High Ethylene Production through ODHE Membrane Reactors based on Fast Oxygen-Ion Conductors

This is the peer reviewed version of the following article :Lobera González, MP.; Escolástico Rozalén, S.; Serra Alfaro, JM. (2011). High Ethylene Production through ODHE Membrane Reactors based on Fast Oxygen-Ion Conductors. ChemCatChem. 3:1503-1508. doi:10.1002/cctc.201100055, which has been published in final form at http://dx.doi.org/10.1002/cctc.201100055. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] High ethylene productivity through the oxidative dehydrogenation of ethane has been achieved in a catalytic membrane reactor based on a highly solid-state oxygen permeable material (Ba0.5Sr0.5Co0.8Fe0.2O3 d). Ethylene is selectively produced by avoiding the direct contact of molecular oxygen and hydrocarbons, thereby minimizing the oxygen concentration in the reaction side. Another key aspect in the process is the dilution of ethane in the feed to achieve high ethylene yields. There exists a specific combination of the ethane concentration and feed flow that maximizes ethylene productivity, whereas the diluting gas nature has a direct impact on the formation of higher olefins and coking issues. Indeed, the use of methane as an almost-inert dilutant allows the reduction of oligomerization and aromatization of the formed ethylene and therefore improves the reactor stability even at operating temperatures from 800 to 900 8C. This behavior is attributed to the competitive adsorption of methane and ethane/ethylene, the modification of the radical-driven homogeneous reaction, and the change of partially reducible membrane surface. The productivity values achieved at 8508C were 383 mLmin 1cm 2 for Ar and 353 mLmin 1cm 2 for CH4, with a selectivity of 80 and 90%, respectivelyFinancial support by the Spanish Ministry for Science and Innovation (Project ENE2008-06302 and FPI Grant JAE-Pre 08-0058), the European Union through FP7 NASA-OTM Project (NMP3-SL-2009228701), and the Helmholtz Association of German Research Centres through the Helmholtz Alliance MEM-BRAIN (Initiative and Networking Fund) is kindly acknowledged.Lobera González, MP.; Escolástico Rozalén, S.; Serra Alfaro, JM. (2011). High Ethylene Production through ODHE Membrane Reactors based on Fast Oxygen-Ion Conductors. ChemCatChem. 3:1503-1508. https://doi.org/10.1002/cctc.201100055S15031508

Rare Earth-doped Ceria Catalysts for ODHE Reaction in a Catalytic Modified MIEC Membrane Reactor

[EN] An intensification process for the selective oxidation of hydrocarbons integrates a catalytic reactor and an oxygen separation membrane. This work presents the study of oxidative dehydrogenation of ethane at 1123 K in a catalytic membrane reactor based on mixed ionic-electronic conducting (MIEC) membranes. The surface of a membrane made of Ba0.5Sr0.5Co0.8Fe0.2O3-d has been activated using different porous catalytic layers based on rare earth-doped cerias (fluorite structure) and the porous catalytic coating was deposited by screen printing (coating around 15 mu m). The different catalyst formulations were developed by partial substitution of Ce and were synthesized by co-precipitation followed by cobalt impregnation when required. Specifically, seven different catalysts based on the system Ce1-xLnxO2-d (x=0.1 or 0.2; Ln=Tb, Pr, Er, Gd, and Tb+Er), including the effect of cobalt addition (2?% molar) in Ce0.8Tb0.2O2-d, were studied. The ceria catalysts were studied by XRD, SEM, DC-conductivity as a function of oxygen partial pressure, and the high-temperature stability in a CO2 environment was assessed using thermogravimetry. Then, the influence of the ceria catalytic coating on the oxygen permeation flux through the MIEC membrane was studied using argon and methane as the sweep gas in the permeate side. Finally, oxidative dehydrogenation of ethane reaction tests were performed at 1123 K, as a function of the ethane concentration in the feed. The use of a disk-shaped membrane in the reactor made it possible to prevent the direct contact of gaseous oxygen and hydrocarbons and thus to increase the ethylene yield. High ethylene yields (up to approximate to 84?%) were obtained using a catalytic coating based on 20?% Tb-doped ceria including macropores produced by the addition of graphite platelets in the screen printing ink. The high yields obtained in this kind of catalytic membrane are attributed to the combination of: the high catalytic activity; the control of the oxygen concentration in the gas phase (reaction chamber); and the appropriate fluid dynamics, enabling the fast ethylene evacuation.Financial support by the Spanish Ministry for Science and Innovation (ENE2011-24761 FPI BES-2009-015835 grants), EU through FP7 NASA-OTM Project (NMP3-SL-2009-228701), and the Helmholtz Association of German Research Centres through the Helmholtz Alliance MEM-BRAIN (Initiative and Networking Fund) is kindly acknowledged.Lobera González, MP.; Balaguer Ramírez, M.; García Fayos, J.; Serra Alfaro, JM. (2012). Rare Earth-doped Ceria Catalysts for ODHE Reaction in a Catalytic Modified MIEC Membrane Reactor. ChemCatChem. 4(12):2102-2111. https://doi.org/10.1002/cctc.201200212S2102211141

Ethylene Production by ODHE in Catalytic Modified Ba0.5Sr0.5Co0.8Fe0.2O3 Membrane Reactors

[EN] Process intensification by the integration of membranes and high-temperature reactors offers several advantages with regard to conventional process schemes, that is, energy saving, safe operation, reduced plant/unit size, and higher process performance, for example, higher productivity, catalytic activity, selectivity, or stability. We present the study of oxidative dehydrogenation of ethane at 850 8C on a catalytic membrane reactor based on a mixed ionic¿electronic conducting membrane. The surface of the membrane made of Ba0.5Sr0.5Co0.8Fe0.2O3 d has been activated by using different porous catalytic layers based on perovskites. The layer was deposited by screen printing, and the porosity and thickness was studied for the catalyst composition. The different catalyst formulations are based on partial substitution of A- and B-site atoms of doped strontium ferrite/cobaltites (A0.6Sr0.4Co0.5Fe0.5O3 d and Ba0.6Sr0.4BO3 d) and were synthesized by an ethylenediaminetetraacetic acid¿citrate complexation route. The use of a disk-shaped membrane in the reactor enabled the direct contact of gaseous oxygen and hydrocarbons to be avoided, and thus, the ethylene content increased. High ethylene yields (up to 81%) were obtained by using a catalytic coating based on Ba0.5Sr0.5Co0.8Fe0.2O3 d, which included macropores produced by the addition of graphite platelets into the screen-printing ink. The promising catalytic results obtained with this catalytically modified membrane reactor are attributed to the combination of 1) the high activity, as a result of the high temperature and oxygen species diffusing through the membrane; 2) the control of oxygen dosing and the low concentration of molecules in the gas phase; and 3) suitable fluid dynamics, which enables appropriate feed contact with the membrane and the rapid removal of products.Financial support by the Spanish Ministry for Science and Innovation (Project ENE2008-06302, ENE2011-24761 and FPI Grant JAE-Pre 08-0058), the EU through the FP7 NASA-OTM Project (NMP3-SL-2009-228701), and the Helmholtz Association of German Research Centres through the Helmholtz Alliance MEM-BRAIN (Initiative and Networking Fund) is kindly acknowledged. We thank S. Jimenez for material preparation, M. Fabuel for TPD experiments, and Forschungszentrum Julich for SEM analysis of BSCF catalytic layer.Lobera González, MP.; Escolástico Rozalén, S.; García Fayos, J.; Serra Alfaro, JM. (2012). Ethylene Production by ODHE in Catalytic Modified Ba0.5Sr0.5Co0.8Fe0.2O3 Membrane Reactors. ChemSusChem. 5:1587-1596. https://doi.org/10.1002/cssc.201100747S15871596

Déshydrogénation de l'éthane en réacteur membranaire céramique semi-perméable à l'oxygène

La déshydrogénation oxydante de l'éthane (ODHE) est considérée comme une alternative attrayante au vapocraquage pour la production d'éthylène. Cependant, un haut rendement en éthylène (minimum 70 %) est nécessaire en vue d'une industrialisation de ce procédé pour compenser la perte de crédits d'hydrogène. En employant l'air comme oxydant, les meilleurs catalyseurs rapportés dans la littérature n'atteignent pas à l'heure actuelle, le rendement désiré. D'autre part, en utilisant de l'air enrichi ou de l'oxygène pur, le rendement reste toujours insuffisant pour compenser le coût de l'unité de séparation de l'oxygène. Ainsi, l'utilisation de réacteurs catalytiques membranaires qui combinent séparation d'oxygène et conversion d'éthane dans une même unité semble une voie prometteuse. Le développement de céramiques d'oxydes mixtes comme membrane dense et perméable uniquement à l'oxygène ionique permet d'envisager leur emploi pour fournir une forme d'oxygène adapté au procédé de déshydrogénation sélective. L'objectif de ce travail a été premièrement de caractériser une céramique d'oxyde mixte Ba0,5 Sr0,5 Co0,8 Fe0,2 O3-[delta] modifiée ou non en surface par l'ajout de catalyseurs et plus particulièrement la semi perméabilité électrochimique à l'oxygène. Dans un second temps, les membranes ont été évaluées pour la déshydrogénation de l'éthane en éthylène et le mécanisme de cette réaction a été partiellement élucidé. En matière de performance, des résultats très encourageants ont été obtenus, avec notamment des rendements en éthylène supérieurs à 70 % ce qui a permis la rédaction de deux brevets et de plusieurs publicationsLYON1-BU.Sciences (692662101) / SudocSudocFranceF

Oxidative activation of ethane on catalytic modified dense ionic oxygen conducting membranes

A reactor using dense mixed ion electron conducting membranes was successfully studied in the oxidative dehydrogenation of ethane to ethylene. Already bare Ba0.5Sr0.5Co0.8Fe0.2O3-delta membranes allowed reasonable operation with yields beyond state-of-the-art steam cracking. The application of a surface catalyst was found to enhance performance even further. Long term stable operation and ethylene yields of about 75% were obsd. when using membranes with V/MgO micron grain or Pd nano cluster modified surfaces at temps. of 1040 or 1050 K, resp. Being one key factor for the performance of the membrane reactor, the influence of the surface catalysts on the oxygen permeation is reported in a detailed study

Oxidation in catalytic membrane reactors

International audienceThis paper presents a series of applications of catalytic membrane reactors (CMR) to oxidation reactions. Four reactions were tested in our group. Alkane activation (C2, C3 and C4) or total oxidation (WAO) is implemented in various membrane reactor modes, using dense, microporous or mesoporous membranes. In some cases, a catalyst bed is associated with a membrane, whereas other applications use an intrinsically active membrane. Progresses in catalyst and membrane design, along with careful operational conditions led to overall higher performances when compared to conventional processes