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Desulfurization of air at high and low H2S concentrations / Yehya Elsayed in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 594-602 Titre : Desulfurization of air at high and low H2S concentrations Type de document : texte imprimé Auteurs : Yehya Elsayed, Auteur ; Mykola Seredych, Auteur ; Andrew Dallas, Auteur Année de publication : 2010 Article en page(s) : pp. 594-602 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Activated  carbons  H2S  adsorption  Surface  chemistry  Pore  structure  Reactive  adsorption Index. décimale : 660 Résumé : Several commercially available coconut-based activated carbons were tested as adsorbents of hydrogen sulfide (H2S) at high and low H2S concentrations. These carbons were compared to an experimental coconut-based carbon modified by impregnation with strongly basic compounds and an oxidant. The breakthrough curves for H2S at 3000 ppm and 10 ppm were measured at room temperature. The effects of humidity and water content on H2S removal were investigated. The carbon samples were characterized before and after H2S adsorption using XRF, sorption of nitrogen, thermal analysis in combination with mass spectrometry (TGA–MS) and thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS), along with pH measurements. These methods were used to track the activated carbon surface chemical changes upon H2S adsorption/reactive adsorption. The amount of H2S adsorbed on all activated carbons was found to be dependent on the amount of surface basic groups. TGA–MS and TD–GC–MS analysis revealed H2S is adsorbed via reactive adsorption mechanisms. Metal sulfates, elemental sulfur, carbon sulfide, oxides of sulfur and dihydrogen disulfide are the products of surface reactions. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X1SBK5-3&_user=6 [...] [article] Desulfurization of air at high and low H2S concentrations [texte imprimé] / Yehya Elsayed, Auteur ; Mykola Seredych, Auteur ; Andrew Dallas, Auteur . - 2010 . - pp. 594-602. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 594-602 Mots-clés : Activated  carbons  H2S  adsorption  Surface  chemistry  Pore  structure  Reactive  adsorption Index. décimale : 660 Résumé : Several commercially available coconut-based activated carbons were tested as adsorbents of hydrogen sulfide (H2S) at high and low H2S concentrations. These carbons were compared to an experimental coconut-based carbon modified by impregnation with strongly basic compounds and an oxidant. The breakthrough curves for H2S at 3000 ppm and 10 ppm were measured at room temperature. The effects of humidity and water content on H2S removal were investigated. The carbon samples were characterized before and after H2S adsorption using XRF, sorption of nitrogen, thermal analysis in combination with mass spectrometry (TGA–MS) and thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS), along with pH measurements. These methods were used to track the activated carbon surface chemical changes upon H2S adsorption/reactive adsorption. The amount of H2S adsorbed on all activated carbons was found to be dependent on the amount of surface basic groups. TGA–MS and TD–GC–MS analysis revealed H2S is adsorbed via reactive adsorption mechanisms. Metal sulfates, elemental sulfur, carbon sulfide, oxides of sulfur and dihydrogen disulfide are the products of surface reactions. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X1SBK5-3&_user=6 [...]

Investigation of the thermal regeneration efficiency of activated carbons used in the desulfurization of model diesel fuel / Mykola Seredych in Industrial & engineering chemistry research, Vol. 50 N° 24 (Décembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp.14097–14104 Titre : Investigation of the thermal regeneration efficiency of activated carbons used in the desulfurization of model diesel fuel Type de document : texte imprimé Auteurs : Mykola Seredych, Auteur ; Juliene Rawlins, Auteur ; Teresa J. Bandosz, Auteur Année de publication : 2012 Article en page(s) : pp.14097–14104 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Thermal  regeneration Résumé : Adsorption of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (DMDBT) from model diesel fuel (MDF) was investigated on a thermally regenerated wood-based carbon and two polymer-derived carbons. The materials were characterized by thermal analysis, potentiometric titration, elemental analysis, adsorption of nitrogen, and mass spectroscopy. The selectivities of DBT and DMDBT were calculated using naphthalene as a reference. The regenerated carbons were found to be very good adsorbents for the desulfurization of MDF. Although most sulfur-containing compounds were adsorbed in the micropores, where dispersive forces govern the adsorption process, DBT and DMDBT were also retained in the larger pores as a result of acid–base and/or polar interactions. This increases the overall adsorption capacity and selectivity. Moreover, thermal regeneration of carbons containing acidic oxygen groups increases their sulfur content and, thus, the contribution of specific adsorption forces involving sulfur–sulfur interactions in both small and larger pores. A significant quantity of the DBT and DMDBT adsorbed in pores larger than 10 Å is oxidized to sulfoxides and sulfones. Sulfur functional groups likely promote this process through oxygen activation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202159a [article] Investigation of the thermal regeneration efficiency of activated carbons used in the desulfurization of model diesel fuel [texte imprimé] / Mykola Seredych, Auteur ; Juliene Rawlins, Auteur ; Teresa J. Bandosz, Auteur . - 2012 . - pp.14097–14104. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp.14097–14104 Mots-clés : Thermal  regeneration Résumé : Adsorption of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (DMDBT) from model diesel fuel (MDF) was investigated on a thermally regenerated wood-based carbon and two polymer-derived carbons. The materials were characterized by thermal analysis, potentiometric titration, elemental analysis, adsorption of nitrogen, and mass spectroscopy. The selectivities of DBT and DMDBT were calculated using naphthalene as a reference. The regenerated carbons were found to be very good adsorbents for the desulfurization of MDF. Although most sulfur-containing compounds were adsorbed in the micropores, where dispersive forces govern the adsorption process, DBT and DMDBT were also retained in the larger pores as a result of acid–base and/or polar interactions. This increases the overall adsorption capacity and selectivity. Moreover, thermal regeneration of carbons containing acidic oxygen groups increases their sulfur content and, thus, the contribution of specific adsorption forces involving sulfur–sulfur interactions in both small and larger pores. A significant quantity of the DBT and DMDBT adsorbed in pores larger than 10 Å is oxidized to sulfoxides and sulfones. Sulfur functional groups likely promote this process through oxygen activation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202159a