiency. The calcium conversion rate for the bag filter sample depended on the solids concentration distribution as well as the particle residence time in the moderate temperature range, which indicated that prolonging the particle residence time for the fresh sorbent and the fall off calcium-containing particles was important to further improve the desulfurization performance. These results provided good guidance for realizing high desulfurization efficiency and low flow resistance in dry FGD processes. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100988r [article] Effect of internal structure on flue gas mesulfurization with rapidly hydrated sorbent in a circulating fluidized bed at moderate temperatures [texte imprimé] / Jie Zhang, Auteur ; Changfu You, Auteur ; Changhe Chen, Auteur . - 2011 . - pp. 11464–11470. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 22 (Novembre 2010) . - pp. 11464–11470 Mots-clés : Gas  desulfurization  Sorbent Résumé : A moderate-temperature desulfurization process at 600−800 °C was studied in a pilot-scale circulating fluidized bed flue gas desulfurization (CFB-FGD) experimental facility with the addition of the internal structure. The rapidly hydrated sorbent and the desulfurization products were analyzed to clarify the influence mechanism of the internal structure on the moderate-temperature desulfurization process. The results show that the desulfurization efficiency with the internal structure at 600−800 °C was 74−93% for the calcium to sulfur (Ca/S) molar ratio of 2.0, which was higher than the desulfurization efficiency without the internal structure of 67−83%. As for the calcium-containing compositions, the desulfurization products included about 70% cyclone recirculation sample and about 30% bag filter sample. The cyclone recirculation sample was mainly composed of CaSO4 and CaO. The bag filter sample not only contained high contents of CaSO4 and CaO but also contained a considerable amount of CaCO3 and even some unreacted Ca(OH)2. With the addition of the internal structure, the calcium conversion rate of the cyclone recirculation sample greatly increased from 42.8 to 47.4% while that of the bag filter sample just increased from 29.4 to 30.7%. It demonstrated that the main contributor for the improved desulfurization efficiency was the cyclone recirculation sample due to the improved solids concentration distribution and the enhanced gas−solid contact efficiency. The calcium conversion rate for the bag filter sample depended on the solids concentration distribution as well as the particle residence time in the moderate temperature range, which indicated that prolonging the particle residence time for the fresh sorbent and the fall off calcium-containing particles was important to further improve the desulfurization performance. These results provided good guidance for realizing high desulfurization efficiency and low flow resistance in dry FGD processes. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100988r

Nitrogen oxides absorption on calcium hydroxide at low temperature / Xiaowen Zhang in Industrial & engineering chemistry research, Vol. 47 n°11 (Juin 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°11 (Juin 2008) . - p. 3827–3833 Titre : Nitrogen oxides absorption on calcium hydroxide at low temperature Type de document : texte imprimé Auteurs : Xiaowen Zhang, Auteur ; Huiling Tong, Auteur ; Hu Zhang, Auteur ; Changhe Chen, Auteur Année de publication : 2008 Article en page(s) : p. 3827–3833 Note générale : Bibliogr. p. 3833 Langues : Anglais (eng) Mots-clés : Calcium  hydroxide;  Nitrogen  oxides;  Water  vapor;  Absorption  process Résumé : Solid Ca(OH)2 was used to absorb NO and NO2 with water vapor present in the flue gas. Nitrogen oxides were captured as nitrite and nitrate, and part of NO could be released into the gas as the HNO2 decomposed, which was produced in the absorption process. A mathematical model was founded to predict the process of NOx absorption and nitrite and nitrate production. With the overall kinetic parameters (OKPs) evaluated by the typical experimental result at 70 °C and 60% relative humidity, the model can simulate the experimental results at various conditions quantitatively. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie070660d [article] Nitrogen oxides absorption on calcium hydroxide at low temperature [texte imprimé] / Xiaowen Zhang, Auteur ; Huiling Tong, Auteur ; Hu Zhang, Auteur ; Changhe Chen, Auteur . - 2008 . - p. 3827–3833. Bibliogr. p. 3833 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°11 (Juin 2008) . - p. 3827–3833 Mots-clés : Calcium  hydroxide;  Nitrogen  oxides;  Water  vapor;  Absorption  process Résumé : Solid Ca(OH)2 was used to absorb NO and NO2 with water vapor present in the flue gas. Nitrogen oxides were captured as nitrite and nitrate, and part of NO could be released into the gas as the HNO2 decomposed, which was produced in the absorption process. A mathematical model was founded to predict the process of NOx absorption and nitrite and nitrate production. With the overall kinetic parameters (OKPs) evaluated by the typical experimental result at 70 °C and 60% relative humidity, the model can simulate the experimental results at various conditions quantitatively. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie070660d