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Effects of coal interaction with supercritical CO2 / Benson B. Gathitu in Industrial & engineering chemistry research, Vol. 48 N° 10 (Mai 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 10 (Mai 2009) . - pp. 5024–5034 Titre : Effects of coal interaction with supercritical CO2 : physical structure Type de document : texte imprimé Auteurs : Benson B. Gathitu, Auteur ; Wei-Yin Chen, Auteur ; Michael McClure, Auteur Année de publication : 2009 Article en page(s) : pp. 5024–5034 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Coal  Gas  sorption  technique  Scanning  electron  microscope  CO2 Résumé : It is known that polar solvents swell coal, break hydrogen-bonds in the macromolecular structure, and enhance coal liquefaction efficiencies. The effects of drying, interaction with supercritical CO2 and degassing on the physical structure of coal have been studied using gas sorption technique and a scanning electron microscope (SEM). Both drying and interaction with supercritical CO2 drastically change the micropore and mesopore surface area, absolute volume, and volume distribution in both bituminous coal and lignite. Degassing removes debris in the pore space which allows for better analysis of the changes in the morphology that were induced by drying and exposure to supercritical CO2. SEM reveals that interaction of bituminous coal with supercritical CO2 results in an abundance of carbon structures similar to the maceral collinite. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9000162 [article] Effects of coal interaction with supercritical CO2 : physical structure [texte imprimé] / Benson B. Gathitu, Auteur ; Wei-Yin Chen, Auteur ; Michael McClure, Auteur . - 2009 . - pp. 5024–5034. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 10 (Mai 2009) . - pp. 5024–5034 Mots-clés : Coal  Gas  sorption  technique  Scanning  electron  microscope  CO2 Résumé : It is known that polar solvents swell coal, break hydrogen-bonds in the macromolecular structure, and enhance coal liquefaction efficiencies. The effects of drying, interaction with supercritical CO2 and degassing on the physical structure of coal have been studied using gas sorption technique and a scanning electron microscope (SEM). Both drying and interaction with supercritical CO2 drastically change the micropore and mesopore surface area, absolute volume, and volume distribution in both bituminous coal and lignite. Degassing removes debris in the pore space which allows for better analysis of the changes in the morphology that were induced by drying and exposure to supercritical CO2. SEM reveals that interaction of bituminous coal with supercritical CO2 results in an abundance of carbon structures similar to the maceral collinite. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9000162

Effects of pretreatment of coal by CO2 on nitric Oxide emission and unburned carbon in various combustion environments / Benson B. Gathitu in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10364–10374 Titre : Effects of pretreatment of coal by CO2 on nitric Oxide emission and unburned carbon in various combustion environments Type de document : texte imprimé Auteurs : Benson B. Gathitu, Auteur ; Wei-Yin Chen, Auteur Année de publication : 2010 Article en page(s) : pp. 10364–10374 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Effects--Pretreatment--CO2--Nitric  Oxide--Emission--Unburned--Carbon--Various--Combustion--Environments Résumé : Polar solvents are known to swell coal, break hydrogen bonds in the macromolecular structure, and enhance coal liquefaction efficiencies. The effects of the pretreatment of coal using supercritical CO2 on its physical structure and combustion properties have been studied at the bench-scale level. Emphasis has been placed on NO reburning, NO emissions during air-fired and oxy-fired combustion, and loss on ignition (LOI). Pretreatment was found to increase porosity and to significantly alter the fuel nitrogen reaction pathways. Consequently, NO reduction during reburning using bituminous coal increased, and NO emissions during oxidation of lignite decreased. These two benefits were achieved without negative impacts on LOI. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901069k [article] Effects of pretreatment of coal by CO2 on nitric Oxide emission and unburned carbon in various combustion environments [texte imprimé] / Benson B. Gathitu, Auteur ; Wei-Yin Chen, Auteur . - 2010 . - pp. 10364–10374. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10364–10374 Mots-clés : Effects--Pretreatment--CO2--Nitric  Oxide--Emission--Unburned--Carbon--Various--Combustion--Environments Résumé : Polar solvents are known to swell coal, break hydrogen bonds in the macromolecular structure, and enhance coal liquefaction efficiencies. The effects of the pretreatment of coal using supercritical CO2 on its physical structure and combustion properties have been studied at the bench-scale level. Emphasis has been placed on NO reburning, NO emissions during air-fired and oxy-fired combustion, and loss on ignition (LOI). Pretreatment was found to increase porosity and to significantly alter the fuel nitrogen reaction pathways. Consequently, NO reduction during reburning using bituminous coal increased, and NO emissions during oxidation of lignite decreased. These two benefits were achieved without negative impacts on LOI. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901069k