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Enhanced kinetics of CO2 hydrate formation under static conditions / Junshe Zhang in Industrial & engineering chemistry research, Vol. 48 N° 13 (Juillet 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 13 (Juillet 2009) . - pp. 5934–5942 Titre : Enhanced kinetics of CO2 hydrate formation under static conditions Type de document : texte imprimé Auteurs : Junshe Zhang, Auteur ; Jae W. Lee, Auteur Année de publication : 2009 Article en page(s) : pp. 5934–5942 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : CO2  hydrate  formation  Cyclopentane  Nonstirred  batch  reactor Résumé : Trapping CO2 in hydrates is one of the new technologies for CO2 capture and storage. One of the primary obstacles to this option is the low formation rate. This work presents the rapid formation of CO2 hydrates with a small amount of cyclopentane (CP). The formation kinetics was investigated in a 474 cm3 nonstirred batch reactor with 100 and 200 cm3 of water. At volume ratios of CP to water between 0.01 and 0.1, the maximum growth rate is 0.32 mol h−1 at CO2 pressures ranging from 1.9 to 3.4 MPa and at 274 K. CO2 hydrates (sI) and CO2 + CP (sII) binary hydrates coexist at the end of hydrate growth. The mole ratio of CO2 entrapped in the sI hydrates to that in the sII binary hydrates is higher with 100 cm3 of water than with 200 cm3 of water. The same trend is also observed for the total amount of CO2 entrapped in the hydrate phase. The growth rate depends not only on the water volume but also on the pressure. The hydrate growth rate and the water conversion reach a maximum at 3.06 MPa and then decrease as the pressure increases from 1.9 to 3.4 MPa with 100 cm3 of water and 5 cm3 of CP. The water conversion to the hydrates reaches 52% within 2 h. This accelerated formation kinetics can provide a stepping-stone for developing a new hydrate-based CO2 capture and storage technique. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801170u [article] Enhanced kinetics of CO2 hydrate formation under static conditions [texte imprimé] / Junshe Zhang, Auteur ; Jae W. Lee, Auteur . - 2009 . - pp. 5934–5942. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 13 (Juillet 2009) . - pp. 5934–5942 Mots-clés : CO2  hydrate  formation  Cyclopentane  Nonstirred  batch  reactor Résumé : Trapping CO2 in hydrates is one of the new technologies for CO2 capture and storage. One of the primary obstacles to this option is the low formation rate. This work presents the rapid formation of CO2 hydrates with a small amount of cyclopentane (CP). The formation kinetics was investigated in a 474 cm3 nonstirred batch reactor with 100 and 200 cm3 of water. At volume ratios of CP to water between 0.01 and 0.1, the maximum growth rate is 0.32 mol h−1 at CO2 pressures ranging from 1.9 to 3.4 MPa and at 274 K. CO2 hydrates (sI) and CO2 + CP (sII) binary hydrates coexist at the end of hydrate growth. The mole ratio of CO2 entrapped in the sI hydrates to that in the sII binary hydrates is higher with 100 cm3 of water than with 200 cm3 of water. The same trend is also observed for the total amount of CO2 entrapped in the hydrate phase. The growth rate depends not only on the water volume but also on the pressure. The hydrate growth rate and the water conversion reach a maximum at 3.06 MPa and then decrease as the pressure increases from 1.9 to 3.4 MPa with 100 cm3 of water and 5 cm3 of CP. The water conversion to the hydrates reaches 52% within 2 h. This accelerated formation kinetics can provide a stepping-stone for developing a new hydrate-based CO2 capture and storage technique. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801170u

Estimation of still trajectory for batch reactive distillation systems / James Chin 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. 3930–3936 Titre : Estimation of still trajectory for batch reactive distillation systems Type de document : texte imprimé Auteurs : James Chin, Auteur ; Jae W. Lee, Auteur Année de publication : 2008 Article en page(s) : p. 3930–3936 Note générale : Bibliogr. p. 3936 Langues : Anglais (eng) Mots-clés : Liquid  still  trajectory;  Batch  reactive  distillation Résumé : This work addresses a new method for estimating the liquid still composition trajectory of batch reactive distillation systems based on material balance and reaction equilibrium data. The still trajectory information is essential to determining whether pure products are reachable from this still pot trajectory when several distillation boundaries are present, initial feed compositions can vary, and the number of components exceeds our visualization capability. For a given feed to product flow ratio with constant feed charge and product compositions, the still pot composition trajectory is mathematically confined to the intersection between the reaction equilibrium manifold and a “material balance plane” that is the union of stoichiometric lines and material balance rays connecting still and product compositions. Starting from this estimated still pot trajectory, we can easily extend feasibility studies of various batch reactive distillation configurations even for multireaction systems. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0713947 [article] Estimation of still trajectory for batch reactive distillation systems [texte imprimé] / James Chin, Auteur ; Jae W. Lee, Auteur . - 2008 . - p. 3930–3936. Bibliogr. p. 3936 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°11 (Juin 2008) . - p. 3930–3936 Mots-clés : Liquid  still  trajectory;  Batch  reactive  distillation Résumé : This work addresses a new method for estimating the liquid still composition trajectory of batch reactive distillation systems based on material balance and reaction equilibrium data. The still trajectory information is essential to determining whether pure products are reachable from this still pot trajectory when several distillation boundaries are present, initial feed compositions can vary, and the number of components exceeds our visualization capability. For a given feed to product flow ratio with constant feed charge and product compositions, the still pot composition trajectory is mathematically confined to the intersection between the reaction equilibrium manifold and a “material balance plane” that is the union of stoichiometric lines and material balance rays connecting still and product compositions. Starting from this estimated still pot trajectory, we can easily extend feasibility studies of various batch reactive distillation configurations even for multireaction systems. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0713947

Inhibition effect of surfactants on CO2 enclathration with cyclopentane in an unstirred batch reactor / Junshe Zhang 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. 4703–4709 Titre : Inhibition effect of surfactants on CO2 enclathration with cyclopentane in an unstirred batch reactor Type de document : texte imprimé Auteurs : Junshe Zhang, Auteur ; Jae W. Lee, Auteur Année de publication : 2009 Article en page(s) : pp. 4703–4709 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Sodium  dodecyl  sulfate  Cetyl  trimethylammonium  bromide  Fatty  alcohol  EO/PO  CO2  absorption Résumé : The effect of sodium dodecyl sulfate (SDS), cetyl trimethylammonium bromide (CTAB), and fatty alcohol EO/PO derivative (LS54) on unsteady-state CO2 absorption in the metastable region of CO2 hydrates and CO2 enclathration with cyclopentane (CP) was investigated in an unstirred batch reactor. These surfactants have no measurable effect on the mass transfer of CO2 across the gas−liquid interface into water. However, they retard CO2 enclathration, and this inhibition effect becomes significant at 200 ppm of SDS and 100 ppm of LS54 or CTAB. A layer of clathrate hydrates is visually observed if charging CO2 and CP sequentially. Even though this layer cannot be macroscopically detected when swapping the order of CO2 and CP charge, the existence of this layer can be inferred from the unchanged pressure profile. This layer prevents CO2 from contacting with water and thus delays CO2 enclathration. The habit of clathrate hydrates growing along the reactor wall without agitation is discussed based on the magnitude of temperature spikes at the initial stage of the enclathration. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8019328 [article] Inhibition effect of surfactants on CO2 enclathration with cyclopentane in an unstirred batch reactor [texte imprimé] / Junshe Zhang, Auteur ; Jae W. Lee, Auteur . - 2009 . - pp. 4703–4709. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 10 (Mai 2009) . - pp. 4703–4709 Mots-clés : Sodium  dodecyl  sulfate  Cetyl  trimethylammonium  bromide  Fatty  alcohol  EO/PO  CO2  absorption Résumé : The effect of sodium dodecyl sulfate (SDS), cetyl trimethylammonium bromide (CTAB), and fatty alcohol EO/PO derivative (LS54) on unsteady-state CO2 absorption in the metastable region of CO2 hydrates and CO2 enclathration with cyclopentane (CP) was investigated in an unstirred batch reactor. These surfactants have no measurable effect on the mass transfer of CO2 across the gas−liquid interface into water. However, they retard CO2 enclathration, and this inhibition effect becomes significant at 200 ppm of SDS and 100 ppm of LS54 or CTAB. A layer of clathrate hydrates is visually observed if charging CO2 and CP sequentially. Even though this layer cannot be macroscopically detected when swapping the order of CO2 and CP charge, the existence of this layer can be inferred from the unchanged pressure profile. This layer prevents CO2 from contacting with water and thus delays CO2 enclathration. The habit of clathrate hydrates growing along the reactor wall without agitation is discussed based on the magnitude of temperature spikes at the initial stage of the enclathration. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8019328

Methane enclathration with sodium dodecyl sulfate: effect of cyclopentane and two salts on formation kinetics / Junshe S. Zhang in Industrial & engineering chemistry research, Vol. 49 N° 17 (Septembre 1, 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 17 (Septembre 1, 2010) . - pp 8267–8270 Titre : Methane enclathration with sodium dodecyl sulfate: effect of cyclopentane and two salts on formation kinetics Type de document : texte imprimé Auteurs : Junshe S. Zhang, Auteur ; Jo A. Salera, Auteur ; Jae W. Lee, Auteur Année de publication : 2010 Article en page(s) : pp 8267–8270 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Methane  Sodium  Dodecyl  Kinetics. Résumé : This work presents the effect of NaCl and NaClO4 on the kinetics of methane enclathration with cyclopentane (CP) and sodium dodecyl sulfate (SDS) in a nonstirred batch reactor. Methane and 1 cm3 of CP were charged sequentially to 150 cm3 of solutions in a high-pressure vessel and the reaction system was cooled down to 274.6 K with an initial pressure of 7.1 MPa. Hydrates are visually observed within 1 h after the onset of cooling at a SDS concentration range of 0−200 ppm. At the end of a growth period of 2.5 h, the pressure reduces to 6.4 MPa for SDS concentrations below 20 ppm, whereas it decreases to 3.2 MPa for SDS concentrations above 50 ppm without any salts, which is very close to the hydrate equilibrium pressure. With 20 ppm SDS and 1 cm3 of CP, the average enclathration rate maximizes at 1.0 mM NaCl or 5.0 mM NaClO4 as the salt concentration increases from 0 to 100 mM. However, with 100 ppm SDS, it decreases monotonically with the increased salt concentration. These results not only provide an implication of reducing the SDS dosage (down to 50 ppm or less) in regard to fast enclathration but also further our understanding of the promoting role of surfactants. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100759p [article] Methane enclathration with sodium dodecyl sulfate: effect of cyclopentane and two salts on formation kinetics [texte imprimé] / Junshe S. Zhang, Auteur ; Jo A. Salera, Auteur ; Jae W. Lee, Auteur . - 2010 . - pp 8267–8270. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 17 (Septembre 1, 2010) . - pp 8267–8270 Mots-clés : Methane  Sodium  Dodecyl  Kinetics. Résumé : This work presents the effect of NaCl and NaClO4 on the kinetics of methane enclathration with cyclopentane (CP) and sodium dodecyl sulfate (SDS) in a nonstirred batch reactor. Methane and 1 cm3 of CP were charged sequentially to 150 cm3 of solutions in a high-pressure vessel and the reaction system was cooled down to 274.6 K with an initial pressure of 7.1 MPa. Hydrates are visually observed within 1 h after the onset of cooling at a SDS concentration range of 0−200 ppm. At the end of a growth period of 2.5 h, the pressure reduces to 6.4 MPa for SDS concentrations below 20 ppm, whereas it decreases to 3.2 MPa for SDS concentrations above 50 ppm without any salts, which is very close to the hydrate equilibrium pressure. With 20 ppm SDS and 1 cm3 of CP, the average enclathration rate maximizes at 1.0 mM NaCl or 5.0 mM NaClO4 as the salt concentration increases from 0 to 100 mM. However, with 100 ppm SDS, it decreases monotonically with the increased salt concentration. These results not only provide an implication of reducing the SDS dosage (down to 50 ppm or less) in regard to fast enclathration but also further our understanding of the promoting role of surfactants. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100759p