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Activation of methane over perovskite catalysts / Jun Li in Industrial & engineering chemistry research, Vol. 48 N°2 (Janvier 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°2 (Janvier 2009) . - p 641–646 Titre : Activation of methane over perovskite catalysts Type de document : texte imprimé Auteurs : Jun Li, Auteur ; Ling Zhao, Auteur ; Lu Guanzhong, Auteur Année de publication : 2009 Article en page(s) : p 641–646 Note générale : chemical engenireeng Langues : Anglais (eng) Mots-clés : Electrochemical  measurements Résumé : Perovskite-type catalysts group one Ln0.6Sr0.4FexCo1−xO3 (Ln = Nd, Pr, Gd, Sm, La, 0 < x < 1), (La0.8Sr0.2)0.9MnO3 and La0.8Sr0.2CrO3, and group two sodium-doped ACoO3 (Na:A = 1:4) and A0.8Na0.2MnO3 (A = La, Gd, Sm) were synthesized, and their properties for activation of methane were evaluated in a quartz reactor first. Catalysts group one presented much higher activity than catalysts group two at temperatures below 740 °C, and the main product was, however, carbon dioxide. Group two showed much higher selectivity to C2 hydrocarbons than group one. Electrochemical measurements were conducted in a solid oxide membrane reactor with sodium-doped LaCoO3 as the catalyst electrode. It was found that electrochemical supply of O2− to the catalyst film can significantly change the rate of methane consumption and C2 hydrocarbon selectivity. The total selectivity to C2 hydrocarbon exceeded 80% in the case of the electrochemical supply of oxygen. On the basis of the experimental results, a kinetic model was suggested to describe the reaction results. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8008007#afn1 [article] Activation of methane over perovskite catalysts [texte imprimé] / Jun Li, Auteur ; Ling Zhao, Auteur ; Lu Guanzhong, Auteur . - 2009 . - p 641–646. chemical engenireeng Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°2 (Janvier 2009) . - p 641–646 Mots-clés : Electrochemical  measurements Résumé : Perovskite-type catalysts group one Ln0.6Sr0.4FexCo1−xO3 (Ln = Nd, Pr, Gd, Sm, La, 0 < x < 1), (La0.8Sr0.2)0.9MnO3 and La0.8Sr0.2CrO3, and group two sodium-doped ACoO3 (Na:A = 1:4) and A0.8Na0.2MnO3 (A = La, Gd, Sm) were synthesized, and their properties for activation of methane were evaluated in a quartz reactor first. Catalysts group one presented much higher activity than catalysts group two at temperatures below 740 °C, and the main product was, however, carbon dioxide. Group two showed much higher selectivity to C2 hydrocarbons than group one. Electrochemical measurements were conducted in a solid oxide membrane reactor with sodium-doped LaCoO3 as the catalyst electrode. It was found that electrochemical supply of O2− to the catalyst film can significantly change the rate of methane consumption and C2 hydrocarbon selectivity. The total selectivity to C2 hydrocarbon exceeded 80% in the case of the electrochemical supply of oxygen. On the basis of the experimental results, a kinetic model was suggested to describe the reaction results. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8008007#afn1

Calculation of solid−liquid−gas equilibrium for binary systems containing CO2 / Jindui Hong in Industrial & engineering chemistry research, Vol. 48 N° 9 (Mai 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 9 (Mai 2009) . - pp. 4579–4586 Titre : Calculation of solid−liquid−gas equilibrium for binary systems containing CO2 Type de document : texte imprimé Auteurs : Jindui Hong, Auteur ; Hui Chen, Auteur ; Jun Li, Auteur Année de publication : 2009 Article en page(s) : pp. 4579–4586 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Solid−liquid−gas  equilibrium  Pure-solid  vapor  pressure  Pure-liquid  vapor  pressure  Semipredictive  model  GE  modelsPeng−Robinson  EoS Résumé : Two equations typically used for the pure-solid fugacity proved to be identical by selecting an appropriate relation for the pure-solid vapor pressure and the pure-liquid vapor pressure. On the basis of the pure-solid fugacity, a semipredictive model using solubility data (SMS) and a calculation model combining with GE models (CMG) were developed to calculate the solid−liquid−gas (SLG) coexistence lines of pure substances in the presence of CO2. For the SMS model, the Peng−Robinson equation of state (PR-EoS) with the van der Waals one-fluid mixing rule is used to correlate the solute solubility in CO2 to obtain the interaction parameter k12, which is further employed to predict the SLG coexistence lines by two methods: one adopts the fugacity coefficient of the solute in the liquid phase by an equation of state calculation (SMS-φ); the other uses the activity coefficient of the solute in the liquid phase calculated from the UNIFAC model (SMS-γ). For the CMG model, the PR-EoS with the linear combination of Vidal and Michelsen (LCVM) mixing rule, the Michelsen modified Huron-Vidal (MHV1) mixing rule, and a modified version (mLCVM) with the re-evaluated parameter λ = 0.18 are used. Results show that the SMS model can provide acceptable calculations of the SLG coexistence lines for most of the investigated systems. The predicted melting temperatures and solute compositions in liquid phase from a constant k12 are slightly better than those from the correlated one, while the predicted solute solubility data in CO2 from a constant k12 are worse than those from the correlated one. The CMG model with the mLCVM mixing rule calculates well the melting temperatures and solute compositions in liquid phase at SLG equilibrium and also gives acceptable calculations of the solute solubilities in supercritical CO2. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801179a [article] Calculation of solid−liquid−gas equilibrium for binary systems containing CO2 [texte imprimé] / Jindui Hong, Auteur ; Hui Chen, Auteur ; Jun Li, Auteur . - 2009 . - pp. 4579–4586. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 9 (Mai 2009) . - pp. 4579–4586 Mots-clés : Solid−liquid−gas  equilibrium  Pure-solid  vapor  pressure  Pure-liquid  vapor  pressure  Semipredictive  model  GE  modelsPeng−Robinson  EoS Résumé : Two equations typically used for the pure-solid fugacity proved to be identical by selecting an appropriate relation for the pure-solid vapor pressure and the pure-liquid vapor pressure. On the basis of the pure-solid fugacity, a semipredictive model using solubility data (SMS) and a calculation model combining with GE models (CMG) were developed to calculate the solid−liquid−gas (SLG) coexistence lines of pure substances in the presence of CO2. For the SMS model, the Peng−Robinson equation of state (PR-EoS) with the van der Waals one-fluid mixing rule is used to correlate the solute solubility in CO2 to obtain the interaction parameter k12, which is further employed to predict the SLG coexistence lines by two methods: one adopts the fugacity coefficient of the solute in the liquid phase by an equation of state calculation (SMS-φ); the other uses the activity coefficient of the solute in the liquid phase calculated from the UNIFAC model (SMS-γ). For the CMG model, the PR-EoS with the linear combination of Vidal and Michelsen (LCVM) mixing rule, the Michelsen modified Huron-Vidal (MHV1) mixing rule, and a modified version (mLCVM) with the re-evaluated parameter λ = 0.18 are used. Results show that the SMS model can provide acceptable calculations of the SLG coexistence lines for most of the investigated systems. The predicted melting temperatures and solute compositions in liquid phase from a constant k12 are slightly better than those from the correlated one, while the predicted solute solubility data in CO2 from a constant k12 are worse than those from the correlated one. The CMG model with the mLCVM mixing rule calculates well the melting temperatures and solute compositions in liquid phase at SLG equilibrium and also gives acceptable calculations of the solute solubilities in supercritical CO2. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801179a

Dynamics of CO2 absorption and desorption processes in alkanolamine with cosolvent polyethylene glycol / Jun Li in Industrial & engineering chemistry research, Vol. 51 N° 37 (Septembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12081–12088 Titre : Dynamics of CO2 absorption and desorption processes in alkanolamine with cosolvent polyethylene glycol Type de document : texte imprimé Auteurs : Jun Li, Auteur ; Chenjia You, Auteur ; Lifang Chen, Auteur Année de publication : 2012 Article en page(s) : pp. 12081–12088 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Dynamics  Absorption Résumé : To reduce the high energy consumption and equipment corrosion in conventional processes of CO2 capture with aqueous amine solutions, the mixed nonaqueous solvents of monoethanolamine (MEA), diethanolamine (DEA), and diglycolamine (DGA) with polyethylene glycol (PEG) as cosolvent were explored for CO2 capture. The dynamic experiments of CO2 absorption and desorption were carried out to evaluate the performance of the studied nonaqueous solutions. It demonstrated that the mixed solutions of amines and PEG exhibited higher CO2 cyclic capacity and regeneration efficiency compared with the only aqueous amine solutions. Especially, the solution of 3 mol/L DGA-PEG200 exhibits a high cyclic capacity of 0.438 mol CO2/mol DGA and a high regeneration efficiency of 94.6%, which indicates its great potential in industrial application. Moreover, the very low vapor pressure of PEG helps the mixed solution for CO2 capture with reduced corrosion, energy consumption, and environmental pollution. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301164v [article] Dynamics of CO2 absorption and desorption processes in alkanolamine with cosolvent polyethylene glycol [texte imprimé] / Jun Li, Auteur ; Chenjia You, Auteur ; Lifang Chen, Auteur . - 2012 . - pp. 12081–12088. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12081–12088 Mots-clés : Dynamics  Absorption Résumé : To reduce the high energy consumption and equipment corrosion in conventional processes of CO2 capture with aqueous amine solutions, the mixed nonaqueous solvents of monoethanolamine (MEA), diethanolamine (DEA), and diglycolamine (DGA) with polyethylene glycol (PEG) as cosolvent were explored for CO2 capture. The dynamic experiments of CO2 absorption and desorption were carried out to evaluate the performance of the studied nonaqueous solutions. It demonstrated that the mixed solutions of amines and PEG exhibited higher CO2 cyclic capacity and regeneration efficiency compared with the only aqueous amine solutions. Especially, the solution of 3 mol/L DGA-PEG200 exhibits a high cyclic capacity of 0.438 mol CO2/mol DGA and a high regeneration efficiency of 94.6%, which indicates its great potential in industrial application. Moreover, the very low vapor pressure of PEG helps the mixed solution for CO2 capture with reduced corrosion, energy consumption, and environmental pollution. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301164v

Effects of inlet preswirl and cell diameter and depth on honeycomb seal characteristics / Xin Yan in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 12 (Décembre 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 12 (Décembre 2010) . - 13 p. Titre : Effects of inlet preswirl and cell diameter and depth on honeycomb seal characteristics Type de document : texte imprimé Auteurs : Xin Yan, Auteur ; Jun Li, Auteur ; Zhenping Feng, Auteur Année de publication : 2011 Article en page(s) : 13 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Flow  Honeycomb  structures  Mach  number  Navier-Stokes  equations  Seals  (stoppers)  Surface  discharges Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Three-dimensional Reynolds-averaged Navier–Stokes solutions are employed to investigate the discharge and total temperature increase characteristics of the stepped labyrinth seal with honeycomb land. First, the relations between the windage heating number and the circumferential Mach number at different Reynolds numbers for different honeycomb seals are calculated and compared with the experimental data. The obtained numerical results show that the present three-dimensional periodic model can properly predict the total temperature increase in honeycomb seals. Then, a range of pressure ratios, three inlet preswirl ratios, four sizes of honeycomb cell diameter, and nine sizes of cell depth are selected to investigate the influence of inlet preswirl ratios and honeycomb geometry sizes on the discharge and total temperature increase characteristics of the stepped labyrinth seal. It shows that the leakage rate increases with the increase in cell diameter, and the cell depth has a strong influence on the discharge behavior. However, the influence of the inlet preswirl on the leakage rate is found to be little in the present study. For the total temperature increase characteristic, the inlet preswirl ratio and pressure ratio have more pronounced influence than those of cell depth and diameter. Furthermore, the relations between the leakage rate and cell depth and diameter, as well as the relations between the windage heating power and cell depth and diameter, are not monotonic functions if the pressure ratio is kept constant. DEWEY : 620.10 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Effects of inlet preswirl and cell diameter and depth on honeycomb seal characteristics [texte imprimé] / Xin Yan, Auteur ; Jun Li, Auteur ; Zhenping Feng, Auteur . - 2011 . - 13 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 12 (Décembre 2010) . - 13 p. Mots-clés : Flow  Honeycomb  structures  Mach  number  Navier-Stokes  equations  Seals  (stoppers)  Surface  discharges Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Three-dimensional Reynolds-averaged Navier–Stokes solutions are employed to investigate the discharge and total temperature increase characteristics of the stepped labyrinth seal with honeycomb land. First, the relations between the windage heating number and the circumferential Mach number at different Reynolds numbers for different honeycomb seals are calculated and compared with the experimental data. The obtained numerical results show that the present three-dimensional periodic model can properly predict the total temperature increase in honeycomb seals. Then, a range of pressure ratios, three inlet preswirl ratios, four sizes of honeycomb cell diameter, and nine sizes of cell depth are selected to investigate the influence of inlet preswirl ratios and honeycomb geometry sizes on the discharge and total temperature increase characteristics of the stepped labyrinth seal. It shows that the leakage rate increases with the increase in cell diameter, and the cell depth has a strong influence on the discharge behavior. However, the influence of the inlet preswirl on the leakage rate is found to be little in the present study. For the total temperature increase characteristic, the inlet preswirl ratio and pressure ratio have more pronounced influence than those of cell depth and diameter. Furthermore, the relations between the leakage rate and cell depth and diameter, as well as the relations between the windage heating power and cell depth and diameter, are not monotonic functions if the pressure ratio is kept constant. DEWEY : 620.10 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Effects of pressure ratio and rotational speed on leakage flow and cavity pressure in the staggered labyrinth seal / Zhigang Li in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 06 p. Titre : Effects of pressure ratio and rotational speed on leakage flow and cavity pressure in the staggered labyrinth seal Type de document : texte imprimé Auteurs : Zhigang Li, Auteur ; Jun Li, Auteur ; Xin Yan, Auteur Année de publication : 2012 Article en page(s) : 06 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Flow  simulation  Flowmeters  Navier-Stokes  equations  Numerical  analysis  Pressure  measurement  Rotational  flow  Seals  (stoppers)  Turbines  Turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Effects of pressure ratio and rotational speed on the leakage flow and cavity pressure characteristics of the rotating staggered labyrinth seal were investigated by means of experimental measurements and numerical simulations. The rotating seal test rig with turbine flowmeter and pressure measuring instruments was utilized to investigate the leakage flow of the staggered labyrinth seal at eight pressure ratios and five rotational speeds. The repeatability of the experimental data was demonstrated by three times measurements at different pressure ratios and fixed rotational speed. The three-dimensional Reynolds-averaged Navier–Stokes equations and standard k-epsilon turbulent model were also applied to study the leakage flow characteristics of the staggered labyrinth seal at the experimental conditions. The validation of the numerical approach was verified through comparison of the experimental data. The detailed flow field in the staggered labyrinth seal was illustrated according to the numerical simulations. The experimental and numerical results show that the leakage flow coefficient increases with increasing pressure ratio at the fixed rotational speed and is more sensitive to the smaller pressure ratio. The influence of rotational speed on the leakage flow coefficient is not obvious in the present rotational speed limitations. The cavity pressure coefficient in the staggered labyrinth seal decreases and is significantly influenced by the cavity structure along the flow direction. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Effects of pressure ratio and rotational speed on leakage flow and cavity pressure in the staggered labyrinth seal [texte imprimé] / Zhigang Li, Auteur ; Jun Li, Auteur ; Xin Yan, Auteur . - 2012 . - 06 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 06 p. Mots-clés : Flow  simulation  Flowmeters  Navier-Stokes  equations  Numerical  analysis  Pressure  measurement  Rotational  flow  Seals  (stoppers)  Turbines  Turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Effects of pressure ratio and rotational speed on the leakage flow and cavity pressure characteristics of the rotating staggered labyrinth seal were investigated by means of experimental measurements and numerical simulations. The rotating seal test rig with turbine flowmeter and pressure measuring instruments was utilized to investigate the leakage flow of the staggered labyrinth seal at eight pressure ratios and five rotational speeds. The repeatability of the experimental data was demonstrated by three times measurements at different pressure ratios and fixed rotational speed. The three-dimensional Reynolds-averaged Navier–Stokes equations and standard k-epsilon turbulent model were also applied to study the leakage flow characteristics of the staggered labyrinth seal at the experimental conditions. The validation of the numerical approach was verified through comparison of the experimental data. The detailed flow field in the staggered labyrinth seal was illustrated according to the numerical simulations. The experimental and numerical results show that the leakage flow coefficient increases with increasing pressure ratio at the fixed rotational speed and is more sensitive to the smaller pressure ratio. The influence of rotational speed on the leakage flow coefficient is not obvious in the present rotational speed limitations. The cavity pressure coefficient in the staggered labyrinth seal decreases and is significantly influenced by the cavity structure along the flow direction. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Experimental and numerical investigations on the leakage flow characteristics of the labyrinth brush seal / Jun Li in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 10 (Octobre 2012) 

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Investigations on the rotordynamic coefficients of pocket damper seals using the multifrequency, one-dimensional, whirling orbit model and RANS solutions / Jun Li in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 10 (Octobre 2012) 

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A novel aromatic - aliphatic copolyester of poly (ethylene - co - diethylene terephthalate) - co - poly (l-lactic acid) / Jun Li in Industrial & engineering chemistry research, Vol. 49 N° 20 (Octobre 2010) 

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Selective oxidation of cyclohexane over transition - metal - incorporated HMS in a solvent - free system / Jun Li in Industrial & engineering chemistry research, Vol. 49 N° 11 (Juin 2010) 

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Study on Mg2+ removal from ammonium dihydrogen phosphate solution by predispersed solvent extraction / JianHong Luo in Industrial & engineering chemistry research, Vol. 48 N°4 (Février 2009) 

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