WorldWideScience

Sample records for catalytic membrane reactors

  1. Novel Catalytic Membrane Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Stuart Nemser, PhD

    2010-10-01

    There are many industrial catalytic organic reversible reactions with amines or alcohols that have water as one of the products. Many of these reactions are homogeneously catalyzed. In all cases removal of water facilitates the reaction and produces more of the desired chemical product. By shifting the reaction to right we produce more chemical product with little or no additional capital investment. Many of these reactions can also relate to bioprocesses. Given the large number of water-organic compound separations achievable and the ability of the Compact Membrane Systems, Inc. (CMS) perfluoro membranes to withstand these harsh operating conditions, this is an ideal demonstration system for the water-of-reaction removal using a membrane reactor. Enhanced reaction synthesis is consistent with the DOE objective to lower the energy intensity of U.S. industry 25% by 2017 in accord with the Energy Policy Act of 2005 and to improve the United States manufacturing competitiveness. The objective of this program is to develop the platform technology for enhancing homogeneous catalytic chemical syntheses.

  2. Inorganic membranes and catalytic reactors

    OpenAIRE

    Rangel, Maria do Carmo

    1997-01-01

    Membrane reactors are reviewed with emphasis in their applications in catalysis field. The basic principles of these systems are presented as well as a historical development. The several kinds of catalytic membranes and their preparations are discussed including the problems, needs and challenges to be solved in order to use these reactors in commercial processes. Some applications of inorganic membrane reactors are also shown. It was concluded that these systems have a great potential for i...

  3. Novel Catalytic Membrane Reactors

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-02-01

    This factsheet describes a research project that will focus on the development and application of nonporous high gas flux perfluoro membranes with high temperature rating and excellent chemical resistance.

  4. Electro-catalytic membrane reactors and the development of bipolar membrane technology

    NARCIS (Netherlands)

    Balster, J.H.; Stamatialis, Dimitrios; Wessling, Matthias

    2004-01-01

    Membrane reactors are currently under extensive research and development. Hardly any concept, however, is realized yet in practice. Frequently, forgotten as membrane reactors are electro-catalytic membrane reactors where electrodes perform chemical conversations and membranes separate the locations

  5. Dense ceramic catalytic membranes and membrane reactors for energy and environmental applications.

    Science.gov (United States)

    Dong, Xueliang; Jin, Wanqin; Xu, Nanping; Li, Kang

    2011-10-21

    Catalytic membrane reactors which carry out separation and reaction in a single unit are expected to be a promising approach to achieve green and sustainable chemistry with less energy consumption and lower pollution. This article presents a review of the recent progress of dense ceramic catalytic membranes and membrane reactors, and their potential applications in energy and environmental areas. A basic knowledge of catalytic membranes and membrane reactors is first introduced briefly, followed by a short discussion on the membrane materials including their structures, composition and strategies for material development. The configuration of catalytic membranes, the design of membrane reaction processes and the high temperature sealing are also discussed. The performance of catalytic membrane reactors for energy and environmental applications are summarized and typical catalytic membrane reaction processes are presented and discussed. Finally, current challenges and difficulties related to the industrialization of dense ceramic membrane reactors are addressed and possible future research is also outlined.

  6. Reverse flow catalytic membrane reactors for energy efficient syngas production

    OpenAIRE

    Smit, Joris

    2006-01-01

    To improve the recuperative heat exchange, a Reverse Flow Catalytic Membrane Reactor (RFCMR) with porous membranes is proposed in this thesis, in which very efficient heat exchange between the feed and product streams is achieved by using the reverse flow concept (i.e. periodic alternation of the flow direction of the gas through a fixed catalyst bed).

  7. Reverse flow catalytic membrane reactors for energy efficient syngas production

    NARCIS (Netherlands)

    Smit, Joris

    2006-01-01

    To improve the recuperative heat exchange, a Reverse Flow Catalytic Membrane Reactor (RFCMR) with porous membranes is proposed in this thesis, in which very efficient heat exchange between the feed and product streams is achieved by using the reverse flow concept (i.e. periodic alternation of the

  8. Catalytic Dehydrogenation of Ethane in Hydrogen Membrane Reactor

    Science.gov (United States)

    Galuszka, Jan; Giddings, Terry; Clelland, Ian

    The effect of a hydrogen permselective membrane (H-membrane) reactor on catalytic dehydrogenation of ethane was assessed using a fixed bed conventional reactor and a double tubular H-membrane reactor. A 5.0wt.% Cr2O3/γ-Al2O3 catalyst prepared by incipient wetness impregnation of a γ-Al2O3 (BET surface area = 50 m2/g) support was used at 555°C and 600°C. Although about 40% of H2 produced during dehydrogenation of ethane in the membrane reactor passed through the membrane, only moderate enhancement in ethane conversion was observed. The slow processes on the catalyst surface are thought to counterbalance the positive effect of membrane assisted hydrogen removal. Also, decreased selectivity to ethylene due to enhanced carbon formation in the membrane reactor led to faster deactivation of the catalyst. A strategy for commercialization of catalytic dehydrogenation of ethane through the development of a better hydrogen membrane might require a reevaluation.

  9. Catalytic membrane reactor for water and wastewater treatment

    Science.gov (United States)

    Heng, Samuel

    A double membrane reactor was fabricated and assessed for continuous treatment of water containing organic contaminants by ozonation. This innovative reactor consisted of a zeolite membrane prepared on the inner surface of a porous a-alumina support, which served as water selective extractor and active contactor, and a porous stainless membrane which was the ozone gas diffuser. The coupling of membrane separation and chemical oxidation was found to be highly beneficial to both processes. The total organic carbon (TOC) removal rate at the retentate was enhanced by up to 2.2 times, as compared to membrane ozonation. Simultaneously, clean water (membrane support, was shown to further enhance TOC degradation, permeated TOC concentration, permeate flux, and moreover, ozone yield. The achievements of this project included: (1) The development of a novel low-temperature zeolite membrane activation method that generates consistently high quality membranes (i.e. high reproducibility and fewer defects). (2) The demonstration that gamma-alumina and gamma-alumina supported catalysts do not have significant activity and that the TOC removal enhancement usually observed during catalytic ozonation was due primarily to the contribution of adsorption and metal leaching. Thermogravimetric analysis (TGA) and elemental analysis (EA) of the spent catalyst showed that, during catalytic ozonation, oxygenated by-products of increased adsorbability were concentrated onto the gamma-alumina contactor, and were subsequently degraded. (3) The development of a method for coating high surface area gamma-alumina layers onto the grains of zeolite membrane support used as the active membrane contactor.

  10. Solid state oxygen anion and electron mediating membrane and catalytic membrane reactors containing them

    Science.gov (United States)

    Schwartz, Michael; White, James H.; Sammels, Anthony F.

    2000-01-01

    This invention relates to gas-impermeable, solid state materials fabricated into membranes for use in catalytic membrane reactors. This invention particularly relates to solid state oxygen anion- and electron-mediating membranes for use in catalytic membrane reactors for promoting partial or full oxidation of different chemical species, for decomposition of oxygen-containing species, and for separation of oxygen from other gases. Solid state materials for use in the membranes of this invention include mixed metal oxide compounds having the brownmillerite crystal structure.

  11. Lipase immobilized catalytically active membrane for synthesis of lauryl stearate in a pervaporation membrane reactor.

    Science.gov (United States)

    Zhang, Weidong; Qing, Weihua; Ren, Zhongqi; Li, Wei; Chen, Jiangrong

    2014-11-01

    A composite catalytically active membrane immobilized with Candida rugosa lipase has been prepared by immersion phase inversion technique for enzymatic synthesis of lauryl stearate in a pervaporation membrane reactor. SEM images showed that a "sandwich-like" membrane structure with a porous lipase-PVA catalytic layer uniformly coated on a polyvinyl alcohol (PVA)/polyethersulfone (PES) bilayer was obtained. Optimum conditions for lipase immobilization in the catalytic layer were determined. The membrane was proved to exhibit superior thermal stability, pH stability and reusability than free lipase under similar conditions. In the case of pervaporation coupled synthesis of lauryl stearate, benefited from in-situ water removal by the membrane, a conversion enhancement of approximately 40% was achieved in comparison to the equilibrium conversion obtained in batch reactors. In addition to conversion enhancement, it was also found that excess water removal by the catalytically active membrane appears to improve activity of the lipase immobilized. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Oxygen transport membrane system and method for transferring heat to catalytic/process reactors

    Science.gov (United States)

    Kelly, Sean M; Kromer, Brian R; Litwin, Michael M; Rosen, Lee J; Christie, Gervase Maxwell; Wilson, Jamie R; Kosowski, Lawrence W; Robinson, Charles

    2014-01-07

    A method and apparatus for producing heat used in a synthesis gas production is provided. The disclosed method and apparatus include a plurality of tubular oxygen transport membrane elements adapted to separate oxygen from an oxygen containing stream contacting the retentate side of the membrane elements. The permeated oxygen is combusted with a hydrogen containing synthesis gas stream contacting the permeate side of the tubular oxygen transport membrane elements thereby generating a reaction product stream and radiant heat. The present method and apparatus also includes at least one catalytic reactor containing a catalyst to promote the stream reforming reaction wherein the catalytic reactor is surrounded by the plurality of tubular oxygen transport membrane elements. The view factor between the catalytic reactor and the plurality of tubular oxygen transport membrane elements radiating heat to the catalytic reactor is greater than or equal to 0.5.

  13. Catalytic membrane-installed microchannel reactors for one-second allylic arylation.

    Science.gov (United States)

    Yamada, Yoichi M A; Watanabe, Toshihiro; Torii, Kaoru; Uozumi, Yasuhiro

    2009-10-07

    A variety of catalytic membranes of palladium-complexes with linear polymer ligands were prepared inside a microchannel reactor via coordinative and ionic molecular convolution to provide catalytic membrane-installed microdevices, which were applied to the instantaneous allylic arylation reaction of allylic esters and aryl boron reagents under microflow conditions to afford the corresponding coupling products within 1 second of residence time.

  14. Solid state proton and electron mediating membrane and use in catalytic membrane reactors

    Science.gov (United States)

    White, James H.; Schwartz, Michael; Sammells, Anthony F.

    1998-01-01

    This invention provides catalytic proton and electron mediating membranes useful in catalytic reactors. The membranes have an oxidation and a reduction surface and comprise a single-phase mixed metal oxide material of the formula: AB.sub.1-x B'.sub.x O.sub.3-y wherein A is selected from Ca, Sr or Ba ions; B is selected from Ce, Tb, Pr, or Th ions; B' is selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Al, Ga, or In ions, or combinations thereof; and x is greater than or equal to 0.02 and less than or equal to 0.5. The membranes can further comprise a catalyst on either the oxidation or reduction surface, or both. Membranes include those which are fabricated-by combining powders of metal oxides or metal carbonates of metal A ion, metal B ion and metal B' ion such that the stoichiometric ratio A:B:B' is 1:1-x:x where 0.2.ltoreq..times.0.5, repeatedly calcining and milling the combined powders until a single-phase material is obtained and pressing and sintering the singlephase material to obtain a membrane.

  15. Catalytic membrane reactor for tritium extraction system from He purge

    International Nuclear Information System (INIS)

    Santucci, Alessia; Incelli, Marco; Sansovini, Mirko; Tosti, Silvano

    2016-01-01

    Highlights: • In the HCBB blanket, the produced tritium is recovered by purging with helium; membrane technologies are able to separate tritium from helium. • The paper presents the results of two experimental campaigns. • In the first, a Pd–Ag diffuser for hydrogen separation is tested at several operating conditions. • In the second, the ability of a Pd–Ag membrane reactor for water decontamination is assessed by performing isotopic swamping and water gas shift reactions. - Abstract: In the Helium Cooled Pebble Bed (HCPB) blanket concept, the produced tritium is recovered purging the breeder with helium at low pressure, thus a tritium extraction system (TES) is foreseen to separate the produced tritium (which contains impurities like water) from the helium gas purge. Several R&D activities are running in parallel to experimentally identify most promising TES technologies: particularly, Pd-based membrane reactors (MR) are under investigation because of their large hydrogen selectivity, continuous operation capability, reliability and compactness. The construction and operation under DEMO relevant conditions (that presently foresee a He purge flow rate of about 10,000 Nm 3 /h and a H 2 /He ratio of 0.1%) of a medium scale MR is scheduled for next year, while presently preliminary experiments on a small scale reactor are performed to identify most suitable operative conditions and catalyst materials. This work presents the results of an experimental campaign carried out on a Pd-based membrane aimed at measuring the capability of this device in separating hydrogen from the helium. Many operative conditions have been investigated by considering different He/H 2 feed flow ratios, several lumen pressures and reactor temperatures. Moreover, the performances of a membrane reactor (composed of a Pd–Ag tube having a wall thickness of about 113 μm, length 500 mm and diameter 10 mm) in processing the water contained in the purge gas have been measured by using

  16. Catalytic membrane reactor for tritium extraction system from He purge

    Energy Technology Data Exchange (ETDEWEB)

    Santucci, Alessia, E-mail: alessia.santucci@enea.it [ENEA for EUROfusion, Via E. Fermi 45, 00044 Frascati, Roma (Italy); Incelli, Marco [ENEA for EUROfusion, Via E. Fermi 45, 00044 Frascati, Roma (Italy); DEIM, University of Tuscia, Via del Paradiso 47, 01100 Viterbo (Italy); Sansovini, Mirko; Tosti, Silvano [ENEA for EUROfusion, Via E. Fermi 45, 00044 Frascati, Roma (Italy)

    2016-11-01

    Highlights: • In the HCBB blanket, the produced tritium is recovered by purging with helium; membrane technologies are able to separate tritium from helium. • The paper presents the results of two experimental campaigns. • In the first, a Pd–Ag diffuser for hydrogen separation is tested at several operating conditions. • In the second, the ability of a Pd–Ag membrane reactor for water decontamination is assessed by performing isotopic swamping and water gas shift reactions. - Abstract: In the Helium Cooled Pebble Bed (HCPB) blanket concept, the produced tritium is recovered purging the breeder with helium at low pressure, thus a tritium extraction system (TES) is foreseen to separate the produced tritium (which contains impurities like water) from the helium gas purge. Several R&D activities are running in parallel to experimentally identify most promising TES technologies: particularly, Pd-based membrane reactors (MR) are under investigation because of their large hydrogen selectivity, continuous operation capability, reliability and compactness. The construction and operation under DEMO relevant conditions (that presently foresee a He purge flow rate of about 10,000 Nm{sup 3}/h and a H{sub 2}/He ratio of 0.1%) of a medium scale MR is scheduled for next year, while presently preliminary experiments on a small scale reactor are performed to identify most suitable operative conditions and catalyst materials. This work presents the results of an experimental campaign carried out on a Pd-based membrane aimed at measuring the capability of this device in separating hydrogen from the helium. Many operative conditions have been investigated by considering different He/H{sub 2} feed flow ratios, several lumen pressures and reactor temperatures. Moreover, the performances of a membrane reactor (composed of a Pd–Ag tube having a wall thickness of about 113 μm, length 500 mm and diameter 10 mm) in processing the water contained in the purge gas have been

  17. On the study of catalytic membrane reactor for water detritiation: Modeling approach

    Energy Technology Data Exchange (ETDEWEB)

    Liger, Karine, E-mail: karine.liger@cea.fr [CEA, DEN, DTN/SMTA/LIPC Cadarache, Saint Paul-lez-Durance F-13108 (France); Mascarade, Jérémy [CEA, DEN, DTN/SMTA/LIPC Cadarache, Saint Paul-lez-Durance F-13108 (France); Joulia, Xavier; Meyer, Xuan-Mi [Université de Toulouse, INPT, UPS, Laboratoire de Génie Chimique, 4, Allée Emile Monso, Toulouse F-31030 (France); CNRS, Laboratoire de Génie Chimique, Toulouse F-31030 (France); Troulay, Michèle; Perrais, Christophe [CEA, DEN, DTN/SMTA/LIPC Cadarache, Saint Paul-lez-Durance F-13108 (France)

    2016-11-01

    Highlights: • Experimental results for the conversion of tritiated water (using deuterium as a simulant of tritium) by means of a catalytic membrane reactor in view of tritium recovery. • Phenomenological 2D model to represent catalytic membrane reactor behavior including the determination of the compositions of gaseous effluents. • Good agreement between the simulation results and experimental measurements performed on the dedicated facility. • Explanation of the unexpected behavior of the catalytic membrane reactor by the modeling results and in particular the gas composition estimation. - Abstract: In the framework of tritium recovery from tritiated water, efficiency of packed bed membrane reactors have been successfully demonstrated. Thanks to protium isotope swamping, tritium bonded water can be recovered under the valuable Q{sub 2} form (Q = H, D or T) by means of isotope exchange reactions occurring on catalyst surface. The use of permselective Pd-based membrane allows withdrawal of reactions products all along the reactor, and thus limits reverse reaction rate to the benefit of the direct one (shift effect). The reactions kinetics, which are still little known or unknown, are generally assumed to be largely greater than the permeation ones so that thermodynamic equilibriums of isotope exchange reactions are generally assumed. This paper proposes a new phenomenological 2D model to represent catalytic membrane reactor behavior with the determination of gas effluents compositions. A good agreement was obtained between the simulation results and experimental measurements performed on a dedicated facility. Furthermore, the gas composition estimation permits to interpret unexpected behavior of the catalytic membrane reactor. In the next future, further sensitivity analysis will be performed to determine the limits of the model and a kinetics study will be conducted to assess the thermodynamic equilibrium of reactions.

  18. Ceramic membranes for catalytic membrane reactors with high ionic conductivities and low expansion properties

    Science.gov (United States)

    Mackay, Richard; Sammells, Anthony F.

    2000-01-01

    Ceramics of the composition: Ln.sub.x Sr.sub.2-x-y Ca.sub.y B.sub.z M.sub.2-z O.sub.5+.delta. where Ln is an element selected from the fblock lanthanide elements and yttrium or mixtures thereof; B is an element selected from Al, Ga, In or mixtures thereof; M is a d-block transition element of mixtures thereof; 0.01.ltoreq.x.ltoreq.1.0; 0.01.ltoreq.y.ltoreq.0.7; 0.01.ltoreq.z.ltoreq.1.0 and .delta. is a number that varies to maintain charge neutrality are provided. These ceramics are useful in ceramic membranes and exhibit high ionic conductivity, high chemical stability under catalytic membrane reactor conditions and low coefficients of expansion. The materials of the invention are particularly useful in producing synthesis gas.

  19. Membranas Inorgânicas e reatores catalíticos Inorganic membranes and catalytic reactors

    Directory of Open Access Journals (Sweden)

    Maria do Carmo Rangel

    1997-10-01

    Full Text Available Membrane reactors are reviewed with emphasis in their applications in catalysis field. The basic principles of these systems are presented as well as a historical development. The several kinds of catalytic membranes and their preparations are discussed including the problems, needs and challenges to be solved in order to use these reactors in commercial processes. Some applications of inorganic membrane reactors are also shown. It was concluded that these systems have a great potential for improving yield and selectivity of high temperature catalytic reactions. However, it is still an imerging technology with a need for a lot of fundamental research; several challenges should be overcome for the successful commercial application of these systems.

  20. A study of the isobutane dehydrogenation in a porous membrane catalytic reactor: design, use and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Casanave, D.

    1996-01-26

    The aim of this study was to set up and model a catalytic fixed-bed membrane reactor for the isobutane dehydrogenation. The catalyst, developed at Catalysis Research Institute (IRC), was a silicalite-supported Pt-based catalyst. Their catalytic performances (activity, selectivity, stability) where found better adapted to the membrane reactor, when compared with commercial Pt or Cr based catalysts. The kinetic study of the reaction has been performed in a differential reactor and led to the determination of a kinetic law, suitable when the catalyst is used near thermodynamic equilibrium. The mass transfer mechanisms were determined in meso-porous and microporous membranes through both permeability and gas mixtures (iC{sub 4}/H{sub 2}/N{sub 2}) separation measurements. For the meso-porous {gamma}-alumina, the mass transfer is ensured by a Knudsen diffusion mechanism which can compete with surface diffusion for condensable gas like isobutane. The resulting permselectivity H{sub 2}/iC4 of this membrane is low ({approx} 4). For the microporous zeolite membrane, molecular sieving occurs due to steric hindrance, leading to higher permselectivity {approx}14. Catalyst/membrane associations were compared in terms of isobutane dehydrogenation performances, for both types of membranes (meso-porous and microporous) and for two different reactor configurations (co-current and counter-current sweep gas flow). The best experimental results were obtained with the zeolite membrane, when sweeping the outer compartment in a co-current flow. The equilibrium displacement observed with the {gamma}-alumina membrane was lower and mainly due to a dilution effect of the reaction mixture by the sweep gas. A mathematical model was developed, which correctly describes all the experimental results obtained with the zeolite membrane, when the co-current mode is used. (Abstract Truncated)

  1. The catalytic oxidation of H2S in a stainless steel membrane reactor with separate feed of reactants.

    NARCIS (Netherlands)

    Neomagus, H.W.J.P.; van Swaaij, Willibrordus Petrus Maria; Versteeg, Geert

    1998-01-01

    The oxidation of H2S is studied in a membrane reactor with separate feed of reactants. As a novelty in the concept of separate introduction of the reactants, a sintered stainless steel membrane is used, because this type of material is easy to integrate into the reactor, and the catalytic properties

  2. The catalytic oxidation of H2S in a stainless steel membrane reactor with separate feed of reactants

    NARCIS (Netherlands)

    Neomagus, H.W.J.P.; Swaaij, W.P.M. van; Versteeg, G.F.

    1998-01-01

    The oxidation of H2S is studied in a membrane reactor with separate feed of reactants. As a novelty in the concept of separate introduction of the reactants, a sintered stainless steel membrane is used, because this type of material is easy to integrate into the reactor, and the catalytic properties

  3. A self-catalytic mixed-conducting membrane reactor for effective production of hydrogen from methane

    Science.gov (United States)

    Dong, Xueliang; Liu, Zhengkun; Jin, Wanqin; Xu, Nanping

    A supported mixed-conducting LNCO membrane with a pore-gradient structure LNO support was successfully prepared via a dry pressing and co-sintering route. The match of sintering behaviors between membrane and support was realized by the preparation of an ABB‧B‧‧B‧BA-type membrane. A scanning electron microscopy (SEM) test demonstrated that the surface of the supported membrane was dense and crack-free and the pore-gradient structure of the support can be observed clearly. The oxygen flux of the supported membrane was about 5.6 times that of the symmetric LNCO membrane. A self-catalytic mixed-conducting membrane reactor was constructed using the prepared membrane for hydrogen production from methane. It was found that this membrane reactor exhibited high performance and good stability for hydrogen production. At 1123 K, the CH 4 conversion, hydrogen selectivity and hydrogen production remained at about 60%, 89% and 8.0 ml(STP) cm -2 min -1, respectively, for more than 120 h.

  4. Computer-aided modeling framework – a generic modeling template for catalytic membrane fixed bed reactors

    DEFF Research Database (Denmark)

    Fedorova, Marina; Sin, Gürkan; Gani, Rafiqul

    2013-01-01

    This work focuses on development of computer-aided modeling framework. The framework is a knowledge-based system that is built on a generic modeling language and structured based on workflows for different general modeling tasks. The overall objective of this work is to support the model develope...... membrane fixed bed models is developed. The application of the modeling template is highlighted with a case study related to the modeling of a catalytic membrane reactor coupling dehydrogenation of ethylbenzene with hydrogenation of nitrobenzene....

  5. Production of hydrogen from bio-ethanol in catalytic membrane reactor

    International Nuclear Information System (INIS)

    Gernot, E.; Aupretre, F.; Deschamps, A.; Etievant, C.; Epron, F.; Marecot, P.; Duprez, D.

    2006-01-01

    Production of hydrogen from renewable energy sources offers a great potential for CO 2 emission reduction, responsible for global warming. Among renewable energies, liquid biofuels are very convenient hydrogen carriers for decentralized applications such as micro-cogeneration and transports. Ethanol, produced from sugar plants and cereals, allows a reduction of more than 60% of CO 2 emissions in comparison to gasoline. BIOSTAR is an R and D project, co-funded by the French Agency for Environment and Energy Management (ADEME) which aims at developing an efficient source of hydrogen from bio-ethanol, suitable for proton exchange membrane fuel cell systems. The objectives are to obtain, through catalytic process at medium temperature range, an efficient conversion of bio-ethanol into pure hydrogen directly usable for PEMFC. CETH has developed a catalytic membrane reformer (CMR), based on a patented technology, integrating a steam reforming catalyst as well as a combustion catalyst. Both catalysts have been developed and optimized for membrane reactor in partnership with the University of Poitiers. The composite metallic membrane developed by CETH allows hydrogen extraction near the hydrogen production sites, which enhances both efficiency and compactness. (authors)

  6. Elaboration by tape-casting and co-sintering of multilayer catalytic membrane reactor- performances

    International Nuclear Information System (INIS)

    Julian, A.

    2008-12-01

    This research deals with the increasing interest of the conversion of natural gas into liquid fuels (diesel, kerosene) using the Gas To Liquid (GTL) process. Within this context, Catalytic Membrane-based Reactors (CMR) would allow an improvement of the process efficiency and a reduction of investment and production costs with respect to the present technologies. They allow performing the separation of oxygen from air, and the conversion of natural gas into synthesis gas within a single step. After having highlighted the economical and technological advantages of using a ceramic membrane for the production of syngas (H 2 + CO 2 ), the author describes the protocols of synthesis of powders selected for the dense membrane and the porous support, and their physical characteristics. The obtained powders are then adapted to the tape-casting forming process. Graded-composition multilayer structures and microstructure are then elaborated by co-sintering. Performances in terms of membrane oxygen flows are presented. Mechanisms limiting the oxygen flow are discussed in order to propose ways of improving membrane performances. The limits of the studied system are defined in terms of elastic properties, and optimization ways are proposed for the dense membrane material composition in terms of mechanical properties and performance in oxygen semi-permeation

  7. Polymeric Membrane Reactors

    OpenAIRE

    José M. Sousa; Luís M. Madeira; João C. Santos; Adélio Mendes

    2008-01-01

    The aim of this chapter is the study of membrane reactors with polymeric membranes, particularly catalytic polymeric membranes. After an introduction where the main advantages and disadvantages of the use of polymeric membranes are summarised, a review of the main areas where they have been applied, integrated in chemical reactors, is presented. This excludes the field of bio-membranes processes, which is analysed in a specific chapter of this book. Particular attention is then given to model...

  8. Modeling and simulation of ammonia removal from purge gases of ammonia plants using a catalytic Pd-Ag membrane reactor

    International Nuclear Information System (INIS)

    Rahimpour, M.R.; Asgari, A.

    2008-01-01

    In this work, the removal of ammonia from synthesis purge gas of an ammonia plant has been investigated. Since the ammonia decomposition is thermodynamically limited, a membrane reactor is used for complete decomposition. A double pipe catalytic membrane reactor is used to remove ammonia from purge gas. The purge gas is flowing in the reaction side and is converted to hydrogen and nitrogen over nickel-alumina catalyst. The hydrogen is transferred through the Pd-Ag membrane of tube side to the shell side. A mathematical model including conservation of mass in the tube and shell side of reactor is proposed. The proposed model was solved numerically and the effects of different parameters on the rector performance were investigated. The effects of pressure, temperature, flow rate (sweep ratio), membrane thickness and reactor diameter have been investigated in the present study. Increasing ammonia conversion was observed by raising the temperature, sweep ratio and reducing membrane thickness. When the pressure increases, the decomposition is gone toward completion but, at low pressure the ammonia conversion in the outset of reactor is higher than other pressures, but complete destruction of the ammonia cannot be achieved. The proposed model can be used for design of an industrial catalytic membrane reactor for removal of ammonia from ammonia plant and reducing NO x emissions

  9. Phenomenological modeling and study of a catalytic membrane reactor for water detritiation

    International Nuclear Information System (INIS)

    Mascarade, Jeremy

    2015-01-01

    Tritium is produced in light and heavy water reactor fuel by ternary fission or neutron activation. This by-product is used as fuel in fusion fuel reactors such as JET in Culham or ITER in Cadarache (France). The growing interest of this research area will make the tritium fluxes increase; it is then worth addressing the question of its future whether it will be used or flushed out from liquid and gaseous effluents or waste. This thesis studies the recovery of tritium as fuel for fusion machines by means of packed bed membrane reactor (PBMR). Such a reactor combines catalytic conversion of tritiated water thanks to isotope exchange with hydrogen according to the reversible reaction Q 2 O+H 2 ↔H 2 O+Q 2 (Q=H,D or T) and selective permeation of Q 2 through Pd-based membrane. In fact, palladium has the ability to bond with hydrogen isotopes, creating a selective permeation barrier. In the PBMR, thanks to the reaction products withdrawal, these permeation fluxes drive the heavy water conversion rate, to higher values than those reached in conventional fixed bed reactors (Le Chatelier's law). In order to study PBMRs, the CEA has built a test bench, using deuterium instead of tritium, allowing the analysis of their conversion and separation performances at the laboratory scale. An in-house method has been developed to determine simultaneously hydrogen and water isotopologues content by mass spectrometer analysis. It was experimentally shown that the activity of Ni-based catalyst used in this study was sufficient to allow the isotope exchange reactions to reach their thermodynamic equilibrium in a very short time. In addition, hydrogen permeation flux was shown to follow a Richardson's law. Sensitivity studies performed on the PBMR's main operating parameters revealed that its global performance (i.e. de-deuteration factor) increases with the temperature, the transmembrane pressure difference, the sweep gas flow rate and the residence time in the catalyst

  10. Effect of UV on De-NOx performance and microbial community of a hybrid catalytic membrane biofilm reactor

    Science.gov (United States)

    Chen, Zhouyang; Huang, Zhensha; He, Yiming; Xiao, Xiaoliang; Wei, Zaishan

    2018-02-01

    The hybrid membrane catalytic biofilm reactor provides a new way of flue gas denitration. However, the effects of UV on denitrification performance, microbial community and microbial nitrogen metabolism are still unknown. In this study, the effects of UV on deNO x performance, nitrification and denitrification, microbial community and microbial nitrogen metabolism of a bench scale N-TiO2/PSF hybrid catalytic membrane biofilm reactor (HCMBR) were evaluated. The change from nature light to UV in the HCMBR leads to the fall of NO removal efficiency of HCMBR from 92.8% to 81.8%. UV affected the microbial community structure, but did not change microbial nitrogen metabolism, as shown by metagenomics sequencing method. Some dominant phyla, such as Gammaproteobacteria, Bacteroidetes, Firmicutes, Actinobacteria, and Alphaproteobacteria, increased in abundance, whereas others, such as Proteobacteria and Betaproteobacteria, decreased. There were nitrification, denitrification, nitrogen fixation, and organic nitrogen metabolism in the HCMBR.

  11. A Catalytically Active Membrane Reactor for Fast, Highly Exothermic, Heterogeneous Gas Reactions. A Pilot Plant Study

    NARCIS (Netherlands)

    Veldsink, Jan W.; Versteeg, Geert F.; Swaaij, Wim P.M. van

    1995-01-01

    Membrane reactors have been frequently studied because of their ability to combine chemical activity and separation properties into one device. Due to their thermal stability and mechanical strength, ceramic membranes are preferred over polymeric ones, but small transmembrane fluxes obstruct a

  12. A catalytically membrane reactor for fast, highly exothermic, heterogeneous gas reactions : a pilot plant study

    NARCIS (Netherlands)

    Veldsink, J.W.; Veldsink, J.W.; Versteeg, Geert; van Swaaij, Willibrordus Petrus Maria

    1995-01-01

    Membrane reactors have been frequently studied because of their ability to combine chemical activity and separation properties into one device. Due to their thermal stability and mechanical strength, ceramic membranes are preferred over polymeric ones, but small transmembrane fluxes obstruct a

  13. Development of a Novel Catalytic Membrane Reactor for Heterogeneous Catalysis in Supercritical CO2

    Science.gov (United States)

    Islam, Nazrul M.; Chatterjee, Maya; Ikushima, Yutaka; Yokoyama, Toshiro; Kawanami, Hajime

    2010-01-01

    A novel type of high-pressure membrane reactor has been developed for hydrogenation in supercritical carbon dioxide (scCO2). The main objectives of the design of the reactor are the separate feeding of hydrogen and substrate in scCO2 for safe reactions in a continuous flow process, and to reduce the reaction time. By using this new reactor, hydrogenation of cinnamaldehyde into hydrocinnamaldehyde has been successfully carried out with 100% selectivity at 50 °C in 10 MPa (H2: 1 MPa, CO2: 9 MPa) with a flow rate of substrate ranging from 0.05 to 1.0 mL/min. PMID:20162008

  14. Pretreated Landfill Gas Conversion Process via a Catalytic Membrane Reactor for Renewable Combined Fuel Cell-Power Generation

    Directory of Open Access Journals (Sweden)

    Zoe Ziaka

    2013-01-01

    Full Text Available A new landfill gas-based reforming catalytic processing system for the conversion of gaseous hydrocarbons, such as incoming methane to hydrogen and carbon oxide mixtures, is described and analyzed. The exit synthesis gas (syn-gas is fed to power effectively high-temperature fuel cells such as SOFC types for combined efficient electricity generation. The current research work is also referred on the description and design aspects of permreactors (permeable reformers carrying the same type of landfill gas-reforming reactions. Membrane reactors is a new technology that can be applied efficiently in such systems. Membrane reactors seem to perform better than the nonmembrane traditional reactors. The aim of this research includes turnkey system and process development for the landfill-based power generation and fuel cell industries. Also, a discussion of the efficient utilization of landfill and waste type resources for combined green-type/renewable power generation with increased processing capacity and efficiency via fuel cell systems is taking place. Moreover, pollution reduction is an additional design consideration in the current catalytic processors fuel cell cycles.

  15. Experimental demonstration of the reverse flow catalytic membrane reactor concept for energy efficient syngas production. Part 1: Influence of operating conditions

    NARCIS (Netherlands)

    Smit, J.; Bekink, G.J.; van Sint Annaland, M.; Kuipers, J.A.M.

    2007-01-01

    In this contribution the technical feasibility of the reverse flow catalytic membrane reactor (RFCMR) concept with porous membranes for energy efficient syngas production is investigated. In earlier work an experimental proof of principle was already provided [Smit, J., Bekink, G.J., van Sint

  16. Development of a Novel Catalytic Membrane Reactor for Heterogeneous Catalysis in Supercritical CO2

    Directory of Open Access Journals (Sweden)

    Toshiro Yokoyama

    2010-01-01

    Full Text Available A novel type of high-pressure membrane reactor has been developed for hydrogenation in supercritical carbon dioxide (scCO2. The main objectives of the design of the reactor are the separate feeding of hydrogen and substrate in scCO2 for safe reactions in a continuous flow process, and to reduce the reaction time. By using this new reactor, hydrogenation of cinnamaldehyde into hydrocinnamaldehyde has been successfully carried out with 100% selectivity at 50 °C in 10 MPa (H2: 1 MPa, CO2: 9 MPa with a flow rate of substrate ranging from 0.05 to 1.0 mL/min.

  17. Maximizing the productivity of catalytic biofilms on solid supports in membrane aerated reactors.

    Science.gov (United States)

    Halan, Babu; Schmid, Andreas; Buehler, Katja

    2010-07-01

    A new solid support membrane aerated biofilm reactor was designed for the synthesis of enantiopure (S)-styrene oxide utilizing Pseudomonas sp. strain VLB120DeltaC growing in a biofilm as biocatalyst. In analogy to traditional packed bed systems, maximizing the volumetric oxygen mass transfer capability (k(L)a) was identified as the most critical issue enabling a consistent productivity, as this parameter was shown to directly influence biofilm growth and biotransformation performance. A microporous ceramic unit was identified as an ideal microenvironment for biofilm growth and for efficient oxygen transfer. A uniform and dense biofilm developed on this matrix. Due to this dual function, the reactor configuration could be significantly simplified by eliminating additional packing materials, as used in traditional packed bed reactors. Up to now, a maximum productivity of 28 g L(ab) (-1) day(-1) was achieved by integrating an in situ substrate feed and an in situ product recovery technique based on a silicone membrane. The system was stable for more than 30 days before it was actively terminated.

  18. Ceramic oxygen transport membrane array reactor and reforming method

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Sean M.; Christie, Gervase Maxwell; Robinson, Charles; Wilson, Jamie R.; Gonzalez, Javier E.; Doraswami, Uttam R.

    2016-11-08

    The invention relates to a commercially viable modular ceramic oxygen transport membrane reforming reactor configured using repeating assemblies of oxygen transport membrane tubes and catalytic reforming reactors.

  19. Environmentally benign synthesis of amides and ureas via catalytic dehydrogenation coupling of volatile alcohols and amines in a Pd-Ag membrane reactor

    KAUST Repository

    Chen, Tao

    2016-05-31

    In this study, we report the direct synthesis of amides and ureas via the catalytic dehydrogenation of volatile alcohols and amines using the Milstein catalyst in a Pd-Ag/ceramic membrane reactor. A series of amides and ureas, which could not be synthesized in an open system by catalytic dehydrogenation coupling, were obtained in moderate to high yields via catalytic dehydrogenation of volatile alcohols and amines. This process could be monitored by the hydrogen produced. Compared to the traditional method of condensation, this catalytic system avoids the stoichiometric pre-activation or in situ activation of reagents, and is a much cleaner process with high atom economy. This methodology, only possible by employing the Pd-Ag/ceramic membrane reactor, not only provides a new environmentally benign synthetic approach of amides and ureas, but is also a potential method for hydrogen storage.

  20. Experimental, kinetic and numerical modeling of hydrogen production by catalytic reforming of crude ethanol over a commercial catalyst in packed bed tubular reactor and packed bed membrane reactor

    International Nuclear Information System (INIS)

    Aboudheir, Ahmed; Akande, Abayomi; Idem, Raphael

    2006-01-01

    The demand for hydrogen energy has increased tremendously in recent years essentially because of the increase in the word energy consumption as well as recent developments in fuel cell technologies. The energy information administration has projected that world energy consumption will increase by 59% over the next two decades, from 1999 to 2020, in which the largest share is still dominated by fossil fuels (oil, natural gas and coal). Carbon dioxide (CO 2 ) emissions resulting from the combustion of these fossil fuels currently are estimated to account for three-fourth of human-caused CO 2 emissions worldwide. Greenhouse gas emission, including CO 2 , should be limited, as recommended at the Kyoto Conference, Japan, in December 1997. In this regard, hydrogen (H 2 ) has a significant future potential as an alternative fuel that can solve the problems of CO 2 emissions as well as the emissions of other air contaminants. One of the techniques to produce hydrogen is by reforming of hydrocarbons or biomass. Crude ethanol (a form of biomass, which essentially is fermentation broth) is easy to produce, is free of sulphur, has low toxicity, and is also safe to handle, transport and store. In addition, crude ethanol consists of oxygenated hydrocarbons, such as ethanol, lactic acid, glycerol, and maltose. These oxygenated hydrocarbons can be reformed completely to H 2 and CO 2 , the latter of which could be separated from H 2 by membrane technology. This provides for CO 2 capture for eventual storage or destruction. In the case of using crude ethanol, this will result in negative CO 2 , emissions. In this paper, we conducted experimental work on production of hydrogen by the catalytic reforming of crude ethanol over a commercial promoted Ni-based catalyst in a packed bed tubular reactor as well as a packed bed membrane reactor. As well, a rigorous numerical model was developed to simulate this process in both the catalytic packed bed tubular reactor and packed bed membrane

  1. Hydrogen production by steam reforming of bio-alcohols. The use of conventional and membrane-assisted catalytic reactors

    Energy Technology Data Exchange (ETDEWEB)

    Seelam, P. K.

    2013-11-01

    The energy consumption around the globe is on the rise due to the exponential population growth and urbanization. There is a need for alternative and non-conventional energy sources, which are CO{sub 2}-neutral, and a need to produce less or no environmental pollutants and to have high energy efficiency. One of the alternative approaches is hydrogen economy with the fuel cell (FC) technology which is forecasted to lead to a sustainable society. Hydrogen (H{sub 2}) is recognized as a potential fuel and clean energy carrier being at the same time a carbon-free element. Moreover, H{sub 2} is utilized in many processes in chemical, food, metallurgical, and pharmaceutical industry and it is also a valuable chemical in many reactions (e.g. refineries). Non-renewable resources have been the major feedstock for H{sub 2} production for many years. At present, {approx}50% of H{sub 2} is produced via catalytic steam reforming of natural gas followed by various down-stream purification steps to produce {approx}99.99% H{sub 2}, the process being highly energy intensive. Henceforth, bio-fuels like biomass derived alcohols (e.g. bio-ethanol and bio-glycerol), can be viable raw materials for the H{sub 2} production. In a membrane based reactor, the reaction and selective separation of H{sub 2} occur simultaneously in one unit, thus improving the overall reactor efficiency. The main motivation of this work is to produce H{sub 2} more efficiently and in an environmentally friendly way from bio-alcohols with a high H{sub 2} selectivity, purity and yield. In this thesis, the work was divided into two research areas, the first being the catalytic studies using metal decorated carbon nanotube (CNT) based catalysts in steam reforming of ethanol (SRE) at low temperatures (<450 deg C). The second part was the study of steam reforming (SR) and the water-gas-shift (WGS) reactions in a membrane reactor (MR) using dense and composite Pd-based membranes to produce high purity H{sub 2}. CNTs

  2. Purge gas recovery of ammonia synthesis plant by integrated configuration of catalytic hydrogen-permselective membrane reactor and solid oxide fuel cell as a novel technology

    Science.gov (United States)

    Siavashi, Fakhteh; Saidi, Majid; Rahimpour, Mohammad Reza

    2014-12-01

    The purge gas emission of ammonia synthesis plant which contains hazardous components is one of the major sources of environmental pollution. Using integrated configuration of catalytic hydrogen-permselective membrane reactor and solid oxide fuel cell (SOFC) system is a new approach which has a great impact to reduce the pollutant emission. By application of this method, not only emission of ammonia and methane in the atmosphere is prevented, hydrogen is produced through the methane steam reforming and ammonia decomposition reactions that take place simultaneously in a catalytic membrane reactor. The pure generated hydrogen by recovery of the purge gas in the Pd-Ag membrane reactor is used as a feed of SOFC. Since water is the only byproduct of the electrochemical reaction in the SOFC, it is recycled to the reactor for providing the required water of the reforming reaction. Performance investigation of the reactor represents that the rate of hydrogen permeation increases with enhancing the reactor temperature and pressure. Also modeling results indicate that the SOFC performance improves with increasing the temperature and fuel utilization ratio. The generated power by recovery of the purging gas stream of ammonia synthesis plant in the Razi petrochemical complex is about 8 MW.

  3. Ethylene production by ODHE in catalytically modified Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3-δ) membrane reactors.

    Science.gov (United States)

    Lobera, M Pilar; Escolástico, Sonia; Garcia-Fayos, Julio; Serra, José M

    2012-08-01

    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 °C on a catalytic membrane reactor based on a mixed ionic-electronic conducting membrane. The surface of the membrane made of Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3-δ) 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 (A(0.6)Sr(0.4)Co(0.5)Fe(0.5)O(3-δ) and Ba(0.6)Sr(0.4)BO(3-δ)) 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 Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3-δ), 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. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T [Huntington Beach, CA; Sahimi, Muhammad [Altadena, CA; Fayyaz-Najafi, Babak [Richmond, CA; Harale, Aadesh [Los Angeles, CA; Park, Byoung-Gi [Yeosu, KR; Liu, Paul K. T. [Lafayette Hill, PA

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  5. Engineering reactors for catalytic reactions

    Indian Academy of Sciences (India)

    ... improvements in reactor performance. In this article, application of recent (and not so recent) developments in engineering reactors for catalytic reactions is discussed. Some examples where performance enhancement was realized by catalyst design, appropriate choice of reactor, better injection and dispersion strategies ...

  6. Catalytic reforming of methane to syngas in an oxygen-permeative membrane reactor

    Science.gov (United States)

    Urano, Takeshi; Kubo, Keiko; Saito, Tomoyuki; Hitomi, Atsushi

    2011-05-01

    For fuel cell applications, partial oxidative reforming of methane to syngas, hydrogen and carbon monoxide, was performed via a dense oxygen-permeative ceramic membrane composed by both ionic and electronic conductive materials. The modification of Ni-based catalyst by noble metals was investigated to increase oxygen permeation flux and decrease carbon deposition during reforming reaction. The role of each component in catalyst was also discussed.

  7. Catalytic Membrane Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, T.J.; Brinker, C.J.; Gardner, T.J.; Hughes, R.C.; Sault, A.G.

    1998-12-01

    The proposed "catalytic membrane sensor" (CMS) was developed to generate a device which would selectively identify a specific reagent in a complex mixture of gases. This was to be accomplished by modifying an existing Hz sensor with a series of thin films. Through selectively sieving the desired component from a complex mixture and identifying it by decomposing it into Hz (and other by-products), a Hz sensor could then be used to detect the presence of the select component. The proposed "sandwich-type" modifications involved the deposition of a catalyst layered between two size selective sol-gel layers on a Pd/Ni resistive Hz sensor. The role of the catalyst was to convert organic materials to Hz and organic by-products. The role of the membraneo was to impart both chemical specificity by molecukir sieving of the analyte and converted product streams, as well as controlling access to the underlying Pd/Ni sensor. Ultimately, an array of these CMS elements encompassing different catalysts and membranes were to be developed which would enable improved selectivity and specificity from a compiex mixture of organic gases via pattern recognition methodologies. We have successfully generated a CMS device by a series of spin-coat deposited methods; however, it was determined that the high temperature required to activate the catalyst, destroys the sensor.

  8. Engineering reactors for catalytic reactions

    Indian Academy of Sciences (India)

    on selectivity can make substantial impact on process viability and economics. Extensive studies have been conducted to establish sound basis for design and engineering of reactors for practising such catalytic reactions and for realizing improvements in reactor performance. In this article, application of recent (and not so ...

  9. Supported ionic liquid membrane in membrane reactor

    Science.gov (United States)

    Makertihartha, I. G. B. N.; Zunita, M.; Dharmawijaya, P. T.; Wenten, I. G.

    2017-01-01

    Membrane reactor is a device that integrates membrane based separation and (catalytic) chemical reaction vessel in a single device. Ionic liquids, considered to be a relatively recent magical chemical due to their unique properties, have a large variety of applications in all areas of chemical industries. Moreover, the ionic liquid can be used as membrane separation layer and/or catalytically active site. This paper will review utilization of ionic liquid in membrane reactor related applications especially Fischer-Tropsch, hydrogenation, and dehydrogenation reaction. This paper also reviews about the capability of ionic liquid in equilibrium reaction that produces CO2 product so that the reaction will move towards the product. Water gas shift reaction in ammonia production also direct Dimethyl Ether (DME) synthesis that produces CO2 product will be discussed. Based on a review of numerous articles on supported ionic liquid membrane (SILM) indicate that ionic liquids have the potential to support the process of chemical reaction and separation in a membrane reactor.

  10. New nanosized catalytic membrane reactors for hydrogenation with stored hydrogen: Prerequisites and the experimental basis for their creation

    Science.gov (United States)

    Soldatov, A. P.; Tsodikov, M. V.; Parenago, O. P.; Teplyakov, V. V.

    2010-12-01

    The prerequisites and prospects for creating a new generation of nanosized membrane reactors are considered. For the first time, hydrogenation reactions take place in ceramic membrane pores with hydrogen adsorbed beforehand in mono- and multilayered oriented carbon nanotubes with graphene walls (OCNTGs) formed on the internal pore surface. It is shown for Trumem microfiltration membranes with D avg ˜130 nm that oxidation reactions of CO on a Cu0.03Ti0.97O2 ± δ catalyst and the oxidative conversion of methane into synthesis gas and light hydrocarbons on La + Ce/MgO are considerably enhanced when they occur in membranes. Regularities of hydrogen adsorption, storage, and desorption in nanosized membrane reactors are investigated through OCNTG formation in Trumem ultrafiltration membrane pores with D avg = 50 and 90 nm and their saturation with hydrogen at a pressure of 10-13 MPa. It is shown that the amount of adsorbed hydrogen reaches 14.0% of OCNTG mass. Using thermogravimetric analysis in combination with mass-spectrometric analysis, hydrogen adsorption in OCNTG is first determined and its desorption is found to proceed at atmospheric pressure at a temperature of ˜175°C. It is shown that adsorbed hydrogen affects the transport properties of the membranes, reducing their efficiency with respect to liquids by 4-26 times. This is indirect confirmation of its high activity, due apparently the dissociative mechanism of adsorption.

  11. Membrane assisted fluidized bed reactors: Potentials and hurdles

    NARCIS (Netherlands)

    Deshmukh, S.A.R.K.; Heinrich, S.; Mörl, L.; van Sint Annaland, M.; Kuipers, J.A.M.

    2007-01-01

    Recent advances in the development of more stable membranes with increased permeance have significantly enhanced the possibilities for integrating membranes into catalytic reactors in order to achieve a major increase in reactor performance by process integration and process intensification. Several

  12. Catalytic combustion of the retentate gas from a CO2/H2 separation membrane reactor for further CO2 enrichment and energy recovery

    International Nuclear Information System (INIS)

    Hwang, Kyung-Ran; Park, Jin-Woo; Lee, Sung-Wook; Hong, Sungkook; Lee, Chun-Boo; Oh, Duck-Kyu; Jin, Min-Ho; Lee, Dong-Wook; Park, Jong-Soo

    2015-01-01

    The CCR (catalytic combustion reaction) of the retentate gas, consisting of 90% CO 2 and 10% H 2 obtained from a CO 2 /H 2 separation membrane reactor, was investigated using a porous Ni metal catalyst in order to recover energy and further enrich CO 2 . A disc-shaped porous Ni metal catalyst, namely Al[0.1]/Ni, was prepared by a simple method and a compact MCR (micro-channel reactor) equipped with a catalyst plate was designed for the CCR. CO 2 and H 2 concentrations of 98.68% and 0.46%, respectively, were achieved at an operating temperature of 400 °C, GHSV (gas-hourly space velocity) of 50,000 h −1 and a H 2 /O 2 ratio (R/O) of 2 in the unit module. In the case of the MCR, a sheet of the Ni metal catalyst was easily installed along with the other metal plates and the concentration of CO 2 in the retentate gas increased up to 96.7%. The differences in temperatures measured before and after the CCR were 31 °C at the product outlet and 19 °C at the N 2 outlet in the MCR. The disc-shaped porous metal catalyst and MCR configuration used in this study exhibit potential advantages, such as high thermal transfer resulting in improved energy recovery rate, simple catalyst preparation, and easy installation of the catalyst in the MCR. - Highlights: • The catalytic combustion of a retentate gas obtained from the H 2 /CO 2 separation membrane. • A disc-shaped porous nickel metal catalyst and a micro-channel reactor for catalytic hydrogen combustion. • CO 2 enrichment up to 98.68% at 400 °C, 50,000 h −1 and H 2 /O 2 ratio of 2.

  13. Integration of Methane Steam Reforming and Water Gas Shift Reaction in a Pd/Au/Pd-Based Catalytic Membrane Reactor for Process Intensification.

    Science.gov (United States)

    Castro-Dominguez, Bernardo; Mardilovich, Ivan P; Ma, Liang-Chih; Ma, Rui; Dixon, Anthony G; Kazantzis, Nikolaos K; Ma, Yi Hua

    2016-09-19

    Palladium-based catalytic membrane reactors (CMRs) effectively remove H₂ to induce higher conversions in methane steam reforming (MSR) and water-gas-shift reactions (WGS). Within such a context, this work evaluates the technical performance of a novel CMR, which utilizes two catalysts in series, rather than one. In the process system under consideration, the first catalyst, confined within the shell side of the reactor, reforms methane with water yielding H₂, CO and CO₂. After reforming is completed, a second catalyst, positioned in series, reacts with CO and water through the WGS reaction yielding pure H₂O, CO₂ and H₂. A tubular composite asymmetric Pd/Au/Pd membrane is situated throughout the reactor to continuously remove the produced H₂ and induce higher methane and CO conversions while yielding ultrapure H₂ and compressed CO₂ ready for dehydration. Experimental results involving (i) a conventional packed bed reactor packed (PBR) for MSR, (ii) a PBR with five layers of two catalysts in series and (iii) a CMR with two layers of two catalysts in series are comparatively assessed and thoroughly characterized. Furthermore, a comprehensive 2D computational fluid dynamics (CFD) model was developed to explore further the features of the proposed configuration. The reaction was studied at different process intensification-relevant conditions, such as space velocities, temperatures, pressures and initial feed gas composition. Finally, it is demonstrated that the above CMR module, which was operated for 600 h, displays quite high H₂ permeance and purity, high CH₄ conversion levels and reduced CO yields.

  14. Gas pollutant cleaning by a membrane reactor

    Directory of Open Access Journals (Sweden)

    Kaldis Sotiris

    2006-01-01

    Full Text Available An alternative technology for the removal of gas pollutants at the integrated gasification combined cycle process for power generation is the use of a catalytic membrane reactor. In the present study, ammonia decomposition in a catalytic reactor, with a simultaneous removal of hydrogen through a ceramic membrane, was investigated. A Ni/Al2O3 catalyst was prepared by the dry and wet impregnation method and characterized by the inductively coupled plasma method, scanning electron microscopy, X-ray diffraction, and N2 adsorption before and after activation. Commercially available a-Al2O3 membranes were also characterized and the permeabilities and permselectivities of H2, N2, and CO2 were measured by the variable volume method. In parallel with the experimental analysis, the necessary mathematical models were developed to describe the operation of the catalytic membrane reactor and to compare its performance with the conventional reactor. .

  15. Recent advances on polymeric membranes for membrane reactors

    KAUST Repository

    Buonomenna, M. G.

    2012-06-24

    Membrane reactors are generally applied in high temperature reactions (>400 °C). In the field of fine chemical synthesis, however, much milder conditions are generally applicable and polymeric membranes were applied without their damage. The successful use of membranes in membrane reactors is primary the result of two developments concerning: (i) membrane materials and (ii) membrane structures. The selection of a suited material and preparation technique depends on the application the membrane is to be used in. In this chapter a review of up to date literature about polymers and configuration catalyst/ membranes used in some recent polymeric membrane reactors is given. The new emerging concept of polymeric microcapsules as catalytic microreactors has been proposed. © 2012 Bentham Science Publishers. All rights reserved.

  16. Integration of Methane Steam Reforming and Water Gas Shift Reaction in a Pd/Au/Pd-Based Catalytic Membrane Reactor for Process Intensification

    Directory of Open Access Journals (Sweden)

    Bernardo Castro-Dominguez

    2016-09-01

    Full Text Available Palladium-based catalytic membrane reactors (CMRs effectively remove H2 to induce higher conversions in methane steam reforming (MSR and water-gas-shift reactions (WGS. Within such a context, this work evaluates the technical performance of a novel CMR, which utilizes two catalysts in series, rather than one. In the process system under consideration, the first catalyst, confined within the shell side of the reactor, reforms methane with water yielding H2, CO and CO2. After reforming is completed, a second catalyst, positioned in series, reacts with CO and water through the WGS reaction yielding pure H2O, CO2 and H2. A tubular composite asymmetric Pd/Au/Pd membrane is situated throughout the reactor to continuously remove the produced H2 and induce higher methane and CO conversions while yielding ultrapure H2 and compressed CO2 ready for dehydration. Experimental results involving (i a conventional packed bed reactor packed (PBR for MSR, (ii a PBR with five layers of two catalysts in series and (iii a CMR with two layers of two catalysts in series are comparatively assessed and thoroughly characterized. Furthermore, a comprehensive 2D computational fluid dynamics (CFD model was developed to explore further the features of the proposed configuration. The reaction was studied at different process intensification-relevant conditions, such as space velocities, temperatures, pressures and initial feed gas composition. Finally, it is demonstrated that the above CMR module, which was operated for 600 h, displays quite high H2 permeance and purity, high CH4 conversion levels and reduced CO yields.

  17. Synthesis of a catalytic reactor membrane for synthesis gas production; Elaboration d'une membrane de reacteur catalytique pour la production de gaz de synthese

    Energy Technology Data Exchange (ETDEWEB)

    Juste, E.; Julian, A.; Chartier, T. [Limoges Univ., Lab. Science des Procedes Ceramiques et de Traitements de Surface (SPCTS, UMR 6638 CNRS), 87 (France); Juste, E.; Julian, A.; Del Gallo, P.; Richet, N. [Centre de Recherche Claude-Delorme, Air Liquide, 78 - Jouy en Josas (France)

    2007-07-01

    The conversion of natural gas to synthesis gas (mixture of H{sub 2} and CO) is a main challenge for the hydrogen and clean fuels production. Mixed (ionic O{sup 2-} and electronic) conducing ceramics membrane reactors seem particularly promising. The design considered for the membrane is a tri-layer system integrating a reforming catalyst and a dense membrane laying on a porous support. Among the materials considered for the dense membrane, perovskites La{sub 1-x}Sr{sub x}Fe{sub 1-y}Ga{sub y}O{sub 3-{delta}} seem to be interesting for their performances and stability. The oxygen flux through the membrane is measured in terms of temperature under different oxygen partial pressure gradients. In the industrial experimental conditions, the membrane is submitted to a strong oxygen (air/methane) partial pressure gradient of about 900 C which induces mechanical stresses, on account of the material expansion difference, in terms of p{sub O2}. In this framework, the evolutions of the performances and of the expansion coefficient have been followed in terms of the substitutions rates in La{sub (1-x)}Sr{sub x}Fe{sub (1-y)}Ga{sub y}O{sub 3-{delta}} with x{<=}0.5 and y{<=}0.5. (O.M.)

  18. Catalytic Membranes Embedding Selective Catalysts: Preparation and Applications

    Science.gov (United States)

    Drioli, Enrico; Fontananova, Enrica

    The embedding of a catalyst in membranes is today recognized as a promising strategy to develop highly efficient and eco-friendly heterogeneous catalytic chemical processes. When a catalyst is heterogenized within or on the surface of a membrane, the membrane composition (characteristics of the membrane material: hydrophobic or hydrophilic, presence of chemical groups with specific functionality, etc.) and the membrane structure (dense or porous, symmetric or asymmetric), can positively influence the catalyst performance, not only by the selective sorption and diffusion of reagents and/or products, but also influencing the catalyst activity by electronic and conformational effect. These effects are similar to those occurring in biological membranes. In this chapter, after a preliminary presentation of the basic principles of membrane reactors and polymer membranes, the preparation, characterization and applications of polymeric catalytic membranes, will be discussed.

  19. Continuous esterification to produce biodiesel by SPES/PES/NWF composite catalytic membrane in flow-through membrane reactor: experimental and kinetic studies.

    Science.gov (United States)

    Shi, Wenying; He, Benqiao; Cao, Yuping; Li, Jianxin; Yan, Feng; Cui, Zhenyu; Zou, Zhiqun; Guo, Shiwei; Qian, Xiaomin

    2013-02-01

    A novel composite catalytic membrane (CCM) was prepared from sulfonated polyethersulfone (SPES) and polyethersulfone (PES) blend supported by non-woven fabrics, as a heterogeneous catalyst to produce biodiesel from continuous esterification of oleic acid with methanol in a flow-through mode. A kinetic model of esterification was established based on a plug-flow assumption. The effects of the CCM structure (thickness, area, porosity, etc.), reaction temperature and the external and internal mass transfer resistances on esterification were investigated. The results showed that the CCM structure had a significant effect on the acid conversion. The external mass transfer resistance could be neglected when the flow rate was over 1.2 ml min(-1). The internal mass transfer resistance impacted on the conversion when membrane thickness was over 1.779 mm. An oleic acid conversion kept over 98.0% for 500 h of continuous running. The conversions obtained from the model are in good agreement with the experimental data. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. High aspect ratio catalytic reactor and catalyst inserts therefor

    Science.gov (United States)

    Lin, Jiefeng; Kelly, Sean M.

    2018-04-10

    The present invention relates to high efficient tubular catalytic steam reforming reactor configured from about 0.2 inch to about 2 inch inside diameter high temperature metal alloy tube or pipe and loaded with a plurality of rolled catalyst inserts comprising metallic monoliths. The catalyst insert substrate is formed from a single metal foil without a central supporting structure in the form of a spiral monolith. The single metal foil is treated to have 3-dimensional surface features that provide mechanical support and establish open gas channels between each of the rolled layers. This unique geometry accelerates gas mixing and heat transfer and provides a high catalytic active surface area. The small diameter, high aspect ratio tubular catalytic steam reforming reactors loaded with rolled catalyst inserts can be arranged in a multi-pass non-vertical parallel configuration thermally coupled with a heat source to carry out steam reforming of hydrocarbon-containing feeds. The rolled catalyst inserts are self-supported on the reactor wall and enable efficient heat transfer from the reactor wall to the reactor interior, and lower pressure drop than known particulate catalysts. The heat source can be oxygen transport membrane reactors.

  1. Advanced Catalytic Hydrogenation Retrofit Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Reinaldo M. Machado

    2002-08-15

    Industrial hydrogenation is often performed using a slurry catalyst in large stirred-tank reactors. These systems are inherently problematic in a number of areas, including industrial hygiene, process safety, environmental contamination, waste production, process operability and productivity. This program proposed the development of a practical replacement for the slurry catalysts using a novel fixed-bed monolith catalyst reactor, which could be retrofitted onto an existing stirred-tank reactor and would mitigate many of the minitations and problems associated with slurry catalysts. The full retrofit monolith system, consisting of a recirculation pump, gas/liquid ejector and monolith catalyst, is described as a monolith loop reactor or MLR. The MLR technology can reduce waste and increase raw material efficiency, which reduces the overall energy required to produce specialty and fine chemicals.

  2. Engineering reactors for catalytic reactions

    Indian Academy of Sciences (India)

    cation strategies for effective translation of laboratory process to practise. ... control). Several tools for modelling of chemical kinetics and reactions are already well-developed and routinely used in practice for facilitating engineering of reactors. Sev- eral excellent ... in absence of catalyst and is often controlled by mix-.

  3. 3. International conference on catalysis in membrane reactors

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    The 3. International Conference on Catalysis in Membrane Reactors, Copenhagen, Denmark, is a continuation of the previous conferences held in Villeurbanne 1994 and Moscow 1996 and will deal with the rapid developments taking place within membranes with emphasis on membrane catalysis. The approx. 80 contributions in form of plenary lectures and posters discuss hydrogen production, methane reforming into syngas, selectivity and specificity of various membranes etc. The conference is organised by the Danish Catalytic Society under the Danish Society for Chemical Engineering. (EG)

  4. OXIDATIVE COUPLING OF METHANE USING INORGANIC MEMBRANE REACTORS

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Y.H. Ma; Dr. W.R. Moser; Dr. A.G. Dixon; Dr. A.M. Ramachandra; Dr. Y. Lu; C. Binkerd

    1998-04-01

    The objective of this research is to study the oxidative coupling of methane in catalytic inorganic membrane reactors. A specific target is to achieve conversion of methane to C{sub 2} hydrocarbons at very high selectivity and higher yields than in conventional non-porous, co-feed, fixed bed reactors by controlling the oxygen supply through the membrane. A membrane reactor has the advantage of precisely controlling the rate of delivery of oxygen to the catalyst. This facility permits balancing the rate of oxidation and reduction of the catalyst. In addition, membrane reactors minimize the concentration of gas phase oxygen thus reducing non selective gas phase reactions, which are believed to be a main route for the formation of CO{sub x} products. Such gas phase reactions are a cause of decreased selectivity in the oxidative coupling of methane in conventional flow reactors. Membrane reactors could also produce higher product yields by providing better distribution of the reactant gases over the catalyst than the conventional plug flow reactors. Membrane reactor technology also offers the potential for modifying the membranes both to improve catalytic properties as well as to regulate the rate of the permeation/diffusion of reactants through the membrane to minimize by-product generation. Other benefits also exist with membrane reactors, such as the mitigation of thermal hot-spots for highly exothermic reactions such as the oxidative coupling of methane. The application of catalytically active inorganic membranes has potential for drastically increasing the yield of reactions which are currently limited by either thermodynamic equilibria, product inhibition, or kinetic selectivity.

  5. Muon catalytic fusion power reactor

    International Nuclear Information System (INIS)

    Jarnagin, W.S.

    1985-01-01

    Three main ideas are proposed using negative muoun catalyis in a fusion power reactor. Firstly, let low energy muons attack the lower end of a (dense plasma's distribution curve. This simultaneously helps clear the plasma of slow particles (by fusing them) and raises the plasma's average temperature. Concurrently, the upper end of the distribution curve is attacked as usual (here, with plasma beams from built-in reaccelerators). Secondly, let deuterium or tritium be substituted for hydrogen in the chemical formation of boron-hydrides or other macromelecular fuel. Thence fusion of clusters of (DTμ-) by thermal muons may ignite whole macromelecules. Energy release could be great. For instance, the large icosahedron (B/sub 12/H/sub 12/)/sup -2/, with D-T substitutions for H--at least in places--may release on the order of 300 MeV energy. A single muon (costing about 5 GeV)catalyzing the fusion of 100 of these macromolecules could, in principle, release about 30 GeV energy. Thirdly, it may be possible to reaccelerate muons back up to relativistic energies before they decay (to electrons, neutrions, antineutrinos). If so, then by relativity theory, their decay clocks should be reset, that is, their lifetime re-established. This should be significantly cheaper in energy than producing new pions which decay to muons. This step alone may be sufficient to yield net power from muon catalysts

  6. Polymer-stabilized palladium nanoparticles for catalytic membranes: ad hoc polymer fabrication

    Science.gov (United States)

    Domènech, Berta; Muñoz, Maria; Muraviev, Dmitri N.; Macanás, Jorge

    2011-06-01

    Metal nanoparticles are known as highly effective catalysts although their immobilization on solid supports is frequently required to prevent aggregation and to facilitate the catalyst application, recovery, and reuse. This paper reports the intermatrix synthesis of Pd0 nanoparticles in sulfonated polyethersulfone with Cardo group membranes and their use as nanocomposite catalytic membrane reactors. The synthesized polymer and the corresponding nanocomposite were characterized by spectroscopic and microscopic techniques. The catalytic efficiency of catalytic membranes was evaluated by following the reduction of p-nitrophenol in the presence of NaBH4.

  7. Polymer-stabilized palladium nanoparticles for catalytic membranes: ad hoc polymer fabrication

    Directory of Open Access Journals (Sweden)

    Macanás Jorge

    2011-01-01

    Full Text Available Abstract Metal nanoparticles are known as highly effective catalysts although their immobilization on solid supports is frequently required to prevent aggregation and to facilitate the catalyst application, recovery, and reuse. This paper reports the intermatrix synthesis of Pd0 nanoparticles in sulfonated polyethersulfone with Cardo group membranes and their use as nanocomposite catalytic membrane reactors. The synthesized polymer and the corresponding nanocomposite were characterized by spectroscopic and microscopic techniques. The catalytic efficiency of catalytic membranes was evaluated by following the reduction of p-nitrophenol in the presence of NaBH4.

  8. Current progress on zeolite membrane reactor for CO2 hydrogenation

    Science.gov (United States)

    Makertiharta, I. G. B. N.; Dharmawijaya, P. T.; Wenten, I. G.

    2017-01-01

    Carbon capture and storage via catalytic hydrogenation into methanol have been recognized as the most promising solution to not only global warming issue but also high fuel and methanol demand worldwide. However, methanol synthesis from CO2 involves equilibrium limited reaction that can be optimized using membrane reactor (MR). Among all selective membrane layer, the zeolite is the most promising material because it can selectively remove water and methanol from reaction mixture component, especially H2. To present a clear background of zeolite membrane reactor, this paper will bring the brief discussion on the recent progress towards utilization of zeolite membrane reactor for CO2 hydrogenation. The progress of selective layer used in said MR will be examined in detail. Critical issues related to zeolite membrane reactor will also be discussed to develop it further.

  9. Flame assisted synthesis of catalytic ceramic membranes

    DEFF Research Database (Denmark)

    Johansen, Johnny; Mosleh, Majid; Johannessen, Tue

    2004-01-01

    Membranes consisting of one or more metal oxides can be synthesized by flame pyrolysis. The general principle behind flame pyrolysis is the decomposition and oxidation of evaporated organo-metallic precursors in a flame, thereby forming metal oxide monomers. Because of the extreme supersaturation...... technology it is possible to make supported catalysts, composite metal oxides, catalytically active surfaces, and porous ceramic membranes. Membrane layers can be formed by using a porous substrate tube (or surface) as a nano-particle filter. The aerosol gas from the flame is led through a porous substrate......, membranes with pore sizes below 5 nm have been produced by this continuous filtration of nano-particles. In this way, top-layers with Knudsen separation have been achieved by a reduction of the pore size of three orders of magnitude within an hour. It has previously been shown that it also is possible...

  10. Nanostructured Catalytic Reactors for Air Purification, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I project proposes the development of lightweight compact nanostructured catalytic reactors for air purification from toxic gaseous organic...

  11. Nanostructured Catalytic Reactors for Air Purification, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase II project proposes the development of lightweight compact nanostructured catalytic reactors for air purification from toxic gaseous organic...

  12. Carbon nanofibers in catalytic membrane microreactors

    NARCIS (Netherlands)

    Aran, H.C.; Pacheco Benito, Sergio; Luiten-Olieman, Maria W.J.; Er, S.; Wessling, Matthias; Lefferts, Leonardus; Benes, Nieck Edwin; Lammertink, Rob G.H.

    2011-01-01

    In this study, we report on the fabrication and operation of new hybrid membrane microreactors for gas–liquid–solid (G–L–S) reactions. The presented reactors consist of porous stainless steel tubes onto which carbon nanofibers (CNFs) are grown as catalyst support, all encapsulated by a gas permeable

  13. Oxidative coupling of methane using inorganic membrane reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Y.H.; Moser, W.R.; Dixon, A.G. [Worcester Polytechnic Institute, MA (United States)] [and others

    1995-12-31

    The goal of this research is to improve the oxidative coupling of methane in a catalytic inorganic membrane reactor. A specific target is to achieve conversion of methane to C{sub 2} hydrocarbons at very high selectivity and relatively higher yields than in fixed bed reactors by controlling the oxygen supply through the membrane. A membrane reactor has the advantage of precisely controlling the rate of delivery of oxygen to the catalyst. This facility permits balancing the rate of oxidation and reduction of the catalyst. In addition, membrane reactors minimize the concentration of gas phase oxygen thus reducing non selective gas phase reactions, which are believed to be a main route for formation of CO{sub x} products. Such gas phase reactions are a cause for decreased selectivity in oxidative coupling of methane in conventional flow reactors. Membrane reactors could also produce higher product yields by providing better distribution of the reactant gases over the catalyst than the conventional plug flow reactors. Modeling work which aimed at predicting the observed experimental trends in porous membrane reactors was also undertaken in this research program.

  14. Microchannel Reactor System for Catalytic Hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Adeniyi Lawal; Woo Lee; Ron Besser; Donald Kientzler; Luke Achenie

    2010-12-22

    We successfully demonstrated a novel process intensification concept enabled by the development of microchannel reactors, for energy efficient catalytic hydrogenation reactions at moderate temperature, and pressure, and low solvent levels. We designed, fabricated, evaluated, and optimized a laboratory-scale microchannel reactor system for hydrogenation of onitroanisole and a proprietary BMS molecule. In the second phase of the program, as a prelude to full-scale commercialization, we designed and developed a fully-automated skid-mounted multichannel microreactor pilot plant system for multiphase reactions. The system is capable of processing 1 – 10 kg/h of liquid substrate, and an industrially relevant immiscible liquid-liquid was successfully demonstrated on the system. Our microreactor-based pilot plant is one-of-akind. We anticipate that this process intensification concept, if successfully demonstrated, will provide a paradigm-changing basis for replacing existing energy inefficient, cost ineffective, environmentally detrimental slurry semi-batch reactor-based manufacturing practiced in the pharmaceutical and fine chemicals industries.

  15. A study on naphtha catalytic reforming reactor simulation and analysis.

    Science.gov (United States)

    Liang, Ke-min; Guo, Hai-yan; Pan, Shi-wei

    2005-06-01

    A naphtha catalytic reforming unit with four reactors in series is analyzed. A physical model is proposed to describe the catalytic reforming radial flow reactor. Kinetics and thermodynamics equations are selected to describe the naphtha catalytic reforming reactions characteristics based on idealizing the complex naphtha mixture by representing the paraffin, naphthene, and aromatic groups by single compounds. The simulation results based above models agree very well with actual operation unit data.

  16. A study on naphtha catalytic reforming reactor simulation and analysis

    OpenAIRE

    Liang, Ke-min; Guo, Hai-yan; Pan, Shi-wei

    2005-01-01

    A naphtha catalytic reforming unit with four reactors in series is analyzed. A physical model is proposed to describe the catalytic reforming radial flow reactor. Kinetics and thermodynamics equations are selected to describe the naphtha catalytic reforming reactions characteristics based on idealizing the complex naphtha mixture by representing the paraffin, naphthene, and aromatic groups by single compounds. The simulation results based above models agree very well with actual operation uni...

  17. Catalytic reactor for low-Btu fuels

    Science.gov (United States)

    Smith, Lance; Etemad, Shahrokh; Karim, Hasan; Pfefferle, William C.

    2009-04-21

    An improved catalytic reactor includes a housing having a plate positioned therein defining a first zone and a second zone, and a plurality of conduits fabricated from a heat conducting material and adapted for conducting a fluid therethrough. The conduits are positioned within the housing such that the conduit exterior surfaces and the housing interior surface within the second zone define a first flow path while the conduit interior surfaces define a second flow path through the second zone and not in fluid communication with the first flow path. The conduit exits define a second flow path exit, the conduit exits and the first flow path exit being proximately located and interspersed. The conduits define at least one expanded section that contacts adjacent conduits thereby spacing the conduits within the second zone and forming first flow path exit flow orifices having an aggregate exit area greater than a defined percent of the housing exit plane area. Lastly, at least a portion of the first flow path defines a catalytically active surface.

  18. Catalytic Reactor For Oxidizing Mercury Vapor

    Science.gov (United States)

    Helfritch, Dennis J.

    1998-07-28

    A catalytic reactor (10) for oxidizing elemental mercury contained in flue gas is provided. The catalyst reactor (10) comprises within a flue gas conduit a perforated corona discharge plate (30a, b) having a plurality of through openings (33) and a plurality of projecting corona discharge electrodes (31); a perforated electrode plate (40a, b, c) having a plurality of through openings (43) axially aligned with the through openings (33) of the perforated corona discharge plate (30a, b) displaced from and opposing the tips of the corona discharge electrodes (31); and a catalyst member (60a, b, c, d) overlaying that face of the perforated electrode plate (40a, b, c) opposing the tips of the corona discharge electrodes (31). A uniformly distributed corona discharge plasma (1000) is intermittently generated between the plurality of corona discharge electrode tips (31) and the catalyst member (60a, b, c, d) when a stream of flue gas is passed through the conduit. During those periods when corona discharge (1000) is not being generated, the catalyst molecules of the catalyst member (60a, b, c, d) adsorb mercury vapor contained in the passing flue gas. During those periods when corona discharge (1000) is being generated, ions and active radicals contained in the generated corona discharge plasma (1000) desorb the mercury from the catalyst molecules of the catalyst member (60a, b, c, d), oxidizing the mercury in virtually simultaneous manner. The desorption process regenerates and activates the catalyst member molecules.

  19. Adlayers of palladium particles and their aggregates on porous polypropylene hollow fiber membranes as hydrogenization contractors/reactors

    NARCIS (Netherlands)

    Volkov, V.V.; Lebedeva, V.I.; Petrova, I.V.; Bobyl, A.V.; Konnikov, S.G.; Roldughin, V.I.; Erkel, J. van; Tereshchenko, G.F.

    2011-01-01

    Principal approaches for the preparation of catalytic membrane reactors based on polymer membranes containing palladium nanoparticles and for the description of their characteristics are presented. The method for the development of adlayers composed of palladium nanoparticles and their aggregates on

  20. Polymer-stabilized palladium nanoparticles for catalytic membranes: ad hoc polymer fabrication

    OpenAIRE

    Dom?nech, Berta; Mu?oz, Maria; Muraviev, Dmitri N; Macan?s, Jorge

    2011-01-01

    Metal nanoparticles are known as highly effective catalysts although their immobilization on solid supports is frequently required to prevent aggregation and to facilitate the catalyst application, recovery, and reuse. This paper reports the intermatrix synthesis of Pd0 nanoparticles in sulfonated polyethersulfone with Cardo group membranes and their use as nanocomposite catalytic membrane reactors. The synthesized polymer and the corresponding nanocomposite were characterized by spectr...

  1. Analysis of heterogeneous oxygen exchange and fuel oxidation on the catalytic surface of perovskite membranes

    KAUST Repository

    Hong, Jongsup

    2013-10-01

    The catalytic kinetics of oxygen surface exchange and fuel oxidation for a perovskite membrane is investigated in terms of the thermodynamic state in the immediate vicinity of or on the membrane surface. Perovskite membranes have been shown to exhibit both oxygen perm-selectivity and catalytic activity for hydrocarbon conversion. A fundamental description of their catalytic surface reactions is needed. In this study, we infer the kinetic parameters for heterogeneous oxygen surface exchange and catalytic fuel conversion reactions, based on permeation rate measurements and a spatially resolved physical model that incorporates detailed chemical kinetics and transport in the gas-phase. The conservation equations for surface and bulk species are coupled with those of the gas-phase species through the species production rates from surface reactions. It is shown that oxygen surface exchange is limited by dissociative/associative adsorption/desorption of oxygen molecules onto/from the membrane surface. On the sweep side, while the catalytic conversion of methane to methyl radical governs the overall surface reactions at high temperature, carbon monoxide oxidation on the membrane surface is dominant at low temperature. Given the sweep side conditions considered in ITM reactor experiments, gas-phase reactions also play an important role, indicating the significance of investigating both homogeneous and heterogeneous chemistry and their coupling when examining the results. We show that the local thermodynamic state at the membrane surface should be considered when constructing and examining models of oxygen permeation and heterogeneous chemistry. © 2013 Elsevier B.V.

  2. Preparation of amino-functionalized regenerated cellulose membranes with high catalytic activity.

    Science.gov (United States)

    Wang, Wei; Bai, Qian; Liang, Tao; Bai, Huiyu; Liu, Xiaoya

    2017-09-01

    The modification of regenerated cellulose (RC) membranes was carried out by using silane coupling agents presenting primary and secondary amino-groups. The grafting of the amino groups onto the modified cellulose molecule was confirmed by X-ray photoelectron spectroscopies and 13 C nuclear magnetic resonance spectroscopic analyses. The crystallinity of the cellulose membranes (CM) decreased after chemical modification as indicated by the X-ray diffraction results. Moreover, a denser structure was observed at the surface and cross section of the modified membranes by SEM images. The contact angle measurements showed that the silane coupling treatment enhanced the hydrophobicity of the obtained materials. Then the catalytic properties of two types of modified membranes were studied in a batch process by evaluating their catalytic performance in a Knoevenagel condensation. The results indicated that the cellulose membrane grafted with many secondary amines exhibited a better catalytic activity compared to the one grafted only by primary amines. In addition, the compact structure of the modified membranes permitted their application in a pervaporation catalytic membrane reactor. Therefore, functional CM that prepared in this paper represented a promising material in the field of industrial catalysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. One-Step Synthesis of Zeolite Membranes Containing Catalytic Metal Nanoclusters.

    Science.gov (United States)

    Kim, Seok-Jhin; Tan, Shuai; Taborga Claure, Micaela; Briones Gil, Laura; More, Karren L; Liu, Yujun; Moore, Jason S; Dixit, Ravindra S; Pendergast, John G; Sholl, David S; Jones, Christopher W; Nair, Sankar

    2016-09-21

    Metal-loaded zeolitic membranes are promising candidates as catalytic membrane reactors. We report a one-step synthesis method to synthesize zeolite membranes containing metal nanoclusters, that has advantages in comparison to multistep methods such as impregnation and ion exchange. Pure-silica MFI zeolite-Pt hybrid membranes were prepared by hydrothermal synthesis with addition of 3-mercaptopropyl-trimethoxysilane (MPS) and a platinum precursor. Composition analysis and mapping by energy-dispersive X-ray spectroscopy (EDX) reveal that Pt ions/clusters are uniformly distributed along the membrane cross-section. High-magnification scanning transmission electron microscopy (STEM) analysis shows that Pt metal clusters in the hybrid zeolite membrane have a diameter distribution in the range of 0.5-2.0 nm. In contrast, a pure-silica MFI membrane synthesized from an MPS-free solution shows negligible incorporation of Pt metal clusters. To characterize the properties of the hybrid (zeolite/metal) membrane, it was used as a catalytic membrane reactor (CMR) for high-temperature propane dehydrogenation (PDH) at 600 °C and 1 atm. The results indicate that Pt metal clusters formed within the MFI zeolite membrane can serve as effective catalysts for high-temperature PDH reaction along with H2 removal via membrane permeation, thereby increasing both conversion and selectivity in relation to a conventional membrane reactor containing an equivalent amount of packed Pt catalyst in contact with an MFI membrane. The hybrid zeolite-Pt CMR also showed stable conversion and selectivity upon extended high-temperature operation (12 h), indicating that encapsulation in the zeolite allowed thermal stabilization of the Pt nanoclusters and reduced catalyst deactivation.

  4. Degradation pathway of malachite green in a novel dual-tank photoelectrochemical catalytic reactor

    International Nuclear Information System (INIS)

    Diao, Zenghui; Li, Mingyu; Zeng, Fanyin; Song, Lin; Qiu, Rongliang

    2013-01-01

    Highlights: • A novel dual-tank photoelectrochemical catalytic reactor was designed. • Malachite green degraded in bipolar double-effect mode. • Salt bridge replaced by a cation exchange membrane in the reactor. • Degradation pathways of malachite green in the cathode and anode tanks were similar. -- Abstract: A novel dual-tank photoelectrochemical catalytic reactor was designed to investigate the degradation pathway of malachite green. A thermally formed TiO 2 /Ti thin film electrode was used as photoanode, graphite was used as cathode, and a saturated calomel electrode was employed as the reference electrode in the reactor. In the reactor, the anode and cathode tanks were connected by a cation exchange membrane. Results showed that the decolorization ratio of malachite green in the anode and cathode was 98.5 and 96.5% after 120 min, respectively. Malachite green in the two anode and cathode tanks was oxidized, achieving the bipolar double effect. Malachite green in both the anode and cathode tanks exhibited similar catalytic degradation pathways. The double bond of the malachite green molecule was attacked by strong oxidative hydroxyl radicals, after which the organic compound was degraded by the two pathways into 4,4-bis(dimethylamino) benzophenone, 4-(dimethylamino) benzophenone, 4-(dimethylamino) phenol, and other intermediate products. Eventually, malachite green was degraded into oxalic acid as a small molecular organic acid, which was degraded by processes such as demethylation, deamination, nitration, substitution, addition, and other reactions

  5. Degradation pathway of malachite green in a novel dual-tank photoelectrochemical catalytic reactor

    Energy Technology Data Exchange (ETDEWEB)

    Diao, Zenghui [Department of Environmental Engineering, Jinan University, Guangzhou 510630 (China); School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Li, Mingyu, E-mail: tlimy@jnu.edu.cn [Department of Environmental Engineering, Jinan University, Guangzhou 510630 (China); Zeng, Fanyin; Song, Lin [Department of Environmental Engineering, Jinan University, Guangzhou 510630 (China); Qiu, Rongliang [School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)

    2013-09-15

    Highlights: • A novel dual-tank photoelectrochemical catalytic reactor was designed. • Malachite green degraded in bipolar double-effect mode. • Salt bridge replaced by a cation exchange membrane in the reactor. • Degradation pathways of malachite green in the cathode and anode tanks were similar. -- Abstract: A novel dual-tank photoelectrochemical catalytic reactor was designed to investigate the degradation pathway of malachite green. A thermally formed TiO{sub 2}/Ti thin film electrode was used as photoanode, graphite was used as cathode, and a saturated calomel electrode was employed as the reference electrode in the reactor. In the reactor, the anode and cathode tanks were connected by a cation exchange membrane. Results showed that the decolorization ratio of malachite green in the anode and cathode was 98.5 and 96.5% after 120 min, respectively. Malachite green in the two anode and cathode tanks was oxidized, achieving the bipolar double effect. Malachite green in both the anode and cathode tanks exhibited similar catalytic degradation pathways. The double bond of the malachite green molecule was attacked by strong oxidative hydroxyl radicals, after which the organic compound was degraded by the two pathways into 4,4-bis(dimethylamino) benzophenone, 4-(dimethylamino) benzophenone, 4-(dimethylamino) phenol, and other intermediate products. Eventually, malachite green was degraded into oxalic acid as a small molecular organic acid, which was degraded by processes such as demethylation, deamination, nitration, substitution, addition, and other reactions.

  6. High temperature ceramic membrane reactors for coal liquid upgrading

    Energy Technology Data Exchange (ETDEWEB)

    Tsotsis, T.T. (University of Southern California, Los Angeles, CA (United States). Dept. of Chemical Engineering); Liu, P.K.T. (Aluminum Co. of America, Pittsburgh, PA (United States)); Webster, I.A. (Unocal Corp., Los Angeles, CA (United States))

    1992-01-01

    Membrane reactors are today finding extensive applications for gas and vapor phase catalytic reactions (see discussion in the introduction and recent reviews by Armor [92], Hsieh [93] and Tsotsis et al. [941]). There have not been any published reports, however, of their use in high pressure and temperature liquid-phase applications. The idea to apply membrane reactor technology to coal liquid upgrading has resulted from a series of experimental investigations by our group of petroleum and coal asphaltene transport through model membranes. Coal liquids contain polycyclic aromatic compounds, which not only present potential difficulties in upgrading, storage and coprocessing, but are also bioactive. Direct coal liquefaction is perceived today as a two-stage process, which involves a first stage of thermal (or catalytic) dissolution of coal, followed by a second stage, in which the resulting products of the first stage are catalytically upgraded. Even in the presence of hydrogen, the oil products of the second stage are thought to equilibrate with the heavier (asphaltenic and preasphaltenic) components found in the feedstream. The possibility exists for this smaller molecular fraction to recondense with the unreacted heavy components and form even heavier undesirable components like char and coke. One way to diminish these regressive reactions is to selectively remove these smaller molecular weight fractions once they are formed and prior to recondensation. This can, at least in principle, be accomplished through the use of high temperature membrane reactors, using ceramic membranes which are permselective for the desired products of the coal liquid upgrading process. An additional incentive to do so is in order to eliminate the further hydrogenation and hydrocracking of liquid products to undesirable light gases.

  7. The Membrane Gradostat Reactor: Secondary metabolite production ...

    African Journals Online (AJOL)

    SERVER

    2007-05-16

    May 16, 2007 ... immobilise microbial cells or enzymes, depending on the bioreactor's application. Operational ... perspective. Key words: Membrane bioreactor, gradostat reactor, secondary metabolite production, biofilm, wastewater treatment. INTRODUCTION ... suitable to immobilize P. chrysosporium biofilms in MGR.

  8. Hydrogen Production by Catalytic Partial Oxidation of Coke Oven Gas in BaCo0.7Fe0.3-xZrxO3-δ Ceramic Membrane Reactors

    Directory of Open Access Journals (Sweden)

    Yao Weilin

    2016-01-01

    Full Text Available The BaCo0.7Fe0.3-xZrxO3-δ (BCFZ, x = 0.04–0.12 mixed ionic–electronic conducting (MIEC membranes were synthesized with a sol–gel method and evaluated as potential membrane reactor materials for the partial oxidation of coke oven gas (COG. The effect of zirconium content on the phase structure, microstructure and performance of the BCFZ membrane under He or COG atmosphere were systemically investigated. The BaCo0.7Fe0.24Zr0.06O3-δ membrane exhibited the best oxygen permeability and good operation stability, which could be a potential candidate of the membrane materials for hydrogen production through the partial oxidation of COG.

  9. Polymer and Membrane Design for Low Temperature Catalytic Reactions

    KAUST Repository

    Villalobos, Luis Francisco

    2016-02-29

    Catalytically active asymmetric membranes have been developed with high loadings of palladium nanoparticles located solely in the membrane\\'s ultrathin skin layer. The manufacturing of these membranes requires polymers with functional groups, which can form insoluble complexes with palladium ions. Three polymers have been synthesized for this purpose and a complexation/nonsolvent induced phase separation followed by a palladium reduction step is carried out to prepare such membranes. Parameters to optimize the skin layer thickness and porosity, the palladium loading in this layer, and the palladium nanoparticles size are determined. The catalytic activity of the membranes is verified with the reduction of a nitro-compound and with a liquid phase Suzuki-Miyaura coupling reaction. Very low reaction times are observed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Role of membranes and membrane reactors in the hydrogen supply of fuel cells for transports

    Energy Technology Data Exchange (ETDEWEB)

    Julbe, A.; Guizard, Ch. [Institut Europeen des Membranes, UMII, Lab. des Materiaux et des Procedes Membranaires, CNRS UMR 5635, 34 - Montpellier (France)

    2000-07-01

    Production, storage and supply of high-purity hydrogen as a clean and efficient fuel is central to fuel cells technology, in particular in vehicle traction. Actually, technologies for handling liquefied or gaseous hydrogen in transports are not available so that a number of alternative fuels are considered with the aim of in-situ generation of hydrogen through catalytic processes. The integrated concept of membrane reactors (MRs) can greatly benefit to these technologies. Particular emphasis is put on inorganic membranes and their role in MRs performance for H{sub 2} production.

  11. Free-standing hierarchical α-MnO2@CuO membrane for catalytic filtration degradation of organic pollutants.

    Science.gov (United States)

    Luo, Xinsheng; Liang, Heng; Qu, Fangshu; Ding, An; Cheng, Xiaoxiang; Tang, Chuyang Y; Li, Guibai

    2018-06-01

    Catalytic membrane, due to its compact reactor assembling, high catalytic performance as well as low energy consumption, has proved to be more attractive for wastewater treatment. In this work, a free-standing α-MnO 2 @CuO membrane with hierarchical nanostructures was prepared and evaluated as the catalytic membrane to generate radicals from peroxymonosulfate (PMS) for the oxidative degradation of organic dyes in aqueous solution. Benefiting from the high mass transport efficiency and the hierarchical nanostructures, a superior catalytic activity of the membrane was observed for organic dyes degradation. As a typical organic dye, more than 99% of methylene blue (MB) was degraded within 0.23 s using dead-end filtration cell. The effects of flow rate, PMS concentration and buffer solution on MB degradation were further investigated. Besides MB, the catalytic membrane also showed excellent performance for the removal of other dyes, such as congo red, methyl orange, rhodamine B, acid chrome blue K and malachite green. Moreover, the mechanism study indicated that OH and SO 4 - generated from the interaction between PMS and Mn/Cu species with different oxidation states mainly accounted for the dyes degradation. The catalytic filtration process using α-MnO 2 @CuO catalytic membrane could provide a novel method for wastewater purification with high efficiency and low energy consumption. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Use of a Ceramic Membrane to Improve the Performance of Two-Separate-Phase Biocatalytic Membrane Reactor.

    Science.gov (United States)

    Ranieri, Giuseppe; Mazzei, Rosalinda; Wu, Zhentao; Li, Kang; Giorno, Lidietta

    2016-03-14

    Biocatalytic membrane reactors (BMR) combining reaction and separation within the same unit have many advantages over conventional reactor designs. Ceramic membranes are an attractive alternative to polymeric membranes in membrane biotechnology due to their high chemical, thermal and mechanical resistance. Another important use is their potential application in a biphasic membrane system, where support solvent resistance is highly needed. In this work, the preparation of asymmetric ceramic hollow fibre membranes and their use in a two-separate-phase biocatalytic membrane reactor will be described. The asymmetric ceramic hollow fibre membranes were prepared using a combined phase inversion and sintering technique. The prepared fibres were then used as support for lipase covalent immobilization in order to develop a two-separate-phase biocatalytic membrane reactor. A functionalization method was proposed in order to increase the density of the reactive hydroxyl groups on the surface of ceramic membranes, which were then amino-activated and treated with a crosslinker. The performance and the stability of the immobilized lipase were investigated as a function of the amount of the immobilized biocatalytst. Results showed that it is possible to immobilize lipase on a ceramic membrane without altering its catalytic performance (initial residual specific activity 93%), which remains constant after 6 reaction cycles.

  13. Use of a Ceramic Membrane to Improve the Performance of Two-Separate-Phase Biocatalytic Membrane Reactor

    Directory of Open Access Journals (Sweden)

    Giuseppe Ranieri

    2016-03-01

    Full Text Available Biocatalytic membrane reactors (BMR combining reaction and separation within the same unit have many advantages over conventional reactor designs. Ceramic membranes are an attractive alternative to polymeric membranes in membrane biotechnology due to their high chemical, thermal and mechanical resistance. Another important use is their potential application in a biphasic membrane system, where support solvent resistance is highly needed. In this work, the preparation of asymmetric ceramic hollow fibre membranes and their use in a two-separate-phase biocatalytic membrane reactor will be described. The asymmetric ceramic hollow fibre membranes were prepared using a combined phase inversion and sintering technique. The prepared fibres were then used as support for lipase covalent immobilization in order to develop a two-separate-phase biocatalytic membrane reactor. A functionalization method was proposed in order to increase the density of the reactive hydroxyl groups on the surface of ceramic membranes, which were then amino-activated and treated with a crosslinker. The performance and the stability of the immobilized lipase were investigated as a function of the amount of the immobilized biocatalytst. Results showed that it is possible to immobilize lipase on a ceramic membrane without altering its catalytic performance (initial residual specific activity 93%, which remains constant after 6 reaction cycles.

  14. Staged membrane oxidation reactor system

    Science.gov (United States)

    Repasky, John Michael; Carolan, Michael Francis; Stein, VanEric Edward; Chen, Christopher Ming-Poh

    2012-09-11

    Ion transport membrane oxidation system comprising (a) two or more membrane oxidation stages, each stage comprising a reactant zone, an oxidant zone, one or more ion transport membranes separating the reactant zone from the oxidant zone, a reactant gas inlet region, a reactant gas outlet region, an oxidant gas inlet region, and an oxidant gas outlet region; (b) an interstage reactant gas flow path disposed between each pair of membrane oxidation stages and adapted to place the reactant gas outlet region of a first stage of the pair in flow communication with the reactant gas inlet region of a second stage of the pair; and (c) one or more reactant interstage feed gas lines, each line being in flow communication with any interstage reactant gas flow path or with the reactant zone of any membrane oxidation stage receiving interstage reactant gas.

  15. Chemically-Modified Cellulose Paper as a Microstructured Catalytic Reactor

    Directory of Open Access Journals (Sweden)

    Hirotaka Koga

    2015-01-01

    Full Text Available We discuss the successful use of chemically-modified cellulose paper as a microstructured catalytic reactor for the production of useful chemicals. The chemical modification of cellulose paper was achieved using a silane-coupling technique. Amine-modified paper was directly used as a base catalyst for the Knoevenagel condensation reaction. Methacrylate-modified paper was used for the immobilization of lipase and then in nonaqueous transesterification processes. These catalytic paper materials offer high reaction efficiencies and have excellent practical properties. We suggest that the paper-specific interconnected microstructure with pulp fiber networks provides fast mixing of the reactants and efficient transport of the reactants to the catalytically-active sites. This concept is expected to be a promising route to green and sustainable chemistry.

  16. CATALYTIC RECOMBINER FOR A NUCLEAR REACTOR

    Science.gov (United States)

    King, L.D.P.

    1960-07-01

    A hydrogen-oxygen recombiner is described for use with water-boiler type reactors. The catalyst used is the wellknown platinized alumina, and the novelty lies in the structural arrangement used to prevent flashback through the gas input system. The recombiner is cylindrical, the gases at the input end being deflected by a baffle plate through a first flashback shield of steel shot into an annular passage adjacent to and extending the full length of the housing. Below the baffle plate the gases flow first through an outer annular array of alumina pellets which serve as a second flashback shield, a means of distributing the flowing gases evenly and as a means of reducing radiation losses to the walls. Thereafter the gases flow inio the centrally disposed catalyst bed where recombination is effected. The steam and uncombined gases flow into a centrally disposed cylindrical passage inside the catalyst bod and thereafter out through the exit port. A high rate of recombination is effected.

  17. High Flux Metallic Membranes for Hydrogen Recovery and Membrane Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Buxbaum, Robert

    2010-06-30

    We made and tested over 250 new alloys for use as lower cost, higher flux hydrogen extraction membrane materials. Most of these were intermetallic, or contained significant intermetallic content, particularly based on B2 alloy compositions with at least one refractory component; B2 intermetallics resemble BCC alloys, in structure, but the atoms have relatively fixed positions, with one atom at the corners of the cube, the other at the centers. The target materals we were looking for would contain little or no expensive elements, no strongly toxic or radioactive elements, would have high flux to hydrogen, while being fabricable, brazable, and relatively immune to hydrogen embrittlement and corrosion in operation. The best combination of properties of the membrane materials we developed was, in my opinion, a Pd-coated membrane consisting of V -9 atomic % Pd. This material was relatively cheap, had 5 times the flux of Pd under the same pressure differential, was reasonably easy to fabricate and braze, and not bad in terms of embrittlement. Based on all these factors we project, about 1/3 the cost of Pd, on an area basis for a membrane designed to last 20 years, or 1/15 the cost on a flux basis. Alternatives to this membrane replaced significant fractions of the Pd with Ni and or Co. The cost for these membranes was lower, but so was the flux. We produced successful brazed products from the membrane materials, and made them into flat sheets. We tested, unsuccessfully, several means of fabricating thematerials into tubes, and eventually built a membrane reactor using a new, flat-plate design: a disc and doughnut arrangement, a design that seems well- suited to clean hydrogen production from coal. The membranes and reactor were tested successfully at Western Research. A larger equipment company (Chart Industries) produced similar results using a different flat-plate reactor design. Cost projections of the membrane are shown to be attractive.

  18. Coal hydrogenation and deashing in ebullated bed catalytic reactor

    Science.gov (United States)

    Huibers, Derk T. A.; Johanson, Edwin S.

    1983-01-01

    An improved process for hydrogenation of coal containing ash with agglomeration and removal of ash from an ebullated bed catalytic reactor to produce deashed hydrocarbon liquid and gas products. In the process, a flowable coal-oil slurry is reacted with hydrogen in an ebullated catalyst bed reaction zone at elevated temperature and pressure conditions. The upward velocity and viscosity of the reactor liquid are controlled so that a substantial portion of the ash released from the coal is agglomerated to form larger particles in the upper portion of the reactor above the catalyst bed, from which the agglomerated ash is separately withdrawn along with adhering reaction zone liquid. The resulting hydrogenated hydrocarbon effluent material product is phase separated to remove vapor fractions, after which any ash remaining in the liquid fraction can be removed to produce substantially ash-free coal-derived liquid products.

  19. Carbon nano-fiber based membrane reactor for selective nitrite hydrogenation

    NARCIS (Netherlands)

    Brunet Espinosa, Roger; Rafieian, D.; Lammertink, Rob G.H.; Lefferts, Leonardus

    2016-01-01

    Catalytic hydrogenation of nitrite in drinking water demands control over the selectivity towards nitrogen, minimizing the formation of ammonia. This selectivity is strongly influenced by the H/N ratio of reaction intermediates at the catalyst surface. Therefore, we fabricated a membrane reactor

  20. Biodiesel production using a membrane reactor.

    Science.gov (United States)

    Dubé, M A; Tremblay, A Y; Liu, J

    2007-02-01

    The immiscibility of canola oil in methanol provides a mass-transfer challenge in the early stages of the transesterification of canola oil in the production of fatty acid methyl esters (FAME or biodiesel). To overcome or rather, exploit this situation, a two-phase membrane reactor was developed to produce FAME from canola oil and methanol. The transesterification of canola oil was performed via both acid- or base-catalysis. Runs were performed in the membrane reactor in semi-batch mode at 60, 65 and 70 degrees C and at different catalyst concentrations and feed flow rates. Increases in temperature, catalyst concentration and feedstock (methanol/oil) flow rate significantly increased the conversion of oil to biodiesel. The novel reactor enabled the separation of reaction products (FAME/glycerol in methanol) from the original canola oil feed. The two-phase membrane reactor was particularly useful in removing unreacted canola oil from the FAME product yielding high purity biodiesel and shifting the reaction equilibrium to the product side.

  1. Membrane reactors for continuous coenzyme regeneration

    Science.gov (United States)

    Wandrey, C.; Wichmann, R.

    1982-12-01

    The importance of continuous coenzyme regeneration is discussed with respect to chemical reaction engineering. The benefit of coenzymes covalently bound to water soluble polymers is especially stressed. The performance of membrane reactors for coenzyme regeneration is discussed in comparison with other reactor concepts. The coenzyme dependent production of L-amino acids from the corresponding alpha-keto acids is used to illustrate how precise turnover numbers as a function of enzyme/coenzyme ratio, initial substrate concentration, and conversion are obtained. Thus, it becomes possible to develop a concept for optimal operating points with respect to enzyme, coenzyme, and substrate costs per unit weight of product.

  2. Anodized Aluminum Oxide Templated Synthesis of Metal-Organic Frameworks Used as Membrane Reactors.

    Science.gov (United States)

    Yu, Yifu; Wu, Xue-Jun; Zhao, Meiting; Ma, Qinglang; Chen, Junze; Chen, Bo; Sindoro, Melinda; Yang, Jian; Han, Shikui; Lu, Qipeng; Zhang, Hua

    2017-01-09

    The incorporation of metal-organic frameworks (MOFs) into membrane-shaped architectures is of great importance for practical applications. The currently synthesized MOF-based membranes show many disadvantages, such as poor compatibility, low dispersity, and instability, which severely limit their utility. Herein, we present a general, facile, and robust approach for the synthesis of MOF-based composite membranes through the in situ growth of MOF plates in the channels of anodized aluminum oxide (AAO) membranes. After being used as catalysis reactors, they exhibit high catalytic performance and stability in the Knoevenagel condensation reaction. The high catalytic performance might be attributed to the intrinsic structure of MOF-based composite membranes, which can remove the products from the reaction zone quickly, and prevent the aggregation and loss of catalysts during reaction and recycling process. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Experimental studies on catalytic hydrogen recombiners for light water reactors

    International Nuclear Information System (INIS)

    Drinovac, P.

    2006-01-01

    In the course of core melt accidents in nuclear power plants a large amount of hydrogen can be produced and form an explosive or even detonative gas mixture with aerial oxygen in the reactor building. In the containment atmosphere of pressurized water reactors hydrogen combines a phlogistically with the oxygen present to form water vapor even at room temperature. In the past, experimental work conducted at various facilities has contributed little or nothing to an understanding of the operating principles of catalytic recombiners. Hence, the purpose of the present study was to conduct detailed investigations on a section of a recombiner essentially in order to deepen the understanding of reaction kinetics and heat transport processes. The results of the experiments presented in this dissertation form a large data base of measurements which provides an insight into the processes taking place in recombiners. The reaction-kinetic interpretation of the measured data confirms and deepens the diffusion theory - proposed in an earlier study. Thus it is now possible to validate detailed numeric models representing the processes in recombiners. Consequently the present study serves to broaden and corroborate competence in this significant area of reactor technology. In addition, the empirical knowledge thus gained may be used for a critical reassessment of previous numeric model calculations. (orig.)

  4. Catalytic reactor for promoting a chemical reaction on a fluid passing therethrough

    Science.gov (United States)

    Roychoudhury, Subir (Inventor); Pfefferle, William C. (Inventor)

    2001-01-01

    A catalytic reactor with an auxiliary heating structure for raising the temperature of a fluid passing therethrough whereby the catalytic reaction is promoted. The invention is a apparatus employing multiple electrical heating elements electrically isolated from one another by insulators that are an integral part of the flow path. The invention provides step heating of a fluid as the fluid passes through the reactor.

  5. A review on patents for hydrogen production using membrane reactors

    NARCIS (Netherlands)

    Gallucci, F.; Basile, Angelo; Iulianelli, Adolfo; Kuipers, J.A.M.

    2009-01-01

    Membrane reactors are a modern configuration which integrates reaction and separation units in one vessel and results in a tremendous degree of process intensification. Application of membrane reactors for hydrogen production has been widely studied in literature because membranes with infinite

  6. Phospholipase C-catalyzed sphingomyelin hydrolysis in a membrane reactor for ceramide production

    DEFF Research Database (Denmark)

    Zhang, Long; Liang, Shanshan; Hellgren, Lars

    2008-01-01

    A membrane reactor for the production of ceramide through sphingomyelin hydrolysis with phospholipase C from Clostridium perfringens was studied for the first time. Ceramide has raised a large interest as an active component in both pharmaceutical and cosmetic industry. The enzymatic hydrolysis...... of sphingomyelin has been proven to be a feasible method to produce ceramide. In the membrane reactor constructed, the aqueous phase and the organic phase were separated by a membrane containing the immobilized enzyme, while the organic phasewas continuously circulated. Among the 10 selected membranes, the enzyme...... immobilized in membrane RC 70PP had low immobilization efficiency, but retained the highest catalytic activity. Three immobilization methods, i.e. filtration (adsorption/entrapment), covalent binding, and cross-linking, were compared. The enzyme immobilized by filtration had the highest activity even under...

  7. Method for recovering catalytic elements from fuel cell membrane electrode assemblies

    Science.gov (United States)

    Shore, Lawrence [Edison, NJ; Matlin, Ramail [Berkeley Heights, NJ; Heinz, Robert [Ludwigshafen, DE

    2012-06-26

    A method for recovering catalytic elements from a fuel cell membrane electrode assembly is provided. The method includes converting the membrane electrode assembly into a particulate material, wetting the particulate material, forming a slurry comprising the wetted particulate material and an acid leachate adapted to dissolve at least one of the catalytic elements into a soluble catalytic element salt, separating the slurry into a depleted particulate material and a supernatant containing the catalytic element salt, and washing the depleted particulate material to remove any catalytic element salt retained within pores in the depleted particulate material.

  8. Hydrogen enrichment and separation from synthesis gas by the use of a membrane reactor

    International Nuclear Information System (INIS)

    Sanchez, J.M.; Barreiro, M.M.; Marono, M.

    2011-01-01

    One of the objectives of the CHRISGAS project was to study innovative gas separation and gas upgrading systems that have not been developed sufficiently yet to be tested at a demonstration scale within the time frame of the project, but which show some attractive merits and features for further development. In this framework CIEMAT studied, at bench scale, hydrogen enrichment and separation from syngas by the use of membranes and membrane catalytic reactors. In this paper results about hydrogen separation from synthesis gas by means of selective membranes are presented. Studies dealt with the evaluation of permeation and selectivity to hydrogen of prepared and pre-commercial Pd-based membranes. Whereas prepared membranes turned out to be non-selective, due to discontinuities of the palladium layer, studies conducted with the pre-commercial membrane showed that by means of a membrane reactor it is possible to completely separate hydrogen from the other gas components and produce pure hydrogen as a permeate stream, even in the case of complex reaction system (H 2 /CO/CO 2 /H 2 O) under WGS conditions gas mixtures. The advantages of using a water-gas shift membrane reactor (MR) over a traditional fixed bed reactor (TR) have also been studied. The experimental device included the pre-commercial Pd-based membrane and a commercial high temperature Fe-Cr-based, WGS catalyst, which was packed in the annulus between the membrane and the reactor outer shell. Results show that in the MR concept, removal of H 2 from the reaction side has a positive effect on WGS reaction, reaching higher CO conversion than in a traditional packed bed reactor at a given temperature. On increasing pressure on the reaction side permeation is enhanced and hence carbon monoxide conversion increases. -- Highlights: → H 2 enrichment and separation using a bench-scale membrane reactor MR is studied. → Permeation and selectivity to H 2 of Pd-based membranes was determined. → Complete separation

  9. Upgrading of Gasification Gases by means of a Catalytic Membrane Reactor: WGS Catalysts and Inorganic Palladium Membranes HENRECA Project (ENE2004-07758-CO2-01). Final Report; Estudios de Enriquecimiento en H{sub 2} de Gases de Gasificacion mediante el Uso Reactor Catalitico de Membranas: Catalizadores WGS y Membranas Inorganicas de Paladio. Informe Final Proyecto HENRECA (ENE2004-07758-C02-01)

    Energy Technology Data Exchange (ETDEWEB)

    Maranon Bujan, M.; Sanchez Hervas, J. M.; Barreiro Carou, M. del

    2008-07-01

    The combination of a CO catalytic converter with a highly hydrogen selective membrane out stands as a very promising technology for the upgrading of biomass gasification gases. The advantages of this combined system over the traditional two stages WGS technology has been investigated within the HENRECA project, financed under the Spanish PN 2004-2007 of the Ministry of Science and Technology. This project started in September 2004 and had a duration of three years. The Division of Combustion and Gasification of CIEMAT participates in this project in three main activities: the study of the catalytic activity of WGS catalysts synthesised by the other partner of the project (University Rey Juan Carlos), the design of the reaction-separation system and the design and construction of a bench-scale pilot plant where the performance of the membranes prepared by URJC and the catalytic membrane system were investigated. This report describes the activities carried out within the project and the main results obtained. (Author) 14 ref.

  10. A Self-Switchable Polymer Reactor for Controlled Catalytic Chemistry Processes with a Hyperbranched Structure

    Directory of Open Access Journals (Sweden)

    Rong Luo

    2018-02-01

    Full Text Available A self-switchable polymer reactor with a hyperbranched structure for controlled catalytic chemistry processes is reported. This polymer reactor was made of silver nanoparticles and a polymer carrier consisting of hyperbranched polyethylenimine and hydroxyethyl acrylate that behaved as thermally switchable domains. Below the transfer temperature, relatively strong catalytic reactivity was demonstrated due to the leading role of hydrophilic groups in the switchable domains, which opened access to the substrate for the packaged silver nanoparticles. In contrast, it showed weak catalysis at relatively high temperatures, reducing from the significantly increased hydrophobicity in the switchable domains. In this way, the polymer reactor displays controllable, tunable, catalytic activity based on this approach. This novel design opens up the opportunity to develop intelligent polymer reactors for controlled catalytic processes.

  11. Novel, Regenerable Microlith Catalytic Reactor for CO2 Reduction via Bosch Process, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Precision Combustion, Inc. (PCI) proposes to develop an extremely compact, lightweight and regenerable MicrolithREG catalytic CO2 reduction reactor, capable of...

  12. Lactose hydrolysis in an enzymatic membrane reactor

    Energy Technology Data Exchange (ETDEWEB)

    Mertens, B.; Huyghebaert, A.

    1987-10-01

    The enzymatic hydrolysis of lactose in whey permeate with subsequent recuperation of Saccharomyces lactis lactase by means of ultrafiltration was investigated. In whey permeate, S. lactis lactase shows maximal activity at pH 6.5; the optimal temperature was found to be 45/sup 0/C and is limited by strong thermal inactivation beyond this temperature. High activity combined with acceptable thermal inactivation (< 10% after 5 h incubation) was established at 30/sup 0/C. S. lactis lactase also displays considerable activity at low temperature (5/sup 0/C). Enzyme stability is reduced drastically by demineralisation: addition of low concentrations of manganese ions (10/sup -3/ M) considerably enhances stability. Using a DDS Lab-Unit 35 fitted with GR61PP polysulphon membranes (cut-off: 20.000), pilot scale experiments were carried out (pH 6.5; 30/sup 0/C) in which whey permeate was hydrolyzed to a degree of hydrolysis of 82% minimum. Enzyme recuperation amounted to 96.5% per batch, all enzyme activity loss being due to thermal inactivation. Microbiological examination of the enzymatic membrane reactor showed that growth of mcicroorganisms can largely be suppressed by working at lower temperature (5/sup 0/C). Eventually, 50 ppm H/sub 2/O/sub 2/ or sterile filtration will adequately solve microbiological problems without affecting enzyme activity.

  13. Hydrogen Production from Ammonia Using a Plasma Membrane Reactor

    Directory of Open Access Journals (Sweden)

    Shinji Kambara

    2016-06-01

    Full Text Available In this study, an efficient method for using pulsed plasma to produce hydrogen from ammonia was developed. An original pulsed plasma reactor with a hydrogen separation membrane was developed for efficient hydrogen production, and its hydrogen production performance was investigated. Hydrogen production in the plasma was affected by the applied voltage and flow rate of ammonia gas. The maximum hydrogen production flow rate of a typical plasma reactor was 8.7 L/h, whereas that of the plasma membrane reactor was 21.0 L/h. We found that ammonia recombination reactions in the plasma controlled hydrogen production in the plasma reactor. In the plasma membrane reactor, a significant increase in hydrogen production was obtained because ammonia recombination reactions were inhibited by the permeation of hydrogen radicals generated in the plasma through a palladium alloy membrane. The energy efficiency was 4.42 mol-H2/kWh depending on the discharge power.

  14. Catalytic partial oxidation and membrane separation to optimize the conversion of natural gas to syngas and hydrogen.

    Science.gov (United States)

    Capoferri, Daniela; Cucchiella, Barbara; Iaquaniello, Gaetano; Mangiapane, Alessia; Abate, Salvatore; Centi, Gabriele

    2011-12-16

    The multistep integration of hydrogen-selective membranes into catalytic partial oxidation (CPO) technology to convert natural gas into syngas and hydrogen is reported. An open architecture for the membrane reactor is presented, in which coupling of the reaction and hydrogen separation is achieved independently and the required feed conversion is reached through a set of three CPO reactors working at 750, 750 and 920 °C, compared to 1030 °C for conventional CPO technology. Obtaining the same feed conversion at milder operating conditions translates into less natural gas consumption (and CO(2) emissions) and a reduction of variable operative costs of around 10 %. It is also discussed how this energy-efficient process architecture, which is suited particularly to small-to-medium applications, may improve the sustainability of other endothermic, reversible reactions to form hydrogen. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Operation of staged membrane oxidation reactor systems

    Science.gov (United States)

    Repasky, John Michael

    2012-10-16

    A method of operating a multi-stage ion transport membrane oxidation system. The method comprises providing a multi-stage ion transport membrane oxidation system with at least a first membrane oxidation stage and a second membrane oxidation stage, operating the ion transport membrane oxidation system at operating conditions including a characteristic temperature of the first membrane oxidation stage and a characteristic temperature of the second membrane oxidation stage; and controlling the production capacity and/or the product quality by changing the characteristic temperature of the first membrane oxidation stage and/or changing the characteristic temperature of the second membrane oxidation stage.

  16. Liberated PKA Catalytic Subunits Associate with the Membrane via Myristoylation to Preferentially Phosphorylate Membrane Substrates.

    Science.gov (United States)

    Tillo, Shane E; Xiong, Wei-Hong; Takahashi, Maho; Miao, Sheng; Andrade, Adriana L; Fortin, Dale A; Yang, Guang; Qin, Maozhen; Smoody, Barbara F; Stork, Philip J S; Zhong, Haining

    2017-04-18

    Protein kinase A (PKA) has diverse functions in neurons. At rest, the subcellular localization of PKA is controlled by A-kinase anchoring proteins (AKAPs). However, the dynamics of PKA upon activation remain poorly understood. Here, we report that elevation of cyclic AMP (cAMP) in neuronal dendrites causes a significant percentage of the PKA catalytic subunit (PKA-C) molecules to be released from the regulatory subunit (PKA-R). Liberated PKA-C becomes associated with the membrane via N-terminal myristoylation. This membrane association does not require the interaction between PKA-R and AKAPs. It slows the mobility of PKA-C and enriches kinase activity on the membrane. Membrane-residing PKA substrates are preferentially phosphorylated compared to cytosolic substrates. Finally, the myristoylation of PKA-C is critical for normal synaptic function and plasticity. We propose that activation-dependent association of PKA-C renders the membrane a unique PKA-signaling compartment. Constrained mobility of PKA-C may synergize with AKAP anchoring to determine specific PKA function in neurons. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Recent Advances on Carbon Molecular Sieve Membranes (CMSMs and Reactors

    Directory of Open Access Journals (Sweden)

    Margot A. Llosa Tanco

    2016-08-01

    Full Text Available Carbon molecular sieve membranes (CMSMs are an important alternative for gas separation because of their ease of manufacture, high selectivity due to molecular sieve separation, and high permeance. The integration of separation by membranes and reaction in only one unit lead to a high degree of process integration/intensification, with associated benefits of increased energy, production efficiencies and reduced reactor or catalyst volume. This review focuses on recent advances in carbon molecular sieve membranes and their applications in membrane reactors.

  18. Fouling-induced enzyme immobilization for membrane reactors

    DEFF Research Database (Denmark)

    Luo, Jianquan; Meyer, Anne S.; Jonsson, Gunnar Eigil

    2013-01-01

    A simple enzyme immobilization method accomplished by promoting membrane fouling formation is proposed. The immobilization method is based on adsorption and entrapment of the enzymes in/on the membrane. To evaluate the concept, two membrane orientations, skin layer facing feed (normal mode......, but the reverse mode allowed for higher enzyme loading and stability, and irreversible fouling (i.e. pore blocking) developed more readily in the support structure than in the skin layer. Compared with an enzymatic membrane reactor (EMR) with free enzymes, the novel EMR with enzymes immobilized in membrane...... support improved the enzyme reusability (especially for ADH), and reduced the product inhibition (especially for GDH). © 2013 Elsevier Ltd....

  19. Recovery of hydrogen from impurities using a palladium membrane reactor

    International Nuclear Information System (INIS)

    Willms, R.S.; Okuno, K.

    1993-01-01

    One of the important steps in processing the exhaust from a fusion reactor is recovering tritium which is incorporated into molecules such as water and methane. One device which may prove to be very effective for this purpose is a palladium membrane reactor. This is a reactor which incorporates a Pd/Ag membrane in the reactor geometry. Reactions such as water gas shift, steam reforming and methane cracking can be carried out over the reactor catalyst, and the product hydrogen can be simultaneously removed from the reacting mixture. Because product is removed, greater than usual conversions can be obtained. In addition ultrapure hydrogen is produced, eliminating the need for an additional processing step. A palladium membrane reactor has been built and tested with three different catalysts. Initial results with a Ni-based catalyst show that it is very effective at promoting all three reactions listed above. Under the proper conditions, hydrogen recoveries approaching 100% have been observed. This study serves to experimentally validate the palladium membrane reactor as potentially important tool for fusion fuel processing

  20. Ceramic oxygen transport membrane array reactor and reforming method

    Science.gov (United States)

    Kelly, Sean M.; Christie, Gervase Maxwell; Robinson, Charles; Wilson, Jamie R; Gonzalez, Javier E.; Doraswami, Uttam R.

    2017-10-03

    The invention relates to a commercially viable modular ceramic oxygen transport membrane system for utilizing heat generated in reactively-driven oxygen transport membrane tubes to generate steam, heat process fluid and/or provide energy to carry out endothermic chemical reactions. The system provides for improved thermal coupling of oxygen transport membrane tubes to steam generation tubes or process heater tubes or reactor tubes for efficient and effective radiant heat transfer.

  1. Adlayers of palladium particles and their aggregates on porous polypropylene hollow fiber membranes as hydrogenization contractors/reactors.

    Science.gov (United States)

    Volkov, V V; Lebedeva, V I; Petrova, I V; Bobyl, A V; Konnikov, S G; Roldughin, V I; van Erkel, J; Tereshchenko, G F

    2011-05-11

    Principal approaches for the preparation of catalytic membrane reactors based on polymer membranes containing palladium nanoparticles and for the description of their characteristics are presented. The method for the development of adlayers composed of palladium nanoparticles and their aggregates on the surface of hydrophobic polypropylene porous hollow fiber membranes is proposed, and their comprehensive study is performed. Various regimes of the deposition of palladium on individual fibers and on membrane surface inside membrane modulus are considered. The sizes of primary Pd particles range from 10 to 500 nm, and dimensions of their aggregates vary from 200 nm to tens of microns. The sizes of primary particles in a free state and in their aggregates are estimated by the methods of X-ray analysis and scanning electron microscopy. The proposed approach is used for the preparation of catalytic membrane contactors/reactors for the removal of dissolved oxygen from water. In the systems under study, the limiting stage of dissolved oxygen removal is concerned with diffusion-controlled delivery of oxygen to the surface of catalytic particles. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Current hurdles to the success of high temperature membrane reactors

    NARCIS (Netherlands)

    Saracco, G.; Versteeg, Geert; van Swaaij, Willibrordus Petrus Maria

    1994-01-01

    High-temperature catalytic processs performed using inorganic membranes have been in recent years a fast growing area of research, which seems to have not yet reached its peak. Chemical engineers, catalysts and materials scientists have addressed this topic from different viewpoint in a common

  3. Preliminary design of fusion reactor fuel cleanup system by palladium alloy membrane method

    International Nuclear Information System (INIS)

    Yoshida, Hiroshi; Konishi, Satoshi; Naruse, Yuji

    1981-10-01

    A design of palladium diffuser and Fuel Cleanup System (FCU) for D-T fusion reactor is proposed. Feasibility of palladium alloy membrane method is discussed based on the early studies by the authors. Operating conditions of the palladium diffuser are determined experimentally. Dimensions of the diffuser are estimated from computer simulation. FCU system is designed under the feed conditions of Tritium Systems Test Assembly (TSTA) at Los Alamos Scientific Laboratory. The system is composed of Pd-diffusers, catalytic oxidizer, freezer and zink beds, and has some advantages in system layout and operation. This design can readily be extended to other conditions of plasma exhaust gases. (author)

  4. The Membrane Gradostat Reactor: Secondary metabolite production ...

    African Journals Online (AJOL)

    This manuscript focuses on the aspect of a membrane gradostat as an entirely different concept compared to submerged hollow fibre modules. The use of membrane bioreactor (MBR) technology is rapidly advancing in the wastewater treatment industries. However, this is not the case in the biopharmaceutical ...

  5. Selective catalytic reduction of NO in a reverse-flow reactor: Modelling and experimental validation

    International Nuclear Information System (INIS)

    Muñoz, Emilio; Marín, Pablo; Díez, Fernando V.; Ordóñez, Salvador

    2015-01-01

    Highlights: • Reverse-flow reactors easily overcome feed concentration disturbances. • Central feeding improves ammonia adsorption in reverse-flow reactors. • Dynamic heterogeneous model validated with bench-scale experiments. • Optimum reverse-flow reactor design improves efficiency and reduces reactor size. - Abstract: The abatement of nitrogen oxides produced in combustion processes and in the chemical industry requires efficient and reliable technologies capable of fulfilling strict environmental regulations. Selective catalytic reduction (SCR) with ammonia in fixed-bed (monolithic) reactors has stood out among other techniques in the last decades. In this work, the use of reverse-flow reactors, operated under the forced un-steady state generated by the periodic reversal of the flow direction, is studied for improving the SCR performance. This reactor can take advantage of ammonia adsorption in the catalyst to enhance concentration profiles in the reactor, increasing reaction rate, efficiency and reducing the emission of un-reacted ammonia. The process has been studied experimentally in a bench-scale device using a commercial monolithic catalyst. The optimum operating conditions, best ammonia feed configuration (side or central) and capacity of the reactor to deal with feed concentration disturbances is analysed. The experiments have also been used for validating a mathematical model of the reactor based on mass conservation equations, and the model has been used to design a full-size reverse-flow reactor able of operating at industrial conditions

  6. Simulation and calculation of three-reactor system of catalytic reforming

    International Nuclear Information System (INIS)

    Rikalovska, Tatjana; Markovska, Liljana; Meshko, Vera; Poposka, Filimena

    1999-01-01

    The process of catalytic reforming has been operated for quite a long time, one can not always find real data for the kinetics and thermodynamics of the reactions that take place during the catalytic reforming process in order to facilitate the designing of reactor system or its simulation in a wide:ran e of process parameters. Kinetic and thermodynamic data have been collected for the reactions that take place during the catalytic reforming process. The stress has been pointed on four major reactions: dehydrogenation of naphthenes (aromatization), dehydrocyclization of paraffins and hydrocracking of naphthenes and paraffins. On the base of such a kinetic model, the reforming process has been described with a system of differential equations. For the purpose of solving these equations computer programs for simulation of a three-reactor system for adiabatic operation of the reactors. The computer simulation of the mathematical model of this three-reactor system has been accomplished by use of the ISIM-dynamic simulator. The results obtained out of the simulation agree very good with the data of the real process of catalytic reforming in OKTA Crude Oil Refinery in Skopje, Macedonia. (Author)

  7. Catalytic non-thermal plasma reactor for the decomposition of a ...

    Indian Academy of Sciences (India)

    The decomposition of mixture of selected volatile organic compounds (VOCs) has been studied in a catalytic non-thermal plasma dielectric barrier discharge reactor. The VOCs mixture consisting n-hexane, cyclo-hexane and -xylene was chosen for the present study. The decomposition characteristics of mixture of VOCs ...

  8. Prediction of Improved Performance of Catalytic Hydrogenation Reactor by Periodic Modulation of the Feed Rate

    Czech Academy of Sciences Publication Activity Database

    Staněk, Vladimír; Hanika, Jiří; Jiřičný, Vladimír; Stavárek, Petr; Tukač, V.; Lederer, J.

    2009-01-01

    Roč. 23, č. 3 (2009), s. 251-257 ISSN 1451-9372 R&D Projects: GA MPO FT-TA/039 Institutional research plan: CEZ:AV0Z40720504 Keywords : trickle bed * feed modulation * catalytic reactor Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  9. N2O Catalytic Decomposition – from Laboratory Experiment to Industry Reactor

    Czech Academy of Sciences Publication Activity Database

    Obalová, L.; Jirátová, Květa; Karásková, K.; Chromčáková, Ž.

    2012-01-01

    Roč. 191, č. 1 (2012), s. 116-120 ISSN 0920-5861 R&D Projects: GA TA ČR TA01020336 Institutional support: RVO:67985858 Keywords : N2O * catalytic decomposition * fixed bed reactor Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.980, year: 2012

  10. Enzymatic membrane reactor for full saccharification of ionic liquid-pretreated microcrystalline cellulose.

    Science.gov (United States)

    Lozano, Pedro; Bernal, Berenice; Jara, Antonio G; Belleville, Marie-Pierre

    2014-01-01

    Ultrafiltration reactors based on polymeric or ceramic membranes were shown to be suitable catalytic systems for fast enzymatic saccharification of cellulose, allowing the full recovery and reuse of enzymes. By pre-treating cellulose with the IL 1-butyl-3-methylimidazolium chloride, the suitability of this substrate for enzymatic saccharification in a reactor based on polymeric ultrafiltration membranes was demonstrated, leading to 95% cellulose hydrolysis in 4h at 50°C. The filtration process gave a clear glucose solution (up to 113 mM) at constant permeate flow (24.7 L h(-1) m(-2)), allowing the enzyme to be reused for 9 operation cycles under semi-continuous operation, without any loss of enzyme activity. Under continuous operation mode and using ceramic ultrafiltration membranes at different residence times, the enzymatic reactor showed constant profiles in both the permeate flow rate and the glucose concentration, demonstrating the excellent suitability of the proposed approach for the saccharification of cellulose. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Periodic Operation of Three-Phase Catalytic Reactors

    Czech Academy of Sciences Publication Activity Database

    Silveston, P.T.; Hanika, Jiří

    2005-01-01

    Roč. 82, č. 6 (2005), s. 1105-1142 ISSN 0008-4034 Institutional research plan: CEZ:AV0Z4072921 Keywords : three-phase reactors * trickle bed * periodic operation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.574, year: 2005

  12. Catalytic membranes for CO oxidation in fuel cells

    Science.gov (United States)

    Sandi-Tapia, Giselle; Carrado Gregar, Kathleen; Kizilel, Riza

    2010-06-08

    A hydrogen permeable membrane, which includes a polymer stable at temperatures of about 200 C having clay impregnated with Pt or Au or Ru or Pd particles or mixtures thereof with average diameters of less than about 10 nanometers (nms) is disclosed. The membranes are useful in fuel cells or any device which requires hydrogen to be separated from carbon monoxide.

  13. Ex situ thermo-catalytic upgrading of biomass pyrolysis vapors using a traveling wave microwave reactor

    International Nuclear Information System (INIS)

    Muley, P.D.; Henkel, C.E.; Aguilar, G.; Klasson, K.T.; Boldor, D.

    2016-01-01

    Highlights: • Ex-situ microwave reactor was used to heat catalyst bed for pyrolysis upgrading. • Results were compared with conventional catalytic reactor. • Microwave heating yielded higher aromatic compounds. • Catalyst deactivation due to coking was lower in microwave reactor. • 30% decrease in energy input for microwave reactor. - Abstract: Microwave heating offers a number of advantages over conventional heating methods, such as, rapid and volumetric heating, precise temperature control, energy efficiency and lower temperature gradient. In this article we demonstrate the use of 2450 MHz microwave traveling wave reactor to heat the catalyst bed for thermo-catalytic upgrading of pyrolysis vapors. HZSM-5 catalyst was tested at three different temperatures (290°, 330° and 370 °C) at a catalyst to biomass ratio of 2. Results were compared with conventional heating and induction heating method of catalyst bed. The yields of aromatic compounds and coke deposition were dependent on temperature and method of heating. Microwave heating yielded higher aromatic compounds and lower coke deposition. Microwave heating was also energy efficient compared to conventional reactors. The rate of catalyst deterioration was lower for catalyst heated in microwave system.

  14. System and method for air temperature control in an oxygen transport membrane based reactor

    Science.gov (United States)

    Kelly, Sean M

    2016-09-27

    A system and method for air temperature control in an oxygen transport membrane based reactor is provided. The system and method involves introducing a specific quantity of cooling air or trim air in between stages in a multistage oxygen transport membrane based reactor or furnace to maintain generally consistent surface temperatures of the oxygen transport membrane elements and associated reactors. The associated reactors may include reforming reactors, boilers or process gas heaters.

  15. System and method for temperature control in an oxygen transport membrane based reactor

    Science.gov (United States)

    Kelly, Sean M.

    2017-02-21

    A system and method for temperature control in an oxygen transport membrane based reactor is provided. The system and method involves introducing a specific quantity of cooling air or trim air in between stages in a multistage oxygen transport membrane based reactor or furnace to maintain generally consistent surface temperatures of the oxygen transport membrane elements and associated reactors. The associated reactors may include reforming reactors, boilers or process gas heaters.

  16. Dense inorganic membranes - studies on transport properties, defect chemistry and catalytic behaviour

    NARCIS (Netherlands)

    ten Elshof, Johan E.

    1997-01-01

    Oxygen separation with dense oxide membranes may be an attractive method for the production of oxygen from air. Another possible application is the direct supply of oxygen in membrane reactors for the (partial) oxidation of hydrocarbons. The driving force for oxygen permeation through dense mixed

  17. Catalytic Layer Optimization for Hydrogen Permeation Membranes Based on La5.5WO11.25-δ/La0.87Sr0.13CrO3-δComposites.

    Science.gov (United States)

    Escolástico, Sonia; Solı S, Cecilia; Kjølseth, Christian; Serra, Jose Manuel

    2017-10-18

    (LWO/LSC) composite is one of the most promising mixed ionic-electronic conducting materials for hydrogen separation at high temperature. However, these materials present limited catalytic surface activity toward H 2 activation and water splitting, which determines the overall H 2 separation rate. For the implementation of these materials as catalytic membrane reactors, effective catalytic layers have to be developed that are compatible and stable under the reaction conditions. This contribution presents the development of catalytic layers based on sputtered metals (Cu and Pd), electrochemical characterization by impendace spectroscopy, and the study of the H 2 flow obtained by coating them on 60/40-LWO/LSC membranes. Stability of the catalytic layers is also evaluated under H 2 permeation conditions and CH 4 -containing atmospheres.

  18. Simulation of Water Gas Shift Zeolite Membrane Reactor

    Science.gov (United States)

    Makertiharta, I. G. B. N.; Rizki, Z.; Zunita, Megawati; Dharmawijaya, P. T.

    2017-07-01

    The search of alternative energy sources keeps growing from time to time. Various alternatives have been introduced to reduce the use of fossil fuel, including hydrogen. Many pathways can be used to produce hydrogen. Among all of those, the Water Gas Shift (WGS) reaction is the most common pathway to produce high purity hydrogen. The WGS technique faces a downstream processing challenge due to the removal hydrogen from the product stream itself since it contains a mixture of hydrogen, carbon dioxide and also the excess reactants. An integrated process using zeolite membrane reactor has been introduced to improve the performance of the process by selectively separate the hydrogen whilst boosting the conversion. Furthermore, the zeolite membrane reactor can be further improved via optimizing the process condition. This paper discusses the simulation of Zeolite Membrane Water Gas Shift Reactor (ZMWGSR) with variation of process condition to achieve an optimum performance. The simulation can be simulated into two consecutive mechanisms, the reaction prior to the permeation of gases through the zeolite membrane. This paper is focused on the optimization of the process parameters (e.g. temperature, initial concentration) and also membrane properties (e.g. pore size) to achieve an optimum product specification (concentration, purity).

  19. Use of stable emulsion to improve stability, activity, and enantioselectivity of lipase immobilized in a membrane reactor.

    Science.gov (United States)

    Giorno, L; Li, N; Drioli, E

    2003-12-20

    The enantiocatalytic performance of immobilized lipase in an emulsion membrane reactor using stable emulsion prepared by membrane emulsification technology was studied. The production of optical pure (S)-naproxen from racemic naproxen methyl ester was used as a model reaction system. The O/W emulsion, containing the substrate in the organic phase, was fed to the enzyme membrane reactor from shell-to-lumen. The enzyme was immobilized in the sponge layer (shell side) of capillary polyamide membrane with 50 kDa cut-off. The aqueous phase was able to permeate through the membrane while the microemulsion was retained by the thin selective layer. Therefore, the substrate was kept in the enzyme-loaded membrane while the water-soluble product was continuously removed from the reaction site. The results show that lipase maintained stable activity during the entire operation time (more than 250 h), showing an enantiomeric excess (96 +/- 2%) comparable to the free enzyme (98 +/- 1%) and much higher compared to similar lipase-loaded membrane reactors used in two-separate phase systems (90%). The results demonstrate that immobilized enzymes can achieve high stability as well as high catalytic activity and enantioselectivity. Copyright 2003 Wiley Periodicals, Inc.

  20. Methane-benzene binary mixture destruction in a reverse flow catalytic reactor

    International Nuclear Information System (INIS)

    Geng, Chen; Yong, Chi; Chunpeng, Pan; Yan, Jian-hua; Ni, Ming-Jian

    2010-01-01

    A reverse flow reactor (RFR) is a packed catalytic bed reactor in which feed flow direction is periodically reversed. When an exothermic catalytic combustion is conducted in a RFR, a hot zone is trapped in the center while both ends of the reactor act as regenerative heat exchanger. This enables an auto thermal operation at high temperatures even for feeds having a low adiabatic temperature rise. These features make RFR highly competitive for VOCs combustion. An experimental study of binary mixture purification in bench scale reverse flow reactor, with an inner diameter of 60 mm, has been carried out. Methane and benzene are chosen due to their different properties. The ignition temperature of methane is higher than any other hydrocarbons and benzene is widely used as solvent in industry. With periodic reversal feed, auto thermal catalytic combustion of very lean binary mixture can be achieved. When peak temperature in the hot zone reaches about 550 degree Celsius, both methane and benzene are well removed and little NOx or no other secondary pollutants are detected. The influence of several operation parameters, such as gas velocity, cycle period and methane-to-benzene ratio are discussed. A mathematical model has been developed and solved using a FORTRAN code, good correspondence being observed between both approaches. This provides a solution if VOC concentration in the contaminated air is too low to maintain an auto thermal operation, while natural gas (which is mainly methane) can be added as auxiliary fuel. (author)

  1. Modeling and data analysis of a palladium membrane reactor for tritiated impurities cleanup

    International Nuclear Information System (INIS)

    Birdsell, S.A.; Willms, R.S.

    1995-01-01

    A Palladium Membrane Reactor (PMR) is under consideration for the tritium plant for the International Thermonuclear Experimental Reactor (ITER). The ITER reactor exhaust will contain tritiated impurities such as water and methane. Tritium will need to be recovered from these impurities for environmental and economic reasons. For this purpose a promising device, PMR, has been proposed. The PMR is a combined permeator and catalytic reactor. Shift catalysts are used to foster reactions such as water-gas shift, H 2 O + CO → H 2 + CO 2 , and methane steam reforming, CH 4 + H 2 O → 3H 2 + CO. Due to thermodynamic limitations these reactions only proceed to partial completion. Thus, a Pd/Ag membrane, which is exclusively permeable to hydrogen isotopes, is incorporated into the reactor. By maintaining a vacuum on the permeate, product hydrogen isotopes are removed, enabling the reactions to proceed to completion. A model has been developed to study the complex interactions in a PMR so that the optimal design can be determined. The model accounts for the coupled effects of transport-limited permeation of hydrogen isotopes and chemical reactions. The permeation model is an extension of previous models that include the effects of temperature, wall thickness, reaction-side pressure, and permeate-side pressure. Reaction rates for methane steam reforming and the water-gas shift reaction are incorporated into the model along with the respective reverse reactions. The model is compared to PMR data and used to investigate the concentration and pressure profiles in the reactor. Due to the interactions of permeation and reaction complex profiles can be produced in a PMR. For example, the water concentration often increases after the inlet to the PMR to a maximum value, and then decreases to the low values expected with a PMR. Detailed information like this is required for the design and optimization of PMRs for the ITER tritium plant

  2. One Step Biomass Gas Reforming-Shift Separation Membrane Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Michael J. [Gas Technology Institute; Souleimanova, Razima [Gas Technology Institute

    2012-12-28

    GTI developed a plan where efforts were concentrated in 4 major areas: membrane material development, membrane module development, membrane process development, and membrane gasifier scale-up. GTI assembled a team of researchers to work in each area. Task 1.1 Ceramic Membrane Synthesis and Testing was conducted by Arizona State University (ASU), Task 1.2 Metallic Membrane Synthesis and Testing was conducted by the U.S. National Energy Technology Laboratory (NETL), Task 1.3 was conducted by SCHOTT, and GTI was to test all membranes that showed potential. The initial focus of the project was concentrated on membrane material development. Metallic and glass-based membranes were identified as hydrogen selective membranes under the conditions of the biomass gasification, temperatures above 700C and pressures up to 30 atmospheres. Membranes were synthesized by arc-rolling for metallic type membranes and incorporating Pd into a glass matrix for glass membranes. Testing for hydrogen permeability properties were completed and the effects of hydrogen sulfide and carbon monoxide were investigated for perspective membranes. The initial candidate membrane of Pd80Cu20 chosen in 2008 was selected for preliminary reactor design and cost estimates. Although the H2A analysis results indicated a $1.96 cost per gge H2 based on a 5A (micron) thick PdCu membrane, there was not long-term operation at the required flux to satisfy the go/no go decision. Since the future PSA case yielded a $2.00/gge H2, DOE decided that there was insufficient savings compared with the already proven PSA technology to further pursue the membrane reactor design. All ceramic membranes synthesized by ASU during the project showed low hydrogen flux as compared with metallic membranes. The best ceramic membrane showed hydrogen permeation flux of 0.03 SCFH/ft2 at the required process conditions while the metallic membrane, Pd80Cu20 showed a flux of 47.2 SCFH/ft2 (3 orders of magnitude difference). Results from

  3. Effect of catalytic cylinders on autothermal reforming of methane for hydrogen production in a microchamber reactor.

    Science.gov (United States)

    Yan, Yunfei; Guo, Hongliang; Zhang, Li; Zhu, Junchen; Yang, Zhongqing; Tang, Qiang; Ji, Xin

    2014-01-01

    A new multicylinder microchamber reactor is designed on autothermal reforming of methane for hydrogen production, and its performance and thermal behavior, that is, based on the reaction mechanism, is numerically investigated by varying the cylinder radius, cylinder spacing, and cylinder layout. The results show that larger cylinder radius can promote reforming reaction; the mass fraction of methane decreased from 26% to 21% with cylinder radius from 0.25 mm to 0.75 mm; compact cylinder spacing corresponds to more catalytic surface and the time to steady state is decreased from 40 s to 20 s; alteration of staggered and aligned cylinder layout at constant inlet flow rates does not result in significant difference in reactor performance and it can be neglected. The results provide an indication and optimize performance of reactor; it achieves higher conversion compared with other reforming reactors.

  4. Effect of Catalytic Cylinders on Autothermal Reforming of Methane for Hydrogen Production in a Microchamber Reactor

    Directory of Open Access Journals (Sweden)

    Yunfei Yan

    2014-01-01

    Full Text Available A new multicylinder microchamber reactor is designed on autothermal reforming of methane for hydrogen production, and its performance and thermal behavior, that is, based on the reaction mechanism, is numerically investigated by varying the cylinder radius, cylinder spacing, and cylinder layout. The results show that larger cylinder radius can promote reforming reaction; the mass fraction of methane decreased from 26% to 21% with cylinder radius from 0.25 mm to 0.75 mm; compact cylinder spacing corresponds to more catalytic surface and the time to steady state is decreased from 40 s to 20 s; alteration of staggered and aligned cylinder layout at constant inlet flow rates does not result in significant difference in reactor performance and it can be neglected. The results provide an indication and optimize performance of reactor; it achieves higher conversion compared with other reforming reactors.

  5. Membrane contactor/separator for an advanced ozone membrane reactor for treatment of recalcitrant organic pollutants in water

    International Nuclear Information System (INIS)

    Chan, Wai Kit; Jouët, Justine; Heng, Samuel; Yeung, King Lun; Schrotter, Jean-Christophe

    2012-01-01

    An advanced ozone membrane reactor that synergistically combines membrane distributor for ozone gas, membrane contactor for pollutant adsorption and reaction, and membrane separator for clean water production is described. The membrane reactor represents an order of magnitude improvement over traditional semibatch reactor design and is capable of complete conversion of recalcitrant endocrine disrupting compounds (EDCs) in water at less than three minutes residence time. Coating the membrane contactor with alumina and hydrotalcite (Mg/Al=3) adsorbs and traps the organics in the reaction zone resulting in 30% increase of total organic carbon (TOC) removal. Large surface area coating that diffuses surface charges from adsorbed polar organic molecules is preferred as it reduces membrane polarization that is detrimental to separation. - Graphical abstract: Advanced ozone membrane reactor synergistically combines membrane distributor for ozone, membrane contactor for sorption and reaction and membrane separator for clean water production to achieve an order of magnitude enhancement in treatment performance compared to traditional ozone reactor. Highlights: ► Novel reactor using membranes for ozone distributor, reaction contactor and water separator. ► Designed to achieve an order of magnitude enhancement over traditional reactor. ► Al 2 O 3 and hydrotalcite coatings capture and trap pollutants giving additional 30% TOC removal. ► High surface area coating prevents polarization and improves membrane separation and life.

  6. Membrane contactor/separator for an advanced ozone membrane reactor for treatment of recalcitrant organic pollutants in water

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Wai Kit, E-mail: kekyeung@ust.hk [Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong); Joueet, Justine; Heng, Samuel; Yeung, King Lun [Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong); Schrotter, Jean-Christophe [Water Research Center of Veolia, Anjou Recherche, Chemin de la Digue, BP 76. 78603, Maisons Laffitte, Cedex (France)

    2012-05-15

    An advanced ozone membrane reactor that synergistically combines membrane distributor for ozone gas, membrane contactor for pollutant adsorption and reaction, and membrane separator for clean water production is described. The membrane reactor represents an order of magnitude improvement over traditional semibatch reactor design and is capable of complete conversion of recalcitrant endocrine disrupting compounds (EDCs) in water at less than three minutes residence time. Coating the membrane contactor with alumina and hydrotalcite (Mg/Al=3) adsorbs and traps the organics in the reaction zone resulting in 30% increase of total organic carbon (TOC) removal. Large surface area coating that diffuses surface charges from adsorbed polar organic molecules is preferred as it reduces membrane polarization that is detrimental to separation. - Graphical abstract: Advanced ozone membrane reactor synergistically combines membrane distributor for ozone, membrane contactor for sorption and reaction and membrane separator for clean water production to achieve an order of magnitude enhancement in treatment performance compared to traditional ozone reactor. Highlights: Black-Right-Pointing-Pointer Novel reactor using membranes for ozone distributor, reaction contactor and water separator. Black-Right-Pointing-Pointer Designed to achieve an order of magnitude enhancement over traditional reactor. Black-Right-Pointing-Pointer Al{sub 2}O{sub 3} and hydrotalcite coatings capture and trap pollutants giving additional 30% TOC removal. Black-Right-Pointing-Pointer High surface area coating prevents polarization and improves membrane separation and life.

  7. Dehydrogenation of liquid fuel in microchannel catalytic reactor

    Science.gov (United States)

    Toseland, Bernard Allen [Allentown, PA; Pez, Guido Peter [Allentown, PA; Puri, Pushpinder Singh [Emmaus, PA

    2009-02-03

    The present invention is an improved process for the storage and delivery of hydrogen by the reversible hydrogenation/dehydrogenation of an organic compound wherein the organic compound is initially in its hydrogenated state. The improvement in the route to generating hydrogen is in the dehydrogenation step and recovery of the dehydrogenated organic compound resides in the following steps: introducing a hydrogenated organic compound to a microchannel reactor incorporating a dehydrogenation catalyst; effecting dehydrogenation of said hydrogenated organic compound under conditions whereby said hydrogenated organic compound is present as a liquid phase; generating a reaction product comprised of a liquid phase dehydrogenated organic compound and gaseous hydrogen; separating the liquid phase dehydrogenated organic compound from gaseous hydrogen; and, recovering the hydrogen and liquid phase dehydrogenated organic compound.

  8. μ-reactor measurements of catalytic activity of mass selected nano-particles

    DEFF Research Database (Denmark)

    Riedel, Jakob Nordheim

    The work of this thesis revolves around catalytic activity measurements of nano-particles tested using a μ-reactor platform, developed and produced at DTU, in a collaboration between CINF and Nanotech. The thesis contains the results from two separate research projects; both utilising μ-reactors ......The work of this thesis revolves around catalytic activity measurements of nano-particles tested using a μ-reactor platform, developed and produced at DTU, in a collaboration between CINF and Nanotech. The thesis contains the results from two separate research projects; both utilising μ......-reactors in combination with surface science techniques and computer simulations. The first project described is a study of hydrogen dissociation on mono-disperse platinum clusters. The second project studies methanation from carbon monoxide and hydrogen on nano-particles of nickel-iron alloys. The second study is a work...... in progress, and the corresponding chapter aims to summarise the results so far. Other projects are not included in the thesis because they are inconclusive or dead ends. Hydrogen dissociation was studied by the H2/D2 exchange reaction on SiO2-supported mono-disperse platinum clusters in a -reactor...

  9. Recent advances in AFB biomass gasification pilot plant with catalytic reactors in a downstream slip flow

    Energy Technology Data Exchange (ETDEWEB)

    Aznar, M.P.; Gil, J.; Martin, J.A.; Frances, E.; Olivares, A.; Caballero, M.A.; Perez, P. [Saragossa Univ. (Spain). Dept. of Chemistry and Environment; Corella, J. [Madrid Univ. (Spain)

    1996-12-31

    A new 3rd generation pilot plant is being used for hot catalytic raw gas cleaning. It is based on a 15 cm. i.d. fluidized bed with biomass throughputs of 400-650 kg/h.m{sup 2}. Gasification is performed using mixtures of steam and oxygen. The produced gas is passed in a slip flow by two reactors in series containing a calcined dolomite and a commercial reforming catalyst. Tars are periodically sampled and analysed after the three reactors. Tar conversions of 99.99 % and a 300 % increase of the hydrogen content in the gas are obtained. (author) (2 refs.)

  10. A catalytic reactor for the trapping of free radicals from gas phase oxidation reactions

    Science.gov (United States)

    Conte, Marco; Wilson, Karen; Chechik, Victor

    2010-10-01

    A catalytic reactor for the trapping of free radicals originating from gas phase catalytic reactions is described and discussed. Radical trapping and identification were initially carried out using a known radical generator such as dicumyl peroxide. The trapping of radicals was further demonstrated by investigating genuine radical oxidation processes, e.g., benzaldehyde oxidation over manganese and cobalt salts. The efficiency of the reactor was finally proven by the partial oxidation of cyclohexane over MoO3, Cr2O3, and WO3, which allowed the identification of all the radical intermediates responsible for the formation of the products cyclohexanol and cyclohexanone. Assignment of the trapped radicals was carried out using spin trapping technique and X-band electron paramagnetic resonance spectroscopy.

  11. High temperature ceramic membrane reactors for coal liquid upgrading. Final report, September 21, 1989--November 20, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Tsotsis, T.T. [University of Southern California, Los Angeles, CA (United States). Dept. of Chemical Engineering; Liu, P.K.T. [Aluminum Co. of America, Pittsburgh, PA (United States); Webster, I.A. [Unocal Corp., Los Angeles, CA (United States)

    1992-12-31

    Membrane reactors are today finding extensive applications for gas and vapor phase catalytic reactions (see discussion in the introduction and recent reviews by Armor [92], Hsieh [93] and Tsotsis et al. [941]). There have not been any published reports, however, of their use in high pressure and temperature liquid-phase applications. The idea to apply membrane reactor technology to coal liquid upgrading has resulted from a series of experimental investigations by our group of petroleum and coal asphaltene transport through model membranes. Coal liquids contain polycyclic aromatic compounds, which not only present potential difficulties in upgrading, storage and coprocessing, but are also bioactive. Direct coal liquefaction is perceived today as a two-stage process, which involves a first stage of thermal (or catalytic) dissolution of coal, followed by a second stage, in which the resulting products of the first stage are catalytically upgraded. Even in the presence of hydrogen, the oil products of the second stage are thought to equilibrate with the heavier (asphaltenic and preasphaltenic) components found in the feedstream. The possibility exists for this smaller molecular fraction to recondense with the unreacted heavy components and form even heavier undesirable components like char and coke. One way to diminish these regressive reactions is to selectively remove these smaller molecular weight fractions once they are formed and prior to recondensation. This can, at least in principle, be accomplished through the use of high temperature membrane reactors, using ceramic membranes which are permselective for the desired products of the coal liquid upgrading process. An additional incentive to do so is in order to eliminate the further hydrogenation and hydrocracking of liquid products to undesirable light gases.

  12. Experimental and Numerical Evaluation of the By-Pass Flow in a Catalytic Plate Reactor for Hydrogen Production

    DEFF Research Database (Denmark)

    Sigurdsson, Haftor Örn; Kær, Søren Knudsen

    2011-01-01

    Numerical and experimental study is performed to evaluate the reactant by-pass flow in a catalytic plate reactor with a coated wire mesh catalyst for steam reforming of methane for hydrogen generation. By-pass of unconverted methane is evaluated under different wire mesh catalyst width to reactor...... duct width ratios, the results show that altering this ratio from 0.98 to 0.96 results in an increase in by-pass mass flow of 22%. Effect of catalytic wire mesh flow resistance on by-pass flow has also been investigated and results show increased by-pass flow as catalytic wire mesh flow resistance...... increases. The numerical results are in good agreement with experimental data. The study improves the understanding of the underlying transport phenomena in these reactors and shows that the flow maldistribution in a catalytic plate reactor using a coated wire mesh has to be considered....

  13. Dry Reforming of Methane Using a Nickel Membrane Reactor

    Directory of Open Access Journals (Sweden)

    Jonas M. Leimert

    2017-12-01

    Full Text Available Dry reforming is a very interesting process for synthesis gas generation from CH 4 and CO 2 but suffers from low hydrogen yields due to the reverse water–gas shift reaction (WGS. For this reason, membranes are often used for hydrogen separation, which in turn leads to coke formation at the process temperatures suitable for the membranes. To avoid these problems, this work shows the possibility of using nickel self-supported membranes for hydrogen separation at a temperature of 800 ∘ C. The higher temperature effectively suppresses coke formation. The paper features the analysis of the dry reforming reaction in a nickel membrane reactor without additional catalyst. The measurement campaign targeted coke formation and conversion of the methane feedstock. The nickel approximately 50% without hydrogen separation. The hydrogen removal led to an increase in methane conversion to 60–90%.

  14. Anaerobic membrane bio-reactors for severe industrial effluents and urban spill waters : The AMBROSIUS project

    NARCIS (Netherlands)

    Van Lier, J.B.; Ozgun, H.; Ersahin, M.E.; Dereli, R.K.

    2013-01-01

    With growing application experiences from aerobic membrane bioreactors, combination of membrane and anaerobic processes become more and more attractive and feasible. In anaerobic membrane bioreactors (AnMBRs), biomass and particulate organic matter are physically retained inside the reactor,

  15. Supported Pd-Au Membrane Reactor for Hydrogen Production: Membrane Preparation, Characterization and Testing.

    Science.gov (United States)

    Iulianelli, Adolfo; Alavi, Marjan; Bagnato, Giuseppe; Liguori, Simona; Wilcox, Jennifer; Rahimpour, Mohammad Reza; Eslamlouyan, Reza; Anzelmo, Bryce; Basile, Angelo

    2016-05-09

    A supported Pd-Au (Au 7wt%) membrane was produced by electroless plating deposition. Permeation tests were performed with pure gas (H₂, H₂, N₂, CO₂, CH₄) for long time operation. After around 400 h under testing, the composite Pd-Au membrane achieved steady state condition, with an H₂/N₂ ideal selectivity of around 500 at 420 °C and 50 kPa as transmembrane pressure, remaining stable up to 1100 h under operation. Afterwards, the membrane was allocated in a membrane reactor module for methane steam reforming reaction tests. As a preliminary application, at 420 °C, 300 kPa of reaction pressure, space velocity of 4100 h(-1), 40% methane conversion and 35% hydrogen recovery were reached using a commercial Ni/Al₂O₃ catalyst. Unfortunately, a severe coke deposition affected irreversibly the composite membrane, determining the loss of the hydrogen permeation characteristics of the supported Pd-Au membrane.

  16. APPLICATION OF MEMBRANE SORPTION REACTOR TECHNOLOGY FOR LRW MANAGEMENT

    International Nuclear Information System (INIS)

    Glagolenko, Yuri; Dzekun, Evgeny; Myasoedovg, Boris; Gelis, Vladimir; Kozlitin, Evgeny; Milyutin, Vitaly; Trusov, Lev; Rengel, Mike; Mackay, Stewart M.; Johnson, Michael E.

    2003-01-01

    A new membrane-sorption technology has been recently developed and industrially implemented in Russia for the treatment of the Liquid (Low-Level) Radioactive Waste (LRW). The first step of the technology is a precipitation of the radionuclides and/or their adsorption onto sorbents of small particle size. The second step is filtration of the precipitate/sorbent through the metal-ceramic membrane, Trumem.. The unique feature of the technology is a Membrane-Sorption Reactor (MSR), in which the precipitation / sorption and the filtration of the radionuclides occur simultaneously, in one stage. This results in high efficiency, high productivity and compactness of the equipment, which are the obvious advantages of the developed technology. Two types of MSR based on Flat Membranes device and Centrifugal Membrane device were developed. The advantages and disadvantages of application of each type of the reactors are discussed. The MSR technology has been extensively tested and efficiently implemented at ''Mayak '' nuclear facility near Chelyabinsk, Russia as well as at other Russian sites. The results of this and other applications of the MSR technology at the different Russian nuclear facilities are discussed. The results of the first industrial applications of the MSR technology for radioactive waste treatment in Russia and analysis of the available information about LRW accumulated in other countries imply that this technology can be successfully used for the Low Level Radioactive Waste treatment in the USA and in other nuclear countries

  17. Low Temperature Steam Methane Reforming Over Ni Based Catalytic Membrane Prepared by Electroless Palladium Plating.

    Science.gov (United States)

    Lee, Sang Moon; Hong, Sung Chang; Kim, Sung Su

    2018-09-01

    A Pd/Ni-YSZ porous membrane with different palladium loadings and hydrazine as a reducing reagent was prepared by electroless plating and evaluated for the steam methane reforming activity. The steam-reforming activity of a Ni-YSZ porous membrane was greatly increased by the deposition of 4 g/L palladium in the low-temperature range (600 °C). With an increasing amount of reducing reagent, the Pd clusters were well dispersed on the Ni-YSZ surface and were uniform in size (∼500 nm). The Pd/Ni-YSZ catalytic porous membrane prepared by 1 of Pd/hydrazine ratio possessed an abundant amount of metallic Pd. The optimal palladium loadings and Pd/hydrazine ratio increased the catalytic activity in both the steam-reforming reaction and the Pd dispersion.

  18. Block copolymer hollow fiber membranes with catalytic activity and pH-response

    KAUST Repository

    Hilke, Roland

    2013-08-14

    We fabricated block copolymer hollow fiber membranes with self-assembled, shell-side, uniform pore structures. The fibers in these membranes combined pores able to respond to pH and acting as chemical gates that opened above pH 4, and catalytic activity, achieved by the incorporation of gold nanoparticles. We used a dry/wet spinning process to produce the asymmetric hollow fibers and determined the conditions under which the hollow fibers were optimized to create the desired pore morphology and the necessary mechanical stability. To induce ordered micelle assembly in the doped solution, we identified an ideal solvent mixture as confirmed by small-angle X-ray scattering. We then reduced p-nitrophenol with a gold-loaded fiber to confirm the catalytic performance of the membranes. © 2013 American Chemical Society.

  19. Dynamic\tmodelling of catalytic three-phase reactors for hydrogenation and oxidation processes

    Directory of Open Access Journals (Sweden)

    Salmi T.

    2000-01-01

    Full Text Available The dynamic modelling principles for typical catalytic three-phase reactors, batch autoclaves and fixed (trickle beds were described. The models consist of balance equations for the catalyst particles as well as for the bulk phases of gas and liquid. Rate equations, transport models and mass balances were coupled to generalized heterogeneous models which were solved with respect to time and space with algorithms suitable for stiff differential equations. The aspects of numerical solution strategies were discussed and the procedure was illustrated with three case studies: hydrogenation of aromatics, hydrogenation of aldehydes and oxidation of ferrosulphate. The case studies revealed the importance of mass transfer resistance inside the catalyst pallets as well as the dynamics of the different phases being present in the reactor. Reliable three-phase reactor simulation and scale-up should be based on dynamic heterogeneous models.

  20. Development of thin PdeAg supported membranes for fluidized bed membrane reactors including WGS related gases

    OpenAIRE

    Fernandez, E Ekain; Helmi Siasi Farimani, A Arash; Coenen, KT Kai; Meléndez, J; Viviente, JL; Pacheco Tanaka, DA; Sint Annaland, van, M Martin; Gallucci, F Fausto

    2015-01-01

    This paper reports the preparation, characterization and stability tests of Pd-based thin membranes for fluidized bed membrane reactor applications. Various thin membranes have been prepared by simultaneous Pd-Ag electroless plating. A simple technique for sealing of the produced membranes is reported and discussed. The membranes have been characterized for single gas permeation, and afterwards used for permeation of mixtures of gases and under fluidization conditions. The membranes have show...

  1. Low concentration volatile organic pollutants removal in combined adsorber-desorber-catalytic reactor system

    Directory of Open Access Journals (Sweden)

    Arsenijević Zorana

    2008-01-01

    Full Text Available The removal of volatile organic compounds (VOCs from numerous emission sources is of crucial importance due to more rigorous demands on air quality. Different technologies can be used to treat the VOCs from effluent gases: absorption, physical adsorption, open flame combustion, thermal and catalytic incineration. Their appropriateness for the specific process depends on several factors such as efficiency, energy consumption, secondary pollution, capital investments etc. The distinctive features of the catalytic combustion are high efficiency and selectivity toward be­nign products, low energy consumption and absence of secondary polluti­on. The supported noble catalysts are widely used for catalytic incineration due to their low ignition temperatures and high thermal and chemical stability. In our combined system adsorption and desorption are applied in the spouted bed with draft tube (SBDT unit. The annular zone, loaded with sorbent, was divided in adsorption and desorption section. Draft tube enabled sorbent recirculation between sections. Combustion of desorbed gases to CO2 and water vapor are realized in additive catalytic reactor. This integrated device provided low concentrations VOCs removal with reduced energy consumption. Experiments were conducted on a pilot unit of 220 m3/h nominal capacity. The sorbent was activated carbon, type K81/B - Trayal Corporation, Krusevac. A sphere shaped commercial Pt/Al2O3 catalyst with "egg-shell" macro-distribution was used for the investigation of xylene deep oxidation. Within this paper the investigations of removal of xylene vapors, a typical pollutant in production of liquid pesticides, in combined adsorber/desorber/catalytic reactor system is presented.

  2. SEPARATION OF HYDROGEN AND CARBON DIOXIDE USING A NOVEL MEMBRANE REACTOR IN ADVANCED FOSSIL ENERGY CONVERSION PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Shamsuddin Ilias

    2005-02-03

    Inorganic membrane reactors offer the possibility of combining reaction and separation in a single operation at high temperatures to overcome the equilibrium limitations experienced in conventional reactor configurations. Such attractive features can be advantageously utilized in a number of potential commercial opportunities, which include dehydrogenation, hydrogenation, oxidative dehydrogenation, oxidation and catalytic decomposition reactions. However, to be cost effective, significant technological advances and improvements will be required to solve several key issues which include: (a) permselective thin solid film, (b) thermal, chemical and mechanical stability of the film at high temperatures, and (c) reactor engineering and module development in relation to the development of effective seals at high temperature and high pressure. In this project, we are working on the development and application of palladium and palladium-silver alloy thin-film composite membranes in membrane reactor-separator configuration for simultaneous production and separation of hydrogen and carbon dioxide at high temperature. From our research on Pd-composite membrane, we have demonstrated that the new membrane has significantly higher hydrogen flux with very high perm-selectivity than any of the membranes commercially available. The steam reforming of methane by equilibrium shift in Pd-composite membrane reactor is being studied to demonstrate the potential application of this new development. A two-dimensional, pseudo-homogeneous membrane-reactor model was developed to investigate the steam-methane reforming (SMR) reactions in a Pd-based membrane reactor. Radial diffusion was taken into consideration to account for the concentration gradient in the radial direction due to hydrogen permeation through the membrane. With appropriate reaction rate expressions, a set of partial differential equations was derived using the continuity equation for the reaction system. The equations were

  3. HYDROGEN PRODUCTION VIA A COMMERCIALLY READY INORGANIC MEMBRANE REACTOR

    Energy Technology Data Exchange (ETDEWEB)

    Paul K.T. Liu

    2004-07-21

    The porous stainless steel substrate commercially available from Pall offers great potential for large-scale membrane based high temperature gas separations. Our proposed project involves the deposition of the M&P carbon molecular sieve-based hydrogen membrane on AccuSep substrate as a membrane to reactor water-gas-shift reaction. However, the AccuSep substrate was originally designed for liquid phase applications . During the 1st half, this commercial substrate has been modified and improved with regard to its surface topography and end seals. The substrate is now suitable for the deposition of the CMS membrane for hydrogen separation according to the characterization we preformed. In addition, 40{angstrom} Al{sub 2}O{sub 3} membrane layers have been deposited on the improved AccuSep substrate successfully. The SEM, EDX and pore size distribution analysis indicate that the 40{angstrom} membrane is extremely thin, and defect free with a narrow pore size distribution around 40{angstrom} primarily. As the above results suggest, we have made significant progress in preparing a high quality nominal 40{angstrom} (actually 50{angstrom}) layer on the Pall substrate. During the 2nd half of Year 1, we will (1) continue this development work with a focus on eliminating the high pore size peak and (2) begin the CMS layer deposition on the 40{angstrom} deposited AccuSep.

  4. Experimental and Numerical Evaluation of the By-Pass Flow in a Catalytic Plate Reactor for Hydrogen Production

    DEFF Research Database (Denmark)

    Sigurdsson, Haftor Örn; Kær, Søren Knudsen

    2011-01-01

    increases. The numerical results are in good agreement with experimental data. The study improves the understanding of the underlying transport phenomena in these reactors and shows that the flow maldistribution in a catalytic plate reactor using a coated wire mesh has to be considered....

  5. Reverse-Bumpy-Ball-Type-Nanoreactor-Loaded Nylon Membranes as Peroxidase-Mimic Membrane Reactors for a Colorimetric Assay for H₂O₂.

    Science.gov (United States)

    Tong, Ying; Jiao, Xiangyu; Yang, Hankun; Wen, Yongqiang; Su, Lei; Zhang, Xueji

    2016-04-01

    Herein we report for the first time fabrication of reverse bumpy ball (RBB)-type-nanoreactor-based flexible peroxidase-mimic membrane reactors (MRs). The RBB-type nanoreactors with gold nanoparticles embedded in the inner walls of carbon shells were loaded on nylon membranes through a facile filtration approach. The as-prepared flexible catalytic membrane was studied as a peroxidase-mimic MR. It was found that the obtained peroxidase-mimic MR could exhibit several advantages over natural enzymes, such as facile and good recyclability, long-term stability and easy storage. Moreover, the RBB NS-modified nylon MRs as a peroxidase mimic provide a useful colorimetric assay for H₂O₂.

  6. Reverse-Bumpy-Ball-Type-Nanoreactor-Loaded Nylon Membranes as Peroxidase-Mimic Membrane Reactors for a Colorimetric Assay for H2O2

    Science.gov (United States)

    Tong, Ying; Jiao, Xiangyu; Yang, Hankun; Wen, Yongqiang; Su, Lei; Zhang, Xueji

    2016-01-01

    Herein we report for the first time fabrication of reverse bumpy ball (RBB)-type-nanoreactor-based flexible peroxidase-mimic membrane reactors (MRs). The RBB-type nanoreactors with gold nanoparticles embedded in the inner walls of carbon shells were loaded on nylon membranes through a facile filtration approach. The as-prepared flexible catalytic membrane was studied as a peroxidase-mimic MR. It was found that the obtained peroxidase-mimic MR could exhibit several advantages over natural enzymes, such as facile and good recyclability, long-term stability and easy storage. Moreover, the RBB NS-modified nylon MRs as a peroxidase mimic provide a useful colorimetric assay for H2O2. PMID:27043575

  7. Treating domestic sewage by Integrated Inclined-Plate-Membrane bio-reactor

    Science.gov (United States)

    Song, Li Ming; Wang, Zi; Chen, Lei; Zhong, Min; Dong, Zhan Feng

    2017-12-01

    Membrane fouling shorten the service life of the membrane and increases aeration rate for membrane surface cleaning. Two membrane bio-reactors, one for working and another for comparing, were set up to evaluate the feasibility of alleviating membrane fouling and improving wastewater treatment efficiency by integrating inclined-plate precipitation and membrane separation. The result show that: (1) Inclined-plate in reactor had a good effect on pollutant removal of membrane bioreactor. The main role of inclined-plate is dividing reactor space and accelerating precipitation. (2) Working reactor have better performance in COD, TN and TP removal, which can attribute to that working reactor (integrated inclined-plate-Membrane bioreactor) takes both advantages of membrane separation and biological treatment. When influent COD, TP and TN concentration is 163-248 mg/L, 2.08-2.81 mg/L and 24.38-30.49 mg/L in working reactor, effluent concentration is 27-35 mg/L, 0.53-0.59 mg/L and 11.28-11.56 mg/L, respectively. (3) Membrane fouling was well alleviated in integrated inclined-plate-Membrane bioreactor, and membrane normal service time is significantly longer than that in comparing reactor, which can attribute to accelerating precipitation of inclined-plate. In summary, integrated inclined-plate-Membrane bioreactor is a promising technology to alleviating membrane fouling and improving wastewater treatment efficiency, having good performance and bright future in application.

  8. Use of Glucose Oxidase in a Membrane Reactor for Gluconic Acid Production

    Science.gov (United States)

    Das Neves, Luiz Carlos Martins; Vitolo, Michele

    This article aims at the evaluation of the catalytic performance of glucose oxidase (GO) (EC.1.1.3.4) for the glucose/gluconic acid conversion in the ultrafiltration cell type membrane reactor (MB-CSTR). The reactor was coupled with a Millipore ultrafiltration-membrane (cutoff of 100 kDa) and operated for 24 h under agitation of 100 rpm, pH 5.5, and 30°C. The experimental conditions varied were the glucose concentration (2.5, 5.0, 10.0, 20.0, and 40.0 mM), the feeding rate (0.5, 1.0, 3.0, and 6.0/h), dissolved oxygen (8.0 and 16.0 mg/L), GO concentration (2.5, 5.0, 10.0, and 20.0 UGO/mL), and the glucose oxidase/catalase activity ratio (UGO/UCAT)(1∶0, 1∶10, 1∶20, and 1∶30). A conversion yield of 80% and specific reaction rate of 40×10-4 mmol/h·UGO were attained when the process was carried out under the following conditions: D=3.0/h, dissolved oxygen=16.0 mg/L, [G]=40 mM, and (UGO/UCAT)=1∶20. A simplified model for explaining the inhibition of GO activity by hydrogen peroxide, formed during the glucose/gluconic acid conversion, was presented.

  9. Development of a two separate phase submerged biocatalytic membrane reactor for the production of fatty acids and glycerol from residual vegetable oil streams

    International Nuclear Information System (INIS)

    Chakraborty, S.; Drioli, E.; Giorno, L.

    2012-01-01

    Enzymatic membrane bioreactors (MBR) have been studied for very different applications since many years. Submerged MBR has also been successfully used for treatment of wastewater. In the existing submerged configuration, the membrane works as the separation unit operation while the bioconversion is carried out by microorganisms suspended in the tank reactor. In the present work, a novel approach that combines the concept of biocatalytic membranes and submerged modules is proposed for the treatment of biomass. Lipase enzyme from Candida rugosa has been immobilized in polyethersulphone hollow fiber (PES HF) membrane in order to develop a two separate phase biocatalytic submerged membrane reactor in which the membrane works as both catalytic and separation unit. Furthermore, the submerged biocatalytic membrane reactor is intended for production of valuable components from waste biomass, and different physical, chemical and fluid dynamics has been optimized. Response surface methodology (RSM) has been used to model the operating parameters and Box-Behnken method has been applied to maximize the fatty acids production and optimization. At TMP 80 ± 2 kPa, pH 7.40 ± 0.1, temperature 35 ± 0.5 °C with an axial velocity of 0.07 ± 0.01 ms −1 and organic stirring 89.01 rad s −1 the system showed the global examined value within the experimental scope. The proof of principle using fried cooked oils has been performed in later period. -- Highlights: ► Catalytic activity of enzyme in submerged condition has been studied. ► Optimization of submerged biocatalytic membrane reactor for production of value added components. ► Waste valorization by membrane reactor in order to minimization of waste. ► Three different waste oil (as waste biomass) has been studied in respect to product generation and different results obtained.

  10. Simple and rapid hydrogenation of p-nitrophenol with aqueous formic acid in catalytic flow reactors

    Science.gov (United States)

    Kawasaki, Shin-ichiro; Suzuki, Akira

    2013-01-01

    Summary The inner surface of a metallic tube (i.d. 0.5 mm) was coated with a palladium (Pd)-based thin metallic layer by flow electroless plating. Simultaneous plating of Pd and silver (Ag) from their electroless-plating solution produced a mixed distributed bimetallic layer. Preferential acid leaching of Ag from the Pd–Ag layer produced a porous Pd surface. Hydrogenation of p-nitrophenol was examined in the presence of formic acid simply by passing the reaction solution through the catalytic tubular reactors. p-Aminophenol was the sole product of hydrogenation. No side reaction occurred. Reaction conversion with respect to p-nitrophenol was dependent on the catalyst layer type, the temperature, pH, amount of formic acid, and the residence time. A porous and oxidized Pd (PdO) surface gave the best reaction conversion among the catalytic reactors examined. p-Nitrophenol was converted quantitatively to p-aminophenol within 15 s of residence time in the porous PdO reactor at 40 °C. Evolution of carbon dioxide (CO2) was observed during the reaction, although hydrogen (H2) was not found in the gas phase. Dehydrogenation of formic acid did not occur to any practical degree in the absence of p-nitrophenol. Consequently, the nitro group was reduced via hydrogen transfer from formic acid to p-nitrophenol and not by hydrogen generated by dehydrogenation of formic acid. PMID:23843908

  11. Modeling of adsorber/desorber/catalytic reactor system for ethylene oxide removal

    Directory of Open Access Journals (Sweden)

    ZELJKO B. GRBAVCIC

    2004-12-01

    Full Text Available The removal of ethylene oxide (EtO in a combined system adsorber/desorber/catalytic reactor has been investigated. The combined system was a modified draft tube spouted bed reactor loaded with Pt/Al2O3 catalyst. The annular region was divided into two sectons, the “hot” section contained about 7 % of catalyst and it behaved as a desorber and catalytic incinerator, while the “cold” section, with the rest of the catalyst, behaved as a sorber. The catalyst particles were circulated between the two sections by use of a draft tube riser. The Computational Fluid Dynamics (CFD program package FLUENT was used for simulations of the operation of the combined system. In addition, a one-dimensional numerical model for the operation of the packed bed reactor was compared with the corresponding FLUENT calculations. The results of the FLUENT simulations are in very good agreement with the experimental observations, as well as with the results of the one-dimensional numerical simulations.

  12. Simple and rapid hydrogenation of p-nitrophenol with aqueous formic acid in catalytic flow reactors

    Directory of Open Access Journals (Sweden)

    Rahat Javaid

    2013-06-01

    Full Text Available The inner surface of a metallic tube (i.d. 0.5 mm was coated with a palladium (Pd-based thin metallic layer by flow electroless plating. Simultaneous plating of Pd and silver (Ag from their electroless-plating solution produced a mixed distributed bimetallic layer. Preferential acid leaching of Ag from the Pd–Ag layer produced a porous Pd surface. Hydrogenation of p-nitrophenol was examined in the presence of formic acid simply by passing the reaction solution through the catalytic tubular reactors. p-Aminophenol was the sole product of hydrogenation. No side reaction occurred. Reaction conversion with respect to p-nitrophenol was dependent on the catalyst layer type, the temperature, pH, amount of formic acid, and the residence time. A porous and oxidized Pd (PdO surface gave the best reaction conversion among the catalytic reactors examined. p-Nitrophenol was converted quantitatively to p-aminophenol within 15 s of residence time in the porous PdO reactor at 40 °C. Evolution of carbon dioxide (CO2 was observed during the reaction, although hydrogen (H2 was not found in the gas phase. Dehydrogenation of formic acid did not occur to any practical degree in the absence of p-nitrophenol. Consequently, the nitro group was reduced via hydrogen transfer from formic acid to p-nitrophenol and not by hydrogen generated by dehydrogenation of formic acid.

  13. Reactor for nano-focused x-ray diffraction and imaging under catalytic in situ conditions

    Science.gov (United States)

    Richard, M.-I.; Fernández, S.; Hofmann, J. P.; Gao, L.; Chahine, G. A.; Leake, S. J.; Djazouli, H.; De Bortoli, Y.; Petit, L.; Boesecke, P.; Labat, S.; Hensen, E. J. M.; Thomas, O.; Schülli, T.

    2017-09-01

    A reactor cell for in situ studies of individual catalyst nanoparticles or surfaces by nano-focused (coherent) x-ray diffraction has been developed. Catalytic reactions can be studied in flow mode in a pressure range of 10-2-103 mbar and temperatures up to 900 °C. This instrument bridges the pressure and materials gap at the same time within one experimental setup. It allows us to probe in situ the structure (e.g., shape, size, strain, faceting, composition, and defects) of individual nanoparticles using a nano-focused x-ray beam. Here, the setup was used to observe strain and facet evolution of individual model Pt catalysts during in situ experiments. It can be used for heating other (non-catalytically active) nanoparticles (e.g., nanowires) in inert or reactive gas atmospheres or vacuum as well.

  14. Tritium recovery from tritiated water with a two-stage palladium membrane reactor

    Energy Technology Data Exchange (ETDEWEB)

    Birdsell, S.A.; Willms, R.S.

    1997-04-01

    A process to recover tritium from tritiated water has been successfully demonstrated at TSTA. The 2-stage palladium membrane reactor (PMR) is capable of recovering tritium from water without generating additional waste. This device can be used to recover tritium from the substantial amount of tritiated water that is expected to be generated in the International Thermonuclear Experimental Reactor both from torus exhaust and auxiliary operations. A large quantity of tritiated waste water exists world wide because the predominant method of cleaning up tritiated streams is to oxidize tritium to tritiated water. The latter can be collected with high efficiency for subsequent disposal. The PMR is a combined catalytic reactor/permeator. Cold (non-tritium) water processing experiments were run in preparation for the tritiated water processing tests. Tritium was recovered from a container of molecular sieve loaded with 2,050 g (2,550 std. L) of water and 4.5 g of tritium. During this experiment, 27% (694 std. L) of the water was processed resulting in recovery of 1.2 g of tritium. The maximum water processing rate for the PMR system used was determined to be 0.5 slpm. This correlates well with the maximum processing rate determined from the smaller PMR system on the cold test bench and has resulted in valuable scale-up and design information.

  15. Pd-Ag Membrane Coupled to a Two-Zone Fluidized Bed Reactor (TZFBR) for Propane Dehydrogenation on a Pt-Sn/MgAl2O4 Catalyst.

    Science.gov (United States)

    Medrano, José-Antonio; Julián, Ignacio; Herguido, Javier; Menéndez, Miguel

    2013-05-14

    Several reactor configurations have been tested for catalytic propane dehydrogenation employing Pt-Sn/MgAl2O4 as a catalyst. Pd-Ag alloy membranes coupled to the multifunctional Two-Zone Fluidized Bed Reactor (TZFBR) provide an improvement in propane conversion by hydrogen removal from the reaction bed through the inorganic membrane in addition to in situ catalyst regeneration. Twofold process intensification is thereby achieved when compared to the use of traditional fluidized bed reactors (FBR), where coke formation and thermodynamic equilibrium represent important process limitations. Experiments were carried out at 500-575 °C and with catalyst mass to molar flow of fed propane ratios between 15.1 and 35.2 g min mmol-1, employing three different reactor configurations: FBR, TZFBR and TZFBR + Membrane (TZFBR + MB). The results in the FBR showed catalyst deactivation, which was faster at high temperatures. In contrast, by employing the TZFBR with the optimum regenerative agent flow (diluted oxygen), the process activity was sustained throughout the time on stream. The TZFBR + MB showed promising results in catalytic propane dehydrogenation, displacing the reaction towards higher propylene production and giving the best results among the different reactor configurations studied. Furthermore, the results obtained in this study were better than those reported on conventional reactors.

  16. Pd-Ag Membrane Coupled to a Two-Zone Fluidized Bed Reactor (TZFBR for Propane Dehydrogenation on a Pt-Sn/MgAl2O4 Catalyst

    Directory of Open Access Journals (Sweden)

    Miguel Menéndez

    2013-05-01

    Full Text Available Several reactor configurations have been tested for catalytic propane dehydrogenation employing Pt-Sn/MgAl2O4 as a catalyst. Pd-Ag alloy membranes coupled to the multifunctional Two-Zone Fluidized Bed Reactor (TZFBR provide an improvement in propane conversion by hydrogen removal from the reaction bed through the inorganic membrane in addition to in situ catalyst regeneration. Twofold process intensification is thereby achieved when compared to the use of traditional fluidized bed reactors (FBR, where coke formation and thermodynamic equilibrium represent important process limitations. Experiments were carried out at 500–575 °C and with catalyst mass to molar flow of fed propane ratios between 15.1 and 35.2 g min mmol−1, employing three different reactor configurations: FBR, TZFBR and TZFBR + Membrane (TZFBR + MB. The results in the FBR showed catalyst deactivation, which was faster at high temperatures. In contrast, by employing the TZFBR with the optimum regenerative agent flow (diluted oxygen, the process activity was sustained throughout the time on stream. The TZFBR + MB showed promising results in catalytic propane dehydrogenation, displacing the reaction towards higher propylene production and giving the best results among the different reactor configurations studied. Furthermore, the results obtained in this study were better than those reported on conventional reactors.

  17. Zeolite Membranes in Catalysis—From Separate Units to Particle Coatings

    Directory of Open Access Journals (Sweden)

    Radostina Dragomirova

    2015-12-01

    Full Text Available Literature on zeolite membranes in catalytic reactions is reviewed and categorized according to membrane location. From this perspective, the classification is as follows: (i membranes spatially decoupled from the reaction zone; (ii packed bed membrane reactors; (iii catalytic membrane reactors and (iv zeolite capsuled catalyst particles. Each of the resulting four chapters is subdivided by the kind of reactions performed. Over the whole sum of references, the advantage of zeolite membranes in catalytic reactions in terms of conversion, selectivity or yield is evident. Furthermore, zeolite membrane preparation, separation principles as well as basic considerations on membrane reactors are discussed.

  18. Catalytic reactor

    NARCIS (Netherlands)

    Sie, S.T.; Cybulski, A.; Moulijn, J.A.

    2000-01-01

    PCT No. PCT/NL93/00231 Sec. 371 Date Jul. 21, 1995 Sec. 102(e) Date Jul. 21, 1995 PCT Filed Nov. 4, 1993 PCT Pub. No. WO94/09901 PCT Pub. Date May 11, 1994There is described a catalyst element (1) consisting of an integral whole having channels (2) extending therethrough. These channels (2) have, in

  19. Membrane contactor/separator for an advanced ozone membrane reactor for treatment of recalcitrant organic pollutants in water

    Science.gov (United States)

    Kit Chan, Wai; Jouët, Justine; Heng, Samuel; Lun Yeung, King; Schrotter, Jean-Christophe

    2012-05-01

    An advanced ozone membrane reactor that synergistically combines membrane distributor for ozone gas, membrane contactor for pollutant adsorption and reaction, and membrane separator for clean water production is described. The membrane reactor represents an order of magnitude improvement over traditional semibatch reactor design and is capable of complete conversion of recalcitrant endocrine disrupting compounds (EDCs) in water at less than three minutes residence time. Coating the membrane contactor with alumina and hydrotalcite (Mg/Al=3) adsorbs and traps the organics in the reaction zone resulting in 30% increase of total organic carbon (TOC) removal. Large surface area coating that diffuses surface charges from adsorbed polar organic molecules is preferred as it reduces membrane polarization that is detrimental to separation.

  20. Hybrid membrane with TiO2 based bio-catalytic nanoparticle suspension system for the degradation of bisphenol-A.

    Science.gov (United States)

    Hou, Jingwei; Dong, Guangxi; Luu, Belinda; Sengpiel, Robert G; Ye, Yun; Wessling, Matthias; Chen, Vicki

    2014-10-01

    The removal of micropollutant in wastewater treatment has become a key environmental challenge for many industrialized countries. One approach is to use enzymes such as laccase for the degradation of micropollutants such as bisphenol-A. In this work, laccase was covalently immobilized on APTES modified TiO2 nanoparticles, and the effects of particle modification on the bio-catalytic performance were examined and optimized. These bio-catalytic particles were then suspended in a hybrid membrane reactor for BPA removal with good BPA degradation efficiency observed. Substantial improvement in laccase stability was achieved in the hybrid system compared with free laccase under simulated harsh industrial wastewater treatment conditions (such as a wide range of pH and presence of inhibitors). Kinetic study provided insight of the effect of immobilization on the bio-degradation reaction. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. A Miniature Membrane Reactor for Evaluation of Process Design Options on the Enzymatic Degradation of Pectin

    DEFF Research Database (Denmark)

    Zainal Alam, Muhd Nazrul Hisham; Pinelo, Manuel; Arnous, Anis

    2011-01-01

    The objective of this paper is to assess if a membrane microbioreactor system could potentially be used to diagnose consequences of different process design and reactor operation options relevant for larger-scale enzymatic degradation of pectin reactions. The membrane microbioreactor prototype...... design affected the membrane rejection profile. The results obtained thus underlined the suitability of a miniature membrane reactor system for evaluating different process design options that are relevant for larger-scale reactions of enzymatic pectin degradation....

  2. Water Gas Shift Reaction with A Single Stage Low Temperature Membrane Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ciora, Richard J [Media and Process Technology Inc., Pittsburgh, PA (United States); Liu, Paul KT [Media and Process Technology Inc., Pittsburgh, PA (United States)

    2013-12-31

    Palladium membrane and Palladium membrane reactor were developed under this project for hydrogen separation and purification for fuel cell applications. A full-scale membrane reactor was designed, constructed and evaluated for the reformate produced from a commercial scale methanol reformer. In addition, the Pd membrane and module developed from this project was successfully evaluated in the field for hydrogen purification for commercial fuel cell applications.

  3. Experiment and modeling of low-concentration methane catalytic combustion in a fluidized bed reactor

    International Nuclear Information System (INIS)

    Yang, Zhongqing; Yang, Peng; Zhang, Li; Guo, Mingnv; Ran, Jingyu

    2016-01-01

    Highlights: • The catalytic combustion of 0.15~3 vol. % low concentration methane in a fluidized bed was studied. • A mathematical model was proposed on the basis of gas–solid flow theory. • A comparative analysis of the established model with plug flow, mixed flow and K-L models was carried out. • The axial methane profile along fluidized bed was predicted by using the mathematical model. • The bed temperature has greater impact on methane conversion than fluidized velocity. - Abstract: This study undertakes a theoretical analysis and an experimental investigation into the characteristics of low-concentration methane catalytic combustion in a bubbling fluidized bed reactor using 0.5 wt.% Pd/Al 2 O 3 as catalytic particles. A mathematical model is established based on gas–solid flow theory and is used to study the effects of bed temperature and fluidized velocity on methane catalytic combustion, and predict the dimensionless methane concentration axial profile in reactor. It is shown that methane conversion increases with bed temperature, but decreases with increasing fluidized velocity. These theoretical results are found to correlate well with the experimental measurement, with a deviation within 5%. A comparative analysis of the developed model with plug flow, mixed flow and K-L models is also carried out, and this further verifies that the established model better reflects the characteristics of low-concentration methane catalytic combustion in a bubbling fluidized bed. Using this reaction model, it was found that the difference in methane conversion between dense and freeboard zones gradually increases with bed temperature; the dense zone reaction levels off at 650 °C, thereby minimizing the difference between the dense and freeboard regions to around 15%. With an increase in bed temperature, the dimensionless methane concentration in the dense zone decreases exponentially, while in the splash zone, it varies from an exponential decay to a

  4. Reduced membrane fouling in a novel bio-entrapped membrane reactor for treatment of food and beverage processing wastewater.

    Science.gov (United States)

    Ng, Kok-Kwang; Lin, Cheng-Fang; Panchangam, Sri Chandana; Andy Hong, Pui-Kwan; Yang, Ping-Yi

    2011-08-01

    A novel Bio-Entrapped Membrane Reactor (BEMR) packed with bio-ball carriers was constructed and investigated for organics removal and membrane fouling by soluble microbial products (SMP). An objective was to evaluate the stability of the filtration process in membrane bioreactors through backwashing and chemical cleaning. The novel BEMR was compared to a conventional membrane bioreactor (CMBR) on performance, with both treating identical wastewater from a food and beverage processing plant. The new reactor has a longer sludge retention time (SRT) and lower mixed liquor suspended solids (MLSS) content than does the conventional. Three different hydraulic retention times (HRTs) of 6, 9, and 12 h were studied. The results show faster rise of the transmembrane pressure (TMP) with decreasing hydraulic retention time (HRT) in both reactors, where most significant membrane fouling was associated with high SMP (consisting of carbohydrate and protein) contents that were prevalent at the shortest HRT of 6 h. Membrane fouling was improved in the new reactor, which led to a longer membrane service period with the new reactor. Rapid membrane fouling was attributed to increased production of biomass and SMP, as in the conventional reactor. SMP of 10-100 kDa from both MBRs were predominant with more than 70% of the SMP <100 kDa. Protein was the major component of SMP rather than carbohydrate in both reactors. The new reactor sustained operation at constant permeate flux that required seven times less frequent chemical cleaning than did the conventional reactor. The new BEMR offers effective organics removal while reducing membrane fouling. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Supported Pd-Au Membrane Reactor for Hydrogen Production: Membrane Preparation, Characterization and Testing

    Directory of Open Access Journals (Sweden)

    Adolfo Iulianelli

    2016-05-01

    Full Text Available A supported Pd-Au (Au 7wt% membrane was produced by electroless plating deposition. Permeation tests were performed with pure gas (H2, H2, N2, CO2, CH4 for long time operation. After around 400 h under testing, the composite Pd-Au membrane achieved steady state condition, with an H2/N2 ideal selectivity of around 500 at 420 °C and 50 kPa as transmembrane pressure, remaining stable up to 1100 h under operation. Afterwards, the membrane was allocated in a membrane reactor module for methane steam reforming reaction tests. As a preliminary application, at 420 °C, 300 kPa of reaction pressure, space velocity of 4100 h−1, 40% methane conversion and 35% hydrogen recovery were reached using a commercial Ni/Al2O3 catalyst. Unfortunately, a severe coke deposition affected irreversibly the composite membrane, determining the loss of the hydrogen permeation characteristics of the supported Pd-Au membrane.

  6. Fast Pyrolysis Oil Stabilization: An Integrated Catalytic and Membrane Approach for Improved Bio-oils. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Huber, George W.; Upadhye, Aniruddha A.; Ford, David M.; Bhatia, Surita R.; Badger, Phillip C.

    2012-10-19

    with model AFBO excluding guaiacol were also conducted. NF membranes showed retention factors of glucose greater than 80% and of acetic acid less than 15% when operated at transmembrane pressures near 60 bar. Task 3.0 Acid Removal by Catalytic Processing It was found that the TAN reduction in bio-oil was very difficult using low temperature hydrogenation in flow and batch reactors. Acetic acid is very resilient to hydrogenation and we could only achieve about 16% conversion for acetic acid. Although it was observed that acetic acid was not responsible for instability of aqueous fraction of bio-oil during ageing studies (described in task 5). The bimetallic catalyst PtRe/ceria-zirconia was found to be best catalyst because its ability to convert the acid functionality with low conversion to gas phase carbon. Hydrogenation of the whole bio-oil was carried out at 125°C, 1450 psi over Ru/C catalyst in a flow reactor. Again, negligible acetic acid conversion was obtained in low temperature hydrogenation. Hydrogenation experiments with whole bio-oil were difficult to perform because of difficulty to pumping the high viscosity oil and reactor clogging. Task 4.0 Acid Removal using Ion Exchange Resins DOWEX M43 resin was used to carry out the neutralization of bio-oil using a packed bed column. The pH of the bio-oil increased from 2.43 to 3.7. The GC analysis of the samples showed that acetic acid was removed from the bio-oil during the neutralization and recovered in the methanol washing. But it was concluded that process would not be economical at large scale as it is extremely difficult to regenerate the resin once the bio-oil is passed over it. Task 5.0 Characterization of Upgraded Bio-oils We investigated the viscosity, microstructure, and chemical composition of bio-oils prepared by a fast pyrolysis approach, upon aging these fuels at 90ºC for periods of several days. Our results suggest that the viscosity increase is not correlated with the acids or char present in the

  7. Zeolite Membranes in Catalysis—From Separate Units to Particle Coatings

    OpenAIRE

    Radostina Dragomirova; Sebastian Wohlrab

    2015-01-01

    Literature on zeolite membranes in catalytic reactions is reviewed and categorized according to membrane location. From this perspective, the classification is as follows: (i) membranes spatially decoupled from the reaction zone; (ii) packed bed membrane reactors; (iii) catalytic membrane reactors and (iv) zeolite capsuled catalyst particles. Each of the resulting four chapters is subdivided by the kind of reactions performed. Over the whole sum of references, the advantage of zeolite membran...

  8. Catalytic partial oxidation coupled with membrane purification to improve resource and energy efficiency in syngas production.

    Science.gov (United States)

    Iaquaniello, G; Salladini, A; Palo, E; Centi, G

    2015-02-01

    Catalytic partial oxidation coupled with membrane purification is a new process scheme to improve resource and energy efficiency in a well-established and large scale-process like syngas production. Experimentation in a semi industrial-scale unit (20 Nm(3)  h(-1) production) shows that a novel syngas production scheme based on a pre-reforming stage followed by a membrane for hydrogen separation, a catalytic partial oxidation step, and a further step of syngas purification by membrane allows the oxygen-to-carbon ratio to be decreased while maintaining levels of feed conversion. For a total feed conversion of 40 %, for example, the integrated novel architecture reduces oxygen consumption by over 50 %, with thus a corresponding improvement in resource efficiency and an improved energy efficiency and economics, these factors largely depending on the air separation stage used to produce pure oxygen. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Catalytic

    Directory of Open Access Journals (Sweden)

    S.A. Hanafi

    2014-03-01

    Full Text Available A series of dealuminated Y-zeolites impregnated by 0.5 wt% Pt catalysts promoted by different amounts of Ni, Pd or Cr (0.3 and 0.6 wt% were prepared and characterized as hydrocracking catalysts. The physicochemical and structural characterization of the solid catalysts were investigated and reported through N2 physisorption, XRD, TGA-DSC, FT-IR and TEM techniques. Solid catalysts surface acidities were investigated through FT-IR spectroscopy aided by pyridine adsorption. The solid catalytic activities were evaluated through hydroconversion of n-hexane and n-heptane employing micro-catalytic pulse technique directly connected to a gas chromatograph analyzer. The thermal stability of the solids was also investigated up to 800 °C. Crystallinity studies using the XRD technique of all modified samples proved analogous to the parent Y-zeolite, exhibiting nearly an amorphous and microcrystalline character of the second metal oxides. Disclosure of bimetallic catalysts crystalline characterization, through XRD, was not viable. The nitrogen adsorption–desorption isotherms for all samples concluded type I adsorption isotherms, without any hysteresis loop, indicating that the entire pore system is composed of micropores. TEM micrographs of the solid catalysts demonstrate well-dispersed Pt, Ni and Cr nanoparticles having sizes of 2–4 nm and 7–8 nm, respectively. The catalytic activity results indicate that the bimetallic (0.5Pt–0.3Cr/D18H–Y catalyst is the most active towards n-hexane and n-heptane isomerization while (0.5Pt–0.6Ni/D18H–Y catalyst can be designed as most suitable as a cracking catalyst.

  10. Food industrial wastewater reuse by membrane bio-reactor

    Directory of Open Access Journals (Sweden)

    Patthanant Natpinit

    2007-11-01

    Full Text Available The objective of this investigation was to study the possibility and performance of treating food industrial wastewater by Membrane BioReactor (MBR. In addition, the effluent of MBR was treated by Reverse Osmosis system (RO to reuse in boiler or cooling tower. The membranes of hollow fiber type were filled in the aerobic tank with aerobe bacteria. The total area of membrane 6 units was 630 m2 so the flux of the operation was 0.25 m/d or 150 m3/d. The spiral wound RO was operated at 100 m3/d of influent and received 72 m3/d of permeate. The sludge volume (MLSS of MBR was maintained at 8,000-10,000 mg/l. The average COD and SS of MBR influent were 600 mg/l and 300 mg/l respectively. After treating by MBR, COD and SS of effluent were maintained at less than 100 mg/l and less than 10 mg/l respectively. In the same way, COD and SS of RO permeate were less than 10 mg/l and less than 5 mg/l respectively.

  11. Comparison of two different flow types on CO removal along a two-stage hydrogen permselective membrane reactor for methanol synthesis

    International Nuclear Information System (INIS)

    Rahimpour, M.R.; Mazinani, S.; Vaferi, B.; Baktash, M.S.

    2011-01-01

    Carbon monoxide (CO) is a gaseous pollutant with adverse effects on human health and the environment. Industrial chemical processes contribute significantly to CO accumulation in the atmosphere. One of the most important processes for controlling carbon monoxide emissions is the conversion of CO to methanol by catalytic hydrogenation. In this study, the effects of two different flow types on the rate of CO removal along a two-stage hydrogen permselective membrane reactor have been investigated. In the first configuration, fresh synthesis gas flows in the tube side of the membrane reactor co-currently with reacting material in the shell side, so that more hydrogen is provided in the first sections of the reactor. In the second configuration, fresh synthesis gas flows in the tube side of the membrane reactor counter-currently with reacting material in the shell side, so that more hydrogen is provided in the last sections of the reactor. For this membrane system, a one-dimensional dynamic plug flow model in the presence of catalyst deactivation was developed. Comparison between co-current and counter-current configurations shows that the reactor operates with higher conversion of CO and hydrogen permeation rate in the counter-current mode whereas; longer catalyst life is achieved in the co-current configuration. Enhancement of CO removal in the counter-current mode versus the co-current configuration results in an ultimate reduction in CO emissions into the atmosphere.

  12. Reactor design for minimizing product inhibition during enzymatic lignocellulose hydrolysis: II. Quantification of inhibition and suitability of membrane reactors.

    Science.gov (United States)

    Andrić, Pavle; Meyer, Anne S; Jensen, Peter A; Dam-Johansen, Kim

    2010-01-01

    Product inhibition of cellulolytic enzymes affects the efficiency of the biocatalytic conversion of lignocellulosic biomass to ethanol and other valuable products. New strategies that focus on reactor designs encompassing product removal, notably glucose removal, during enzymatic cellulose conversion are required for alleviation of glucose product inhibition. Supported by numerous calculations this review assesses the quantitative aspects of glucose product inhibition on enzyme-catalyzed cellulose degradation rates. The significance of glucose product inhibition on dimensioning of different ideal reactor types, i.e. batch, continuous stirred, and plug-flow, is illustrated quantitatively by modeling different extents of cellulose conversion at different reaction conditions. The main operational challenges of membrane reactors for lignocellulose conversion are highlighted. Key membrane reactor features, including system set-up, dilution rate, glucose output profile, and the problem of cellobiose are examined to illustrate the quantitative significance of the glucose product inhibition and the total glucose concentration on the cellulolytic conversion rate. Comprehensive overviews of the available literature data for glucose removal by membranes and for cellulose enzyme stability in membrane reactors are given. The treatise clearly shows that membrane reactors allowing continuous, complete, glucose removal during enzymatic cellulose hydrolysis, can provide for both higher cellulose hydrolysis rates and higher enzyme usage efficiency (kg(product)/kg(enzyme)). Current membrane reactor designs are however not feasible for large scale operations. The report emphasizes that the industrial realization of cellulosic ethanol requires more focus on the operational feasibility within the different hydrolysis reactor designs, notably for membrane reactors, to achieve efficient enzyme-catalyzed cellulose degradation. (c) 2010 Elsevier Inc. All rights reserved.

  13. Improving carbon tolerance of Ni-YSZ catalytic porous membrane by palladium addition for low temperature steam methane reforming

    Science.gov (United States)

    Lee, Sang Moon; Won, Jong Min; Kim, Geo Jong; Lee, Seung Hyun; Kim, Sung Su; Hong, Sung Chang

    2017-10-01

    Palladium was added on the Ni-YSZ catalytic porous membrane by wet impregnation and electroless plating methods. Its surface morphology characteristics and carbon deposition properties for the low temperature steam methane reforming were investigated. The addition of palladium could obviously be enhanced the catalytic activity as well as carbon tolerance of the Ni-YSZ porous membrane. The porous membranes were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed reduction (H2-TPR), CH4 temperature-programmed reduction (CH4-TPR), and O2 temperature-programmed oxidation (O2-TPO). It was found that the Pd-Ni-YSZ catalytic porous membrane showed the superior stability as well as the deposition of carbon on the surface during carbon dissociation adsorption at 650 °C was also suppressed.

  14. Pd-Ag membrane reactor for steam reforming reactions: a comparison between different fuels

    NARCIS (Netherlands)

    Gallucci, F.; Basile, A.

    2008-01-01

    The simulation of a dense Pd-based membrane reactor for carrying out the methane, the methanol and the ethanol steam reforming (SR) reactions for pure hydrogen production is performed. The same simulation is also performed in a traditional reactor. This modelling work shows that the use of membrane

  15. Noncatalytic hydrogenation of decene-1 with hydrogen accumulated in a hybrid carbon nanostructure in nanosized membrane reactors

    Science.gov (United States)

    Soldatov, A. P.

    2014-08-01

    Studies on the creation of nanosized membrane reactors (NMRs) of a new generation with accumulated hydrogen and a regulated volume of reaction zone were continued at the next stage. Hydrogenation was performed in the pores of ceramic membranes with hydrogen preliminarily adsorbed in mono- and multilayered orientated carbon nanotubes with graphene walls (OCNTGs)—a new hybrid carbon nanostructure formed on the inner pore surface. Quantitative determination of hydrogen adsorption in OCNTGs was performed using TRUMEM ultrafiltration membranes with D av = 50 and 90 nm and showed that hydrogen adsorption was up to ˜1.5% of the mass of OCNTG. The instrumentation and procedure for noncatalytic hydrogenation of decene-1 at 250-350°C using hydrogen accumulated and stored in OCNTG were developed. The conversion of decene-1 into decane was ˜0.2-1.8% at hydrogenation temperatures of 250 and 350°C, respectively. The rate constants and activation energy of hydrogenation were determined. The latter was found to be 94.5 kJ/mol, which is much smaller than the values typical for noncatalytic hydrogenations and very close to the values characteristic for catalytic reactions. The quantitative distribution of the reacting compounds in each pore regarded as a nanosized membrane reactor was determined. The activity of hydrogen adsorbed in a 2D carbon nanostructure was evaluated. Possible mechanisms of noncatalytic hydrogenation were discussed.

  16. Nuclear power plant laundry drain treatment using membrane bio reactor

    International Nuclear Information System (INIS)

    Tsukamoto, Masaaki; Kohanawa, Osamu; Kinugasa, Atsushi; Ogawa, Naoki; Murogaki, Kenta

    2012-01-01

    In nuclear power plant, the radioactive effluent generated by washing the clothes worn in controlled area and the hand and shower water used at the controlled area are treated in laundry drain treatment system. Although various systems which treat such liquid waste preexist, the traditional treatment system has disadvantages such as high running cost and a large amount of secondary waste generation. To solve these matters, we have considered application of an activated sludge system, membrane bio reactor, which has been practically used in general industry. For nuclear power plant, the activated sludge system has been developed, tested in its adaptability and the adequacy has been proved. Some preexisting treatment systems have been replaced with this activated sludge system for the first time in a domestic nuclear power plant, and the renewal system is now in operation. The result is reported. (author)

  17. EVALUATING HYDROGEN PRODUCTION IN BIOGAS REFORMING IN A MEMBRANE REACTOR

    Directory of Open Access Journals (Sweden)

    F. S. A. Silva

    2015-03-01

    Full Text Available Abstract Syngas and hydrogen production by methane reforming of a biogas (CH4/CO2 = 2.85 using carbon dioxide was evaluated in a fixed bed reactor with a Pd-Ag membrane in the presence of a nickel catalyst (Ni 3.31% weight/γ-Al2O3 at 773 K, 823 K, and 873 K and 1.01×105 Pa. Operation with hydrogen permeation at 873 K increased the methane conversion to approximately 83% and doubled the hydrogen yield relative to operation without hydrogen permeation. A mathematical model was formulated to predict the evolution of the effluent concentrations. Predictions based on the model showed similar evolutions for yields of hydrogen and carbon monoxide at temperatures below 823 K for operations with and without the hydrogen permeation. The hydrogen yield reached approximately 21% at 823 K and 47% at 873 K under hydrogen permeation conditions.

  18. Zeolite Membrane Reactor for Water Gas Shift Reaction for Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jerry Y.S. [Arizona State Univ., Mesa, AZ (United States)

    2013-01-29

    Gasification of biomass or heavy feedstock to produce hydrogen fuel gas using current technology is costly and energy-intensive. The technology includes water gas shift reaction in two or more reactor stages with inter-cooling to maximize conversion for a given catalyst volume. This project is focused on developing a membrane reactor for efficient conversion of water gas shift reaction to produce a hydrogen stream as a fuel and a carbon dioxide stream suitable for sequestration. The project was focused on synthesizing stable, hydrogen perm-selective MFI zeolite membranes for high temperature hydrogen separation; fabricating tubular MFI zeolite membrane reactor and stable water gas shift catalyst for membrane reactor applications, and identifying experimental conditions for water gas shift reaction in the zeolite membrane reactor that will produce a high purity hydrogen stream. The project has improved understanding of zeolite membrane synthesis, high temperature gas diffusion and separation mechanisms for zeolite membranes, synthesis and properties of sulfur resistant catalysts, fabrication and structure optimization of membrane supports, and fundamentals of coupling reaction with separation in zeolite membrane reactor for water gas shift reaction. Through the fundamental study, the research teams have developed MFI zeolite membranes with good perm-selectivity for hydrogen over carbon dioxide, carbon monoxide and water vapor, and high stability for operation in syngas mixture containing 500 part per million hydrogen sulfide at high temperatures around 500°C. The research teams also developed a sulfur resistant catalyst for water gas shift reaction. Modeling and experimental studies on the zeolite membrane reactor for water gas shift reaction have demonstrated the effective use of the zeolite membrane reactor for production of high purity hydrogen stream.

  19. DESIGN AND CONSTRUCTION OF A MEMBRANE REACTOR SILVER FOR THE STUDY OF OXYGEN PERMEABILITY

    OpenAIRE

    Cjuno H., Jesús A.; Barba R., Alejandro; Arroyo C., Juan

    2014-01-01

    To study the permeability of oxygen through a membrane of silver (thickness 0.13 mm) and the definition of parameters, it has designed and constructed a reactor formed by a cone silver membrane inserted into a cylindrical glass tube borosilicate. This assembly is assembled within a cylindrical thermostated oven electronically. The membrane reactor was conentado to an oxygen tank, and two peristaltic pump mercury manometer, enabling control of inflow of methanol, the temperature and internal p...

  20. Development and assessment of photo-catalytic membranes for water purification using solar radiation

    Science.gov (United States)

    Coto, M.; Troughton, S. C.; Duan, J.; Kumar, R. V.; Clyne, T. W.

    2018-03-01

    This paper describes a novel set-up for characterization of the performance of membranes designed for purification of water. It involves a recirculatory system, with continuous monitoring of the concentration in the water of a representative pollutant (Methylene Blue). Pressures, flow rates and temperatures are also measured. Results, in the form of rate constants for reduction in pollutant concentration, are presented for three different types of membrane, all of which incorporate relatively high surface areas of titania and have permeability values in a range making them suitable for this type of processing (∼10-11 m2). These results are rationalized in terms of the surface areas of the membranes, and the likely water flow characteristics within them. It is concluded that all of the titania surfaces within them have similar efficiencies for photo-catalytic oxidation of pollutants, but there are significant differences in the ways that the water is exposed to these surfaces, and hence in the pollutant oxidation rates. These points are relevant to the optimization of membrane design for this purpose.

  1. Glycerol Production and Transformation: A Critical Review with Particular Emphasis on Glycerol Reforming Reaction for Producing Hydrogen in Conventional and Membrane Reactors.

    Science.gov (United States)

    Bagnato, Giuseppe; Iulianelli, Adolfo; Sanna, Aimaro; Basile, Angelo

    2017-03-23

    Glycerol represents an emerging renewable bio-derived feedstock, which could be used as a source for producing hydrogen through steam reforming reaction. In this review, the state-of-the-art about glycerol production processes is reviewed, with particular focus on glycerol reforming reactions and on the main catalysts under development. Furthermore, the use of membrane catalytic reactors instead of conventional reactors for steam reforming is discussed. Finally, the review describes the utilization of the Pd-based membrane reactor technology, pointing out the ability of these alternative fuel processors to simultaneously extract high purity hydrogen and enhance the whole performances of the reaction system in terms of glycerol conversion and hydrogen yield.

  2. Development of a novel bioelectrochemical membrane reactor for wastewater treatment.

    Science.gov (United States)

    Wang, Yun-Kun; Sheng, Guo-Ping; Li, Wen-Wei; Huang, Yu-Xi; Yu, Yang-Yang; Zeng, Raymond J; Yu, Han-Qing

    2011-11-01

    A novel bioelectrochemical membrane reactor (BEMR), which takes advantage of a membrane bioreactor (MBR) and microbial fuel cells (MFC), is developed for wastewater treatment and energy recovery. In this system, stainless steel mesh with biofilm formed on it serves as both the cathode and the filtration material. Oxygen reduction reactions are effectively catalyzed by the microorganisms attached on the mesh. The effluent turbidity from the BEMR system was low during most of the operation period, and the chemical oxygen demand and NH(4)(+)-N removal efficiencies averaged 92.4% and 95.6%, respectively. With an increase in hydraulic retention time and a decrease in loading rate, the system performance was enhanced. In this BEMR process, a maximum power density of 4.35 W/m(3) and a current density of 18.32 A/m(3) were obtained at a hydraulic retention time of 150 min and external resister of 100 Ω. The Coulombic efficiency was 8.2%. Though the power density and current density of the BEMR system were not very high, compared with other high-output MFC systems, electricity recovery could be further enhanced through optimizing the operation conditions and BEMR configurations. Results clearly indicate that this innovative system holds great promise for efficient treatment of wastewater and energy recovery.

  3. Study on membrane reactors for biodiesel production by phase behaviors of canola oil methanolysis in batch reactors.

    Science.gov (United States)

    Cheng, Li-Hua; Yen, Shih-Yang; Su, Li-Sheng; Chen, Junghui

    2010-09-01

    In comparison with the general stirring batch reactor, the membrane reactor has been reported to have higher molar ratios of methanol to oil but ultralow catalyst concentration in the biodiesel production. In this research, the methanolysis of canola oil is conducted in a stirring batch reactor in the presence of NaOH as a catalyst. Based on the investigation of the effects of operating conditions, including methanol to oil molar ration, catalyst concentrations and temperatures, the time course of the reaction path for the reactant composition in the ternary phase diagram of oil-FAME-MeOH offers an effective way to understand the operation of membrane reactors in the biodiesel production. The results show that increasing the residence time of the whole reactant system within the two-phase zone is good for the separation operation through the membranes. (c) 2010 Elsevier Ltd. All rights reserved.

  4. Performance of integrated bioelectrochemical membrane reactor: Energy recovery, pollutant removal and membrane fouling alleviation

    Science.gov (United States)

    Dong, Yue; He, Weihua; Li, Chao; Liang, Dandan; Qu, Youpeng; Han, Xiaoyu; Feng, Yujie

    2018-04-01

    A novel hybrid bioelectrochemical membrane reactor with integrated microfiltration membrane as the separator between electrodes is developed for domestic wastewater treatment. After accumulation of biofilm, the organic pollutants are mainly degraded in anodic compartment, and microfiltration membrane blocks the adverse leakage of dissolved oxygen from aerated cathodic compartment. The maximum system power output is restricted by gas-water ratio following a Monod-like relationship. Within the tested gas-water ratios ranging from 0.6 to 42.9, the half-saturation constant (KQ) is 5.9 ± 0.9 with a theoretic maximum power density of 20.4 ± 1.0 W m-3. Energy balance analysis indicates an appropriate gas-water ratio regulation (from 2.3 to 28.6) for cathodic compartment is necessary to obtain positive energy output for the system. A maximum net electricity output is 9.09 × 10-3 kWh m-3 with gas-water ratio of 17.1. Notably, the system achieves the chemical oxygen demand removal of 98.3 ± 0.3%, ammonia nitrogen removal of 99.6 ± 0.1%, and total nitrogen removal of 80.0 ± 0.9%. This work verifies an effective integration of microfiltration membrane into bioelectrochemical system as separator for high-quality effluent and provides an insight into the operation and regulation of biocathode system for effective electrical energy output.

  5. Les réacteurs à membranes : possibilités d'application dans l'industrie pétrolière et pétrochimique Membrane Reactors: Possibilities of Application in the Petroleum and Petrochemical Industry

    Directory of Open Access Journals (Sweden)

    Guy C.

    2006-11-01

    Full Text Available Cet article fait le point sur l'état de la recherche dans le domaine des réacteurs chimiques avec séparation par membrane intégrée et de leur applications dans le domaine du raffinage et de la pétrochimie. Trois applications potentiellement intéressantes sont identifiées et, pour chacune, les avantages de l'utilisation d'un réacteur à membrane sont discutés. Ce sont : la déshydrogénation du propane en propylène, la déshydrogénation d'un naphtène cyclohexanique et le vaporéformage du gaz naturel. Pour ces réactions, les membranes à base de palladium apparaissent les plus performantes compte tenu de leur tenue en température, de leur sélectivité et de leur perméabilité à l'hydrogène. Quelques éléments relatifs à leur développement sont présentés en conclusion. Recently, the use of membrane in reaction engineering has been more and more advocated. The selective separation of the products from the reaction mixture allows to achieve higher conversion or better selectivity or to operate under less severe conditions or with smaller units. This paper presents an update on the recent advances in the field of chemical membrane reactors and on their applications in refining and petrochemistry. Previous work. Most of the possible applications of membrane reactors in petroleum and petrochemical industry concern gaseous catalytic reactions. For this reason, gas permeation membranes are the primary component of membrane reactors. Gas permeation membranes present different types of physical structure : dense, microporous or asymmetric which is a combination of the two. Separating properties of dense membranes are function of the solubility and diffusivity of each gaseous component in the membrane material. For microporous membranes, they follow four mechanisms : Knudsen diffusion, surface diffusion, capillary condensation or molecular sieving. Although organic polymers are the common constituent of gas permeation membrane, their

  6. 3D printing in chemical engineering and catalytic technology: structured catalysts, mixers and reactors.

    Science.gov (United States)

    Parra-Cabrera, Cesar; Achille, Clement; Kuhn, Simon; Ameloot, Rob

    2018-01-02

    Computer-aided fabrication technologies combined with simulation and data processing approaches are changing our way of manufacturing and designing functional objects. Also in the field of catalytic technology and chemical engineering the impact of additive manufacturing, also referred to as 3D printing, is steadily increasing thanks to a rapidly decreasing equipment threshold. Although still in an early stage, the rapid and seamless transition between digital data and physical objects enabled by these fabrication tools will benefit both research and manufacture of reactors and structured catalysts. Additive manufacturing closes the gap between theory and experiment, by enabling accurate fabrication of geometries optimized through computational fluid dynamics and the experimental evaluation of their properties. This review highlights the research using 3D printing and computational modeling as digital tools for the design and fabrication of reactors and structured catalysts. The goal of this contribution is to stimulate interactions at the crossroads of chemistry and materials science on the one hand and digital fabrication and computational modeling on the other.

  7. A catalytic reactor for the organocatalyzed enantioselective continuous flow alkylation of aldehydes.

    Science.gov (United States)

    Porta, Riccardo; Benaglia, Maurizio; Puglisi, Alessandra; Mandoli, Alessandro; Gualandi, Andrea; Cozzi, Pier Giorgio

    2014-12-01

    The use of immobilized metal-free catalysts offers the unique possibility to develop sustainable processes in flow mode. The challenging intermolecular organocatalyzed enantioselective alkylation of aldehydes was performed for the first time under continuous flow conditions. By using a packed-bed reactor filled with readily available supported enantiopure imidazolidinone, different aldehydes were treated with three distinct cationic electrophiles. In the organocatalyzed α-alkylation of aldehydes with 1,3-benzodithiolylium tetrafluoroborate, excellent enantioselectivities, in some cases even better than those obtained in the flask process (up to 95% ee at 25 °C), and high productivity (more than 3800 h(-1) ) were obtained, which thus shows that a catalytic reactor may continuously produce enantiomerically enriched compounds. Treatment of the alkylated products with Raney-nickel furnished enantiomerically enriched α-methyl derivatives, key intermediates for active pharmaceutical ingredients and natural products. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Effect of inlet temperature on the performance of a catalytic reactor. [air pollution control

    Science.gov (United States)

    Anderson, D. N.

    1978-01-01

    A 12 cm diameter by 15 cm long catalytic reactor was tested with No. 2 diesel fuel in a combustion test rig at inlet temperatures of 700, 800, 900, and 1000 K. Other test conditions included pressures of 3 and 6 x 10 to the 5th power Pa, reference velocities of 10, 15, and 20 m/s, and adiabatic combustion temperatures in the range 1100 to 1400 K. The combustion efficiency was calculated from measurements of carbon monoxide and unburned hydrocarbon emissions. Nitrogen oxide emissions and reactor pressure drop were also measured. At a reference velocity of 10 m/s, the CO and unburned hydrocarbons emissions, and, therefore, the combustion efficiency, were independent of inlet temperature. At an inlet temperature of 1000 K, they were independent of reference velocity. Nitrogen oxides emissions resulted from conversion of the small amount (135 ppm) of fuel-bound nitrogen in the fuel. Up to 90 percent conversion was observed with no apparent effect of any of the test variables. For typical gas turbine operating conditions, all three pollutants were below levels which would permit the most stringent proposed automotive emissions standards to be met.

  9. Optimization of a membrane reactor for hydrogen production with genetic algorithms

    International Nuclear Information System (INIS)

    Raceanu, Mircea; Iordache, Ioan; Curuia, Marian; Rasoi, Gabriel; Patularu, Laurentiu; Enache, Adrian

    2009-01-01

    Full text: Hydrogen is produced via steam reforming of hydrocarbons such as natural gas or methane by using conventional systems. Unfortunately, these systems need at least four different stages, consisting of three reactors and a purification system. Moreover, the steam reforming reaction is an endothermic thermodynamically limited system, meaning that high temperature energy supply is needed for complete conversion. Among different technologies related to production, separation and purification of H 2 , membrane technologies seem to really play a fundamental role. The specific thermodynamic limits are overcome using the so-called membrane reactors, systems in which both reaction and separation occur simultaneously. The hydrogen is driven across the membrane by the pressure difference, depending on the temperature, pressure and reactor length the methane can be completely converted and consequently very pure hydrogen is produced. A membrane reactor has two components which can be optimized namely, the membrane and the reactor dimensions. This paper presents a study on optimization of membrane reactor for enhancing the overall production. A mathematical heterogeneous model of the reactor was used for optimization of reactor performance. Genetic algorithms were used as powerful methods for optimization of complex problems. (authors)

  10. CFD Simulation of an Anaerobic Membrane BioReactor (AnMBR to Treat Industrial Wastewater

    Directory of Open Access Journals (Sweden)

    Laura C. Zuluaga

    2015-06-01

    Full Text Available A Computational Fluid Dynamics (CFD simulation has been developed for an Anaerobic Membrane BioReactor (AnMBR to treat industrial wastewater. As the process consists of a side-stream MBR, two separate simulations were created: (i reactor and (ii membrane. Different cases were conducted for each one, so the surrounding temperature and the total suspended solids (TSS concentration were checked. For the reactor, the most important aspects to consider were the dead zones and the mixing, whereas for the ceramic membrane, it was the shear stress over the membrane surface. Results show that the reactor's mixing process was adequate and that the membrane presented higher shear stress in the 'triangular' channel.

  11. Integrated Water Gas Shift Membrane Reactors Utilizing Novel, Non Precious Metal Mixed Matrix Membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ferraris, John P. [Univ. of Texas-Dallas, Richardson, TX (United States). Dept. of Chemistry

    2013-09-30

    Nanoparticles of zeolitic imidazolate frameworks and other related hybrid materials were prepared by modifying published synthesis procedures by introducing bases, changing stoichiometric ratios, or adjusting reaction conditions. These materials were stable at temperatures >300 °C and were compatible with the polymer matrices used to prepare mixed- matrix membranes (MMMs). MMMs tested at 300 °C exhibited a >30 fold increase in permeability, compared to those measured at 35 °C, while maintaining H2/CO2 selectivity. Measurements at high pressure (up to 30 atm) and high temperature (up to 300 °C) resulted in an increase in gas flux across the membrane with retention of selectivity. No variations in permeability were observed at high pressures at either 35 or 300 °C. CO2-induced plasticization was not observed for Matrimid®, VTEC, and PBI polymers or their MMMs at 30 atm and 300 °C. Membrane surface modification by cross-linking with ethanol diamine resulted in an increase in H2/CO2 selectivity at 35 °C. Spectrometric analysis showed that the cross-linking was effective to temperatures <150 °C. At higher temperatures, the cross-linked membranes exhibit a H2/CO2 selectivity similar to the uncross-linked polymer. Performance of the polybenzimidazole (PBI) hollow fibers prepared at Santa Fe Science and Technology (SFST, Inc.) showed increased flux and selectivity at 300 °C, which is comparable to a flat PBI membrane. A water-gas shift reactor has been built and currently being optimized for testing under DOE conditions.

  12. Pre-Combustion Carbon Dioxide Capture by a New Dual Phase Ceramic-Carbonate Membrane Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jerry Y. S. [Arizona State Univ., Tempe, AZ (United States)

    2015-01-31

    This report documents synthesis, characterization and carbon dioxide permeation and separation properties of a new group of ceramic-carbonate dual-phase membranes and results of a laboratory study on their application for water gas shift reaction with carbon dioxide separation. A series of ceramic-carbonate dual phase membranes with various oxygen ionic or mixed ionic and electronic conducting metal oxide materials in disk, tube, symmetric, and asymmetric geometric configurations was developed. These membranes, with the thickness of 10 μm to 1.5 mm, show CO2 permeance in the range of 0.5-5×10-7 mol·m-2·s-1·Pa-1 in 500-900°C and measured CO2/N2 selectivity of up to 3000. CO2 permeation mechanism and factors that affect CO2 permeation through the dual-phase membranes have been identified. A reliable CO2 permeation model was developed. A robust method was established for the optimization of the microstructures of ceramic-carbonate membranes. The ceramic-carbonate membranes exhibit high stability for high temperature CO2 separations and water gas shift reaction. Water gas shift reaction in the dual-phase membrane reactors was studied by both modeling and experiments. It is found that high temperature syngas water gas shift reaction in tubular ceramic-carbonate dual phase membrane reactor is feasible even without catalyst. The membrane reactor exhibits good CO2 permeation flux, high thermal and chemical stability and high thermal shock resistance. Reaction and separation conditions in the membrane reactor to produce hydrogen of 93% purity and CO2 stream of >95% purity, with 90% CO2 capture have been identified. Integration of the ceramic-carbonate dual-phase membrane reactor with IGCC process for carbon dioxide capture was analyzed. A methodology was developed to identify optimum operation conditions for a

  13. Modeling and Design Optimization of Multifunctional Membrane Reactors for Direct Methane Aromatization.

    Science.gov (United States)

    Fouty, Nicholas J; Carrasco, Juan C; Lima, Fernando V

    2017-08-29

    Due to the recent increase of natural gas production in the U.S., utilizing natural gas for higher-value chemicals has become imperative. Direct methane aromatization (DMA) is a promising process used to convert methane to benzene, but it is limited by low conversion of methane and rapid catalyst deactivation by coking. Past work has shown that membrane separation of the hydrogen produced in the DMA reactions can dramatically increase the methane conversion by shifting the equilibrium toward the products, but it also increases coke production. Oxygen introduction into the system has been shown to inhibit this coke production while not inhibiting the benzene production. This paper introduces a novel mathematical model and design to employ both methods in a multifunctional membrane reactor to push the DMA process into further viability. Multifunctional membrane reactors, in this case, are reactors where two different separations occur using two differently selective membranes, on which no systems studies have been found. The proposed multifunctional membrane design incorporates a hydrogen-selective membrane on the outer wall of the reaction zone, and an inner tube filled with airflow surrounded by an oxygen-selective membrane in the middle of the reactor. The design is shown to increase conversion via hydrogen removal by around 100%, and decrease coke production via oxygen addition by 10% when compared to a tubular reactor without any membranes. Optimization studies are performed to determine the best reactor design based on methane conversion, along with coke and benzene production. The obtained optimal design considers a small reactor (length = 25 cm, diameter of reaction tube = 0.7 cm) to subvert coke production and consumption of the product benzene as well as a high permeance (0.01 mol/s·m²·atm 1/4 ) through the hydrogen-permeable membrane. This modeling and design approach sets the stage for guiding further development of multifunctional membrane reactor

  14. Hydrogen Permeability of Palladium Membrane for Steam-Reforming of Bio-Ethanol Using the Membrane Reactor

    Science.gov (United States)

    Kinouchi, Kouji; Katoh, Masahiro; Horikawa, Toshihide; Yoshikawa, Takushi; Wada, Mamoru

    A Palladium membrane was prepared by electro-less plating method on porous stainless steel. The catalytic hydrogen production by steam-reforming of biomass-derived ethanol (bio-ethanol) using a Pd membrane was analyzed by comparing it with those for the reaction using reagent ethanol (the reference sample). And the hydrogen permeability of the palladium membrane was investigated using the same palladium membrane (H2/He selectivity = 249, at ΔP = 0.10 MPa, 873 K). As a result, for bio-ethanol, deposited carbon had a negative influence on the hydrogen-permeability of the palladium membrane and hydrogen purity. The sulfur content in the bio-ethanol may have promoted carbon deposition. By using a palladium membrane, it was confirmed that H2 yield (%) was increased. It can be attributed that methane was converted from ethanol and produced more hydrogen by steam reforming, due to the in situ removal of hydrogen from the reaction location.

  15. CFD modelling of a membrane reactor for hydrogen production from ammonia

    Science.gov (United States)

    Shwe Hla, San; Dolan, Michael D.

    2018-01-01

    Despite the growing use of hydrogen (H2) as a transport fuel, one of the major barriers still remaining is efficient and inexpensive fuel distribution and storage. Current approaches, such as compression, liquefaction or metal hydride formation, incur a significant energy penalty. Ammonia (NH3) has long been considered a prospective H2 medium, exhibiting a higher volumetric H2 density than liquid H2, through liquid-phase storage at mild pressure. Decomposition of NH3 into H2 and N2 can be achieved via use of catalytic reactors and fuel-cell-grade H2 can be produced using metal membranes at H2 distribution sites.In this study, a 3-Dimensional (3D) Computational Fluid Dynamics (CFD) model has been developed to understand the performance of the H2 separation process in gas mixtures derived from an NH3-cracking reaction. The reactor consists of 19 tubular membrane tubes, each 470 mm long, inside a tubular shell with an inner diameter of 130 mm. Standard transport and energy equations governing a 3D, pressure-based, steady-state model were derived from the laws of conservation of mass, momentum and energy. The governing equations were solved using commercial CFD software ANSYS Fluent 18.0. Gas flow and mixing were modelled by the two-equation standard k-epsilon model for closure. Coupled solver was used for pressure-velocity coupling, enabling a pseudo-transient option with pseudo time steps of 0.01 s. To estimate H2 permeation through the metal membrane, a constant H2 permeability of 3.0E-07 mol.m-1 s-1 Pa-0.5 derived from series of experiments tested under a range of industrial conditions, was used. Model simulations were conducted for an adiabatic temperature of 300 °C, a feed-side pressure of 7.8 bara and a permeate side pressure of 0.1 bara. A parametric analysis was carried out to explore the effects of variation in total feed-gas flow and effects of changes in NH3-cracking efficiency on H2 production rates and H2 yields. The model estimated that 4.6-11.6 kg H2

  16. Structural investigations of the active-site mutant Asn156Ala of outer membrane phospholipase A: Function of the Asn-His interaction in the catalytic triad

    NARCIS (Netherlands)

    Snijder, H.J.; van Eerde, J.H.; Kalk, K.H.; Dekker, N.; Egmond, M.R.; Dijkstra, B.W.

    2010-01-01

    Outer membrane phospholipase A (OMPLA) from Escherichia coli is an integral-membrane enzyme with a unique His-Ser-Asn catalytic triad. In serine proteases and serine esterases usually an Asp occurs in the catalytic triad; its role has been the subject of much debate. Here the role of the uncharged

  17. A conceptual design of catalytic gasification fuel cell hybrid power plant with oxygen transfer membrane

    Science.gov (United States)

    Shi, Wangying; Han, Minfang

    2017-09-01

    A hybrid power generation system integrating catalytic gasification, solid oxide fuel cell (SOFC), oxygen transfer membrane (OTM) and gas turbine (GT) is established and system energy analysis is performed. In this work, the catalytic gasifier uses steam, recycled anode off-gas and pure oxygen from OTM system to gasify coal, and heated by hot cathode off-gas at the same time. A zero-dimension SOFC model is applied and verified by fitting experimental data. Thermodynamic analysis is performed to investigate the integrated system performance, and system sensitivities on anode off-gas back flow ratio, SOFC fuel utilization, temperature and pressure are discussed. Main conclusions are as follows: (1) System overall electricity efficiency reaches 60.7%(HHV) while the gasifier operates at 700 °C and SOFC at 850 °C with system pressure at 3.04 bar; (2) oxygen enriched combustion simplify the carbon-dioxide capture process, which derives CO2 of 99.2% purity, but results in a penalty of 6.7% on system electricity efficiency; (3) with SOFC fuel utilization or temperature increasing, the power output of SOFC increases while GT power output decreases, and increasing system pressure can improve both the performance of SOFC and GT.

  18. Reactor design for minimizing product inhibition during enzymatic lignocellulose hydrolysis II. Quantification of inhibition and suitability of membrane reactors

    DEFF Research Database (Denmark)

    Andric, Pavle; Meyer, Anne S.; Jensen, Peter Arendt

    2010-01-01

    ideal reactor types, i.e. batch, continuous stirred, and plug-flow, is illustrated quantitatively by modeling different extents of cellulose conversion at different reaction conditions. The main operational challenges of membrane reactors for lignocellulose conversion are highlighted. Key membrane......Product inhibition of cellulolytic enzymes affects the efficiency of the biocatalytic conversion of lignocellulosic biomass to ethanol and other valuable products. New strategies that focus on reactor designs encompassing product removal, notably glucose removal, during enzymatic cellulose...... reactor features, including system set-up, dilution rate, glucose output profile, and the problem of cellobiose are examined to illustrate the quantitative significance of the glucose product inhibition and the total glucose concentration on the cellulolytic conversion rate. Comprehensive overviews...

  19. Techno-economic assessment of membrane assisted fluidized bed reactors for pure H2 production with CO2 capture

    International Nuclear Information System (INIS)

    Spallina, V.; Pandolfo, D.; Battistella, A.; Romano, M.C.; Van Sint Annaland, M.; Gallucci, F.

    2016-01-01

    Highlights: • Membrane reactors improve the overall efficiency of H 2 production up to 20%. • Respect to conventional reforming, the H 2 yield increases from 12% to 20%. • The COH is reduced of at least 220% using membrane reactors. • FBMR capture 72% of CO 2 with a specific cost of 8 eur/tonn CO2. • MA-CLR can reach 90% of CO 2 avoided with same cost of FTR. - Abstract: This paper addresses the techno-economic assessment of two membrane-based technologies for H 2 production from natural gas, fully integrated with CO 2 capture. In the first configuration, a fluidized bed membrane reactor (FBMR) is integrated in the H 2 plant: the natural gas reacts with steam in the catalytic bed and H 2 is simultaneously separated using Pd-based membranes, and the heat of reaction is provided to the system by feeding air as reactive sweep gas in part of the membranes and by burning part of the permeated H 2 (in order to avoid CO 2 emissions for heat supply). In the second system, named membrane assisted chemical looping reforming (MA-CLR), natural gas is converted in the fuel rector by reaction with steam and an oxygen carrier (chemical looping reforming), and the produced H 2 permeates through the membranes. The oxygen carrier is re-oxidized in a separate air reactor with air, which also provides the heat required for the endothermic reactions in the fuel reactor. The plants are optimized by varying the operating conditions of the reactors such as temperature, pressures (both at feed and permeate side), steam-to-carbon ratio and the heat recovery configuration. The plant design is carried out using Aspen Simulation, while the novel reactor concepts have been designed and their performance have been studied with a dedicated phenomenological model in Matlab. Both configurations have been designed and compared with reference technologies for H 2 production based on conventional fired tubular reforming (FTR) with and without CO 2 capture. The results of the analysis show

  20. Catalytic Upgrading of Biomass Pyrolysis Oxygenates with Vacuum Gas Oil Using a Davison Circulating Riser Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, Mark W. [National Bioenergy Center, National Renewable Energy Laboratory, 15523 Denver West Parkway, Golden, Colorado 80401, United States; Olstad, Jessica [National Bioenergy Center, National Renewable Energy Laboratory, 15523 Denver West Parkway, Golden, Colorado 80401, United States; Parent, Yves [National Bioenergy Center, National Renewable Energy Laboratory, 15523 Denver West Parkway, Golden, Colorado 80401, United States; Deutch, Steve [National Bioenergy Center, National Renewable Energy Laboratory, 15523 Denver West Parkway, Golden, Colorado 80401, United States; Iisa, Kristiina [National Bioenergy Center, National Renewable Energy Laboratory, 15523 Denver West Parkway, Golden, Colorado 80401, United States; Christensen, Earl [National Bioenergy Center, National Renewable Energy Laboratory, 15523 Denver West Parkway, Golden, Colorado 80401, United States; Ben, Haoxi [National Bioenergy Center, National Renewable Energy Laboratory, 15523 Denver West Parkway, Golden, Colorado 80401, United States; Black, Stuart [National Bioenergy Center, National Renewable Energy Laboratory, 15523 Denver West Parkway, Golden, Colorado 80401, United States; Nimlos, Mark [National Bioenergy Center, National Renewable Energy Laboratory, 15523 Denver West Parkway, Golden, Colorado 80401, United States; Magrini, Kim [National Bioenergy Center, National Renewable Energy Laboratory, 15523 Denver West Parkway, Golden, Colorado 80401, United States

    2018-01-22

    We investigate and quantitate the changes in hydrocarbon product composition while evaluating the performance and operability of the National Renewable Energy Laboratory's Davison Circulating Riser (DCR) reactor system when biomass model compounds are cofed with traditional fluid catalyst cracking (FCC) feeds and catalyst: vacuum gas oil (VGO) and equilibrium zeolite catalyst (E-Cat). Three compounds (acetic acid, guaiacol, and sorbitan monooleate) were selected to represent the major classes of oxygenates present in biomass pyrolysis vapors. These vapors can contain 30-50% oxygen as oxygenates, which create conversion complications (increased reactivity and coking) when integrating biomass vapors and liquids into fuel and chemical processes long dominated by petroleum feedstocks. We used these model compounds to determine the appropriate conditions for coprocessing with petroleum and ultimately pure pyrolysis vapors only as compared with standard baseline conditions obtained with VGO and E-Cat only in the DCR. Model compound addition decreased the DCR catalyst circulation rate, which controls reactor temperature and measures reaction heat demand, while increasing catalyst coking rates. Liquid product analyses included 2-dimensional gas chromatography time-of-flight mass spectroscopy (2D GCxGC TOFS), simulated distillation (SIM DIST), 13C NMR, and carbonyl content. Aggregated results indicated that the model compounds were converted during reaction, and despite functional group differences, product distributions for each model compound were very similar. In addition, we determined that adding model compounds to the VGO feed did not significantly affect the DCR's operability or performance. Future work will assess catalytic upgrading of biomass pyrolysis vapor to fungible hydrocarbon products using upgrading catalysts currently being developed at NREL and at Johnson Matthey.

  1. Membrane Guanylate Cyclase catalytic Subdomain: Structure and Linkage with Calcium Sensors and Bicarbonate

    Directory of Open Access Journals (Sweden)

    Sarangan Ravichandran

    2017-06-01

    Full Text Available Membrane guanylate cyclase (MGC is a ubiquitous multi-switching cyclic GMP generating signaling machine linked with countless physiological processes. In mammals it is encoded by seven distinct homologous genes. It is a single transmembrane spanning multi-modular protein; composed of integrated blocks and existing in homo-dimeric form. Its core catalytic domain (CCD module is a common transduction center where all incoming signals are translated into the production of cyclic GMP, a cellular signal second messenger. Crystal structure of the MGC’s CCD does not exist and its precise identity is ill-defined. Here, we define it at a sub-molecular level for the phototransduction-linked MGC, the rod outer segment guanylate cyclase type 1, ROS-GC1. (1 The CCD is a conserved 145-residue structural unit, represented by the segment V820-P964. (2 It exists as a homo-dimer and contains seven conserved catalytic elements (CEs wedged into seven conserved motifs. (3 It also contains a conserved 21-residue neurocalcin δ-modulated structural domain, V836-L857. (4 Site-directed mutagenesis documents that each of the seven CEs governs the cyclase’s catalytic activity. (5 In contrast to the soluble and the bacterium MGC which use Mn2+-GTP substrate for catalysis, MGC CCD uses the natural Mg2+-GTP substrate. (6 Strikingly, the MGC CCD requires anchoring by the Transmembrane Domain (TMD to exhibit its major (∼92% catalytic activity; in isolated form the activity is only marginal. This feature is not linked with any unique sequence of the TMD; there is minimal conservation in TMD. Finally, (7 the seven CEs control each of four phototransduction pathways- -two Ca2+-sensor GCAPs-, one Ca2+-sensor, S100B-, and one bicarbonate-modulated. The findings disclose that the CCD of ROS-GC1 has built-in regulatory elements that control its signal translational activity. Due to conservation of these regulatory elements, it is proposed that these elements also control the

  2. Non-catalytic alcoholysis process for production of biodiesel fuel by using bubble column reactor

    International Nuclear Information System (INIS)

    Hagiwara, S; Nabetani, H; Nakajima, M

    2015-01-01

    -edible lipids by use of the SMV reactor has not been examined yet. Therefore, this study aims to investigate the productivity of biodiesel produced from waste vegetable oils using the SMV reactor. Biodiesel fuel is a replacement for diesel as a fuel produced from biomass resources. It is generally produced as a FAME derived from vegetable oil by using alkaline catalyzed alcoholysis process. This alkaline method requires deacidification process prior to the reaction process and the alkaline catalyst removal process after the reaction. Those process increases the total cost of biodiesel fuel production. In order to solve the problems in the conventional alkaline catalyzed alcoholysis process, the authors proposed a non-catalytic alcoholysis process called the Superheated Methanol Vapor (SMV) method with bubble column reactor. So, this study aims to investigate the productivity of biodiesel produced from vegetable oils and other lipids using the SMV method with bubble column reactor

  3. Non-catalytic alcoholysis process for production of biodiesel fuel by using bubble column reactor

    Science.gov (United States)

    Hagiwara, S.; Nabetani, H.; Nakajima, M.

    2015-04-01

    -edible lipids by use of the SMV reactor has not been examined yet. Therefore, this study aims to investigate the productivity of biodiesel produced from waste vegetable oils using the SMV reactor. Biodiesel fuel is a replacement for diesel as a fuel produced from biomass resources. It is generally produced as a FAME derived from vegetable oil by using alkaline catalyzed alcoholysis process. This alkaline method requires deacidification process prior to the reaction process and the alkaline catalyst removal process after the reaction. Those process increases the total cost of biodiesel fuel production. In order to solve the problems in the conventional alkaline catalyzed alcoholysis process, the authors proposed a non-catalytic alcoholysis process called the Superheated Methanol Vapor (SMV) method with bubble column reactor. So, this study aims to investigate the productivity of biodiesel produced from vegetable oils and other lipids using the SMV method with bubble column reactor.

  4. CFD Flow and Heat Transfer Simulation for Empty and Packed Fixed Bed Reactor in Catalytic Cracking of Naphtha

    OpenAIRE

    D. Salari; A. Niaei; P. Chitsaz Yazdi; M. Derakhshani; S. R. Nabavi

    2007-01-01

    This work aims to test the application of computational fluid dynamics (CFD) modeling to fixed bed catalytic cracking reactors. Studies of CFD with a fixed bed design commonly use a regular packing with N=2 to define bed geometry. CFD allows us to obtain a more accurate view of the fluid flow and heat transfer mechanisms present in fixed bed equipment. Naphtha was used as feedstock and the reactor length was 80cm. It is divided in three sections that catalyst bed packed in the middle section ...

  5. Catalytic Oxidation of Vanillyl Alcohol Using FeMCM-41 Nanoporous Tubular Reactor

    Science.gov (United States)

    Elamathi, P.; Kolli, Murali Krishna; Chandrasekar, G.

    Iron containing nanoporous MCM-41 (FeMCM-41) with different Si/Fe ratios of 50, 100 and 150 was synthesized by hydrothermal synthesis process. The materials obtained from hydrothermal synthesis were characterized by various physico chemical techniques such as XRD, N2 adsorption, DR UV-vis, EPR and FTIR spectroscopy. XRD analyses of FeMCM-41 materials confirmed the presence of well-ordered crystalline structure. N2 isotherm of FeMCM-41 materials showed type IV adsorption isotherm. EPR and DR UV-vis analysis of FeMCM-41 samples indicates the presence of high tetrahedral coordination at the Si/Fe ratios of 100 and 150. The catalytic performance of FeMCM-41 nano tubular reactor was tested in the liquid phase oxidation of vanillyl alcohol into vanillin using H2O2 (50wt% in water). The reaction products were analyzed by gas chromatography in DB-5 capillary column with flame ionization detector. The products were confirmed by 1H NMR, 13C NMR and LC-Mass spectroscopy. The maximum conversion of vanillyl alcohol (85%) and selectivity towards vanillin (82%) were observed using the catalyst FeMCM-41(100) in 30min at 60∘C. The influence of reaction temperature, reaction time, reactants molar ratio, Si/Fe ratio and amount of catalyst were investigated.

  6. A full-flow catalytic reactor at pilot scale for hot gas cleanup in biomass gasification with air

    Energy Technology Data Exchange (ETDEWEB)

    Caballero, M.A.; Aznar, M.P.; Gil, J. [University Complutense, Madrid (Spain); Corella, J.; Martin, J.A. [University of Saragossa (Spain)

    1999-07-01

    A new catalytic reactor for commercial steam reforming (nickel-based) catalysts has been calculated designed, constructed, set up and operated in a full flow mode downstream from a fluidized bed biomass gasifier. It contains 3.9 kg of a commercial catalyst in its full size and shape (rings) and is located in a bed of 75 mm internal diameter and 1.31 m length. Four tests with it has provided excellent results. (author)

  7. Poly-thiosemicarbazide/gold nanoparticles catalytic membrane: In-situ growth of well-dispersed, uniform and stable gold nanoparticles in a polymeric membrane

    KAUST Repository

    Villalobos, Luis Francisco

    2014-11-01

    This work presents a method that achieves the highest loading, published so far, of non-agglomerated and well-distributed gold nanoparticles (AuNPs) inside a polymeric membrane. The method uses poly-thiosemicarbazide (PTSC) as the starting material for fabricating the membranes. This polymer contains one chelate site per monomeric unit, resulting in a high content of adsorption sites. This helps to achieve such high loading without agglomeration, along with the strong interaction of the chelate sites with the metal ions and the fact that they are distributed homogeneously along the membrane structure. The simple and scalable three-step procedure developed in this work resulted in a PTSC membrane containing 33.5 wt.% Au/PTSC in the form of 2.9 nm AuNPs. The membrane demonstrated catalytic activity for the reduction of 4-Nitrophenol (4-NP) to 4-Aminophenol (4-AP). © 2013 Elsevier B.V.

  8. Membrane assisted fluidized bed reactor: experimental demonstration for partial oxidation of methanol

    NARCIS (Netherlands)

    Deshmukh, S.A.R.K.

    2004-01-01

    In this thesis the reactor concept has been developed on the basis of an experimental study on the effect of fluidization conditions on the membrane permeation rate in a MAFBR, the extent of gas back mixing and the tube-to-bed heat transfer rates in the presence of membrane bundles with and without

  9. Utilization of fly ash-derived HZSM-5: catalytic pyrolysis of Jatropha wastes in a fixed-bed reactor.

    Science.gov (United States)

    Vichaphund, S; Sricharoenchaikul, V; Atong, D

    2017-07-01

    Fly ash-derived HZSM-5 catalyst was first applied in the catalytic pyrolysis of Jatropha residues in a semi-continuous fixed-bed reactor. The catalytic performance of HZSM-5 catalysts prepared from chemicals including conventional hydrothermal HZSM-5, Ni/HZSM-5 by ion exchange, and commercial HZSM-5 (Si/Al = 30) was evaluated for comparison. Catalytic pyrolysis of Jatropha residues with HZSM-5 catalysts was investigated in terms of product yields and qualities of bio-oil and bio-char. The liquid yield produced from fly ash-derived HZSM-5 was 29.4%, which was comparable to those obtained from chemicals and commercial (30.2-32.2%). Fly ash-derived HZSM-5 had high efficiency in increasing desirable compounds such as aliphatics and phenols as well as decreasing oxygenates and particularly N-containing compounds in bio-oils. The higher heating values and pH value of catalytic bio-oil achieved from fly ash-derived HZSM-5 were comparable to those achieved from HZSM-5 prepared from chemicals and commercial. The bio-char had 48-50 wt% carbon and was classified as mesoporous material. Overall, HZSM-5 derived from fly ash showed potentials to use as a catalyst for catalytic pyrolysis application.

  10. Mathematical modeling of methyl ester concentration distribution in a continuous membrane tubular reactor and comparison with conventional tubular reactor

    Science.gov (United States)

    Talaghat, M. R.; Jokar, S. M.; Modarres, E.

    2017-10-01

    The reduction of fossil fuel resources and environmental issues made researchers find alternative fuels include biodiesels. One of the most widely used methods for production of biodiesel on a commercial scale is transesterification method. In this work, the biodiesel production by a transesterification method was modeled. Sodium hydroxide was considered as a catalyst to produce biodiesel from canola oil and methanol in a continuous tubular ceramic membranes reactor. As the Biodiesel production reaction from triglycerides is an equilibrium reaction, the reaction rate constants depend on temperature and related linearly to catalyst concentration. By using the mass balance for a membrane tubular reactor and considering the variation of raw materials and products concentration with time, the set of governing equations were solved by numerical methods. The results clearly show the superiority of membrane reactor than conventional tubular reactors. Afterward, the influences of molar ratio of alcohol to oil, weight percentage of the catalyst, and residence time on the performance of biodiesel production reactor were investigated.

  11. ENHANCEMENT OF EQUILIBRIUMSHIFT IN DEHYDROGENATION REACTIONS USING A NOVEL MEMBRANE REACTOR; FINAL

    International Nuclear Information System (INIS)

    Shamsuddin Ilias, Ph.d., P.E.; Franklin G. King, D.Sc.

    2001-01-01

    With the advances in new inorganic materials and processing techniques, there has been renewed interest in exploiting the benefits of membranes in many industrial applications. Inorganic and composite membranes are being considered as potential candidates for use in membrane-reactor configuration for effectively increasing reaction rate, selectivity and yield of equilibrium limited reactions. To investigate the usefulness of a palladium-ceramic composite membrane in a membrane reactor-separator configuration, we investigated the dehydrogenation of cyclohexane by equilibrium shift. A two-dimensional pseudo-homogeneous reactor model was developed to study the dehydrogenation of cyclohexane by equilibrium shift in a tubular membrane reactor. Radial diffusion was considered to account for the concentration gradient in the radial direction due to permeation through the membrane. For a dehydrogenation reaction, the feed stream to the reaction side contained cyclohexane and argon, while the separation side used argon as the sweep gas. Equilibrium conversion for dehydrogenation of cyclohexane is 18.7%. The present study showed that 100% conversion could be achieved by equilibrium shift using Pd-ceramic membrane reactor. For a feed containing cyclohexane and argon of 1.64 x 10(sup -6) and 1.0 x 10(sup -3) mol/s, over 98% conversion could be readily achieved. The dehydrogenation of cyclohexane was also experimentally investigated in a palladium-ceramic membrane reactor. The Pd-ceramic membrane was fabricated by electroless deposition of palladium on ceramic substrate. The performance of Pd-ceramic membrane was compared with a commercially available hydrogen-selective ceramic membrane. From limited experimental data it was observed that by appropriate choice of feed flow rate and sweep gas rate, the conversion of cyclohexane to benzene and hydrogen can increased to 56% at atmospheric pressure and 200 C in a Pd-ceramic membrane reactor. In the commercial ceramic membrane

  12. Modeling and Simulation of the Hydrogenation of α-Methylstyrene on Catalytically Active Metal Foams as Tubular Reactor Packing

    Directory of Open Access Journals (Sweden)

    Farzad Lali

    2016-01-01

    Full Text Available This work presents a one-dimensional reactor model for a tubular reactor packed with a catalytically active foam packing with a pore density of 30 PPI in cocurrent upward flow in the example of hydrogenation reaction of α-methylstyrene to cumene. This model includes material, enthalpy, and momentum balances as well as continuity equations. The model was solved within the parameter space applied for experimental studies under assumption of a bubbly flow. The method of orthogonal collocation on finite elements was applied. For isothermal and polytropic processes and steady state conditions, axial profiles for concentration, temperature, fluid velocities, pressure, and liquid holdup were computed and the conversions for various gas and liquid flow rates were validated with experimental results. The obtained results were also compared in terms of space time yield and catalytic activity with experimental results and stirred tank and also with random packed bed reactor. The comparison shows that the application of solid foams as reactor packing is advantageous compared to the monolithic honeycombs and random packed beds.

  13. Solar reforming of methane in a direct absorption catalytic reactor on a parabolic dish. 2: Modeling and analysis

    Science.gov (United States)

    Skocypec, Russell D.; Hogan, Roy E., Jr.; Muir, James F.

    1991-01-01

    The catalytically enhanced solar absorption receiver (CAESAR) experiment was conducted to determine the thermal, chemical, and mechanical performance of a commercial-scale, dish-mounted, direct catalytic absorption receiver (DCAR) reactor over a range of steady state and transient (cloud) operating conditions. The focus of the experiment is on global performance such as receiver efficiencies and overall methane conversion; it was not intended to provide data for code validation. A numerical model was previously developed to provide guidance in the design of the absorber. The one-dimensional, planar and steady-state model incorporates, the following energy transfer mechanisms: solar and infrared radiation, heterogeneous chemical reaction, conduction in the solid phase, and convection between the fluid and solid phases. A number of upgrades to the model and improved property values are presented here. Model predictions are shown to bound the experimental axial thermocouple data when experimental uncertainties are included. Global predictions are made using a technique in which the incident solar flux distribution is subdivided into flux contour bands. Model predictions for each band are then spatially integrated to provide global predictions such as reactor efficiencies and methane conversions. Global predictions are shown to compare well with experimental data. Reactor predictions for anticipated operating conditions suggest a further decrease in optical density at the front of the absorber inner disk may be beneficial. The need to conduct code-validation experiments is identified as being essential in improving the confidence in the capability to predict large-scale reactor operation.

  14. Microbial activity catalyzes oxygen transfer in membrane-aerated nitritating biofilm reactors

    DEFF Research Database (Denmark)

    Pellicer i Nàcher, Carles; Domingo Felez, Carlos; Lackner, Susanne

    2013-01-01

    The remarkable oxygen transfer efficiencies attainable in membrane-aerated biofilm reactors (MABRs) are expected to favor their prompt industrial implementation. However, tests in clean water, currently used for the estimation of their oxygen transfer potential, lead to wrong estimates once biofilm...... is present, significantly complicating reactor modelling and control. This study shows for the first time the factors affecting oxygen mass transfer across membranes during clean water tests and reactor operation via undisturbed microelectrode inspection and bulk measurements. The mass transfer resistance...... of the liquid boundary layer developed at the membrane-liquid interface during clean water tests accounted for two thirds of the total mass transfer resistance, suggesting a strong underestimation of the oxygen transfer rates when it is absent (e.g. after biofilm growth). Reactor operation to attain partial...

  15. An innovative configuration of a Pd-based membrane reactor for the production of pure hydrogen. Experimental analysis of water gas shift

    Science.gov (United States)

    Barbieri, G.; Brunetti, A.; Tricoli, G.; Drioli, E.

    Pure hydrogen production is of fundamental interest for its use as feed of proton exchange membrane fuel cells. In this work an innovative configuration for a membrane reactor (MR) was proposed: the membrane is located only in the second part of the catalytic bed. This configuration is of particular importance in all the reactions characterized by low kinetics such as, e.g., water gas shift (WGS). Permeation of hydrogen, in the desired direction, takes place when its partial pressure on the reaction side exceeds that on the permeate side. In an MR where the membrane starts at the reactor entrance there is a part of membrane area giving back permeation to the reaction side. The length used in a bad way depends on the kinetics: for fast kinetics reactions (e.g., methane steam reforming) it is very short but is significantly higher for reactions characterized by low kinetics (e.g., WGS). The innovative configuration proposed allows a good exploitation of the whole membrane area for the permeation. This innovative Pd-alloy (60 μm thick) MR was used to analyse the WGS reaction at 280-320 °C, up to 600 kPa, GHSV ranging from 2000 h -1 to 4500 h -1. A significant reduction of the reaction volume required to achieve the same CO conversion was shown by the novel configuration of the MR with respect to the "typical" one used up to now.

  16. Current hurdles to the success of high-temperature membrane reactors

    NARCIS (Netherlands)

    Saracco, G.; Versteeg, G.F.; Swaaij, W.P.M. van

    1994-01-01

    High-temperature catalytic processes performed using inorganic membranes have been in recent years a fast growing area of research, which seems to have not yet reached its peak. Chemical engineers, catalysts and materials scientists have addressed this topic from different viewpoints in a common

  17. Numerical study of methanol–steam reforming and methanol–air catalytic combustion in annulus reactors for hydrogen production

    International Nuclear Information System (INIS)

    Chein, Reiyu; Chen, Yen-Cho; Chung, J.N.

    2013-01-01

    Highlights: ► Performance of mini-scale integrated annulus reactors for hydrogen production. ► Flow rates fed to combustor and reformer control the reactor performance. ► Optimum performance is found from balance of flow rates to combustor and reformer. ► Better performance can be found when shell side is designed as combustor. -- Abstract: This study presents the numerical simulation on the performance of mini-scale reactors for hydrogen production coupled with liquid methanol/water vaporizer, methanol/steam reformer, and methanol/air catalytic combustor. These reactors are designed similar to tube-and-shell heat exchangers. The combustor for heat supply is arranged as the tube or shell side. Based on the obtained results, the methanol/air flow rate through the combustor (in terms of gas hourly space velocity of combustor, GHSV-C) and the methanol/water feed rate to the reformer (in terms of gas hourly space velocity of reformer, GHSV-R) control the reactor performance. With higher GHSV-C and lower GHSV-R, higher methanol conversion can be achieved because of higher reaction temperature. However, hydrogen yield is reduced and the carbon monoxide concentration is increased due to the reversed water gas shift reaction. Optimum reactor performance is found using the balance between GHSV-C and GHSV-R. Because of more effective heat transfer characteristics in the vaporizer, it is found that the reactor with combustor arranged as the shell side has better performance compared with the reactor design having the combustor as the tube side under the same operating conditions.

  18. Improvement of Membrane Performances to Enhance the Yield of Vanillin in a Pervaporation Reactor

    Directory of Open Access Journals (Sweden)

    Giovanni Camera-Roda

    2014-02-01

    Full Text Available In membrane reactors, the interaction of reaction and membrane separation can be exploited to achieve a “process intensification”, a key objective of sustainable development. In the present work, the properties that the membrane must have to obtain this result in a pervaporation reactor are analyzed and discussed. Then, the methods to enhance these properties are investigated for the photocatalytic synthesis of vanillin, which represents a case where the recovery from the reactor of vanillin by means of pervaporation while it is produced allows a substantial improvement of the yield, since its further oxidation is thus prevented. To this end, the phenomena that control the permeation of both vanillin and the reactant (ferulic acid are analyzed, since they ultimately affect the performances of the membrane reactor. The results show that diffusion of the aromatic compounds takes place in the presence of low concentration gradients, so that the process is controlled by other phenomena, in particular by the equilibrium with the vapor at the membrane-permeate interface. On this basis, it is demonstrated that the performances are enhanced by increasing the membrane thickness and/or the temperature, whereas the pH begins to limit the process only at values higher than 6.5.

  19. Production of gaseous fuel from jatropha oil by cerium oxide based catalytic fuel reactor and its utilisation on diesel engine

    Directory of Open Access Journals (Sweden)

    Mylswamy Thirunavukkarasu

    2016-01-01

    Full Text Available In this study, an attempt is made to produce a hydrocarbon fuel from jatropha vegetable oil for Diesel engine applications. The “catalytic cracking” a process recently introduced by the researchers is chosen as an alternative method to trans-esterification process to match the fuel properties to diesel. Jatropha vegetable oil was cracked into a gas using the cerium oxide catalyst in a fixed bed catalytic reactor. The produced gas is introduced at constant rate into the inlet manifold of the Diesel engine. The experimental work was carried out in single cylinder water cooled direct injection Diesel engine coupled with eddy current dynamometer. The combustion parameters are measured by AVL combustion analyser. From the experimental results, the increase in brake thermal efficiency of the engine for full load was observed to be 10% (relative compared with diesel. Notably, emissions such as HC, CO, and smoke are reduced by 18%, 61%, and 18%, respectively, when compared with diesel.

  20. Development of a coupled reactor with a catalytic combustor and steam reformer for a 5 kW solid oxide fuel cell system

    International Nuclear Information System (INIS)

    Kang, Sanggyu; Lee, Kanghun; Yu, Sangseok; Lee, Sang Min; Ahn, Kook-Young

    2014-01-01

    Highlights: • Proposes the scale-up strategy to develop a large-scale coupled reactor. • Investigation of performance of steam reformer coupled with catalytic combustor. • Experimental parameters are inlet temp., air excess ratio, SCR, fuel utilization. • Evaluation of the heat transfer distribution along the gas flow direction. • The mean value of methane conversion rate is approximately 93.4%. - Abstract: The methane (CH 4 ) conversion rate of a steam reformer can be increased by thermal integration with a catalytic combustor, called a coupled reactor. In the present study, a 5 kW coupled reactor has been developed based on a 1 kW coupled reactor in previous work. The geometric parameters of the space velocity, diameter and length of the coupled reactor selected from the 1 kW coupled reactor are tuned and applied to the design of the 5 kW coupled reactor. To confirm the scale-up strategy, the performance of 5 kW coupled reactor is experimentally investigated with variations of operating parameters such as the fuel utilization in the solid oxide fuel cell (SOFC) stack, the inlet temperature of the catalytic combustor, the excess air ratio of the catalytic combustor, and the steam to carbon ratio (SCR) in the steam reformer. The temperature distributions of coupled reactors are measured along the gas flow direction. The gas composition at the steam reformer outlet is measured to find the CH 4 conversion rate of the coupled reactor. The maximum value of the CH 4 conversion rate is approximately 93.4%, which means the proposed scale-up strategy can be utilized to develop a large-scale coupled reactor

  1. Impact of the fouling mechanism on enzymatic depolymerization of xylan in different configurations of membrane reactors

    DEFF Research Database (Denmark)

    Mohd Sueb, Mohd Shafiq Bin; Luo, Jianquan; Meyer, Anne S.

    2017-01-01

    In order to maximize enzymatic xylan depolymerization while simultaneously purifying the resulting monosaccharide (xylose), different ultrafiltration (UF) membrane reactor configurations were evaluated. Initial results showed that the two hydrolytic enzymes required for complete depolymerization......) and the simultaneous reaction-filtration with both enzymes, respectively. This study thus confirmed that the reactor configuration has a crucial impact on the performance of both the reaction and the separation process of xylose during enzymatic xylan degradation, and that the type of fouling mechanism varies...

  2. Experimental evaluation of methane dry reforming process on a membrane reactor to hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Fabiano S.A.; Benachour, Mohand; Abreu, Cesar A.M. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. of Chemical Engineering], Email: f.aruda@yahoo.com.br

    2010-07-01

    In a fixed bed membrane reactor evaluations of methane-carbon dioxide reforming over a Ni/{gamma}- Al{sub 2}O{sub 3} catalyst were performed at 773 K, 823 K and 873 K. A to convert natural gas into syngas a fixed-bed reactor associate with a selective membrane was employed, where the operating procedures allowed to shift the chemical equilibrium of the reaction in the direction of the products of the process. Operations under hydrogen permeation, at 873 K, promoted the increase of methane conversion, circa 83%, and doubled the yield of hydrogen production, when compared with operations where no hydrogen permeation occurred. (author)

  3. Large-scale enzymatic membrane reactors for tetracycline degradation in WWTP effluents.

    Science.gov (United States)

    Abejón, R; De Cazes, M; Belleville, M P; Sanchez-Marcano, J

    2015-04-15

    A mathematical model to simulate the performance of enzymatic membrane reactors was developed. It was applied to investigate the effectiveness of laccase immobilized over ceramic membranes for the degradation of tetracycline, a common antibiotic appearing as micropollutant in effluents of WWTPs. A process based on large-scale enzymatic membrane reactors in series was proposed for the treatment of the effluents from municipal, hospital and industrial wastewater treatment plants (WWTPs). The obtained results demonstrated the need for high improvements in the amount of enzyme grafted on the membranes or on enzymatic kinetics to afford the technical and economic competitiveness of the investigated designs and the possibility to be implemented within existing installations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Waste Water treatment by membrane bioreactors; Tratamiento de aguas residuales urbanas mediante reactores biologicos de membranas

    Energy Technology Data Exchange (ETDEWEB)

    Malfeito, J. J.; Palacios, E.

    2001-07-01

    Wastewater reuse plants can be simplified to a single step process with a membrane bioreactor developed by PRIDESA. The process consists on a biological reactor integrated with immersed membranes that combines clarification and filtration of an activated sludge process into a simplified single step process. Because of the design of the membranes and plate and frame module, the hydrostatic pressure difference is enough to ensure the design permeate flowrate. That means low energy requirements and reduced fouling, as contaminants are not forced into the membrane pores. A 90-days pilot scale operation for reclamation of urban wastewater was studied and the performance of the system was investigated with a sludge retention time (SRT) of 25 days and membrane flux between 50.90 l/h. with different membranes. Averaged 98% of BODS, a 95% of COD and a 99.49% of SS were removed. (Author) 5 refs.

  5. Novel Catalytic Reactor for CO2 Reduction via Sabatier Process, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Precision Combustion, Inc. (PCI) proposes to develop a novel, efficient, and lightweight catalytic Sabatier CO2 methanation unit, capable of converting a mixture of...

  6. Ion transport membrane reactor systems and methods for producing synthesis gas

    Science.gov (United States)

    Repasky, John Michael

    2015-05-12

    Embodiments of the present invention provide cost-effective systems and methods for producing a synthesis gas product using a steam reformer system and an ion transport membrane (ITM) reactor having multiple stages, without requiring inter-stage reactant injections. Embodiments of the present invention also provide techniques for compensating for membrane performance degradation and other changes in system operating conditions that negatively affect synthesis gas production.

  7. Bubbling bed catalytic hydropyrolysis process utilizing larger catalyst particles and smaller biomass particles featuring an anti-slugging reactor

    Science.gov (United States)

    Marker, Terry L; Felix, Larry G; Linck, Martin B; Roberts, Michael J

    2014-09-23

    This invention relates to a process for thermochemically transforming biomass or other oxygenated feedstocks into high quality liquid hydrocarbon fuels. In particular, a catalytic hydropyrolysis reactor, containing a deep bed of fluidized catalyst particles is utilized to accept particles of biomass or other oxygenated feedstocks that are significantly smaller than the particles of catalyst in the fluidized bed. The reactor features an insert or other structure disposed within the reactor vessel that inhibits slugging of the bed and thereby minimizes attrition of the catalyst. Within the bed, the biomass feedstock is converted into a vapor-phase product, containing hydrocarbon molecules and other process vapors, and an entrained solid char product, which is separated from the vapor stream after the vapor stream has been exhausted from the top of the reactor. When the product vapor stream is cooled to ambient temperatures, a significant proportion of the hydrocarbons in the product vapor stream can be recovered as a liquid stream of hydrophobic hydrocarbons, with properties consistent with those of gasoline, kerosene, and diesel fuel. Separate streams of gasoline, kerosene, and diesel fuel may also be obtained, either via selective condensation of each type of fuel, or via later distillation of the combined hydrocarbon liquid.

  8. Bubbling bed catalytic hydropyrolysis process utilizinig larger catalyst particles and small biomass particles featuring an anti-slugging reactor

    Science.gov (United States)

    Marker, Terry L.; Felix, Larry G.; Linck, Martin B.; Roberts, Michael J.

    2016-12-06

    This invention relates to a process for thermochemically transforming biomass or other oxygenated feedstocks into high quality liquid hydrocarbon fuels. In particular, a catalytic hydropyrolysis reactor, containing a deep bed of fluidized catalyst particles is utilized to accept particles of biomass or other oxygenated feedstocks that are significantly smaller than the particles of catalyst in the fluidized bed. The reactor features an insert or other structure disposed within the reactor vessel that inhibits slugging of the bed and thereby minimizes attrition of the catalyst. Within the bed, the biomass feedstock is converted into a vapor-phase product, containing hydrocarbon molecules and other process vapors, and an entrained solid char product, which is separated from the vapor stream after the vapor stream has been exhausted from the top of the reactor. When the product vapor stream is cooled to ambient temperatures, a significant proportion of the hydrocarbons in the product vapor stream can be recovered as a liquid stream of hydrophobic hydrocarbons, with properties consistent with those of gasoline, kerosene, and diesel fuel. Separate streams of gasoline, kerosene, and diesel fuel may also be obtained, either via selective condensation of each type of fuel, or via later distillation of the combined hydrocarbon liquid.

  9. Co-current and counter-current configurations for ethanol steam reforming in a dense Pd-Ag membrane reactor

    NARCIS (Netherlands)

    Gallucci, F.; de Falco, M.; Tosti, S.; Marrelli, L; Basile, A.

    2008-01-01

    The ethanol steam-reforming reaction to produce pure hydrogen has been studied theoretically. A mathematical model has been formulated for a traditional system and a palladium membrane reactor packed with a Co-based catalyst and the simulation results related to the membrane reactor for both

  10. A non-permselective membrane reactor for chemical processes normally requiring strict stoichiometric feed rates of reactants

    NARCIS (Netherlands)

    Sloot, H.J.; Versteeg, Geert; van Swaaij, Willibrordus Petrus Maria

    1990-01-01

    A novel type of membrane reactor with separated feeding of the reactants is presented for chemical processes normally requiring strict stoichiometric feed rates of premixed reactants. The reactants are fed in the reactor to the different sides of a porous membrane which is impregnated with a

  11. Kinetic resolution of chiral amines with omega-transaminase using an enzyme-membrane reactor.

    Science.gov (United States)

    Shin, J S; Kim, B G; Liese, A; Wandrey, C

    2001-05-05

    A kinetic resolution process for the production of chiral amines was developed using an enzyme-membrane reactor (EMR) and a hollow-fiber membrane contactor with (S)-specific omega-transaminases (omega-TA) from Vibrio fluvialis JS17 and Bacillus thuringiensis JS64. The substrate solution containing racemic amine and pyruvate was recirculated through the EMR and inhibitory ketone product was selectively extracted by the membrane contactor until enantiomeric excess of (R)-amine exceeded 95%. Using the reactor set-up with flat membrane reactor (10-mL working volume), kinetic resolutions of alpha-methylbenzylamine (alpha-MBA) and 1-aminotetralin (200 mM, 50 mL) were carried out. During the operation, concentration of ketone product, i.e., acetophenone or alpha-tetralone, in a substrate reservoir was maintained below 0.1 mM, suggesting efficient removal of the inhibitory ketone by the membrane contactor. After 47 and 32.5 h of operation using 5 U/mL of enzyme, 98.0 and 95.5% ee of (R)-alpha-MBA and (R)-1-aminotetralin were obtained at 49.5 and 48.8% of conversion, respectively. A hollow-fiber membrane reactor (39-mL working volume) was used for a preparative-scale kinetic resolution of 1-aminotetralin (200 mM, 1 L). After 133 h of operation, enantiomeric excess reached 95.6% and 14.3 g of (R)-1-aminotetralin was recovered (97.4% of yield). Mathematical modeling of the EMR process including the membrane contactor was performed to evaluate the effect of residence time. The simulation results suggest that residence time should be short to maintain the concentration of the ketone product in EMR sufficiently low so as to decrease conversion per cycle and, in turn, reduce the inhibition of the omega-TA activity. Copyright 2001 John Wiley & Sons, Inc.

  12. A new combination of membranes and membrane reactors for improved tritium management in breeder blanket of fusion machines

    International Nuclear Information System (INIS)

    Demange, D.; Staemmler, S.; Kind, M.

    2011-01-01

    Tritium used as fuel in future fusion machines will be produced within the breeder blanket. The tritium extraction system recovers the tritium to be routed into the inner-fuel cycle of the machine. Accurate and precise tritium accountancy between both systems is mandatory to ensure a reliable operation. Handling in the blanket huge helium flow rates containing tritium as traces in molecular and oxide forms is challenging both for the process and the accountancy. Alternative tritium processes based on combinations of membranes and membrane reactors are proposed to facilitate the tritium management. The PERMCAT process is based on counter-current isotope swamping in a palladium membrane reactor. It allows recovering tritium efficiently from any chemical species. It produces a pure hydrogen stream enriched in tritium of advantage for integration upstream of the accountancy stage. A pre-separation and pre-concentration stage using new zeolite membranes has been studied to optimize the whole process. Such a combination could improve the tritium processes and facilitate accountancy in DEMO.

  13. A packed bed membrane reactor for production of biodiesel using activated carbon supported catalyst.

    Science.gov (United States)

    Baroutian, Saeid; Aroua, Mohamed K; Raman, Abdul Aziz A; Sulaiman, Nik M N

    2011-01-01

    In this study, a novel continuous reactor has been developed to produce high quality methyl esters (biodiesel) from palm oil. A microporous TiO2/Al2O3 membrane was packed with potassium hydroxide catalyst supported on palm shell activated carbon. The central composite design (CCD) of response surface methodology (RSM) was employed to investigate the effects of reaction temperature, catalyst amount and cross flow circulation velocity on the production of biodiesel in the packed bed membrane reactor. The highest conversion of palm oil to biodiesel in the reactor was obtained at 70 °C employing 157.04 g catalyst per unit volume of the reactor and 0.21 cm/s cross flow circulation velocity. The physical and chemical properties of the produced biodiesel were determined and compared with the standard specifications. High quality palm oil biodiesel was produced by combination of heterogeneous alkali transesterification and separation processes in the packed bed membrane reactor. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. Membrane support of accelerated fuel capsules for inertial fusion energy reactors

    International Nuclear Information System (INIS)

    Petzoldt, R.W.; Moir, R.W.

    1993-01-01

    The use of a thin membrane to suspend an (inertial fusion energy) fuel capsule in a holder for injection into a reactor chamber is investigated. Capsule displacement and membrane deformation angle are calculated for an axisymmetric geometry for a range of membrane strain and capsule size. This information is used to calculate maximum target accelerations. Membranes must be thin (perhaps of order one micron) to minimize their effect on capsule implosion symmetry. For example, a 5 μm thick cryogenic mylar membrane is calculated to allow 1,000 m/s 2 acceleration of a 3 mm radius, 100 mg capsule. Vibration analysis (for a single membrane support) shows that if membrane vibration is not deliberately minimized, allowed acceleration may be reduced by a factor of four. A two membrane alternative geometry would allow several times greater acceleration. Therefore, alternative membrane geometry's should be used to provide greater target acceleration potential and reduce capsule displacement within the holder (for a given membrane thickness)

  15. Enrichment and biofilm formation of Anammox bacteria in a non-woven membrane reactor.

    Science.gov (United States)

    Ni, Shou-Qing; Lee, Po-Heng; Fessehaie, Anania; Gao, Bao-Yu; Sung, Shihwu

    2010-03-01

    An innovative reactor configuration for Anammox enrichment by connecting a non-woven membrane module with an anaerobic reactor was developed in this study. The Anammox non-woven membrane reactor (ANMR) exhibited high biomass retention ability through the formation of aggregates in the reactor and biofilm on the interior surface of the non-woven membrane. No fouling problems occurred on the membrane after the development of mature biofilms. After 8 months of operation, the nitrogen loading rate (NLR) and nitrogen removal rate (NRR) reached 1263 mg N/l/d and 1047.5 mg N/l/d, respectively, with a maximum specific ammonium consumption (SAC) of 51 nmol/mg protein/min. At steady state, the average ammonium and nitrite removal efficiencies were 90.9% and 95.0%, respectively. Morphological observation of Anammox aggregates and biofilm showed a high degree of compactness. Also, enrichment of Anammox bacteria was quantified by real-time polymerase chain reaction (PCR) analysis as 97.7%. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  16. Sequentially aerated membrane biofilm reactors for autotrophic nitrogen removal: microbial community composition and dynamics

    DEFF Research Database (Denmark)

    Pellicer i Nàcher, Carles; Franck, Stephanie; Gülay, Arda

    2014-01-01

    Membrane-aerated biofilm reactors performing autotrophic nitrogen removal can be successfully applied to treat concentrated nitrogen streams. However, their process performance is seriously hampered by the growth of nitrite oxidizing bacteria (NOB). In this work we document how sequential aeration...

  17. Simultaneous Removal of NOx and Mercury in Low Temperature Selective Catalytic and Adsorptive Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Neville G. Pinto; Panagiotis G. Smirniotis

    2006-03-31

    The results of a 18-month investigation to advance the development of a novel Low Temperature Selective Catalytic and Adsorptive Reactor (LTSCAR), for the simultaneous removal of NO{sub x} and mercury (elemental and oxidized) from flue gases in a single unit operation located downstream of the particulate collectors, are reported. In the proposed LTSCAR, NO{sub x} removal is in a traditional SCR mode but at low temperature, and, uniquely, using carbon monoxide as a reductant. The concomitant capture of mercury in the unit is achieved through the incorporation of a novel chelating adsorbent. As conceptualized, the LTSCAR will be located downstream of the particulate collectors (flue gas temperature 140-160 C) and will be similar in structure to a conventional SCR. That is, it will have 3-4 beds that are loaded with catalyst and adsorbent allowing staged replacement of catalyst and adsorbent as required. Various Mn/TiO{sub 2} SCR catalysts were synthesized and evaluated for their ability to reduce NO at low temperature using CO as the reductant. It has been shown that with a suitably tailored catalyst more than 65% NO conversion with 100% N{sub 2} selectivity can be achieved, even at a high space velocity (SV) of 50,000 h-1 and in the presence of 2 v% H{sub 2}O. Three adsorbents for oxidized mercury were developed in this project with thermal stability in the required range. Based on detailed evaluations of their characteristics, the mercaptopropyltrimethoxysilane (MPTS) adsorbent was found to be most promising for the capture of oxidized mercury. This adsorbent has been shown to be thermally stable to 200 C. Fixed-bed evaluations in the targeted temperature range demonstrated effective removal of oxidized mercury from simulated flue gas at very high capacity ({approx}>58 mg Hg/g adsorbent). Extension of the capability of the adsorbent to elemental mercury capture was pursued with two independent approaches: incorporation of a novel nano-layer on the surface of the

  18. Potentialities of a Membrane Reactor with Laccase Grafted Membranes for the Enzymatic Degradation of Phenolic Compounds in Water

    Directory of Open Access Journals (Sweden)

    Vorleak Chea

    2014-10-01

    Full Text Available This paper describes the degradation of phenolic compounds by laccases from Trametes versicolor in an enzymatic membrane reactor (EMR. The enzymatic membranes were prepared by grafting laccase on a gelatine layer previously deposited onto α-alumina tubular membranes. The 2,6-dimethoxyphenol (DMP was selected  from among the three different phenolic compounds tested (guaiacol, 4-chlorophenol and DMP to study the performance of the EMR in dead end configuration. At the lowest feed substrate concentration tested (100 mg·L−1, consumption increased with flux (up to 7.9 × 103 mg·h−1·m−2 at 128 L·h−1·m−2, whereas at the highest substrate concentration (500 mg·L−1, it was shown that the reaction was limited by the oxygen content.

  19. The catalytic function of cytochrome P450 is entwined with its membrane-bound nature [version 1; referees: 4 approved

    Directory of Open Access Journals (Sweden)

    Carlo Barnaba

    2017-05-01

    Full Text Available Cytochrome P450, a family of monooxygenase enzymes, is organized as a catalytic metabolon, which requires enzymatic partners as well as environmental factors that tune its complex dynamic. P450 and its reducing counterparts—cytochrome P450-reductase and cytochrome b5—are membrane-bound proteins located in the cytosolic side of the endoplasmic reticulum. They are believed to dynamically associate to form functional complexes. Increasing experimental evidence signifies the role(s played by both protein-protein and protein-lipid interactions in P450 catalytic function and efficiency. However, the biophysical challenges posed by their membrane-bound nature have severely limited high-resolution understanding of the molecular interfaces of these interactions. In this article, we provide an overview of the current knowledge on cytochrome P450, highlighting the environmental factors that are entwined with its metabolic function. Recent advances in structural biophysics are also discussed, setting up the bases for a new paradigm in the study of this important class of membrane-bound enzymes.

  20. Catalytic steam reforming of acetic acid in a fluidized bed reactor with oxygen addition

    Energy Technology Data Exchange (ETDEWEB)

    Medrano, J.A.; Oliva, M.; Ruiz, J.; Garcia, L.; Arauzo, J. [Thermochemical Processes Group (GPT), Aragon Institute for Engineering Research (I3A), University of Zaragoza, Maria de Luna 3, 50018 Zaragoza (Spain)

    2008-08-15

    Catalytic steam reforming of bio-oil is a promising process for producing hydrogen in a sustainable environmentally friendly way that can improve the utilization of local resources (natural sources or wastes). However, there remain drawbacks such as coke formation that produce operational problems and deactivation of the catalysts. Coprecipitated Ni/Al catalysts are here used in a fluidized bed for reforming at 650 C of acetic acid as a model compound of bio-oil-aqueous fraction. Different strategies are applied in order to study their effects on the catalytic steam reforming process: modification of the catalyst by increasing the calcination temperature or adding promoters such as calcium. The addition of small quantities of oxygen is also tested resulting in an optimum percentage to achieve a high carbon conversion process with less coke and without a hydrogen yield penalty production. The results for catalytic steam reforming are compared with other ones from literature. (author)

  1. A Two‐Fluid model study of hydrogen production via water gas shift in fluidized bed membrane reactors

    OpenAIRE

    J.W. Voncken, Ramon; Roghair, Ivo; Van Sint Annaland, Martin

    2017-01-01

    Fluidized bed membrane reactors have been proposed as a promising reactor concept for the production of ultra-pure hydrogen via Water Gas Shift (WGS). High-flux thin-film dense palladium-based membranes are used to selectively extract hydrogen from the reaction medium, which shifts the thermodynamic equilibrium towards the products’ side, increasing the conversion. A Two-Fluid Model (TFM) has been used to investigate the effect of hydrogen extraction via perm-selective membranes on the WGS re...

  2. Continuous Enzymatic Hydrolysis of Lignocellulosic Biomass in a Membrane-Reactor System

    Energy Technology Data Exchange (ETDEWEB)

    Stickel, Jonathan J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sievers, David A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Adhikari, Birendra [University of Colorado; Pellegrino, John [University of Colorado

    2018-02-21

    Converting abundant lignocellulosic biomass to sugars as fungible precursors to fuels and chemicals has the potential to diversify the supply chain for those products, but further process improvements are needed to achieve economic viability. In the current work, process intensification of the key enzymatic hydrolysis unit operation is demonstrated by means of a membrane reactor system that was operated continuously. Lignocellulosic biomass (pretreated corn stover) and buffered enzyme solution were fed to a continuously stirred-tank reactor, and clarified sugar solution was withdrawn via a commercial tubular ultrafiltration membrane. The membrane permeance decline and membrane cleaning efficacy were studied and did not vary significantly when increasing fraction insoluble solids (FIS) from 2.5% to 5%. Continuous enzymatic hydrolysis was successfully operated for more than 80 h. A model for the reactor system was able to predict dynamic behavior that was in reasonable agreement with experimental results. The modeled technical performance of anticipated commercial batch and continuous enzymatic hydrolysis processes were compared and showed that continuous operation would provide at least twice the volumetric productivity for the conditions studied. Further improvements are anticipated by better membrane selection and by increasing FIS.

  3. Fluidized Bed Membrane Reactors for Ultra Pure H2 Production—A Step forward towards Commercialization

    Directory of Open Access Journals (Sweden)

    Arash Helmi

    2016-03-01

    Full Text Available In this research the performance of a fluidized bed membrane reactor for high temperature water gas shift and its long term stability was investigated to provide a proof-of-concept of the new system at lab scale. A demonstration unit with a capacity of 1 Nm3/h of ultra-pure H2 was designed, built and operated over 900 h of continuous work. Firstly, the performance of the membranes were investigated at different inlet gas compositions and at different temperatures and H2 partial pressure differences. The membranes showed very high H2 fluxes (3.89 × 10−6 mol·m−2·Pa−1·s−1 at 400 °C and 1 atm pressure difference with a H2/N2 ideal perm-selectivity (up to 21,000 when integrating five membranes in the module beyond the DOE 2015 targets. Monitoring the performance of the membranes and the reactor confirmed a very stable performance of the unit for continuous high temperature water gas shift under bubbling fluidization conditions. Several experiments were carried out at different temperatures, pressures and various inlet compositions to determine the optimum operating window for the reactor. The obtained results showed high hydrogen recovery factors, and very low CO concentrations at the permeate side (in average <10 ppm, so that the produced hydrogen can be directly fed to a low temperature PEM fuel cell.

  4. Fluidized Bed Membrane Reactors for Ultra Pure H₂ Production--A Step forward towards Commercialization.

    Science.gov (United States)

    Helmi, Arash; Fernandez, Ekain; Melendez, Jon; Pacheco Tanaka, David Alfredo; Gallucci, Fausto; van Sint Annaland, Martin

    2016-03-19

    In this research the performance of a fluidized bed membrane reactor for high temperature water gas shift and its long term stability was investigated to provide a proof-of-concept of the new system at lab scale. A demonstration unit with a capacity of 1 Nm³/h of ultra-pure H₂ was designed, built and operated over 900 h of continuous work. Firstly, the performance of the membranes were investigated at different inlet gas compositions and at different temperatures and H₂ partial pressure differences. The membranes showed very high H₂ fluxes (3.89 × 10(-6) mol·m(-2)·Pa(-1)·s(-1) at 400 °C and 1 atm pressure difference) with a H₂/N₂ ideal perm-selectivity (up to 21,000 when integrating five membranes in the module) beyond the DOE 2015 targets. Monitoring the performance of the membranes and the reactor confirmed a very stable performance of the unit for continuous high temperature water gas shift under bubbling fluidization conditions. Several experiments were carried out at different temperatures, pressures and various inlet compositions to determine the optimum operating window for the reactor. The obtained results showed high hydrogen recovery factors, and very low CO concentrations at the permeate side (in average hydrogen can be directly fed to a low temperature PEM fuel cell.

  5. Surface modification of polysulfone membranes applied for a membrane reactor with immobilized alcohol dehydrogenase

    DEFF Research Database (Denmark)

    Hoffmann, Christian; Silau, Harald; Pinelo, Manuel

    2018-01-01

    Commercially available polysulfone (PSf) membranes with a polypropylene backing are used across a broad range of applications. However, the natural properties of the PSf surface sometimes limit their application. Here we present, how the surface of supported membranes can be heterogeneously...... activated by lithiation followed by functionalization with acid chlorides at 0 °C, permitting modification of commercial PSf membranes without compromising the mechanical integrity of the membrane. Post-functionalization polymer grafting was illustrated through both, a “grafting from” approach by surface...... initiated atom transfer radical polymerization (SI-ATRP) and by a “grafting to” approach exploiting Cu(I) catalyzed 1,3-cycloadditions of alkynes with azides (CuAAC) introducing hydrophilic polymers onto the membrane surface. Poly(1-vinyl imidazole) (pVim) grafted membranes were exploited as support...

  6. Catalytic flash pyrolysis of HDPE in a fluidized bed reactor for recovery of fuel-like hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Remedio Hernandez, M. del; Garcia, Angela N.; Marcilla, Antonio [Department of Chemical Engineering, University of Alicante, 03080, P.O. Box 99, Alicante (Spain)

    2007-03-15

    Products obtained in the flash pyrolysis of HDPE in a fluidized bed reactor, in thermal and catalytic conditions (HZSM-5 or HUSY 20% by weight) at four different temperatures (in the range 500-800 C) have been analyzed in this work focusing on the liquid fraction. The results obtained showed significant differences between condensable compounds generated in presence and absence of catalysts. The liquid fraction obtained without catalyst was composed principally by linear paraffins (C{sub 10}-C{sub 40}) and almost no generation of aromatic compounds was observed. The presence of low amounts of zeolite (HZSM-5 or HUSY) led to a significant reduction of the saturated and unsaturated condensable hydrocarbons, while it favored the formation of aromatics and branched paraffins. Compared with the results reached with HZSM-5 zeolite, HUSY produces higher amount of aromatics and branched alkanes and a narrower distribution of products, independently of the pyrolysis temperature. The reactor employed in this work was a fluidized bed reactor, very similar to that used in generation of gasoline-range hydrocarbons at large scale, which allows to illustrate a very useful method for the recovery of these hydrocarbons. (author)

  7. Experimental studies on catalytic hydrogen recombiners for light water reactors; Experimentelle Untersuchungen zu katalytischen Wasserstoffkombinatoren fuer Leichtwasserreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Drinovac, P.

    2006-06-19

    In the course of core melt accidents in nuclear power plants a large amount of hydrogen can be produced and form an explosive or even detonative gas mixture with aerial oxygen in the reactor building. In the containment atmosphere of pressurized water reactors hydrogen combines a phlogistically with the oxygen present to form water vapor even at room temperature. In the past, experimental work conducted at various facilities has contributed little or nothing to an understanding of the operating principles of catalytic recombiners. Hence, the purpose of the present study was to conduct detailed investigations on a section of a recombiner essentially in order to deepen the understanding of reaction kinetics and heat transport processes. The results of the experiments presented in this dissertation form a large data base of measurements which provides an insight into the processes taking place in recombiners. The reaction-kinetic interpretation of the measured data confirms and deepens the diffusion theory - proposed in an earlier study. Thus it is now possible to validate detailed numeric models representing the processes in recombiners. Consequently the present study serves to broaden and corroborate competence in this significant area of reactor technology. In addition, the empirical knowledge thus gained may be used for a critical reassessment of previous numeric model calculations. (orig.)

  8. Catalytic non-thermal plasma reactor for the decomposition of a ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Among the catalytic study, MnOx/SMF (manganese oxide on sintered metal fibres electrode) shows better performance, probably due to the formation of active oxygen species by in situ decomposition of ozone on the catalyst surface. Water vapour further enhanced the performance due to the in situ ...

  9. The catalytic oxidation of organic contaminants in a packed bed reactor

    NARCIS (Netherlands)

    van de Beld, L.; Bijl, M.P.G.; Reinders, A.; van der Wert, B.; Westerterp, K.R.

    1994-01-01

    The catalytic oxidation of several hydrocarbons was studied over noble metal and metal oxide catalysts. A fast empirical method was developed to determine the minimum operating temperature required to guarantee complete conversion of the hydrocarbon. The influence of the operating parameters such as

  10. Novel Catalytic Reactor for CO2 Reduction via Sabatier Process Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel short contact time Microlith Sabatier reactor system for CO2 reduction offers a significant advance in support of manned spaceflight. Compared to current and...

  11. Degradation of Reactive Black 5 dye using anaerobic/aerobic membrane bioreactor (MBR) and photochemical membrane reactor

    International Nuclear Information System (INIS)

    You, Sheng-Jie; Damodar, Rahul A.; Hou, Sheng-Chon

    2010-01-01

    Three different types of advance treatment methods were evaluated for the degradation of Reactive Black 5 (RB5). The performance of two stage anaerobic SBR-aerobic MBR, anaerobic MBR with immobilized and suspended biocells and an integrated membrane photocatalytic reactor (MPR) using slurry UV/TiO 2 system were investigated. The results suggest that, nearly 99.9% color removal and 80-95% organic COD and TOC removal can be achieved using different reactor systems. Considering the Taiwan EPA effluent standard discharge criteria for COD/TOC, the degree of treatment achieved by combining the anaerobic-aerobic system was found to be acceptable. Anew, Bacilluscereus, high color removal bacterium was isolated from Anaerobic SBR. Furthermore, when this immobilized into PVA-calcium alginate pellets, and suspended in the anaerobic MBR was able to achieve high removal efficiencies, similar to the suspended biocells system. However, the immobilized cell Anaerobic MBR was found to be more advantageous, due to lower fouling rates in the membrane unit. Results from slurry type MPR system showed that this system was capable of mineralizing RB5 dyes with faster degradation rate as compared to other systems. The reactor was also able to separate the catalyst effectively and perform efficiently without much loss of catalyst activity.

  12. Thermo-catalytic pyrolysis of waste polyethylene bottles in a packed bed reactor with different bed materials and catalysts

    International Nuclear Information System (INIS)

    Obeid, Farah; Zeaiter, Joseph; Al-Muhtaseb, Ala’a H.; Bouhadir, Kamal

    2014-01-01

    Highlights: • Thermo-catalytic pyrolysis of waste polyethylene bottles was investigated. • The highest yield of liquid (82%) was obtained over a cement powder bed. • Acidic catalysts narrowed the carbon chain length of the paraffins to C 10 –C 28 . • Combination of cement bed with HBeta catalyst gave the highest yield of liquid. • Significant yield of aromatics was obtained mainly naphthalene and D-limonene. - Abstract: Plastic waste is an increasing economic and environmental problem as such there is a great need to process this waste and reduce its environmental impact. In this work, the pyrolysis of high density polyethylene (HDPE) waste products was investigated using both thermal and catalytic cracking techniques. The experimental work was carried out using packed bed reactor operating under an inert atmosphere at 450 °C. Different reactor bed materials, including sand, cement and white clay were used to enhance the thermal cracking of HDPE. In addition, the catalytic effect of sodium hydroxide, HUSY and HBeta zeolite catalysts on the degradation of HDPE waste was also investigated. The reactor beds were found to significantly alter the yield as well as the product composition. Products such as paraffins (⩽C 44 ), olefins (⩽C 22 ), aromatics (⩽C 14 ) and alcohols (C 16 and C 17 ) were obtained at varying rates. The highest yield of liquid (82%) was obtained over a cement powder bed with a paraffin yield of 58%. The yield of paraffins and olefins followed separate paths, for paraffins it was found to increase in the order or Cement > White clay > Silica Sand, whereas for the olefins it was in the reverse order Silica Sand > White clay > Cement. The results obtained in this work exhibited a higher P/O ratio than expected, where the amount of generated paraffins was greater than 60% in most cases. Less olefin was generated as a consequence. This indicates that the product generated is more suited to be used as a fuel rather than as a chemical

  13. Evaluation of heat transfer in a catalytic fixed bed reactor at high temperatures

    OpenAIRE

    JORGE,L. M. M.; JORGE,R. M. M.; FUJII,F.; GIUDICI,R.

    1999-01-01

    Experimental results of fixed-bed heat-transfer experiments with no chemical reaction are presented and discussed. The runs were carried out in a tubular integral reactor heated by an electrical furnace at temperatures in the range of 100 to 500°C. Experimental temperature profiles were determined for the electrical furnace, for the reactor wall, and for the fixed bed center. Industrial catalyst for the prereforming of hydrocarbons was employed as the packing material. The effects of process ...

  14. A novel fixed-bed reactor design incorporating an electrospun PVA/chitosan nanofiber membrane

    International Nuclear Information System (INIS)

    Esmaeili, Akbar; Beni, Ali Aghababai

    2014-01-01

    Graphical abstract: PVA/Cs nanofiber membrane was prepared by the electrospinning technique. The membrane was installed in a new fixed-bed reactor. The test results showed heavy metals absorbed by the PVA/Cs nanofiber membrane. - Highlights: • PVA/Cs nano-fiber membrane was produced using electrospinning technique. • The prepared nanofiber membrane was mesoporous. • Thermal crosslinking was successful to improve the stability of PVA/Cs nano-fiber membrane. • Experimental data were studied by adsorption isotherm models and thermodynamic relationships. - Abstract: In this research, a novel fixed-bed reactor was designed with a nanofiber membrane composed of a polyvinyl alcohol (PVA)/chitosan nanofiber blend prepared using an electrospinning technique. The applied voltage, tip-collector distance, and solution flow rate of the electrospinning process were 18 kV, 14.5 cm, and 0.5 mL h −1 , respectively. Brunauer–Emmett–Teller (BET) theory, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FT-IR) were employed to characterize and analyze the nanofiber membranes. Homogeneous electrospun nanofibers with an average diameter of 99.47 nm and surface area of 214.12 m 2 g −1 were obtained. Adsorption experiments were carried out in a batch system to investigate the effect of different adsorption parameters such as pH, adsorbent dose, biomass dose, contact time, and temperature. The kinetic data, obtained at the optimal pH of 6, were analyzed by pseudo first-order and pseudo second-order kinetic models. Three isotherm models and thermodynamic parameters (ΔG°, ΔH°, and ΔS°) were applied to describe the equilibrium data of the metal ions adsorbed onto the PVA/chitosan nanofiber membrane

  15. Theoretical Study of Palladium Membrane Reactor Performance During Propane Dehydrogenation Using CFD Method

    Directory of Open Access Journals (Sweden)

    Kamran Ghasemzadeh

    2017-04-01

    Full Text Available This study presents a 2D-axisymmetric computational fluid dynamic (CFD model to investigate the performance Pd membrane reactor (MR during propane dehydrogenation process for hydrogen production. The proposed CFD model provided the local information of temperature and component concentration for the driving force analysis. After investigation of mesh independency of CFD model, the validation of CFD model results was carried out by other modeling data and a good agreement between CFD model results and theoretical data was achieved. Indeed, in the present model, a tubular reactor with length of 150 mm was considered, in which the Pt-Sn-K/Al2O3 as catalyst were filled in reaction zone. Hence, the effects of the important operating parameter (reaction temperature on the performances of membrane reactor (MR were studied in terms of propane conversion and hydrogen yield. The CFD results showed that the suggested MR system during propane dehydrogenation reaction presents higher performance with respect to once obtained in the conventional reactor (CR. In particular, by applying Pd membrane, was found that propane conversion can be increased from 41% to 49%. Moreover, the highest value of propane conversion (X = 91% was reached in case of Pd-Ag MR. It was also established that the feed flow rate of the MR is to be the one of the most important factors defining efficiency of the propane dehydrogenation process.

  16. Retention and regeneration of native NAD(H) in noncharged ultrafiltration membrane reactors: application to L-lactate and gluconate production.

    Science.gov (United States)

    Obón, J M; Manjón, A; Iborra, J L

    1998-03-05

    NAD(H) was retained in a noncharged ultrafiltration membrane reactor for the simultaneous and continuous production of L-lactate and gluconate with coenzyme regeneration. Polyethyleneimine (PEI), a 50-kDa cationic polymer, achieved coenzyme retentions above 0.8 for PEI/NAD(H) molar ratios higher than 5. The ionic strength of the inlet medium caused a decrease of NAD(H) retention that can be counterbalanced by an initial addition of 1% bovine serum albumin (BSA). Continuous reactor performance in the presence of PEI and BSA showed that NAD(H), glucose dehydrogenase, and lactate dehydrogenase were retained by 10-kDa ultrafiltration membranes; L-lactate and gluconate were produced at conversions higher than 95%. PEI enhanced the thermal stability of the enzymes used and increased the catalytic efficiency of glucose dehydrogenase, while no effect was found on the kinetic parameters of lactate dehydrogenase. A model that implements the kinetic equations of the two enzymes describes the reactor behavior satisfactorily. In brief, the use of PEI to retain NAD(H) is a new interesting approach to be widely applied in continuous synthesis with the large number of known dehydrogenases. Copyright 1998 John Wiley & Sons, Inc.

  17. Single Membrane Reactor Configuration for Separation of Hydrogen, Carbon Dioxide and Hydrogen Sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Micheal Roberts; Robert Zabransky; Shain Doong; Jerry Lin

    2008-05-31

    The objective of the project was to develop a novel complementary membrane reactor process that can consolidate two or more downstream unit operations of a coal gasification system into a single module for production of a pure stream of hydrogen and a pure stream of carbon dioxide. The overall goals were to achieve higher hydrogen production efficiencies, lower capital costs and a smaller overall footprint than what could be achieved by utilizing separate components for each required unit process/operation in conventional coal-to-hydrogen systems. Specifically, this project was to develop a novel membrane reactor process that combines hydrogen sulfide removal, hydrogen separation, carbon dioxide separation and water-gas shift reaction into a single membrane configuration. The carbon monoxide conversion of the water-gas-shift reaction from the coal-derived syngas stream is enhanced by the complementary use of two membranes within a single reactor to separate hydrogen and carbon dioxide. Consequently, hydrogen production efficiency is increased. The single membrane reactor configuration produces a pure H{sub 2} product and a pure CO{sub 2} permeate stream that is ready for sequestration. This project focused on developing a new class of CO{sub 2}-selective membranes for this new process concept. Several approaches to make CO{sub 2}-selective membranes for high-temperature applications have been tested. Membrane disks using the technique of powder pressing and high temperature sintering were successfully fabricated. The powders were either metal oxide or metal carbonate materials. Experiments on CO{sub 2} permeation testing were also performed in the temperature range of 790 to 940 C for the metal carbonate membrane disks. However, no CO{sub 2} permeation rate could be measured, probably due to very slow CO{sub 2} diffusion in the solid state carbonates. To improve the permeation of CO{sub 2}, one approach is to make membranes containing liquid or molten carbonates

  18. Effect of Mass-Transport Limitations on the Performance of a Packed Bed Membrane Reactor for Partial Oxidations. Transport from the Membrane to the Packed Bed

    NARCIS (Netherlands)

    van Sint Annaland, M.; Kurten, U.; Kuipers, J.A.M.

    2007-01-01

    With a packed bed membrane reactor, the product yield can be significantly enhanced for partial oxidation systems, via distributive addition of oxygen to the reaction mixture along the axial coordinate of the reactor, provided that the reaction order in oxygen of the formation rate of the target

  19. Catalytic wet-air oxidation of lignin in a three-phase reactor with aromatic aldehyde production

    Directory of Open Access Journals (Sweden)

    Sales F.G.

    2004-01-01

    Full Text Available In the present work a process of catalytic wet air oxidation of lignin obtained from sugar-cane bagasse is developed with the objective of producing vanillin, syringaldehyde and p-hydroxybenzaldehyde in a continuous regime. Palladium supported on g-alumina was used as the catalyst. The reactions in the lignin degradation and aldehyde production were described by a kinetic model as a system of complex parallel and series reactions, in which pseudo-first-order steps are found. For the purpose of producing aromatic aldehydes in continuous regime, a three-phase fluidized reactor was built, and it was operated using atmospheric air as the oxidizer. The best yield in aromatic aldehydes was of 12%. The experimental results were compatible with those values obtained by the pseudo-heterogeneous axial dispersion model (PHADM applied to the liquid phase.

  20. Dynamical and technological consequences of multiple isolas of steady states in a catalytic fluidised-bed reactor

    Directory of Open Access Journals (Sweden)

    Bizon Katarzyna

    2017-09-01

    Full Text Available Steady-state characteristics of a catalytic fluidised bed reactor and its dynamical consequences are analyzed. The occurrence of an untypical steady-state structure manifesting in a form of multiple isolas is described. A two-phase bubbling bed model is used for a quantitative description of the bed of catalyst. The influence of heat exchange intensity and a fluidisation ratio onto the generation of isolated solution branches is presented for two kinetic schemes. Dynamical consequences of the coexistence of such untypical branches of steady states are presented. The impact of linear growth of the fluidisation ratio and step change of the cooling medium temperature onto the desired product yield is analyzed. The results presented in this study confirm that the identification of a region of the occurrence of multiple isolas is important due to their strong impact both on the process start-up and its control.

  1. Effects of Weight Hourly Space Velocity and Catalyst Diameter on Performance of Hybrid Catalytic-Plasma Reactor for Biodiesel Synthesis over Sulphated Zinc Oxide Acid Catalyst

    Directory of Open Access Journals (Sweden)

    Luqman Buchori

    2017-05-01

    Full Text Available Biodiesel synthesis through transesterification of soybean oil with methanol on hybrid catalytic-plasma reactor over sulphated zinc oxide (SO42-/ZnO active acid catalyst was investigated. This research was aimed to study effects of Weight Hourly Space Velocity (WHSV and the catalyst diameter on performance of the hybrid catalytic-plasma reactor for biodiesel synthesis. The amount (20.2 g of active sulphated zinc oxide solid acid catalysts was loaded into discharge zone of the reactor. The WHSV and the catalyst diameter were varied between 0.89 to 1.55 min-1 and 3, 5, and 7 mm, respectively. The molar ratio of methanol to oil as reactants of 15:1 is fed to the reactor, while operating condition of the reactor was kept at reaction temperature of 65 oC and ambient pressure. The fatty acid methyl ester (FAME component in biodiesel product was identified by Gas Chromatography - Mass Spectrometry (GC-MS. The results showed that the FAME yield decreases with increasing WHSV. It was found that the optimum FAME yield was achieved of 56.91 % at WHSV of 0.89 min-1 and catalyst diameter of 5 mm and reaction time of 1.25 min. It can be concluded that the biodiesel synthesis using the hybrid catalytic-plasma reactor system exhibited promising the FAME yield. Copyright © 2017 BCREC Group. All rights reserved Received: 15th November 2016; Revised: 24th December 2016; Accepted: 16th February 2017 How to Cite: Buchori, L., Istadi, I., Purwanto, P. (2017. Effects of Weight Hourly Space Velocity and Catalyst Diameter on Performance of Hybrid Catalytic-Plasma Reactor for Biodiesel Synthesis over Sulphated Zinc Oxide Acid Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (2: 227-234 (doi:10.9767/bcrec.12.2.775.227-234 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.2.775.227-234

  2. Synergetic mechanism of methanol–steam reforming reaction in a catalytic reactor with electric discharges

    International Nuclear Information System (INIS)

    Kim, Taegyu; Jo, Sungkwon; Song, Young-Hoon; Lee, Dae Hoon

    2014-01-01

    Highlights: • Methanol–steam reforming was performed on Cu catalysts under an electric discharge. • Discharge had a synergetic effect on the catalytic reaction for methanol conversion. • Discharge lowered the temperature for catalyst activation or light off. • Discharge controlled the yield and selectivity of species in a reforming process. • Adsorption triggered by a discharge was a possible mechanism for a synergetic effect. - Abstract: Methanol–steam reforming was performed on Cu/ZnO/Al 2 O 3 catalysts under an electric discharge. The discharge occurred between the electrodes where the catalysts were packed. The electric discharge was characterized by the discharge voltage and electric power to generate the discharge. The existence of a discharge had a synergetic effect on the catalytic reaction for methanol conversion. The electric discharge provided modified reaction paths resulting in a lower temperature for catalyst activation or light off. The discharge partially controlled the yield and selectivity of species in a reforming process. The aspect of control was examined in view of the reaction kinetics. The possible mechanisms for the synergetic effect between the catalytic reaction and electric discharge on methanol–steam reforming were addressed. A discrete reaction path, particularly adsorption triggered by an electric discharge, was suggested to be the most likely mechanism for the synergetic effect. These results are expected to provide a guide for understanding the plasma–catalyst hybrid reaction

  3. Sucrose hydrolysis by invertase using a membrane reactor: effect of membrane cut-off on enzyme performance

    Directory of Open Access Journals (Sweden)

    Francesco Di Addezio

    2014-04-01

    Full Text Available Sucrose hydrolysis by invertase [EC.3.2.1.26] produces inverted sugar syrup, an ingredient mainly used in the food industry. To properly catalyze hydrolysis, the enzyme should be reused after this reaction. It is advisable to maintain constant activity over a considerable period. Thus, sucrose hydrolysis was performed in a membrane bioreactor - a continuously stirred tank reactor coupled with an ultrafiltration membrane (UFM which provides good diffusion and high activity per unit volume. Molecular weight cut-off for soluble invertase UFMs was up to 100kDa. This study focused on the role of UFM invertase cut-off as it is the main element in the process. We demonstrated that both the cut-off and chemical nature of the UFM affected specific invertase activity.

  4. Microbial community stratification in Membrane-Aerated Biofilm Reactors for Completely Autotrophic Nitrogen Removal

    DEFF Research Database (Denmark)

    Pellicer i Nàcher, Carles; Ruscalleda, Maël; Terada, Akihiko

    of bacterial granules or biofilms. In this sense, completely autotrophic nitrogen removal from high ammonium strength wastewater was achieved in a Membrane-Aereated Biofilm Reactor (MABR) in a single step. Here, a biofilm containing nitrifiers (Aerobic Ammonium and Nitrite Oxidizing Bacteria, AOB and NOB...... to the membrane, while AnAOB were localized next to them in areas where no oxygen was available. NOB were detected in very low amounts. Results proved the feasibility of developing biofilm structures for high-rate completely autotrophic nitrogen removal....

  5. Feasibility Study of a Novel Membrane Reactor for Syngas Production. Part 1: Experimental Study of O2 Permeation through Perovskite Membranes under Reducing and Non-Reducing Atmospheres

    NARCIS (Netherlands)

    Zhang Wenxing, Z.W.; Zhang, Wenxing; Smit, J.; van Sint Annaland, M.; Kuipers, J.A.M.

    2007-01-01

    In this contribution, the feasibility of a novel membrane reactor for energy efficient syngas production is investigated by means of an experimental and a simulation study. In Part 1, a detailed experimental study is performed on the O2 permeation through a perovskite membrane with composition

  6. Air purification by catalytic oxidation in a reactor with periodic flow reversal

    NARCIS (Netherlands)

    van de Beld, L.; van de Beld, Bert; Westerterp, K.R.

    1994-01-01

    The behaviour of an adiabatic packed bed reactor with periodic flow reversal has been studied by means of model calculations. A heterogeneous model as well as a pseudo-homogeneous model have been developed. It is shown that a high degree of conversion can be obtained in an autothermal process even

  7. Membrane distillation combined with an anaerobic moving bed biofilm reactor for treating municipal wastewater.

    Science.gov (United States)

    Kim, Hyun-Chul; Shin, Jaewon; Won, Seyeon; Lee, Jung-Yeol; Maeng, Sung Kyu; Song, Kyung Guen

    2015-03-15

    A fermentative strategy with an anaerobic moving bed biofilm reactor (AMBBR) was used for the treatment of domestic wastewater. The feasibility of using a membrane separation technique for post-treatment of anaerobic bio-effluent was evaluated with emphasis on employing a membrane distillation (MD). Three different hydrophobic 0.2 μm membranes made of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and polypropylene (PP) were examined in this study. The initial permeate flux of the membranes ranged from 2.5 to 6.3 L m(-2) h(-1) when treating AMBBR effluent at a temperature difference between the feed and permeate streams of 20 °C, with the permeate flux increasing in the order PP membrane gradually decreased to 84% of the initial flux after the 45 h run for distillation, while a flux decline in MD with either the PVDF or PP membrane was not found under the identical distillation conditions. During long-term distillation with the PVDF membrane, total phosphorus was completely rejected and >98% rejection of dissolved organic carbon was also achieved. The characterization of wastewater effluent organic matter (EfOM) using an innovative suite of analytical tools verified that almost all of the EfOM was rejected via the PVDF MD treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. SELECTIVE CATALYTIC REDUCTION (SCR OF NO BY AMMONIA OVER V2O5/TiO2 CATALYST IN A CATALYTIC FILTER MEDIUM AND HONEYCOMB REACTOR: A KINETIC MODELING STUDY

    Directory of Open Access Journals (Sweden)

    M. Nahavandi

    2015-12-01

    Full Text Available Abstract The present study addresses a numerical modeling and simulation based on the available knowledge of SCR kinetics for prediction of NO conversion over a V2O3/TiO3 catalyst through a catalytic filter medium and honeycomb reactor. After introducing the NH3-SCR system with specific operational criteria, a reactor model was developed to evaluate the effect of various operating parameters such as flue gas temperature, velocity, NH3/NO molar ratio, etc., on the SCR process. Computational investigations were performed based on the proposed model and optimum operational conditions were identified. Simulation results indicate that SCR performance is substantially under the effects of reactant concentration and operating temperature, so that the concentration of unreacted ammonia emitted from reactor discharge (ammonia slip increases significantly at NH3/NO ratios of more than 1.14 and operating temperatures less than 360 ºC and 300 ºC, respectively, in the catalytic filter medium and honeycomb reactor. The results also show that there are three sections in NO conversion variation versus changing temperature and the required conversion with a maximum of almost 87% and low level of ammonia slip can be achieved at the NH3/NO ratio of 1 and temperature range of 240–360 ºC in both reactors.

  9. SELECTIVE CATALYTIC REDUCTION (SCR) OF NO BY AMMONIA OVER V2O5/TiO2 CATALYST IN A CATALYTIC FILTER MEDIUM AND HONEYCOMB REACTOR: A KINETIC MODELING STUDY

    OpenAIRE

    M. Nahavandi

    2015-01-01

    Abstract The present study addresses a numerical modeling and simulation based on the available knowledge of SCR kinetics for prediction of NO conversion over a V2O3/TiO3 catalyst through a catalytic filter medium and honeycomb reactor. After introducing the NH3-SCR system with specific operational criteria, a reactor model was developed to evaluate the effect of various operating parameters such as flue gas temperature, velocity, NH3/NO molar ratio, etc., on the SCR process. Computational in...

  10. Start-up of membrane bioreactor and hybrid moving bed biofilm reactor-membrane bioreactor: kinetic study.

    Science.gov (United States)

    Leyva-Díaz, J C; Poyatos, J M

    2015-01-01

    A hybrid moving bed biofilm reactor-membrane bioreactor (hybrid MBBR-MBR) system was studied as an alternative solution to conventional activated sludge processes and membrane bioreactors. This paper shows the results obtained from three laboratory-scale wastewater treatment plants working in parallel in the start-up and steady states. The first wastewater treatment plant was a MBR, the second one was a hybrid MBBR-MBR system containing carriers both in anoxic and aerobic zones of the bioreactor (hybrid MBBR-MBRa), and the last one was a hybrid MBBR-MBR system which contained carriers only in the aerobic zone (hybrid MBBR-MBRb). The reactors operated with a hydraulic retention time of 30.40 h. A kinetic study for characterizing heterotrophic biomass was carried out and organic matter and nutrients removals were evaluated. The heterotrophic biomass of the hybrid MBBR-MBRb showed the best kinetic performance in the steady state, with yield coefficient for heterotrophic biomass=0.30246 mg volatile suspended solids per mg chemical oxygen demand, maximum specific growth rate for heterotrophic biomass=0.00308 h(-1) and half-saturation coefficient for organic matter=3.54908 mg O2 L(-1). The removal of organic matter was supported by the kinetic study of heterotrophic biomass.

  11. Removal of estrogenic compounds from filtered secondary wastewater effluent in a continuous enzymatic membrane reactor. Identification of biotransformation products.

    Science.gov (United States)

    Lloret, Lucia; Eibes, Gemma; Moreira, M Teresa; Feijoo, Gumersindo; Lema, Juan M

    2013-05-07

    In the present study, a novel and efficient technology based on the use of an oxidative enzyme was developed to perform the continuous removal of estrogenic compounds from polluted wastewaters. A 2 L enzymatic membrane reactor (EMR) was successfully operated for 100 h with minimal requirements of laccase for the transformation of estrone (E1), 17β-estradiol (E2), and 17α-ethinylestradiol (EE2)from both buffer solution and real wastewater (filtered secondary effluent). When the experiments were performed at high and low concentrations of the target compounds, 4 mg/L and 100 μg/L, not only high removal yields (80-100%) but also outstanding reduction of estrogenicity (about 84-95%) were attained. When the EMR was applied for the treatment of municipal wastewaters with real environmental concentrations of the different compounds (0.29-1.52 ng/L), excellent results were also achieved indicating the high efficiency and potential of the enzymatic reactor system. A second goal of this study relied on the identification of the transformation products to elucidate the catalytic mechanism of estrogens' transformation by laccase. The formation of dimers and trimers of E1, E2, and EE2, as well as the decomposition of E2 into E1 by laccase-catalyzed treatment, has been demonstrated by liquid chromatography atmospheric pressure chemical ionization (LC-APCI) analysis and confirmed by determination of accurate masses through liquid chromatography electrospray time-of-flight mass spectrometry (LC-ESI-TOF). Dimeric products of E2 and EE2 were found even when operating at environmental concentrations. Moreover, the reaction pathways of laccase-catalyzed transformation of E2 were proposed.

  12. Oxygen transport membrane reactor based method and system for generating electric power

    Science.gov (United States)

    Kelly, Sean M.; Chakravarti, Shrikar; Li, Juan

    2017-02-07

    A carbon capture enabled system and method for generating electric power and/or fuel from methane containing sources using oxygen transport membranes by first converting the methane containing feed gas into a high pressure synthesis gas. Then, in one configuration the synthesis gas is combusted in oxy-combustion mode in oxygen transport membranes based boiler reactor operating at a pressure at least twice that of ambient pressure and the heat generated heats steam in thermally coupled steam generation tubes within the boiler reactor; the steam is expanded in steam turbine to generate power; and the carbon dioxide rich effluent leaving the boiler reactor is processed to isolate carbon. In another configuration the synthesis gas is further treated in a gas conditioning system configured for carbon capture in a pre-combustion mode using water gas shift reactors and acid gas removal units to produce hydrogen or hydrogen-rich fuel gas that fuels an integrated gas turbine and steam turbine system to generate power. The disclosed method and system can also be adapted to integrate with coal gasification systems to produce power from both coal and methane containing sources with greater than 90% carbon isolation.

  13. Evaluation of heat transfer in a catalytic fixed bed reactor at high temperatures

    Directory of Open Access Journals (Sweden)

    JORGE L. M. M.

    1999-01-01

    Full Text Available Experimental results of fixed-bed heat-transfer experiments with no chemical reaction are presented and discussed. The runs were carried out in a tubular integral reactor heated by an electrical furnace at temperatures in the range of 100 to 500°C. Experimental temperature profiles were determined for the electrical furnace, for the reactor wall, and for the fixed bed center. Industrial catalyst for the prereforming of hydrocarbons was employed as the packing material. The effects of process conditions (furnace temperature, gas flow rate on the heat-transfer coefficients were evaluated. The experimental results were analyzed in terms of the external, wall, and internal thermal resistances, associated in series, and compared with model predictions. Under the conditions studied, the overall coefficient was mostly a function of the external effective heat-transfer coefficient. An alternative data treatment was proposed to determine the internal heat-transfer coefficient in fixed beds when wall temperature is not constant.

  14. Oxidative pyrolysis of polystyrene into styrene monomers in an autothermal fixed-bed catalytic reactor.

    Science.gov (United States)

    Sun, Hui; Rosenthal, Corey; Schmidt, Lanny D

    2012-10-01

    Styrene monomer recovery: A selective stream of styrene from fast pyrolysis of polystyrene is obtained with an autothermal fixed-bed reactor containing noble-metal (Rh, Pt) catalysts. Autothermal fast pyrolysis of polystyrene is an efficient means of recovering monomers from waste polystyrene in a continuous, high-throughput process without external heating. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Catalytic Ionic-Liquid Membranes: The Convergence of Ionic-Liquid Catalysis and Ionic-Liquid Membrane Separation Technologies.

    Czech Academy of Sciences Publication Activity Database

    Izák, Pavel; Bobbink, F.D.; Hulla, M.; Klepic, M.; Friess, K.; Hovorka, Š.; Dyson, P.J.

    2018-01-01

    Roč. 83, č. 1 (2018), s. 7-18 ISSN 2192-6506 R&D Projects: GA ČR(CZ) GA17-00089S; GA ČR GA17-05421S Institutional support: RVO:67985858 Keywords : heterogeneous catalysis * ionic liquids * membranes Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 2.797, year: 2016

  16. Catalytic Ionic-Liquid Membranes: The Convergence of Ionic-Liquid Catalysis and Ionic-Liquid Membrane Separation Technologies.

    Czech Academy of Sciences Publication Activity Database

    Izák, Pavel; Bobbink, F.D.; Hulla, M.; Klepic, M.; Friess, K.; Hovorka, Š.; Dyson, P.J.

    2018-01-01

    Roč. 83, č. 1 (2018), s. 7-18 ISSN 2192-6506 R&D Projects: GA ČR(CZ) GA17-00089S; GA ČR GA17-05421S Institutional support: RVO:67985858 Keywords : heterogeneous catalysis * ionic liquid s * membranes Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 2.797, year: 2016

  17. Coordination kinetics of different metal ions with the amidoximated polyacrylonitrile nanofibrous membranes and catalytic behaviors of their complexes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fu; Dong, Yong Chun; Kang, Wei Min; Cheng, Bowen; Qu, Xiang; Cui, Guixin [School of Textiles, Tianjin Polytechnic University, Tianjin (China)

    2016-12-15

    Two transition metal ions (Fe{sup 3+} and Cu{sup 2+}) and a rare earth metal ion (Ce{sup 3+}) were selected to coordinate with amidoximated polyacrylonitrile (PAN) nanofibrous membrane for preparing three metal modified PAN nanofibrous membrane complexes (M-AO-n-PANs, M = Fe, Cu, or Ce) as the heterogeneous Fenton catalysts for the dye degradation in water under visible irradiation. The coordination kinetics of three metal ions with modified PAN nanofibrous membranes was studied and the catalytic properties of the resulting complexes were also compared. The results indicated that increasing metal ion concentrations in solution or higher coordination temperature led to a significant increase in metal content, particularly in Fe and Cu contents of the complexes. Their coordination process could be described using Langmuir isotherm and pseudo-second-order kinetic equations. Moreover, Fe-AO-n-PAN had the best photocatalytic efficiency for the dye degradation in acidic medium, but a lower photocatalytic activity than Cu-AO-n-PAN in alkali medium.

  18. Using ceramic membranes for the separation of hydrogen produced by dehydrogenation of perhydro- m-terphenyl

    Science.gov (United States)

    Kalenchuk, A. N.; Bogdan, V. I.; Kustov, L. M.

    2015-01-01

    The efficiency of a variety of ceramic membranes for the purification of hydrogen obtained by dehydrogenation of perhydro- m-terphenyl in a catalytic flow reactor from vapors of initial hydrocarbons and dehydrogenation products is investigated.

  19. Application of Forward Osmosis Membrane in a Sequential Batch Reactor for Water Reuse

    KAUST Repository

    Li, Qingyu

    2011-07-01

    Forward osmosis (FO) is a novel membrane process that potentially can be used as an energy-saving alternative to conventional membrane processes. The objective of this study is to investigate the performance of a FO membrane to draw water from wastewater using seawater as draw solution. A study on a novel osmotic sequential batch reactor (OsSBR) was explored. In this system, a plate and frame FO cell including two flat-sheet FO membranes was submerged in a bioreactor treating the wastewater. We found it feasible to treat the wastewater by the OsSBR process. The DOC removal rate was 98.55%. Total nitrogen removal was 62.4% with nitrate, nitrite and ammonium removals of 58.4%, 96.2% and 88.4% respectively. Phosphate removal was almost 100%. In this OsSBR system, the 15-hour average flux for a virgin membrane with air scouring is 3.103 LMH. After operation of 3 months, the average flux of a fouled membrane is 2.390 LMH with air scouring (23% flux decline). Air scouring can help to remove the loose foulants on the active layer, thus helping to maintain the flux. Cleaning of the FO membrane fouled in the active layer was probably not effective under the conditions of immersing the membrane in the bioreactor. LC-OCD results show that the FO membrane has a very good performance in rejecting biopolymers, humics and building blocks, but a limited ability in rejecting low molecular weight neutrals.

  20. Mitigation of Cr(VI) toxicity using Pd-nanoparticles immobilized catalytic reactor (Pd-NICaR) fabricated via plasma and gamma radiation.

    Science.gov (United States)

    Misra, Nilanjal; Kumar, Virendra; Rawat, Swarnima; Goel, Narender Kumar; Shelkar, Shubhangi A; Jagannath; Singhal, Rakesh Kumar; Varshney, Lalit

    2018-03-28

    Catalytic reduction of Cr(VI) to less toxic Cr(III) form using metal nanoparticles is one of the novel approaches adopted to deal with Cr toxicity. In this work, we report the fabrication of a facile, reusable, and robust Pd nanoparticles-immobilized catalytic reactor (Pd-NICaR) system using green, environment-friendly gamma radiolytic, and plasma polymerization processes. A room temperature, RF-powered plasma polymerization process was employed to functionalize a polyethylene-polypropylene (PE-PP) non-woven matrix with epoxy group containing monomer 2,3-epoxypropyl methacrylate (EPMA). EPMA-functionalized PE-PP (EPMA-f-PE-PP) substrate was subsequently used as a template for in situ generation and immobilization of Pd NPs via gamma radiolytic route. The samples were characterized using FTIR, SEM, XPS, and XRF techniques. The catalytic efficacy of Pd-NICaR towards Cr(VI) reduction, in the presence of formic acid (FA) as a reductant, was investigated spectrophotometrically, and reaction parameters were optimized at reaction temperature of 50 °C and [FA]/[Cr(VI)] = 680 to achieve catalytic reduction efficiency of 99.7% within 10 min in batch process. The system showed excellent reusability (~ 20 cycles) and storage stability (> 30 days) without substantial loss (~ 11%) of activity. Practical applicability of the robust catalytic system towards Cr(VI) toxicity mitigation was established in continuous flow mode using a fixed-bed column reactor.

  1. Development of a membrane-assisted fluidized bed reactor - 2 - Experimental demonstration and modeling for the partial oxidation of methanol

    NARCIS (Netherlands)

    Deshmukh, S.A.R.K.; Laverman, J.A.; van Sint Annaland, M.; Kuipers, J.A.M.

    2005-01-01

    A small laboratory-scale membrane-assisted fluidized bed reactor (MAFBR) was constructed in order to experimentally demonstrate the reactor concept for the partial oxidation of methanol to formaldehyde. Methanol conversion and product selectivities were measured at various overall fluidization

  2. Photocatalytic Membrane Reactors (PMRs in Water Treatment: Configurations and Influencing Factors

    Directory of Open Access Journals (Sweden)

    Xiang Zheng

    2017-07-01

    Full Text Available The lack of access to clean water remains a severe issue all over the world. Coupling photocatalysis with the membrane separation process, which is known as a photocatalytic membrane reactor (PMR, is promising for water treatment. PMR has developed rapidly during the last few years, and this paper presents an overview of the progress in the configuration and operational parameters of PMRs. Two main configurations of PMRs (PMRs with immobilized photocatalyst; PMRs with suspended photocatalyst are comprehensively described and characterized. Various influencing factors on the performance of PMRs, including photocatalyst, light source, water quality, aeration and membrane, are detailed. Moreover, a discussion on the current problems and development prospects of PMRs for practical application are presented.

  3. Impedance Spectroscopy and Catalytic Activity Characterization of a La0.85Sr0.15MnO3/Ce0.9Gd0.1O1.95 Electrochemical Reactor for the Oxidation of Propene

    DEFF Research Database (Denmark)

    Ippolito, Davide; Kammer Hansen, Kent

    2014-01-01

    This study aims to characterize the catalytic and electrochemical behavior of a La0.85Sr0.15MnO3/Ce0.9Gd0.1O1.95 porous reactor for the oxidation of propene in the presence of oxygen. The application of anodic polarization strongly increased the propene oxidation rate up to 71 %, although...... the current efficiency remained low. The effect of prolonged polarization on the reactor catalytic activity was evaluated. Prolonged polarization enhanced both the reactor intrinsic catalytic activity and the electrode performance due to the formation of oxygen vacancies on the electrode surface...

  4. Modelling of a reverse flow catalytic membrane reactor for the partial oxidation of methane

    NARCIS (Netherlands)

    Smit, J.; van Sint Annaland, M.; Kuipers, J.A.M.

    2003-01-01

    Gas-To-Liquid (GTL) processes have great potential as alternative to conventional oil and coal processing for the production of liquid fuels. In GTL-processes the partial oxidation of methane (POM) is combined with the Fischer-Tropsch reaction. An important part of the investment costs of a

  5. Advanced treatment of biologically pretreated coal gasification wastewater by a novel integration of catalytic ultrasound oxidation and membrane bioreactor.

    Science.gov (United States)

    Jia, Shengyong; Han, Hongjun; Zhuang, Haifeng; Xu, Peng; Hou, Baolin

    2015-01-01

    Laboratorial scale experiments were conducted to investigate a novel system integrating catalytic ultrasound oxidation (CUO) with membrane bioreactor (CUO-MBR) on advanced treatment of biologically pretreated coal gasification wastewater. Results indicated that CUO with catalyst of FeOx/SBAC (sewage sludge based activated carbon (SBAC) which loaded Fe oxides) represented high efficiencies in eliminating TOC as well as improving the biodegradability. The integrated CUO-MBR system with low energy intensity and high frequency was more effective in eliminating COD, BOD5, TOC and reducing transmembrane pressure than either conventional MBR or ultrasound oxidation integrated MBR. The enhanced hydroxyl radical oxidation, facilitation of substrate diffusion and improvement of cell enzyme secretion were the mechanisms for CUO-MBR performance. Therefore, the integrated CUO-MBR was the promising technology for advanced treatment in engineering applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Pure hydrogen production via autothermal reforming of ethanol in a fluidized bed membrane reactor: A simulation study

    NARCIS (Netherlands)

    Gallucci, F.; van Sint Annaland, M.; Kuipers, J.A.M.

    2010-01-01

    In this paper the production of ultra-pure hydrogen via autothermal reforming of ethanol in a fluidized bed membrane reactor has been studied. The heat needed for the steam reforming of ethanol is obtained by burning part of the hydrogen recovered via the hydrogen perm-selective membrane thereby

  7. Membrane-aerated biofilm reactor for the removal of 1,2-dichloroethane by Pseudomonas sp strain DCA1

    NARCIS (Netherlands)

    Hage, J.C.; Houten, R.T.; Tramper, J.; Hartmans, S.

    2004-01-01

    A membrane-aerated biofilm reactor (MBR) with a biofilm of Pseudomonas sp. strain DCA1 was studied for the removal of 1,2-dichloroethane (DCA) from water. A hydrophobic membrane was used to create a barrier between the liquid and the gas phase. Inoculation of the MBR with cells of strain DCA1 grown

  8. Inorganic Nanoparticles/Metal Organic Framework Hybrid Membrane Reactors for Efficient Photocatalytic Conversion of CO2.

    Science.gov (United States)

    Maina, James W; Schütz, Jürg A; Grundy, Luke; Des Ligneris, Elise; Yi, Zhifeng; Kong, Lingxue; Pozo-Gonzalo, Cristina; Ionescu, Mihail; Dumée, Ludovic F

    2017-10-11

    Photocatalytic conversion of carbon dioxide (CO 2 ) to useful products has potential to address the adverse environmental impact of global warming. However, most photocatalysts used to date exhibit limited catalytic performance, due to poor CO 2 adsorption capacity, inability to efficiently generate photoexcited electrons, and/or poor transfer of the photogenerated electrons to CO 2 molecules adsorbed on the catalyst surface. The integration of inorganic semiconductor nanoparticles across metal organic framework (MOF) materials has potential to yield new hybrid materials, combining the high CO 2 adsorption capacity of MOF and the ability of the semiconductor nanoparticles to generate photoexcited electrons. Herein, controlled encapsulation of TiO 2 and Cu-TiO 2 nanoparticles within zeolitic imidazolate framework (ZIF-8) membranes was successfully accomplished, using rapid thermal deposition (RTD), and their photocatalytic efficiency toward CO 2 conversion was investigated under UV irradiation. Methanol and carbon monoxide (CO) were found to be the only products of the CO 2 reduction, with yields strongly dependent upon the content and composition of the dopant semiconductor particles. CuTiO 2 nanoparticle doped membranes exhibited the best photocatalytic performance, with 7 μg of the semiconductor nanoparticle enhancing CO yield of the pristine ZIF-8 membrane by 233%, and methanol yield by 70%. This work opens new routes for the fabrication of hybrid membranes containing inorganic nanoparticles and MOFs, with potential application not only in catalysis but also in electrochemical, separation, and sensing applications.

  9. Mussel-inspired co-deposition to enhance bisphenol A removal in a bifacial enzymatic membrane reactor

    DEFF Research Database (Denmark)

    Cao, Xiaotong; Luo, Jianquan; Woodley, John M.

    2018-01-01

    were used as the matrix to further exploit the potential of the biocatalytic membranes. such prepared biocatalytic membranes were enzymatically active on both sides, making it possible to construct a bifacial enzymatic membrane reactor (EMR) for highly efficient micro-pollutants removal (taking....... The BPA removal efficiency was highest for the EMR with the PDA/Cu2+ coated membrane attributed to copper-enhanced electron transfer, while it was lowest for the EMR with the PDA/PEI coated membrane due to the high diffusional resistance of the dense PDA/PEI layer. Meanwhile, the mechanism for performance...... transfer improved the substrate accessibility to enzyme together with products removal....

  10. A novel ion transport membrane reactor for fundamental investigations of oxygen permeation and oxy-combustion under reactive flow conditions

    KAUST Repository

    Kirchen, Patrick

    2013-01-01

    Ion transport membrane (ITM) reactors present an attractive technology for combined air separation and fuel conversion in applications such as syngas production, oxidative coupling or oxy-combustion, with the promise of lower capital and operating costs, as well higher product selectivities than traditional technologies. The oxygen permeation rate through a given ITM is defined by the membrane temperature and oxygen chemical potential difference across it. Both of these parameters can be strongly influenced by thermochemical reactions occurring in the vicinity of the membrane, though in the literature they are often characterized in terms of the well mixed product stream at the reactor exit. This work presents the development of a novel ITM reactor for the fundamental investigation of the coupling between fuel conversion and oxygen permeation under well defined fluid dynamic and thermodynamic conditions, including provisions for spatially resolved, in-situ investigations. A planar, finite gap stagnation flow reactor with optical and probe access to the reaction zone is used to facilitate in-situ measurements and cross-validation with detailed numerical simulations. Using this novel reactor, baseline measurements are presented to elucidate the impact of the sweep gas fuel (CH4) fraction on the oxygen permeation and fuel conversion. In addition, the difference between well-mixed gas compositions measured at the reactor outlet and those measured in the vicinity of the membrane surface are discussed, demonstrating the unique utility of the reactor. © 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

  11. Removal of diatrizoate with catalytically active membranes incorporating microbially produced palladium nanoparticles.

    Science.gov (United States)

    Hennebel, Tom; De Corte, Simon; Vanhaecke, Lynn; Vanherck, Katrien; Forrez, Ilse; De Gusseme, Bart; Verhagen, Pieter; Verbeken, Kim; Van der Bruggen, Bart; Vankelecom, Ivo; Boon, Nico; Verstraete, Willy

    2010-03-01

    There is an increasing concern about the fate of iodinated contrast media (ICM) in the environment. Limited removal efficiencies of currently applied techniques such as advanced oxidation processes require more performant strategies. The aim of this study was to establish an innovative degradation process for diatrizoate, a highly recalcitrant ICM, by using biogenic Pd nanoparticles as free suspension or immobilized in polyvinylidene fluoride (PVDF) and polysulfone (PSf) membranes. As measured by HPLC-UV, the removal of 20mg L(-1) diatrizoate by a 10mg L(-1) Pd suspension was completed after 4h at a pH of 10. LC-MS analysis provided evidence for the sequential hydrodeiodination of diatrizoate. Pd did not lose its activity after incorporation in the PVDF and PSf matrix and the highest activity (k(cat)=30.0+/-0.4h(-1) L g(-1) Pd) was obtained with a casting solution of 10% PSf and 500mg L(-1) Pd. Subsequently, water containing 20mg L(-1) diatrizoate was treated in a membrane contactor, in which the water was supplied at one side of the membrane while hydrogen was provided at the other side. In a fed batch configuration, a removal efficiency of 77% after a time period of 48h was obtained. This work showed that membrane contactors with encapsulated biogenic nanoparticles can be instrumental for treatment of water contaminated with diatrizoate. Copyright 2009 Elsevier Ltd. All rights reserved.

  12. Production of Biodiesel Using a Membrane Reactor to Minimize Separation Cost

    Science.gov (United States)

    Olagunju, O. A.; Musonge, P.

    2017-07-01

    This study investigates the performance of a packed bed membrane reactor in the transesterification process of triglycerides to methyl ester using soyabean oil as feedstock. A TiO2/Al2O3 ceramic microporous membrane was selected due to its chemical inert nature and thermal stability to selectively remove the product from the reaction medium. CaO impregnated on the surface of activated carbon was packed into the membrane and acted as catalyst. The synthesized catalyst had a total loading of 40.50 % and was characterized by XRD and temperature-programmed desorption of CO2 (CO2-TPD). The crude biodiesel produced was micro-filtered by the ceramic membrane with a pore size of 0.02 μm to retain the unreacted oil and free glycerol, at the transmembrane pressure of 100 KPa. The best condition was achieved with a temperature of 65 °C, methanol/oil molar ratio of 6:1 for 150 minutes, which resulted in the highest FAME yield of 94 %. Methyl ester produced met the ASTM D6751 and SANS 1935 specifications. The product obtained was mainly composed of methyl esters. Glycerol was not detected in the product stream due to the ability of the membrane to retain the glycerol and the unreacted oil in the medium, which solved the issue of glycerol separation from biodiesel.

  13. Enhancement of operating flux in a membrane bio-reactor coupled with a mechanical sieve unit.

    Science.gov (United States)

    Park, Seongjun; Yeon, Kyung-Min; Moon, Seheum; Kim, Jong-Oh

    2018-01-01

    Filtration flux is one of the key factors in regulating the performance of membrane bio-reactors (MBRs) for wastewater treatment. In this study, we explore the effectiveness of a mechanical sieve unit for effective flux enhancement through retardation of the fouling effect in a modified MBR system (SiMBR). In brief, the coarse sieve unit having 100 μm and 50 μm permits small size microorganism flocs to adjust the biomass concentration from the suspended basin to the membrane basin. As a result, the reduced biofouling effect due to the lowered biomass concentration from 7800 mg/L to 2400 mg/L, enables higher flux through the membrane. Biomass rejection rate of the sieve is identified to be the crucial design parameter for the flux enhancement through the incorporation of numerical simulations and operating critical-flux measurement in a batch reactor. Then, the sieve unit is prepared for 10 L lab-scale continuous SiMBR based on the correlation between sieve pore size and biomass rejection characteristics. During continuous operation of lab-scale SiMBR, biomass concentration is maintained with a higher biomass concentration in the aerobic basin (7400 mg/L) than that in the membrane basin (2400 mg/L). In addition, the SiMBR operations are conducted using three different commercial hollow fiber membranes to compare the permeability to that of conventional MBR operations. For all cases, the modified MBR having a sieve unit clearly results in enhanced permeability. These results successfully validate that SiMBR can effectively improve flux through direct reduction of biomass concentration. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. The different paths and potential risks of photo(-electro)-catalytic degradation for rhodamine B in water by graphene/TiO2membrane.

    Science.gov (United States)

    Ren, Miao; Liu, Haiyang; Qu, Jiao; Zhang, Yanan; Ma, Ying; Yuan, Xing

    2018-03-07

    The graphene (GR)/TiO 2 membrane was prepared by the sol-gel method and coated on the indium tin oxide (ITO) conductive glass, which showed high and stable photo(-electro)-catalytic activities to rhodamine B (Rh-B) in water. Characterization results showed that the GR was dispersed and wrapped in the needle-like TiO 2 . With GR/TiO 2 membrane and simulated sunlight irradiation, the removal efficiency of Rh-B (10 mg l -1 and pH at 5.4) arrived at 87.6% within 300 min. However, the higher removal efficiency for Rh-B reached to 97.8% by the photo-electro-catalytic degradation with the applied voltage 4 v for 30 min. The ·OH that generated in the photo-catalytic degradation process were responsible for Rh-B decomposition. The ·O 2 - played the significant role in the photo-electro-catalytic degradation of Rh-B. Furthermore, the decarboxylation was also occurred in the photo-electro-catalytic degradation for the Rh-B in water except for the deethylation and hydroxylation in the photo-catalytic degradation. In addition, the toxicities of the intermediates were calculated using the ECOSAR program and the EPIWIN software. The results indicated that the toxicities of intermediates from photo-electro-catalytic degradation for the Rh-B were higher than photo-catalytic degradation, due to the generation of decarboxylate.

  15. Mathematical Modelling of Catalytic Fixed-Bed Reactor for Carbon Dioxide Reforming of Methane over Rh/Al2O3 Catalyst

    Directory of Open Access Journals (Sweden)

    New Pei Yee

    2008-04-01

    Full Text Available A one-dimensional mathematical model was developed to simulate the performance of catalytic fixed bedreactor for carbon dioxide reforming of methane over Rh/Al2O3 catalyst at atmospheric pressure. The reactionsinvolved in the system are carbon dioxide reforming of methane (CORM and reverse water gas shiftreaction (RWGS. The profiles of CH4 and CO2 conversions, CO and H2 yields, molar flow rate and molefraction of all species as well as reactor temperature along the axial bed of catalyst were simulated. In addition,the effects of different reactor temperature on the reactor performance were also studied. The modelscan also be applied to analyze the performances of lab-scale micro reactor as well as pilot-plant scale reactorwith certain modifications and model verification with experimental data. © 2008 BCREC UNDIP. All rights reserved.[Received: 20 August 2008; Accepted: 25 September 2008][How to Cite: N.A.S. Amin, I. Istadi, N.P. Yee. (2008. Mathematical Modelling of Catalytic Fixed-Bed Reactor for Carbon Dioxide Reforming of Methane over Rh/Al2O3 Catalyst. Bulletin of Chemical Reaction Engineering and Catalysis, 3 (1-3: 21-29. doi:10.9767/bcrec.3.1-3.19.21-29

  16. Drinking water treatment using a submerged internal-circulation membrane coagulation reactor coupled with permanganate oxidation.

    Science.gov (United States)

    Zhang, Zhongguo; Liu, Dan; Qian, Yu; Wu, Yue; He, Peiran; Liang, Shuang; Fu, Xiaozheng; Li, Jiding; Ye, Changqing

    2017-06-01

    A submerged internal circulating membrane coagulation reactor (MCR) was used to treat surface water to produce drinking water. Polyaluminum chloride (PACl) was used as coagulant, and a hydrophilic polyvinylidene fluoride (PVDF) submerged hollow fiber microfiltration membrane was employed. The influences of trans-membrane pressure (TMP), zeta potential (ZP) of the suspended particles in raw water, and KMnO 4 dosing on water flux and the removal of turbidity and organic matter were systematically investigated. Continuous bench-scale experiments showed that the permeate quality of the MCR satisfied the requirement for a centralized water supply, according to the Standards for Drinking Water Quality of China (GB 5749-2006), as evaluated by turbidity (water flux, the removal of turbidity, TOC and dissolved organic carbon (DOC) in the raw water also increased with increasing TMP in the range of 0.01-0.05MPa. High ZP induced by PACl, such as 5-9mV, led to an increase in the number of fine and total particles in the MCR, and consequently caused serious membrane fouling and high permeate turbidity. However, the removal of TOC and DOC increased with increasing ZP. A slightly positive ZP, such as 1-2mV, corresponding to charge neutralization coagulation, was favorable for membrane fouling control. Moreover, dosing with KMnO 4 could further improve the removal of turbidity and DOC, thereby mitigating membrane fouling. The results are helpful for the application of the MCR in producing drinking water and also beneficial to the research and application of other coagulation and membrane separation hybrid processes. Copyright © 2016. Published by Elsevier B.V.

  17. Catalytic, Conductive Bipolar Membrane Interfaces through Layer-by-Layer Deposition for the Design of Membrane-Integrated Artificial Photosynthesis Systems.

    Science.gov (United States)

    McDonald, Michael B; Freund, Michael S; Hammond, Paula T

    2017-11-23

    In the presence of an electric field, bipolar membranes (BPMs) are capable of initiating water disassociation (WD) within the interfacial region, which can make water splitting for renewable energy in the presence of a pH gradient possible. In addition to WD catalytic efficiency, there is also the need for electronic conductivity in this region for membrane-integrated artificial photosynthesis (AP) systems. Graphene oxide (GO) was shown to catalyze WD and to be controllably reduced, which resulted in electronic conductivity. Layer-by-layer (LbL) film deposition was employed to improve GO film uniformity in the interfacial region to enhance WD catalysis and, through the addition of a conducting polymer in the process, add electronic conductivity in a hybrid film. Three different deposition methods were tested to optimize conducting polymer synthesis with the oxidant in a metastable solution and to yield the best film properties. It was found that an approach that included substrate dipping in a solution containing the expected final monomer/oxidant ratio provided the most predictable film growth and smoothest films (by UV/Vis spectroscopy and atomic force microscopy/scanning electron microscopy, respectively), whereas dipping in excess oxidant or co-spraying the oxidant and monomer produced heterogeneous films. Optimized films were found to be electronically conductive and produced a membrane ohmic drop that was acceptable for AP applications. Films were integrated into the interfacial region of BPMs and revealed superior WD efficiency (≥1.4 V at 10 mA cm -2 ) for thinner films (<10 bilayers≈100 nm) than for either the pure GO catalyst or conducting polymer individually, which indicated that there was a synergistic effect between these materials in the structure configured by the LbL method. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Interdisciplinary study of the influence on effectiveness of catalytic hydrogen recombiners of operating conditions in the reactor containment

    International Nuclear Information System (INIS)

    Kelm, S.; Reinecke, E.A.; Schoppe, L.; Dornseiffer, J.; Leistner, F.; Juehe, S.

    2008-01-01

    At the Emsland nuclear power station, a total of 58 autocatalytic hydrogen recombiners were backfitted in 1999 as an additional measure of risk reduction in connection with major hydrogen releases after events going beyond the design basis. Annual in-service inspections after 2002 revealed that some of the catalyst sheets developed startup delays and marked evolutions of smoke and smell. Recombiners not meeting the inspection criterion were completely regenerated as a measure of precaution. A preventive study was conducted jointly with institutes of the Juelich Research Center and the Aachen Technical University to analyze the composition of the deposits, which was then compared with the chemical characteristics of potential sources in the reactor containment. At the same time, the influence on effectiveness of the catalyst sheets was examined. On the basis of a random evaluation of the in-service inspection logs of the past few years, representative samples were taken whose startup behavior and operating characteristics were studied in a test rig alongside chemical analyses so as to allow a correlation to be established between the analytical findings and the catalytic activity of the samples. The findings made allowed internal sources of the catalyst deposits to be excluded. The impurities are introduced with the outside air. As a consequence, the air ducts in the vicinity of the respective recombiners were inspected and optimization steps were taken in connection with in-service inspections and regeneration procedures. (orig.)

  19. Membrane chemical reactor (MCR) combining photocatalysis and microfiltration for grey water treatment.

    Science.gov (United States)

    Rivero, M J; Parsons, S A; Jeffrey, P; Pidou, M; Jefferson, B

    2006-01-01

    Urban water recycling is now becoming an important issue where water resources are becoming scarce. This paper looks at reusing grey water; the preference is treatment processes based on biological systems to remove the dissolved organic content. Here, an alternative process, photocatalysis is discussed as it is an attractive technology that could be well-suited for treating the recalcitrant organic compounds found in grey water. The photocatalytic process oxidises organic reactants at a catalyst surface in the presence of ultraviolet light. Given enough exposure time, organic compounds will be oxidized into CO2 and water. The best contact is achieved in a slurry reactor but a second step to separate and recover the catalyst is need. This paper discusses a new membrane chemical reactor (MCR) combining photocatalysis and microfiltration for grey water treatment.

  20. Effect of Catalyst Pellet-Diameter and Basicity on Transesterification of Soybean Oil into Biodiesel using K2O/CaO-ZnO Catalyst over Hybrid Catalytic-Plasma Reactor

    OpenAIRE

    Istadi I.; Buchori Luqman; Putri Brigitta B.T.; Hantara Henrikus I.A.

    2018-01-01

    This research is aimed to study the effect of catalyst pellet-diameter and catalyst basicity on the transesterification process of soybean oil into biodiesel over a hybrid catalytic-plasma reactor. Various catalyst diameters (3, 5, and 7 mm) were tested in this reaction system. Catalyst basicity was also examined by comparing fresh and used catalyst as well as with and without K2O promoter. All catalysts testing were performed in a hybrid plasma-catalytic reactor (dielectric barrier discharge...

  1. Enzymatic cleaning of biofouled thin-film composite reverse osmosis (RO) membrane operated in a biofilm membrane reactor.

    Science.gov (United States)

    Khan, Mohiuddin; Danielsen, Steffen; Johansen, Katja; Lorenz, Lindsey; Nelson, Sara; Camper, Anne

    2014-02-01

    Application of environmentally friendly enzymes to remove thin-film composite (TFC) reverse osmosis (RO) membrane biofoulants without changing the physico-chemical properties of the RO surface is a challenging and new concept. Eight enzymes from Novozyme A/S were tested using a commercially available biofouling-resistant TFC polyamide RO membrane (BW30, FilmTech Corporation, Dow Chemical Co.) without filtration in a rotating disk reactor system operated for 58 days. At the end of the operation, the accumulated biofoulants on the TFC RO surfaces were treated with the three best enzymes, Subtilisin protease and lipase; dextranase; and polygalacturonase (PG) based enzymes, at neutral pH (~7) and doses of 50, 100, and 150 ppm. Contact times were 18 and 36 h. Live/dead staining, epifluorescence microscopy measurements, and 5 μm thick cryo-sections of enzyme and physically treated biofouled membranes revealed that Subtilisin protease- and lipase-based enzymes at 100 ppm and 18 h contact time were optimal for removing most of the cells and proteins from the RO surface. Culturable cells inside the biofilm declined by more than five logs even at the lower dose (50 ppm) and shorter incubation period (18 h). Subtilisin protease- and lipase-based enzyme cleaning at 100 ppm and for 18 h contact time restored the hydrophobicity of the TFC RO surface to its virgin condition while physical cleaning alone resulted in a 50° increase in hydrophobicity. Moreover, at this optimum working condition, the Subtilisin protease- and lipase-based enzyme treatment of biofouled RO surface also restored the surface roughness measured with atomic force microscopy and the mass percentage of the chemical compositions on the TFC surface estimated with X-ray photoelectron spectroscopy to its virgin condition. This novel study will encourage the further development and application of enzymes to remove biofoulants on the RO surface without changing its surface properties.

  2. Novel Photocatalytic Membrane Reactor with TiO2 Nanotubes for Azo Dye Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    Wang Ling

    2016-01-01

    Full Text Available Novel photocatalytic membrane reactor (PMR with TiO2 nanotubes (TNTs has been designed and applied in azo dye wastewater treatment. Prepared by hydrothermal method, the TNTs with length of 30–80 nm and diameter of 10 nm had good photocatalytic activity. The result showed that the optimal pH value was 4.5 and catalyst loading of this reaction system was 0.5g/L. The decolorization rate of X-3B with application of TNTs was up to 94.6% after 75min of irradiation. In the combined process, the PES ultrafiltration membrane was adopted to separate and recover the nano catalysts for reuse. The retention rate of TNTs in PMR system reached 100%. All these showed that TNTs photocatalysis integrated with ultrafiltration was capable of removing X-3B dye effectively and simultaneous separating TNTs photocatalysts successfully.

  3. Membrane reactor for water detritiation: a parametric study on operating parameters

    Energy Technology Data Exchange (ETDEWEB)

    Mascarade, J.; Liger, K.; Troulay, M.; Perrais, C. [CEA, DEN, DTN/STPA/LIPC, Centre de Cadarache, Saint-Paul-lez-Durance (France); Joulia, X.; Meyer, X.M. [Universite de Toulouse, INPT, UPS, Laboratoire de Genie Chimique, Toulouse (France); CNRS, Laboratoire de Genie Chimique, Toulouse (France)

    2015-03-15

    This paper presents the results of a parametric study done on a single stage finger-type packed-bed membrane reactor (PBMR) used for heavy water vapor de-deuteration. Parametric studies have been done on 3 operating parameters which are: the membrane temperature, the total feed flow rate and the feed composition through D{sub 2}O content variations. Thanks to mass spectrometer analysis of streams leaving the PBMR, speciation of deuterated species was achieved. Measurement of the amounts of each molecular component allowed the calculation of reaction quotient at the packed-bed outlet. While temperature variation mainly influences permeation efficiency, feed flow rate perturbation reveals dependence of conversion and permeation properties to contact time between catalyst and reacting mixture. The study shows that isotopic exchange reactions occurring on the catalyst particles surface are not thermodynamically balanced. Moreover, the variation of the heavy water content in the feed exhibits competition between permeation and conversion kinetics.

  4. Numerical simulation of ion transport membrane reactors: Oxygen permeation and transport and fuel conversion

    KAUST Repository

    Hong, Jongsup

    2012-07-01

    Ion transport membrane (ITM) based reactors have been suggested as a novel technology for several applications including fuel reforming and oxy-fuel combustion, which integrates air separation and fuel conversion while reducing complexity and the associated energy penalty. To utilize this technology more effectively, it is necessary to develop a better understanding of the fundamental processes of oxygen transport and fuel conversion in the immediate vicinity of the membrane. In this paper, a numerical model that spatially resolves the gas flow, transport and reactions is presented. The model incorporates detailed gas phase chemistry and transport. The model is used to express the oxygen permeation flux in terms of the oxygen concentrations at the membrane surface given data on the bulk concentration, which is necessary for cases when mass transfer limitations on the permeate side are important and for reactive flow modeling. The simulation results show the dependence of oxygen transport and fuel conversion on the geometry and flow parameters including the membrane temperature, feed and sweep gas flow, oxygen concentration in the feed and fuel concentration in the sweep gas. © 2012 Elsevier B.V.

  5. Nuclear Track-Etched Pore Membrane Production Using OAEP's Research Reactor

    International Nuclear Information System (INIS)

    Chittrakarn, Thawat; Bhongsuwan, Tripob; Wanichapichart, Pikul; Nuanuin, Paiboon; Chongkum, Somporn; Khonduangkaew, Areerat; Bordeepong, Sunaree

    2003-10-01

    Result of this study shows that the OAEP's nuclear research reactor is a good source of both fast and thermal neutrons for pore piercing process on polycarbonate thin film. With our experimental design, the fast neutron provides better results in pore piercing comparing with thermal neutron bombardment. This can be explained that most of the latent tracks that occur by thermal neutron bombardment do not piercing through the thin film. Chemical etching process using NaOH solution with an appropriated time, concentration and temperature was employed to enlarge the latent tracks in the bombarded film by fast neutrons. Fast neutron bombardment with 5, 10 and 20 minutes bombarding time successfully produces the nuclear track membrane. Pore size and pore density of the produced membranes examined by SEM were 0.24-1.01 μm and 4.67 - 245 x 10 6 pore/cm 2 , respectively. Bubble point test showed the maximum pore diameter of the produced membrane ranged between 1.18 - 3.25 μm. Water permeability was studied and compared between the produced and commercial membranes

  6. Catalytic hydrogen/oxygen reaction assisted the proton exchange membrane fuel cell (PEMFC) startup at subzero temperature

    Science.gov (United States)

    Sun, Shucheng; Yu, Hongmei; Hou, Junbo; Shao, Zhigang; Yi, Baolian; Ming, Pingwen; Hou, Zhongjun

    Fuel cells for automobile application need to operate in a wide temperature range including freezing temperature. However, the rapid startup of a proton exchange membrane fuel cell (PEMFC) at subfreezing temperature, e.g., -20 °C, is very difficult. A cold-start procedure was developed, which made hydrogen and oxygen react to heat the fuel cell considering that the FC flow channel was the characteristic of microchannel reactor. The effect of hydrogen and oxygen reaction on fuel cell performance at ambient temperature was also investigated. The electrochemical characterizations such as I- V plot and cyclic voltammetry (CV) were performed. The heat generated rate for either the single cell or the stack was calculated. The results showed that the heat generated rate was proportional to the gas flow rate when H 2 concentration and the active area were constant. The fuel cell temperature rose rapidly and steadily by controlling gas flow rate.

  7. A novel water perm-selective membrane dual-type reactor concept for Fischer-Tropsch synthesis of GTL (gas to liquid) technology

    International Nuclear Information System (INIS)

    Rahimpour, M.R.; Mirvakili, A.; Paymooni, K.

    2011-01-01

    The present study proposes a novel configuration of Fischer-Tropsch synthesis (FTS) reactors in which a fixed-bed water perm-selective membrane reactor is followed by a fluidized-bed hydrogen perm-selective membrane reactor. This novel concept which has been named fixed-bed membrane reactor followed by fluidized-bed membrane reactor (FMFMDR) produces gasoline from synthesis gas. The walls of the tubes of a fixed-bed reactor (water-cooled reactor) of FMFMDR configuration are coated by a high water perm-selective membrane layer. In this new configuration, two membrane reactors instead of one membrane reactor are developed for FTS reactions. In other words, two different membrane layers are used. In order to investigate the performance of FMFMDR, a one-dimensional heterogeneous model is taken into consideration. The simulation results of three schemes named fluidized-bed membrane dual-type reactor (FMDR), FMFMDR and conventional fixed-bed reactor (CR) are presented. They have been compared in terms of temperature, gasoline and CO 2 yields, H 2 and CO conversions and the water permeation rate through the membrane layer. Results show that the gasoline yield in FMFMDR is higher than the one in FMDR. The FMFMDR configuration not only decreases the undesired product such as CO 2 but also produces more gasoline. -- Research highlights: → The application of H-SOD membrane layer in FTS reactors. → Approximate 7.5% and 37% increase in the gasoline yield in terms of [g/g feed x 100] in comparison with FMDR and CR, respectively. → A remarkable decrease in CO 2 emission to the environment. → A good configuration mainly due to reduction in catalysts sintering as a result of in situ water removal.

  8. Porous media for catalytic renewable energy conversion

    Science.gov (United States)

    Hotz, Nico

    2012-05-01

    A novel flow-based method is presented to place catalytic nanoparticles into a reactor by sol-gelation of a porous ceramic consisting of copper-based nanoparticles, silica sand, ceramic binder, and a gelation agent. This method allows for the placement of a liquid precursor containing the catalyst into the final reactor geometry without the need of impregnating or coating of a substrate with the catalytic material. The so generated foam-like porous ceramic shows properties highly appropriate for use as catalytic reactor material, e.g., reasonable pressure drop due to its porosity, high thermal and catalytic stability, and excellent catalytic behavior. The catalytic activity of micro-reactors containing this foam-like ceramic is tested in terms of their ability to convert alcoholic biofuel (e.g. methanol) to a hydrogen-rich gas mixture with low concentrations of carbon monoxide (up to 75% hydrogen content and less than 0.2% CO, for the case of methanol). This gas mixture is subsequently used in a low-temperature fuel cell, converting the hydrogen directly to electricity. A low concentration of CO is crucial to avoid poisoning of the fuel cell catalyst. Since conventional Polymer Electrolyte Membrane (PEM) fuel cells require CO concentrations far below 100 ppm and since most methods to reduce the mole fraction of CO (such as Preferential Oxidation or PROX) have CO conversions of up to 99%, the alcohol fuel reformer has to achieve initial CO mole fractions significantly below 1%. The catalyst and the porous ceramic reactor of the present study can successfully fulfill this requirement.

  9. Performance of a palladium membrane reactor using a Ni catalyst for fusion fuel impurities processing

    International Nuclear Information System (INIS)

    Willm, R.S.; Okuno, K.

    1994-01-01

    The palladium membrane reactor (PMR) provides a means to recover hydrogen isotopes from impurities expected to be present in fusion reactor exhaust. This recovery is based on reactions such as water gas shift and steam reforming for which conversion is equilibrium limited. By including a selectively permeable membrane such as Pd/Ag in the catalyst bed, hydrogen isotopes can be removed from the reacting environment, thus promoting the reaction to complete conversion. Such a device has been built and operated at the Tritium Systems Test Assembly (TSTA) at Los Alamos National Laboratory (LANL). For the reactions listed above, earlier study with this unit has shown that hydrogen single-pass recoveries approaching 100% can be achieved. It was also determined that a nickel catalyst is a feasible choice for use with a PMR appropriate for fusion fuel impurities processing. The purpose of this study is to systematically assess the performance of the PMR using a nickel catalyst. Reactions which will be studied include the water gas shift reaction, steam reforming and methane cracking. Extended operation will be performed to detect performance degradation if it exists. The use of methane in these tests may lead to the formation of coke on the catalyst. Methods of removing the coke such as treatment with carbon dioxide or diluted oxygen will be examined

  10. Modelling and sequential simulation of multi-tubular metallic membrane and techno-economics of a hydrogen production process employing thin-layer membrane reactor

    KAUST Repository

    Shafiee, Alireza

    2016-09-24

    A theoretical model for multi-tubular palladium-based membrane is proposed in this paper and validated against experimental data for two different sized membrane modules that operate at high temperatures. The model is used in a sequential simulation format to describe and analyse pure hydrogen and hydrogen binary mixture separations, and then extended to simulate an industrial scale membrane unit. This model is used as a sub-routine within an ASPEN Plus model to simulate a membrane reactor in a steam reforming hydrogen production plant. A techno-economic analysis is then conducted using the validated model for a plant producing 300 TPD of hydrogen. The plant utilises a thin (2.5 μm) defect-free and selective layer (Pd75Ag25 alloy) membrane reactor. The economic sensitivity analysis results show usefulness in finding the optimum operating condition that achieves minimum hydrogen production cost at break-even point. A hydrogen production cost of 1.98 $/kg is estimated while the cost of the thin-layer selective membrane is found to constitute 29% of total process capital cost. These results indicate the competiveness of this thin-layer membrane process against conventional methods of hydrogen production. © 2016 Hydrogen Energy Publications LLC

  11. Enhanced catalytic stability of lipase immobilized on oxidized and disulfide-rich eggshell membrane for esters hydrolysis and transesterification.

    Science.gov (United States)

    Jiang, Chenyu; Cheng, Chuanchuan; Hao, Mei; Wang, Hongbin; Wang, Ziying; Shen, Cai; Cheong, Ling-Zhi

    2017-12-01

    Eggshell membrane (ESM) is an industrial waste that is available in abundance from food industry. Present study investigated the physicochemical properties of oxidized ESM and compared the efficiency of ESM and oxidized ESM as carrier for Burkholderia cepacia lipase (BCL) used in esters hydrolysis and transesterification. Following oxidation treatment, FTIR analysis and Ellman's assay showed amino acid cysteine in ESM was oxidized to form disulfide bond-containing cystine. In addition, AFM analysis showed ESM which exhibited a highly porous filamentous structure appeared to be coalesce following oxidation treatment. Oxidized ESM also showed reduced porosity (38.67%) in comparison to native ESM (51.65%). BCL were successfully immobilized on oxidized ESM through carrier activation method (enzyme loading of 5.01mg protein/g oxidized ESM). These immobilized lipase demonstrated significantly (Ptransesterification (7.83±0.05) activity for at least 10 consecutive runs. Enhanced catalytic stability of BCL immobilized on oxidized ESM might be due to stabilization of the protein structure in oxidized ESM by disulfide bonds which helped formation of a stable bonding with BCL. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Chlorpromazine and dimethyl sulfoxide modulate the catalytic activity of the plasma membrane Ca2+-ATPase from human erythrocyte.

    Science.gov (United States)

    Plenge-Tellechea, Fernando; Domínguez-Solís, Carlos A; Díaz-Sánchez, Ángel G; Meléndez-Martínez, David; Vargas-Medrano, Javier; Sierra-Fonseca, Jorge A

    2018-02-01

    The plasma membrane Ca 2+ -ATPase (PMCA) removes Ca 2+ from the cytosol into the extracellular space. Its catalytic activity can be stimulated by calmodulin (CaM) or by limited proteolysis. We evaluated the effect of chlorpromazine (CPZ) and dimethyl sulfoxide (DMSO) over the hydrolytic activity of PMCA. Activity was monitored in three different forms: native, CaM-activated and proteolyzed by trypsin. CPZ appears to inhibit PMCA without directly interfering with the C-terminal site, since it is affected by CaM and proteolysis. Although the treatment of PMCA with trypsin and CaM produces an activation, it also produces an enzymatic form that is more sensitive to inhibition by CPZ. The same case was observed in the DMSO inhibition experiments. In the absence of CPZ, DMSO produces a progressive loss of activity, but in the presence of CPZ the profile of activity against DMSO changes and produces a recovery of activity, indicating a possible partition of CPZ by the solvent. Increasing Ca 2+ concentrations indicated that CPZ interacts with PMCA rather than with CaM. This observation is supported by docking analysis that suggests that the CPZ-PMCA interaction is non-competitive. We propose that CPZ interacts with the state of lower affinity for Ca 2 + .

  13. Removal of volatile to semi-volatile organic contaminants from water using hollow fiber membrane contactors and catalytic destruction of the contaminants in the gas phase

    OpenAIRE

    Tarafder, Shamsul Abedin

    2007-01-01

    Abstract Chlorinated organic compounds and ether compounds are frequently found in groundwater and efficient treatment options are needed. In this study, the efficient transferal of the compounds from the water phase to the gas phase was studied followed by the catalytic treatment of the gas phase. For the removal of the organic contaminants from water, a microporous polypropylene hollow fiber membrane (HFM) module was operated under low strip gas flow to water flow ratios (_< 5:1). Rem...

  14. System design study of a membrane reforming hydrogen production plant using a small sized sodium cooled reactor

    International Nuclear Information System (INIS)

    Chikazawa, Y.; Konomura, M.; Hori, T.; Sato, H.; Uchida, S.

    2004-01-01

    In this study, a membrane reforming hydrogen production plant using a small sized sodium cooled reactor was designed as one of promising concepts. In the membrane reformer, methane and steam are reformed into carbon dioxide and hydrogen with sodium heat at a temperature 500 deg-C. In the equilibrium condition, steam reforming proceeds with catalyst at a temperature more than 800 deg-C. Using membrane reformers, the steam reforming temperature can be decreased from 800 to 500 deg-C because the hydrogen separation membrane removes hydrogen selectively from catalyst area and the partial pressure of hydrogen is kept much lower than equilibrium condition. In this study, a hydrogen and electric co-production plant has been designed. The reactor thermal output is 375 MW and 25% of the thermal output is used for hydrogen production (70000 Nm 3 /h). The hydrogen production cost is estimated to 21 yen/Nm 3 but it is still higher than the economical goal (17 yen/Nm 3 ). The major reason of the high cost comes from the large size of hydrogen separation reformers because of the limit of hydrogen separation efficiency of palladium membrane. A new highly efficient hydrogen separation membrane is needed to reduce the cost of hydrogen production using membrane reformers. There is possibility of multi-tube failure in the membrane reformers. In future study, a design of measures against tube failure and elemental experiments of reaction between sodium and reforming gas will be needed. (authors)

  15. Modelling of non-catalytic reactors in a gas-solid trickle flow reactor: Dry, regenerative flue gas desulphurization using a silica-supported copper oxide sorbent

    NARCIS (Netherlands)

    Kiel, J.H.A.; Kiel, J.H.A.; Prins, W.; van Swaaij, Willibrordus Petrus Maria

    1992-01-01

    A one-dimensional, two-phase dispersed plug flow model has been developed to describe the steady-state performance of a relatively new type of reactor, the gas-solid trickle flow reactor (GSTFR). In this reactor, an upward-flowing gas phase is contacted with as downward-flowing dilute solids phase

  16. H2 production with low carbon content via MSR in packed bed membrane reactors for high-temperature polymeric electrolyte membrane fuel cell

    International Nuclear Information System (INIS)

    Ribeirinha, P.; Abdollahzadeh, M.; Boaventura, M.; Mendes, A.

    2017-01-01

    Highlights: • H 2 removal diminishes the backward reaction and increases the residence time. • Selective CO 2 removal has low effect on the CH 3 OH conversion compared to H 2 removal. • IL membranes for MSR intents require minimum permeance of ⩾1 × 10 −6 mol s −1 m −2 Pa −1 . • IL-based PBMRs are easier to operate and have low energy consumption. - Abstract: This work compares the hydrogen purity and recovery produced by a methanol steam reforming (MSR) packed bed membrane reactor (PBMR) equipped with a membrane selective to hydrogen (Pd-Ag) and with a membrane selective to carbon dioxide (porous membrane filled with ionic liquids-ILs). A 3-dimensional non-isothermal PBMR model was developed in Fluent (Ansys™) for simulating a PBMR equipped with these two types of membranes and simulating a conventional packed bed reactor (PBR). For the development PBMR models a MSR mechanistic kinetic model was fitted to experimental reaction rates of a commercial catalyst (BASF RP60). The results indicated that selective hydrogen removal from the reaction medium originates a significant increase in the methanol conversion, while the carbon dioxide removal has a smaller effect. CO 2 -PBMR showed to be more efficient in terms of energy consumption than H 2 -PMBR. The simulation results showed also that ILs membranes must have a minimum permeance of ⩾1 x 10 −6 mol s −1 m −2 Pa −1 and CO 2 /H 2 selectivity of ⩾200 at 473 K to be attractive for this type of applications. The advantages and limitations of each reactor configuration are discussed based on experimental and simulated data.

  17. Radial Microchannel Reactor (RMR) used in Steam Reforming CH4

    Science.gov (United States)

    2013-05-13

    Microchannel Reactor , (RMR) used in Steam Reforming CH4 Details 5) Supported Hydrogen Permeable Membrane 6) P&E MFMR Integration with PCI steam reformer... Reactor (RMR) architecture and reports the achieved breakthroughs in heat transfer and thermal efficiency in the catalytic steam reforming of methane...Radial Microchannel Reactor , (RMR) used in Steam Reforming CH$ N00014-11-C-0194 Peter R. Bossard, Ph.D. Power & Energy, Inc. 106 Railroad Drive, Ivyland

  18. Domestic wastewater treatment by a submerged MBR (membrane bio-reactor) with enhanced air sparging.

    Science.gov (United States)

    Chang, I S; Judd, S J

    2003-01-01

    The air sparging technique has been recognised as an effective way to control membrane fouling. However, its application to a submerged MBR (Membrane Bio-Reactor) has not yet been reported. This paper deals with the performances of air sparging on a submerged MBR for wastewater treatment. Two kinds of air sparging techniques were used respectively. First, air is injected into the membrane tube channels so that mixed liquor can circulate in the bioreactor (air-lift mode). Second, a periodic air-jet into the membrane tube is introduced (air-jet mode). Their applicability was evaluated with a series of lab-scale experiments using domestic wastewater. The flux increased from 23 to 33 l m(-2) h(-1) (43% enhancement) when air was injected for the air-lift module. But further increase of flux was not observed as the gas flow increased. The Rc/(Rc+Rf), ratio of cake resistance (Rc) to sum of Rc and Rf (internal fouling resistance), was 23%, indicating that the Rc is not the predominant resistance unlike other MBR studies. It showed that the cake layer was removed sufficiently due to the air injection. Thus, an increase of airflow could not affect the flux performance. The air-jet module suffered from a clogging problem with accumulated sludge inside the lumen. Because the air-jet module has characteristics of dead end filtration, a periodic air-jet was not enough to blast all the accumulated sludge out. But flux was greater than in the air-lift module if the clogging was prevented by an appropriate cleaning regime such as periodical backwashing.

  19. Why use a thermophilic aerobic membrane reactor for the treatment of industrial wastewater/liquid waste?

    Science.gov (United States)

    Collivignarelli, Maria Cristina; Abbà, Alessandro; Bertanza, Giorgio

    2015-01-01

    This paper describes the advantages of thermophilic aerobic membrane reactor (TAMR) for the treatment of high strength wastewaters. The results were obtained from the monitoring of an industrial and a pilot scale plant. The average chemical oxygen demand (COD) removal yield was equal to 78% with an organic loading rate (OLR) up to 8-10 kgCOD m(-3) d(-1) despite significant scattering of the influent wastewater composition. Total phosphorus (TP) was removed with a rate of 90%, the most important removal mechanism being chemical precipitation (as hydroxyapatite, especially), which is improved by the continuous aeration that promotes phosphorus crystallization. Moreover, surfactants were removed with efficiency between 93% and 97%. Finally, the experimental work showed that thermophilic processes (TPPs) are complementary with respect to mesophilic treatments.

  20. Oxygen Transfer Model for a Flow-Through Hollow-Fiber Membrane Biofilm Reactor

    DEFF Research Database (Denmark)

    Gilmore, K. R.; Little, J. C.; Smets, Barth F.

    2009-01-01

    A mechanistic oxygen transfer model was developed and applied to a flow-through hollow-fiber membrane-aerated biofilm reactor. Model results are compared to conventional clean water test results as well as performance data obtained when an actively nitrifying biofilm was present on the fibers......-liquid interface was the most accurate of the predictive models (overpredicted by a factor of 1.1) while a coefficient determined by measuring bulk liquid dissolved oxygen underpredicted the oxygen transfer by a factor of 3. The mechanistic model was found to be an adequate tool for design because it used....... With the biofilm present, oxygen transfer efficiencies between 30 and 55% were calculated from the measured data including the outlet gas oxygen concentration, ammonia consumption stoichiometry, and oxidized nitrogen production stoichiometry, all of which were in reasonable agreement. The mechanistic model...

  1. Directing filtration to narrow molecular weight distribution of oligodextran in an enzymatic membrane reactor

    DEFF Research Database (Denmark)

    Su, Ziran; Luo, Jianquan; Pinelo, Manuel

    2018-01-01

    product, hypersaline wastewater discharge and potential safety hazards. In this work, a novel enzymatic membrane reactor (EMR) system to produce oligodextran is proposed, whereby in-situ product recovery can be manipulated to control the Mw distribution of the resulting products. Results showed......Oligodextrans with molecular weight (Mw) within the range of 5.0–8.0kDa have great commercial potential as precursors of iron-dextran for anemia treatment. Traditional oligodextran production consists of sucrose fermentation, acid hydrolysis and ethanol precipitation, which results in an uneven Mw...... narrow distribution and high productivity. Moreover, high transmembrane pressures (3 bars) and low stirring rates (160rpm) promoted yields beyond 50% in 120min. Higher permeate fluxes prevented further product hydrolysis and enhanced the yield. However, the resulting concentration polarization (CP...

  2. Evaluation of Miniaturized Infrared Sensors for Process Control of the Palladium Membrane Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lascola, R. J.; Howard, D. W.

    2005-07-31

    We have tested the suitability of a miniaturized infrared sensor for measurements of CO and H{sub 2}O in the inlet stream to the Palladium Membrane Reactor (PMR). We demonstrated that both analytes can be measured with absolute accuracies of 2-4% at the process inlet conditions of 120-140 C and approximately 1 atm of each gas. This accuracy must be improved to 1-1.5% for effective PMR process control. The use of a reference detector and independent temperature and pressure measurements to correct the raw signals will improve the accuracy to a level that will approach, if not meet, this goal. With appropriate bandpass filters, the infrared sensors may be used for other gas analysis applications.

  3. Treatment of Spacecraft Wastewater Using a Hollow Fiber Membrane Biofilm Redox Control Reactor

    Science.gov (United States)

    Smith, Daniel P.

    2003-01-01

    The purpose of this project was to develop and evaluate design concepts for biological treatment reactors for the purification of spacecraft wastewater prior to reverse osmosis treatment. The motivating factor is that wastewater recovery represents the greatest single potential reduction in the resupply requirements for crewed space missions. Spacecraft wastewater composition was estimated from the characteristics of the three major component streams: urine/flush water, hygiene water, and atmospheric condensate. The key characteristics of composite spacecraft wastewater are a theoretical oxygen demand of 4519 mg/L, of which 65% is nitrogenous oxygen demand, in a volume of 11.5 liter/crew-day. The organic carbon to nitrogen ratio of composite wastewater is 0.86. Urine represents 93% of nitrogen and 49% of the organic carbon in the composite wastestream. Various bioreaction scenarios were evaluated to project stoichiometric oxygen demands and the ability of wastewater carbon to support denitrification. Ammonia nitrification to the nitrite oxidation state reduced the oxygen requirement and enabled wastewater carbon to provide nearly complete denitrification. A conceptual bioreactor design was established using hollow fiber membranes for bubbleless oxygen transfer in a gravity-free environment, in close spatial juxtaposition to a second interspaced hollow fiber array for supplying molecular hydrogen. Highly versatile redox control and an enhanced ability to engineer syntrophic associations are stated advantages. A prototype reactor was constructed using a microporous hollow fiber membrane module for aeration. Maintaining inlet gas pressure within 0.25 psi of the external water pressure resulted in bubble free operation with no water ingress into hollow fiber lumens. Recommendations include the design and operational testing of hollow fiber bioreactors using: 1) Partial nitrification/nitrite predenitrification; 2) Limited aeration for simultaneous nitrification

  4. Oxygen distribution in packed bed membrane reactors for partial oxidation systems and the effect on the product selectivity

    NARCIS (Netherlands)

    Kurten, U.; van Sint Annaland, M.; Kuipers, J.A.M.

    2004-01-01

    Packed bed membrane reactors (PBMRs) are currently considered for the distributive addition of oxygen in partial oxidation systems. Among other advantages the decreased oxygen concentrations in the PBMR can result in improved product selectivities for reaction systems in which the oxygen dependency

  5. The production of hydrogen through the use of a 77 wt% Pd 23 wt% Ag membrane water gas shift reactor

    CSIR Research Space (South Africa)

    Baloyi, Liberty N

    2016-12-01

    Full Text Available stainless steel (PSS) is evaluated for the production of hydrogen and the potential replacement of the current two-stage Water-Gas Shift (WGS) reaction by a single stage reaction. The permeability of a 20 µm Pd–Ag membrane reactor was examined at 320 °C, 380...

  6. A green approach to ethyl acetate: Quantitative conversion of ethanol through direct dehydrogenation in a Pd-Ag membrane reactor

    KAUST Repository

    Zeng, Gaofeng

    2012-11-07

    Pincers do the trick: The conversion of ethanol to ethyl acetate and hydrogen was achieved using a pincer-Ru catalyst in a Pd-Ag membrane reactor. Near quantitative conversions and yields could be achieved without the need for acid or base promoters or hydrogen acceptors (see scheme). © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Application of a Homogeneous Dodecakis[NCN-Pincer-PdII] Catalyst in a Nanofiltration Membrane Reactor under Continious Reaction Conditions

    NARCIS (Netherlands)

    Koten, G. van; Dijkstra, H.P.; Ronde, N.; Klink, G.P.M. van; Vogt, D.

    2003-01-01

    A shape-persistent nanosize dodecakis(NCN-PdII-aqua) complex (4b) was applied as a homogeneous catalyst in the double Michael reaction between methyl vinyl ketone and ethyl -cyanoacetate under continuous reaction conditions in a nanofiltration membrane reactor. Due to its macromolecular dimensions,

  8. Catalytic Intermediate Pyrolysis of Napier Grass in a Fixed Bed Reactor with ZSM-5, HZSM-5 and Zinc-Exchanged Zeolite-A as the Catalyst

    OpenAIRE

    Isah Yakub Mohammed; Feroz Kabir Kazi; Suzana Yusup; Peter Adeniyi Alaba; Yahaya Muhammad Sani; Yousif Abdalla Abakr

    2016-01-01

    The environmental impact from the use of fossil fuel cum depletion of the known fossil oil reserves has led to increasing interest in liquid biofuels made from renewable biomass. This study presents the first experimental report on the catalytic pyrolysis of Napier grass, an underutilized biomass source, using ZSM-5, 0.3HZSM-5 and zinc exchanged zeolite-A catalyst. Pyrolysis was conducted in fixed bed reactor at 600 °C, 30 °C/min and 7 L/min nitrogen flow rate. The effect of catalyst-biomass ...

  9. Treatment of high strength aqueous wastes in a thermophilic aerobic membrane reactor (TAMR): performance and resilience.

    Science.gov (United States)

    Collivignarelli, Maria Cristina; Abbà, Alessandro; Bertanza, Giorgio; Barbieri, Giacomo

    2017-12-01

    In the present work, the thermophilic aerobic membrane reactor technology was studied for the treatment of high strength aqueous wastes mainly containing dyes, surfactants and solvents. The thermophilic biomass resilience and the process stability under critical conditions (such as rapid rise of the mixed liquor pH, oxygen supply interruption, etc.) were also evaluated. The experimental work was carried out with the use of a pilot plant at semi-industrial scale, which was managed throughout for 14 months; the operation temperature was 49 °C and the organic loading rate was increased from 3 to 12 kg COD m -3 d -1 . Critical conditions, especially the interruption of oxygen supply, affected the pilot plant performance but did not cause a complete system break down. After the temporary reduction of process performance, also proven by the decrease in the oxygen consumption, the normal working conditions were restored. Moreover, the longer non-aerated phase involved a significant reduction (40%) of volatile suspended solids concentration in the biological reactor and the increase of 30% in foaming power; nevertheless, once the oxygen supply was reactivated, optimal conditions were rapidly restored. Therefore, the study showed the high resilience of the thermophilic biomass, which was able to recover full functionality after critical events.

  10. The kinetics of nitrogen removal and biogas production in an anammox non-woven membrane reactor.

    Science.gov (United States)

    Ni, Shou-Qing; Lee, Po-Heng; Sung, Shihwu

    2010-08-01

    The anammox non-woven membrane reactor (ANMR) is a novel reactor configuration to culture the slowly growing anammox bacteria. Different mathematical models were used to study the process kinetics of the nitrogen removal in the ANMR. The kinetics of nitrogen gas production of anammox process was first evaluated in this paper. For substrate removal kinetics, the modified Stover-Kincannon model and the Grau second-order model were more applicable to the ANMR than the first-order model and the Monod model. For nitrogen gas production kinetics, the Van der Meer and Heertjes model was more appropriate than the modified Stover-Kincannon model. Model evaluation was carried out by comparing experimental data with predicted values calculated from suitable models. Both model kinetics study and model testing showed that the Grau second-order model and the Van der Meer and Heertjes model seemed to be the best models to describe the nitrogen removal and nitrogen gas production in the ANMR, respectively. (c) 2010 Elsevier Ltd. All rights reserved.

  11. Sulfamethoxazole removal in membrane-photocatalytic reactor system - experimentation and modelling.

    Science.gov (United States)

    Asha, Raju C; Yadav, M S Priyanka; Kumar, Mathava

    2018-01-29

    In this study, the efficacy of membrane-photocatalytic reactor (MPR) in sulfamethoxazole (SMX) removal was explored at a fixed initial SMX concentration, i.e. 100 mg/L. A supported catalyst, i.e. TiO 2 on granular activated carbon (GAC-TiO 2 ), was used for MPR experiments. The SMX removal efficiency of the MPR was investigated under a range of hydraulic retention time (i.e. HRT from 51 to 152.5 min) and TiO 2 catalyst dosage (55-50 mg/L). A maximum SMX removal efficiency of 83.6% was observed under 220 mg/L catalyst dosage and 80 min HRT. The increase in catalyst dosage from 55 to 550 mg/L has increased the transmembrane pressure of the reactor from 9.8 to 22.2 kPa. A multiple non-linear regression model was developed based on the experimental data and its significance was analyzed using two-way ANOVA. Based on the model, the optimal HRT and catalyst dosage for complete SMX removal (100%) were found out. The comparison of photocatalytic degradation experiments with sorption experiments conducted earlier revealed that SMX removal in the MPR was mainly by photocatalytic degradation and not by adsorption onto GAC-TiO 2 catalyst. However, the performance of MPR in removing other emerging pollutants from real-time wastewaters could be explored before its field-scale application.

  12. SACCHARIFICATION OF NATIVE CASSAVA STARCH AT HIGH DRY SOLIDS IN AN ENZYMATIC MEMBRANE REACTOR

    Directory of Open Access Journals (Sweden)

    I Nyoman Widiasa

    2012-02-01

    Full Text Available This study is aimed to develop a novel process scheme for hydrolysis of native cassava starch at high dry solids using an enzymatic membrane reactor (EMR. Firstly, liquefied cassava starch having solids content up to 50% by weight was prepared by three stage liquefactions in a conventional equipment using a commercially available heat stable a-amylase (Termamyl 120L. The liquefied cassava starch was further saccharified in an EMR using glucoamylase (AMG E. By using the developed process scheme, a highly clear hydrolysate with dextrose equivalent (DE approximately 97 could be produced, provided the increase of solution viscosity during the liquefaction was precisely controlled. The excessive space time could result in reduction in conversion degree of starch. Moreover, a residence time distribution study confirmed that the EMR could be modelled as a simple continuous stirred tank reactor (CSTR. Using Lineweaver-Burk analysis, the apparent Michaelis-Menten constant (Km and glucose production rate constant (k2 were 552 (g/l and 4.04 (min-1, respectively. Application of simple CSTR model with those kinetic parameters was quietly appropriate to predict the reactor’s performance at low space time.

  13. Oxidative CO2 reforming of methane in La0.6Sr0.4Co0.8Ga0.2O3-δ (LSCG) hollow fiber membrane reactor.

    Science.gov (United States)

    Kathiraser, Yasotha; Wang, Zhigang; Kawi, Sibudjing

    2013-12-17

    CO2 utilization in catalytic membrane reactors for syngas production is an environmentally benign solution to counter the escalating global CO2 concerns. In this study, integration of a La0.6Sr0.4Co0.8Ga0.2O3-δ (LSCG) hollow fiber membrane reactor with Ni/LaAlO3-Al2O3 catalyst for the oxidative CO2 reforming of methane (OCRM) reaction was successfully tested for 160 h of reaction. High CH4 and CO2 conversions of ca. 94% and 73% were obtained with O2 flux ca. 1 mL·min(-1)·cm(-2) at 725 °C for the 160-h stability test. Surface temperature programmed desorption studies of the membrane were conducted with H2, CO, and CO2 as probe gases to facilitate understanding on the effect of H2 and CO product gases as well as CO2 reactant gases on the membrane surface. Scanning electron microscopy-energy dispersive X-ray (SEM-EDX), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) analysis of the postreacted membrane after 160-h stability tests suggests Sr-enriched phases with the presence of adsorbed carbonate and hydrogenated carbon. This shows the subsequent reactant spillover on the membrane surface from the catalyst bed took place due to the reaction occurring on the catalyst. However, XRD analysis of the bulk structure does not show any phase impurities, thus confirming the structural integrity of the LSCG hollow fiber membrane.

  14. Rheology and Microbiology of Sludge from a Thermophilic Aerobic Membrane Reactor

    Directory of Open Access Journals (Sweden)

    Alessandro Abbà

    2017-01-01

    Full Text Available A thermophilic aerobic membrane reactor (TAMR treating high-strength COD liquid wastes was submitted to an integrated investigation, with the aim of characterizing the biomass and its rheological behaviour. These processes are still scarcely adopted, also because the knowledge of their biology as well as of the physical-chemical properties of the sludge needs to be improved. In this paper, samples of mixed liquor were taken from a TAMR and submitted to fluorescent in situ hybridization for the identification and quantification of main bacterial groups. Measurements were also targeted at flocs features, filamentous bacteria, and microfauna, in order to characterize the sludge. The studied rheological properties were selected as they influence significantly the performances of membrane bioreactors (MBR and, in particular, of the TAMR systems that operate under thermophilic conditions (i.e., around 50°C with high MLSS concentrations (up to 200 gTS L−1. The proper description of the rheological behaviour of sludge represents a useful and fundamental aspect that allows characterizing the hydrodynamics of sludge suspension devoted to the optimization of the related processes. Therefore, in this study, the effects on the sludge rheology produced by the biomass concentration, pH, temperature, and aeration were analysed.

  15. Performance of a cutinase membrane reactor for the production of biodiesel in organic media.

    Science.gov (United States)

    Badenes, Sara M; Lemos, Francisco; Cabral, Joaquim M S

    2011-06-01

    The enzymatic transesterification of oils with an alcohol, using recombinant cutinase of Fusarium solani pisi microencapsulated in sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/isooctane reversed micelles, was performed in a membrane bioreactor (MBR). A tubular ceramic membrane with a nominal molecular weight cut off of 15,000 Da was used to retain the enzyme, and characterized in terms of rejection coefficients of the reaction components by transmission experiments. The performance of the MBR in a total recirculation-batch mode was compared with results obtained in a stirred batch tank reactor. The continuous operation of the MBR was also evaluated and the influence of the alcohol type and permeate flow rate on conversion degree and productivity (up to 500 g(product) /day/g(enzyme) was attained) were analyzed. Cutinase wild type and mutant T179C were tested for this process and the high long-term operational stability of the cutinase mutant demonstrated its potential as biocatalyst for the enzymatic continuous production of biodiesel. Copyright © 2011 Wiley Periodicals, Inc.

  16. Nanomaterial-enabled membranes for water treatment

    Science.gov (United States)

    Rogensues, Adam Roy

    Incorporating engineered nanomaterials as components of synthetic membranes can improve their separation performance and endow membranes with additional functions. This work explores two approaches to the design of membranes modified with nanomaterials. In the first chapter, exfoliated graphite nanoplatelets (xGnP) decorated with gold nanoparticles were embedded in a polysulfone matrix to fabricate phase inversion nanocomposite membranes. The cast membranes were evaluated as flow-through membrane reactors in experiments on the catalytic reduction of 4-nitrophenol. The nanocomposite membranes were not as catalytically efficient as those fabricated by modifying anodized alumina membranes polyelectrolyte multilayers (PEMs) containing gold nanoparticles. However, because of the facility of membrane casting by phase inversion and new opportunities enabled by the demonstrated hierarchy-based approach to nanocomposite membrane design, such membrane may hold commercial promise. In the second part of the study, the practicability of PEM-based nanofiltration was evaluated under conditions of precipitative fouling (i.e. scaling) by calcium sulfate. Polyelectrolytes were deposited onto 50 kDa polyethersulfone membranes to create PEM-based nanofiltration membranes. The prepared membranes were compared with the commercial NF270 membrane in terms of flux and rejection performance, as well as the morphology of gypsum crystals formed on the membrane surface. None of the PEM coatings tested inhibited scale formation.

  17. Reducing-Agent-Free Instant Synthesis of Carbon-Supported Pd Catalysts in a Green Leidenfrost Droplet Reactor and Catalytic Activity in Formic Acid Dehydrogenation

    Science.gov (United States)

    Lee, Dong-Wook; Jin, Min-Ho; Lee, Young-Joo; Park, Ju-Hyoung; Lee, Chun-Boo; Park, Jong-Soo

    2016-05-01

    The development of green synthesis methods for supported noble metal catalysts remains important challenges to improve their sustainability. Here we first synthesized carbon-supported Pd catalysts in a green Leidenfrost droplet reactor without reducing agents, high-temperature calcination and reduction procedures. When the aqueous solution containing Pd nitrate precursor, carbon support, and water is dripped on a hot plate, vapor layer is formed between a solution droplet and hot surface, which allow the solution droplet to be levitated on the hot surface (Leidenfrost phenomena). Subsequently, Pd nanoparticles can be prepared without reducing agents in a weakly basic droplet reactor created by the Leidenfrost phenomena, and then the as-prepared Pd nanoparticles are loaded on carbon supports during boiling down the droplet on hot surface. Compared to conventional incipient wetness and chemical synthetic methods, the Leidenfrost droplet reactor does not need energy-consuming, time-consuming, and environmentally unfriendly procedures, which leads to much shorter synthesis time, lower carbon dioxide emission, and more ecofriendly process in comparison with conventional synthesis methods. Moreover, the catalysts synthesized in the Leidenfrost droplet reactor provided much better catalytic activity for room-temperature formic acid decomposition than those prepared by the incipient wetness method.

  18. Optimal oxygen feeding policy to maximize the production of Maleic anhydride in unsteady state fixed bed catalytic reactors

    Directory of Open Access Journals (Sweden)

    E. Ali

    2017-07-01

    Full Text Available The effect of different oxygen feeding scenarios in a fixed bed reactor for the production of Maleic anhydride (MA is studied. Two reactor configurations were examined. In the first configuration, a cross flow reactor (CFR with 4 discrete feeding points is considered. Another configuration is the conventional packed-bed reactor (PBR with a single feed. Nonlinear Model Predictive Controller (NLMPC was used as optimal controller to operate the CFR in dynamic mode and to optimize the multiple feed dosages in order to enhance the MA yield. The simulation results indicated that different combinations of the four feed ratios can operate the reactor at the best value for the yield provided the first feeding point is kept as low as possible. For the packed bed reactor configuration, a single oxygen feed is considered and is optimized transiently by NLMPC. The simulation outcomes showed that the reactor performance in terms of the produced MA mole fraction can also be enhanced to the same magnitude obtained by CFR configuration. This improvement requires decreasing the oxygen ratio in the reactor single feed by 70%.

  19. Removal of selected nitrogenous heterocyclic compounds in biologically pretreated coal gasification wastewater (BPCGW) using the catalytic ozonation process combined with the two-stage membrane bioreactor (MBR).

    Science.gov (United States)

    Zhu, Hao; Han, Yuxing; Ma, Wencheng; Han, Hongjun; Ma, Weiwei

    2017-12-01

    Three identical anoxic-aerobic membrane bioreactors (MBRs) were operated in parallel for 300 consecutive days for raw (R 1 ), ozonated (R 2 ) and catalytic ozonated (R 3 ) biologically pretreated coal gasification wastewater (BPCGW) treatment. The results demonstrated that catalytic ozonation process (COP) applied asa pretreatment remarkably improved the performance of the unsatisfactory single MBR. The overall removal efficiencies of COD, NH 3 -N and TN in R 3 were 92.7%, 95.6% and 80.6%, respectively. In addition, typical nitrogenous heterocyclic compounds (NHCs) of quinoline, pyridine and indole were completely removed in the integrated process. Moreover, COP could alter sludge properties and reshape microbial community structure, thus delaying the occurrence of membrane fouling. Finally, the total cost for this integrated process was estimated to be lower than that of single MBR. The results of this study suggest that COP is a good option to enhance pollutants removal and alleviate membrane fouling in the MBR for BPCGW treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Directly catalytic upgrading bio-oil vapor produced by prairie cordgrass pyrolysis over Ni/HZSM-5 using a two stage reactor

    Directory of Open Access Journals (Sweden)

    Shouyun Cheng

    2015-06-01

    Full Text Available Catalytic cracking is one of the most promising processes for thermochemical conversion of biomass to advanced biofuels in recent years. However, current effectiveness of catalysts and conversion efficiency still remain challenges. An investigation of directly catalytic upgrading bio-oil vapors produced in prairie cordgrass (PCG pyrolysis over Ni/HZSM-5 and HZSM-5 in a two stage packed-bed reactor was carried out. The Ni/HZSM-5 catalyst was synthesized using an impregnation method. Fresh and used catalysts were characterized by BET and XRD. The effects of catalysts on pyrolysis products yields and quality were examined. Both catalysts improved bio-oil product distribution compared to non-catalytic treatment. When PCG pyrolysis vapor was treated with absence of catalyst, the produced bio-oils contained higher alcohols (10.97% and furans (10.14%. In contrast, the bio-oils contained the second highest hydrocarbons (34.97%)and the highest phenols (46.97% when PCG pyrolysis vapor was treated with Ni/HZSM-5. Bio-oils containing less ketones and aldehydes were produced by both Ni/HZSM-5 and HZSM-5, but no ketones were found in Ni/HZSM-5 treatment compared to HZSM-5 (2.94%. The pyrolysis gas compositions were also affected by the presenting of HZSM-5 or Ni/HZSM-5 during the catalytic upgrading process. However, higher heating values and elemental compositions (C, H and N of bio-chars produced in all treatments had no significant difference.

  1. Altering bio-oil composition by catalytic treatment of pinewood pyrolysis vapors over zeolites using an auger - packed bed integrated reactor system

    Directory of Open Access Journals (Sweden)

    Vamshi Krishna Guda

    2016-09-01

    Full Text Available Pine wood pyrolysis vapors were catalytically treated using Zeolite catalysts. An auger fed reactor was used for the pinewood pyrolysis while a packed bed reactor mounted on the top of the auger reactor housed the catalyst for the treatment of pinewood pyrolytic vapors. The pyrolytic vapors produced at 450 oC were passed through zeolite catalysts maintained at 425 oC at a weight hourly space velocity (WHSV of 12 h-1. Five zeolites, including ZSM-5, mordenite, ferrierite, Zeolite-Y, and Zeolite-beta (all in H form, were used to study the effect of catalyst properties such as acidity, pore size, and pore structure on catalytic cracking of pinewood pyrolysis vapors. Product bio-oils were analyzed for their chemical composition using GC-MS, water content, density, viscosity, acid value, pH, and elemental compositions. Thermogravimetric analysis (TGA was performed to analyze the extent of coking on zeolite catalysts. Application of catalysis to biomass pyrolysis increased gas product yields at the expense of bio-oil yields. While all the zeolites deoxygenated the pyrolysis vapors, ZSM-5 was found to be most effective. The ZSM-5 catalyzed bio-oil, rich in phenolics and aromatic hydrocarbons, was less viscous, had relatively lower acid number and high pH, and possessed oxygen content nearly half that of un-catalyzed bio-oil. Brønsted acidity, pore size, and shape-selective catalysis of ZSM-5 catalyst proved to be the determining factors for its activity. TGA results implied that the pore size of catalysts highly influenced coking reactions. Regeneration of the used catalysts was successfully completed at 700 oC.

  2. Hydrogen production by reforming of liquid hydrocarbons in a membrane reactor for portable power generation-Experimental studies

    Science.gov (United States)

    Damle, Ashok S.

    One of the most promising technologies for lightweight, compact, portable power generation is proton exchange membrane (PEM) fuel cells. PEM fuel cells, however, require a source of pure hydrogen. Steam reforming of hydrocarbons in an integrated membrane reactor has potential to provide pure hydrogen in a compact system. Continuous separation of product hydrogen from the reforming gas mixture is expected to increase the yield of hydrogen significantly as predicted by model simulations. In the laboratory-scale experimental studies reported here steam reforming of liquid hydrocarbon fuels, butane, methanol and Clearlite ® was conducted to produce pure hydrogen in a single step membrane reformer using commercially available Pd-Ag foil membranes and reforming/WGS catalysts. All of the experimental results demonstrated increase in hydrocarbon conversion due to hydrogen separation when compared with the hydrocarbon conversion without any hydrogen separation. Increase in hydrogen recovery was also shown to result in corresponding increase in hydrocarbon conversion in these studies demonstrating the basic concept. The experiments also provided insight into the effect of individual variables such as pressure, temperature, gas space velocity, and steam to carbon ratio. Steam reforming of butane was found to be limited by reaction kinetics for the experimental conditions used: catalysts used, average gas space velocity, and the reactor characteristics of surface area to volume ratio. Steam reforming of methanol in the presence of only WGS catalyst on the other hand indicated that the membrane reactor performance was limited by membrane permeation, especially at lower temperatures and lower feed pressures due to slower reconstitution of CO and H 2 into methane thus maintaining high hydrogen partial pressures in the reacting gas mixture. The limited amount of data collected with steam reforming of Clearlite ® indicated very good match between theoretical predictions and

  3. Filtration behavior of casein glycomacropeptide (CGMP) in an enzymatic membrane reactor: fouling control by membrane selection and threshold flux operation

    DEFF Research Database (Denmark)

    Luo, Jianquan; Morthensen, Sofie Thage; Meyer, Anne S.

    2014-01-01

    to be the most suitable membrane for this application. Low pH increased CGMP retention but produced more fouling. Higher agitation and lower CGMP concentration induced larger permeate flux and higher CGMP retention. Adsorption fouling and pore blocking by CGMP in/on membranes could be controlled by selecting...... a highly hydrophilic membrane with appropriate pore size. Operating under threshold flux could minimize the concentration polarization and cake/gel/scaling layers, but might not avoid irreversible fouling caused by adsorption and pore blocking. The effects of membrane properties, pH, agitation and CGMP...

  4. Co-generation of synthesis gas and C{sub 2+} hydrocarbons from methane and carbon dioxide in a hybrid catalytic-plasma reactor: A review

    Energy Technology Data Exchange (ETDEWEB)

    Istadi; Nor Aishah Saidina Amin [Universiti Teknologi Malaysia, Johor Bahru (Malaysia). Chemical Reaction Engineering Group (CREG), Faculty of Chemical and Natural Resources Engineering

    2006-03-15

    The topics on conversion and utilization of methane and carbon dioxide are important issues in tackling the global warming effects from the two greenhouse gases. Several technologies including catalytic and plasma have been proposed to improve the process involving conversion and utilization of methane and carbon dioxide. In this paper, an overview of the basic principles, and the effects of CH{sub 4}/CO{sub 2} feed ratio, total feed flow rate, discharge power, catalyst, applied voltage, wall temperature, and system pressure in dielectric-barrier discharge (DBD) plasma reactor are addressed. The discharge power, discharge gap, applied voltage and CH{sub 4}/CO{sub 2} ratio in the feed showed the most significant effects on the reactor performance. Co-feeding carbon dioxide with the methane feed stream reduced coking and increased methane conversion. The H{sub 2}/CO ratio in the products was significantly affected by CH{sub 4}/CO{sub 2} ratio. The synergism of the catalyst placed in the discharge gap and the plasma affected the products distribution significantly. Methane and carbon dioxide conversions were influenced significantly by discharge power and applied voltage. The drawbacks of DBD plasma application in the CH{sub 4}-CO{sub 2} conversion should be taken into consideration before a new plausible reactor system can be implemented. 76 refs., 4 figs., 2 tabs.

  5. Reactor modeling to simulate catalytic partial oxidation and steam reforming of methane. Comparison of temperature profiles and strategies for hot spot minimization

    Energy Technology Data Exchange (ETDEWEB)

    Barrio, V.L.; Cambra, J.F.; Arias, P.L.; Gueemez, M.B. [School of Engineering (UPV/EHU), c/Alameda Urquijo s/n, 48013 Bilbao (Spain); Schaub, G.; Rohde, M. [Engler-Bunte-Institut, Universitaet Karlsruhe, Engler-Bunte-Ring 1, 76131 Karlsruhe (Germany); Rabe, S.; Vogel, F. [Paul Scherrer Institute, Laboratory for Energy and Materials Cycles, CH-5232 Villigen PSI (Switzerland)

    2007-07-15

    Catalytic partial oxidation (CPO) reactions of methane in the presence of steam (low temperature CPO, LTCPO) over a noble metal catalyst were investigated. A quasi-homogeneous one-dimensional model was developed in order to model a lab-scale fixed-bed reactor to produce syngas. These model calculations can contribute to the optimization of the process with respect to the formation of important hot spots ({delta} T{>=}130 ). These useful data can enable the model development in order to study the influence of the space velocity, product composition and other variables. Furthermore, a feed splitting study was performed. In the heat balance an overall heat transport term was included to account for small heat losses/gains along the reactor. The agreement between simulations and the degree of detail in the model is appropriate for the amount and kind of experimental data available. Thus, this model can also assist in a pilot reactor design, materials and further scale-up. (author)

  6. Membrane bio-reactor - Research, pilot installation and measurement campaign; Membranbioreaktor (MBR) - Forschung, Pilotanlage und Messkampagne - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hersener, J.-L. [Ingenieurbuero Hersener, Wiesendangen (Switzerland); Meier, U. [Meritec GmbH, Guntershausen (Switzerland)

    2007-07-01

    This report for the Swiss Federal Office of Energy (SFOE), takes a look at a project involving a fermenter installation in Eastern Switzerland. Research work is noted, the pilot installation is described and the results of a measurement campaign are presented and commented on. The plant is able to handle about 20,000-25,000 tonnes of slurry and organic waste. The plant is built as a membrane bio-reactor and allows the separation of the digested biomass into fractions of solid and liquid fertilisers and useful water. Furthermore, a part of the separated and digested liquid is returned to the fermenter in order to improve the digestion process. For the production of electricity a 1.1 MW generator is installed. The adaptations made during the measurement period are noted and commented on. According to the authors, the results - although difficult to interpret - show that the concept of a membrane bio-reactor can work successfully.

  7. Degradation of pharmaceuticals from membrane biological reactor sludge with Trametes versicolor.

    Science.gov (United States)

    Llorens-Blanch, Guillem; Badia-Fabregat, Marina; Lucas, Daniel; Rodriguez-Mozaz, Sara; Barceló, Damià; Pennanen, Taina; Caminal, Gloria; Blánquez, Paqui

    2015-02-01

    Emerging contaminants are a wide group of chemical products that are found at low concentrations in the environment. These contaminants can be either natural, e.g., estrogens, or synthetics, such as pesticides and pharmaceuticals, which can enter the environment through the water and sludge from wastewater treatment plants (WWTP). The growth of Trametes versicolor on membrane biological reactor (MBR) sludge in bioslurry systems at the Erlenmeyer scale was assessed and its capacity for removing pharmaceutical and personal care products (PPCPs) was evaluated. The ability of the fungus to remove hydrochlorothiazide (HZT) from liquid media cultures was initially assessed. Consequently, different bioslurry media (complete nutrient, glucose and no-nutrient addition) and conditions (sterile and non-sterile) were tested, and the removal of spiked HZT was monitored under each condition. The highest spiked HZT removal was assessed under non-sterile conditions without nutrient addition (93.2%). Finally, the removal assessment of a broad set of pharmaceuticals was performed in non-spiked bioslurry. Under non-sterile conditions, the fungus was able to completely degrade 12 out of the 28 drugs initially detected in the MBR sludge, achieving an overall degradation of 66.9%. Subsequent microbial analysis showed that the microbial diversity increased after 15 days of treatment, but there was still some T. versicolor in the bioslurry. Results showed that T. versicolor can be used to remove PPCPs in bioslurry systems under non-sterile conditions, without extra nutrients in the media, and in matrices as complex as an MBR sludge.

  8. Membrane bioreactors: present and prospects.

    Science.gov (United States)

    Chang, H N; Furusaki, S

    1991-01-01

    Membrane bioreactors have a very handy in-situ separation capability lacking in other types of bioreactors. Combining various functions of membrane separations and biocatalyst characteristics of enzymes, microbial cells, organelles, animal and plant tissues can generate quite a number of membrane bioreactor systems. The cell retaining property of membranes and selective removal of inhibitory byproducts makes high cell density culture possible and utilizes enzyme catalytic activity better, which leads to high productivity of bioreactors. Enzyme reactions utilizing cofactors and hydrolysis of macromolecules are advantageous in membrane bioreactors. Anaerobic cell culture may be efficiently carried out in membrane cell recycle systems, while aerobic cultures work well in dual hollow fiber reactors. Animal and plant cells have much a better chance of success in membrane reactors because of the protective environment of the reactor and the small oxygen uptake rate of these cells. Industrial use of these reactors are still in its infancy and limited to enzyme and animal tissue culture, but applications will expand as existing problems are resolved.

  9. Catalytic and Noncatalytic Conversion of Methane to Olefins and Synthesis Gas in an AC Parallel Plate Discharge Reactor

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Khodagholi

    2013-01-01

    Full Text Available Direct conversion of methane to ethylene, acetylene, and synthesis gas at ambient pressure and temperature in a parallel plate discharge reactor was investigated. The experiments were carried out using a quartz reactor of outer diameter of 9 millimeter and a driving force of ac current of 50 Hz. The input power to the reactor to establish a stable gas discharge varied from 9.6 to maximum 15.3 watts (w. The effects of ZSM5, Fe–ZSM5, and Ni–ZSM5 catalysts combined with corona discharge for conversion of methane to more valued products have been addressed. It was found that in presence or absence of a catalyst in gas discharge reactor, the rate of methane and oxygen conversion increased upon higher input power supplied to the reactor. The effect of Fe–ZSM5 catalyst combined with gas discharge plasma yields C2 hydrocarbons up to 21.9%, which is the highest productions of C2 hydrocarbons in this work. The effect of combined Ni–ZSM5 and gas discharge plasma was mainly production of synthesis gas. The advantage of introducing ZSM5 to the plasma zone was increase in synthesis gas and acetylene production. The highest energy efficiency was 0.22 mmol/kJ, which belongs to lower rate of energy injection to the reactor.

  10. Polyethersulfone hollow fiber modified with poly(styrenesulfonate) and Pd nanoparticles for catalytic reaction

    Science.gov (United States)

    Emin, C.; Gu, Y.; Remigy, J.-C.; Lahitte, J.-F.

    2015-07-01

    The aim of this work is the synthesis of polymer-stabilized Pd nanoparticles (PdNP) inside a functionalized polymeric porous membrane in order to develop hybrid catalytic membrane reactors and to test them in model metal-catalyzed organic reactions. For this goal, a polymeric membrane support (Polyethersulfone hollow fiber-shaped) was firstly functionalized with an ionogenic polymer (i.e. poly(styrenesulfonate) capable to retain PdNP precursors using an UV photo-grafting method. PdNP were then generated inside the polymeric matrix by chemical reduction of precursor salts (intermatrix synthesis). The catalytic performance of the PdNP catalytic membranes was evaluated using reduction of nitrophenol by sodium borohydride (NaBH4) in water.

  11. Catalytic oxidation for treatment of ECLSS and PMMS waste streams

    Science.gov (United States)

    Akse, James R.; Jolly, Clifford D.

    1991-01-01

    It is shown that catalytic oxidation is an effective technique for the removal of trace organic contaminants in a multifiltration potable processor's effluent. Essential elements of this technology are devices that deliver oxygen to the influent, and remove gaseous reaction byproducts from the effluent, via hollow-tube, gas-permeable membranes. Iodine, which poisons existing catalysis, is removed by a small deiodination bed prior to catalytic reactor entrance. The catalyst used is a mixture of Pt and Ru deposited on carbon, operating at 125-160 C and 39-90 psi pressures.

  12. Reactor

    International Nuclear Information System (INIS)

    Toyama, Masahiro; Kasai, Shigeo.

    1978-01-01

    Purpose: To provide a lmfbr type reactor wherein effusion of coolants through a loop contact portion is reduced even when fuel assemblies float up, and misloading of reactor core constituting elements is prevented thereby improving the reactor safety. Constitution: The reactor core constituents are secured in the reactor by utilizing the differential pressure between the high-pressure cooling chamber and low-pressure cooling chamber. A resistance port is formed at the upper part of a connecting pipe, and which is connect the low-pressure cooling chamber and the lower surface of the reactor core constituent. This resistance part is formed such that the internal sectional area of the connecting pipe is made larger stepwise toward the upper part, and the cylinder is formed larger so that it profiles the inner surface of the connecting pipe. (Aizawa, K.)

  13. Reactor

    International Nuclear Information System (INIS)

    Ikeda, Masaomi; Kashimura, Kazuo; Inoue, Kazuyuki; Nishioka, Kazuya.

    1979-01-01

    Purpose: To facilitate the construction of a reactor containment building, whereby the inspections of the outer wall of a reactor container after the completion of the construction of the reactor building can be easily carried out. Constitution: In a reactor accommodated in a container encircled by a building wall, a space is provided between the container and the building wall encircling the container, and a metal wall is provided in the space so that it is fitted in the building wall in an attachable or detatchable manner. (Aizawa, K.)

  14. Catalytic wet air oxidation of bisphenol A solution in a batch-recycle trickle-bed reactor over titanate nanotube-based catalysts.

    Science.gov (United States)

    Kaplan, Renata; Erjavec, Boštjan; Senila, Marin; Pintar, Albin

    2014-10-01

    Catalytic wet air oxidation (CWAO) is classified as an advanced oxidation process, which proved to be highly efficient for the removal of emerging organic pollutant bisphenol A (BPA) from water. In this study, BPA was successfully removed in a batch-recycle trickle-bed reactor over bare titanate nanotube-based catalysts at very short space time of 0.6 min gCAT g(-1). The as-prepared titanate nanotubes, which underwent heat treatment at 600 °C, showed high activity for the removal of aqueous BPA. Liquid-phase recycling (5- or 10-fold recycle) enabled complete BPA conversion already at 200 °C, together with high conversion of total organic carbon (TOC), i.e., 73 and 98 %, respectively. The catalyst was chemically stable in the given range of operating conditions for 189 h on stream.

  15. Preliminary study on application of Pd composite membrane in helium purification system of high-temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Cai Jianhua; Yang Xiaoyong; Wang Jie; Yu Suyuan

    2008-01-01

    Helium purification system (HPS) is the main part of the helium auxiliary system of high-temperature gas-cooled reactors (HTGR), also in fusion reactors. Some exploratory work was carried out on the application of Pd composite membrane in the separation of He and H 2 . A typical single stripper permeator with recycle (SSP) system was designed, based on the design parameters of a small scale He purification test system CIGNE in CADARACHE, CEA, France, and finite element analysis method was used to solve the model. The total length of membrane module is fixed to 0.5 m. The results show that the concentration of H 2 is found to reduce from 1 000 μL/L in feed gas to 5 μL/L in the product He (the upper limitation of HPS in HTGR). And the molar ratio of product He to feed gas is 96.18% with the optimized ratio of sweep gas to retentive gas 0. 3970. It's an exponential distribution of H 2 concentration along the membrane module. The results were also compared with the other two popular designs, two stripper in series permeator (TSSP) and continuous membrane column (CMC). (authors)

  16. Catalytic pyrolysis of black-liquor lignin by co-feeding with different plastics in a fluidized bed reactor.

    Science.gov (United States)

    Zhang, Huiyan; Xiao, Rui; Nie, Jianlong; Jin, Baosheng; Shao, Shanshan; Xiao, Guomin

    2015-09-01

    Catalytic co-pyrolysis of black-liquor lignin and waste plastics (polyethylene, PE; polypropylene PP; polystyrene, PS) was conducted in a fluidized bed. The effects of temperature, plastic to lignin ratio, catalyst and plastic types on product distributions were studied. Both aromatic and olefin yields increased with increasing PE proportion. Petrochemical yield of co-pyrolysis of PE and lignin was LOSA-1 > spent FCC > Gamma-Al2O3 > sand. The petrochemical yield with LOSA-1 is 43.9% which is more than two times of that without catalyst. The feedstock for co-pyrolysis with lignin is polystyrene > polyethylene > polypropylene. Catalytic co-pyrolysis of black-liquor lignin with PS produced the maximum aromatic yield (55.3%), while co-pyrolysis with PE produced the maximum olefin yield (13%). Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Hydrogen production by reforming of liquid hydrocarbons in a membrane reactor for portable power generation-Model simulations

    Science.gov (United States)

    Damle, Ashok S.

    One of the most promising technologies for lightweight, compact, portable power generation is proton exchange membrane (PEM) fuel cells. PEM fuel cells, however, require a source of pure hydrogen. Steam reforming of hydrocarbons in an integrated membrane reactor has potential to provide pure hydrogen in a compact system. In a membrane reactor process, the thermal energy needed for the endothermic hydrocarbon reforming may be provided by combustion of the membrane reject gas. The energy efficiency of the overall hydrogen generation is maximized by controlling the hydrogen product yield such that the heat value of the membrane reject gas is sufficient to provide all of the heat necessary for the integrated process. Optimization of the system temperature, pressure and operating parameters such as net hydrogen recovery is necessary to realize an efficient integrated membrane reformer suitable for compact portable hydrogen generation. This paper presents results of theoretical model simulations of the integrated membrane reformer concept elucidating the effect of operating parameters on the extent of fuel conversion to hydrogen and hydrogen product yield. Model simulations indicate that the net possible hydrogen product yield is strongly influenced by the efficiency of heat recovery from the combustion of membrane reject gas and from the hot exhaust gases. When butane is used as a fuel, a net hydrogen recovery of 68% of that stoichiometrically possible may be achieved with membrane reformer operation at 600 °C (873 K) temperature and 100 psig (0.791 MPa) pressure provided 90% of available combustion and exhaust gas heat is recovered. Operation at a greater pressure or temperature provides a marginal improvement in the performance whereas operation at a significantly lower temperature or pressure will not be able to achieve the optimal hydrogen yield. Slightly higher, up to 76%, net hydrogen recovery is possible when methanol is used as a fuel due to the lower heat

  18. Methane-supported nitrate removal from groundwater in a membrane biofilm reactor.

    Science.gov (United States)

    Luo, Jing-Huan; Chen, Hui; Yuan, Zhiguo; Guo, Jianhua

    2018-04-01

    The discovery of denitrifying anaerobic methane oxidation (DAMO) has not only improved our understanding of global methane and nitrogen cycles, but also provided new technology options for removal of nitrate from nitrate-contaminated water. Previous studies have demonstrated DAMO organisms could remove nitrate and nitrite from wastewater under strictly anaerobically conditions. In the study, we investigate the feasibility of nitrate removal from groundwater, which contains dissolved oxygen in addition to nitrate. A membrane biofilm reactor (MBfR), inoculated with DAMO co-culture, was capable of treating synthetic groundwater containing highly contaminated nitrate (50  mg N/L) and oxygen (7-9 mg O 2 /L), with a maximum volumetric nitrate removal rate of 45 mg N/L-d. Accumulations of acetate and propionate were observed in some transient periods, indicating the possible involvement of acetate and propionate as intermediates in methane oxidation. The 16 S rRNA gene amplicon sequencing revealed that Candidatus Methylomirabilis, a known bacterial DAMO organism able to couple nitrite reduction with anaerobic oxidation of methane (AOM), was the dominant population. No archaeal DAMO organisms that are capable of coupling nitrate to AOM were observed, however, considerable amount of denitrifiers were developed in this system. Based on known metabolisms of these microorganisms and a series of batch studies, it was assumed that methane was oxidized into volatile fatty acids (VFAs) under oxygen-limiting conditions, then the generated VFAs served as carbon sources for these heterotrophic denitrifiers to remove nitrate. This study offers a potential technology for nitrate removal from groundwater by DAMO process in MBfR. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Polymer nanocomposite membranes with hierarchically structured catalysts for high throughput dehalogenation

    Science.gov (United States)

    Crock, Christopher A.

    Halogenated organics are categorized as primary pollutants by the Environmental Protection Agency. Trichloroethylene (TCE), which had broad industrial use in the past, shows persistence in the environment because of its chemical stability. The large scale use and poor control of TCE resulted in its prolonged release into the environment before the carcinogenic risk associated with TCE was fully understood. TCE pollution stemmed from industrial effluents and improper disposal of solvent waste. Membrane reactors are promising technology for treating TCE polluted groundwater because of the high throughput, relatively low cost of membrane fabrication and facile retrofitting of existing membrane based water treatment facilities with catalytic membrane reactors. Compared to catalytic fluidized or fixed bed reactors, catalytic membrane reactors feature minimal diffusional limitation. Additionally, embedding catalyst within the membrane avoids the need for catalyst recovery and can prevent aggregation of catalytic nanoparticles. In this work, Pd/xGnP, Pd-Au/xGnP, and commercial Pd/Al2O3 nanoparticles were employed in batch and flow-through membrane reactors to catalyze the dehalogenation of TCE in the presence of dissolved H2. Bimetallic Pd-Au/xGnP catalysts were shown to be more active than monometallic Pd/xGnP or commercial Pd/Al 2O3 catalysts. In addition to synthesizing nanocomposite membranes for high-throughput TCE dehalogenation, the membrane based dehalogenation process was designed to minimize the detrimental impact of common catalyst poisons (S2-, HS-, and H2S -) by concurrent oxidation of sulfide species to gypsum in the presence of Ca2+ and removal of gypsum through membrane filtration. The engineered membrane dehalogenation process demonstrated that bimetallic Pd-Au/xGnP catalysts resisted deactivation by residual sulfide species after oxidation, and showed complete removal of gypsum during membrane filtration.

  20. A Langmuir-Hinshelwood approach to the kinetic modelling of catalytic ammonia decomposition in an integral reactor.

    Science.gov (United States)

    Armenise, S; García-Bordejé, E; Valverde, J L; Romeo, E; Monzón, A

    2013-08-07

    The increasing interest in ammonia decomposition is due to the fact that this compound can be used advantageously as a hydrogen carrier, allowing the development of single-step hydrogen generation systems. With the aim of developing efficient reactors for ammonia decomposition, e.g. for fuel cell applications, it is imperative to investigate the kinetics and reaction mechanism in depth. The main goal of this work is to develop reliable kinetic models that are able to predict the performance obtained using integral reactors, e.g. monoliths. In this case, an almost complete NH3 conversion is obtained, with a high H2 concentration at the exit of the reactor. The operating conditions, mainly the gas composition, are very different along the reactor. In addition, the temperatures needed to attain such large conversions are usually high. The kinetic models developed in this contribution are based on the Langmuir isotherm, considering that all the adsorbed species can be kinetically relevant, that the slow step or steps can be partially reversible, and that the surface can be considered as energetically uniform, i.e. ideal. Among other conclusions, the results obtained indicate that the variable kinetic orders and apparent activation energies frequently reported in the literature can be direct consequences of the data analysis and can therefore also be explained without considering any change in the controlling step with the reaction temperature or in the hydrogen or ammonia concentration.

  1. Efficient degradation of chlorobenzene in a non-thermal plasma catalytic reactor supported on CeO2/HZSM-5 catalysts.

    Science.gov (United States)

    Jiang, Liying; Nie, Guofeng; Zhu, Runye; Wang, Jiade; Chen, Jianmeng; Mao, Yubo; Cheng, Zhuowei; Anderson, Willam A

    2017-05-01

    Chlorobenzene removal was investigated in a non-thermal plasma reactor using CeO 2 /HZSM-5 catalysts. The performance of catalysts was evaluated in terms of removal and energy efficiency. The decomposition products of chlorobenzene were analyzed. The results show that CeO 2 /HZSM-5 exhibited a good catalytic activity, which resulted in enhancements of chlorobenzene removal, energy efficiency, and the formation of lower amounts of by-products. With regards to CO 2 selectivity, the presence of catalysts favors the oxidation of by-products, leading to a higher CO 2 selectivity. With respect to ozone, which is considered as an unavoidable by-product in air plasma reactors, a noticeable decrease in its concentration was observed in the presence of catalysts. Furthermore, the stability of the catalyst was investigated by analyzing the evolution of conversion in time. The experiment results indicated that CeO 2 /HZSM-5 catalysts have excellent stability: chlorobenzene conversion only decreased from 78% to 60% after 75hr, which means that the CeO 2 /HZSM-5 suffered a slight deactivation. Some organic compounds and chlorinated intermediates were adsorbed or deposited on the catalysts surface as shown by the results of Fourier Transform Infrared (FT-IR) spectroscopy, scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses of the catalyst before and after the reaction, revealing the cause of catalyst deactivation. Copyright © 2016. Published by Elsevier B.V.

  2. Hydrogen-Permeable Tubular Membrane Reactor: Promoting Conversion and Product Selectivity for Non-Oxidative Activation of Methane over an Fe©SiO2Catalyst.

    Science.gov (United States)

    Sakbodin, Mann; Wu, Yiqing; Oh, Su Cheun; Wachsman, Eric D; Liu, Dongxia

    2016-12-23

    Non-oxidative methane conversion over Fe©SiO 2 catalyst was studied for the first time in a hydrogen (H 2 ) permeable tubular membrane reactor. The membrane reactor is composed of a mixed ionic-electronic SrCe 0.7 Zr 0.2 Eu 0.1 O 3-δ thin film (≈20 μm) supported on the outer surface of a one-end capped porous SrCe 0.8 Zr 0.2 O 3-δ tube. Significant improvement in CH 4 conversion was achieved upon H 2 removal from the membrane reactor compared to that in a fixed-bed reactor. The Fe©SiO 2 catalyst in the H 2 permeable membrane reactor demonstrated a stable ≈30 % C 2+ single-pass yield, with up to 30 % CH 4 conversion and 99 % selectivity to C 2 (ethylene and acetylene) and aromatic (benzene and naphthalene) products, at the tested conditions. The selectivity towards C 2 or aromatics was manipulated purposely by adding H 2 into or removing H 2 from the membrane reactor feed and permeate gas streams. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Azo dye decolorization by a laccase/mediator system in a membrane reactor: enzyme and mediator reusability.

    Science.gov (United States)

    Mendoza, Laura; Jonstrup, Maria; Hatti-Kaul, Rajni; Mattiasson, Bo

    2011-10-10

    This paper presents the use of a membrane-integrated reactor system with recycling of laccase and mediator for azo dye decolorization. From initial screening of different laccases and mediators, Trametes versicolor laccase and syringaldehyde provided the best system for decolorization. Decolorization yields of 98, 88, 80 and 78% were obtained for Red FN-2BL, Red BWS, Remazol Blue RR and Blue 4BL, respectively. The reaction parameters were optimized and a membrane reactor was set up for dye decolorization in batch mode with reuse of the enzyme. Between 10 and 20 batches could be run with decolorization yields from 95 to 52% depending on the dye type. To study the possibility of reusing both enzyme and mediator, the reactor was run using 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) coupled to polyethylene glycol (PEG). Nine batches were run for the treatment of Remazol Blue RR, providing decolorization yields of 96-78%. Cost analysis of the processes showed that the costs of laccase/syringaldehyde or laccase/TEMPO were almost equal when running 20 batches, but the cost for the PEG-TEMPO was higher. However, the advantages associated with reuse of the mediator should motivate further development of the concept. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Processing Tritiated Water at the Savannah River Site: A Production-Scale Demonstration of a palladium membrane reactor

    International Nuclear Information System (INIS)

    Sessions, K

    2004-01-01

    The Palladium Membrane Reactor (PMR) process was installed in the Tritium Facilities at the Savannah River Site to perform a production-scale demonstration for the recovery of tritium from tritiated water adsorbed on molecular sieve (zeolite). Unlike the current recovery process that utilizes magnesium, the PMR offers a means to process tritiated water in a more cost effective and environmentally friendly manner. The design and installation of the large-scale PMR process was part of a collaborative effort between the Savannah River Site and Los Alamos National Laboratory. The PMR process operated at the Savannah River Site between May 2001 and April 2003. During the initial phase of operation the PMR processed thirty-four kilograms of tritiated water from the Princeton Plasma Physics Laboratory. The water was processed in fifteen separate batches to yield approximately 34,400 liters (STP) of hydrogen isotopes. Each batch consisted of round-the-clock operations for approximately nine days. In April 2003 the reactor's palladium-silver membrane ruptured resulting in the shutdown of the PMR process. Reactor performance, process performance and operating experiences have been evaluated and documented. A performance comparison between PMR and current magnesium process is also documented

  5. Porous Photocatalytic Membrane Microreactor (P2M2): A new reactor concept for photochemistry

    NARCIS (Netherlands)

    Aran, H.C.; Salamon, David; Rijnaarts, Timon; Rijnaarts, T.; Mul, Guido; Wessling, Matthias; Lammertink, Rob G.H.

    2011-01-01

    In this study, a new membrane microreactor concept for multiphase photocatalytic reactions is demonstrated. Microfabrication, photocatalyst immobilization and surface modification steps were performed to develop a Porous Photocatalytic Membrane Microreactor (P2M2). This concept benefits from a

  6. Ceramic membranes with mixed conductivity and their application

    Science.gov (United States)

    Kozhevnikov, V. L.; Leonidov, I. A.; Patrakeev, M. V.

    2013-08-01

    Data on the catalytic reactors with ceramic membranes possessing mixed oxygen ion and electronic conductivity that make it possible to integrate the processes of oxygen separation and oxidation are analyzed and generalized. The development of this approach is of interest for the design of energy efficient and environmentally friendly processes for processing natural gas and other raw materials. The general issues concerning the primary processing of light alkanes in reactors with oxygen separating membranes are expounded and general demands to the membrane materials are discussed. Particular attention is paid to the process of oxidative conversion of methane to synthesis gas. The bibliography includes 110 references.

  7. Ceramic membranes with mixed conductivity and their application

    International Nuclear Information System (INIS)

    Kozhevnikov, V L; Leonidov, I A; Patrakeev, M V

    2013-01-01

    Data on the catalytic reactors with ceramic membranes possessing mixed oxygen ion and electronic conductivity that make it possible to integrate the processes of oxygen separation and oxidation are analyzed and generalized. The development of this approach is of interest for the design of energy efficient and environmentally friendly processes for processing natural gas and other raw materials. The general issues concerning the primary processing of light alkanes in reactors with oxygen separating membranes are expounded and general demands to the membrane materials are discussed. Particular attention is paid to the process of oxidative conversion of methane to synthesis gas. The bibliography includes 110 references

  8. The production of hydrogen through the use of a 77 wt% Pd 23 wt% Ag membrane water gas shift reactor

    Directory of Open Access Journals (Sweden)

    Liberty N. Baloyi

    2016-12-01

    Full Text Available Hydrogen as an energy carrier has the potential to decarbonize the energy sector. This work presents the application of a palladium-silver (Pd–Ag membrane-based reactor. The membrane reactor which is made from Pd–Ag film supported by porous stainless steel (PSS is evaluated for the production of hydrogen and the potential replacement of the current two-stage Water-Gas Shift (WGS reaction by a single stage reaction. The permeability of a 20 μm Pd–Ag membrane reactor was examined at 320 °C, 380 °C and 430 °C. The effect of continuous hydrogen exposure on the Pd–Ag membrane at high temperature and low temperature was examined to investigate the thermal stability and durability of the membrane. During continuous operation to determine thermal stability, the membrane reactor exhibited stable hydrogen permeation at 320 °C for 120 h and unstable hydrogen permeation at 430 °C was observed. For the WGS reaction, the reactor was loaded with Ferrochrome catalyst. The membrane showed the ability to produce high purity hydrogen, with a CO conversion and an H2 recovery of 84% and 88%, respectively. The membrane suffered from hydrogen embrittlement due to desorption and adsorption of hydrogen on the membrane surface. SEM analysis revealed cracks that occurred on the surface of the membrane after hydrogen exposure. XRD analysis revealed lattice expansion after hydrogen loading which suggests the occurrence of phase change from α-phase to the more brittle β-phase.

  9. Immobilization of catalase on electrospun PVA/PA6-Cu(II) nanofibrous membrane for the development of efficient and reusable enzyme membrane reactor.

    Science.gov (United States)

    Feng, Quan; Zhao, Yong; Wei, Anfang; Li, Changlong; Wei, Qufu; Fong, Hao

    2014-09-02

    In this study, a mat/membrane consisting of overlaid PVA/PA6-Cu(II) composite nanofibers was prepared via the electrospinning technique followed by coordination/chelation with Cu(II) ions; an enzyme of catalase (CAT) was then immobilized onto the PVA/PA6-Cu(II) nanofibrous membrane. The amount of immobilized catalase reached a high value of 64 ± 4.6 mg/g, while the kinetic parameters (Vmax and Km) of enzyme were 3774 μmol/mg·min and 41.13 mM, respectively. Furthermore, the thermal stability and storage stability of immobilized catalase were improved significantly. Thereafter, a plug-flow type of immobilized enzyme membrane reactor (IEMR) was assembled from the PVA/PA6-Cu(II)-CAT membrane. With the increase of operational pressure from 0.02 to 0.2 MPa, the flux value of IEMR increased from 0.20 ± 0.02 to 0.76 ± 0.04 L/m(2)·min, whereas the conversion ratio of H2O2 decreased slightly from 92 ± 2.5% to 87 ± 2.1%. After 5 repeating cycles, the production capacity of IEMR was merely decreased from 0.144 ± 0.006 to 0.102 ± 0.004 mol/m(2)·min. These results indicated that the assembled IEMR possessed high productivity and excellent reusability, suggesting that the IEMR based on electrospun PVA/PA6-Cu(II) nanofibrous membrane might have great potential for various applications, particularly those related to environmental protection.

  10. Catalytic distillation process

    Science.gov (United States)

    Smith, L.A. Jr.

    1982-06-22

    A method is described for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contacting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C[sub 4] feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

  11. Sequential Aeration of Membrane-Aerated Biofilm Reactors for High-Rate Autotrophic Nitrogen Removal: Experimental Demonstration

    DEFF Research Database (Denmark)

    Pellicer i Nàcher, Carles; Sun, Sheng-Peng; Lackner, Susanne

    2010-01-01

    One-stage autotrophic nitrogen (N) removal, requiring the simultaneous activity of aerobic and anaerobic ammonium oxidizing bacteria (AOB and AnAOB), can be obtained in spatially redox-stratified biofilms. However, previous experience with Membrane-Aerated Biofilm Reactors (MABRs) has revealed...... a difficulty in reducing the abundance and activity of nitrite oxidizing bacteria (NOB), which drastically lowers process efficiency. Here we show how sequential aeration is an effective strategy to attain autotrophic N removal in MABRs: Two separate MABRs, which displayed limited or no N removal under......, by applying periodic aeration to MABRs, one-stage autotrophic N removal biofilm reactors can be easily obtained, displaying very competitive removal rates, and negligible N2O emissions....

  12. Treatment of poultry slaughterhouse wastewater using a static granular bed reactor (SGBR) coupled with ultrafiltration (UF) membrane system.

    Science.gov (United States)

    Basitere, M; Rinquest, Z; Njoya, M; Sheldon, M S; Ntwampe, S K O

    2017-07-01

    The South African poultry industry has grown exponentially in recent years due to an increased demand for their products. As a result, poultry plants consume large volumes of high quality water to ensure that hygienically safe poultry products are produced. Furthermore, poultry industries generate high strength wastewater, which can be treated successfully at low cost using anaerobic digesters. In this study, the performance of a bench-scale mesophilic static granular bed reactor (SGBR) containing fully anaerobic granules coupled with an ultrafiltration (UF) membrane system, as a post-treatment system, was investigated. The poultry slaughterhouse wastewater was characterized by a chemical oxygen demand (COD) range between 1,223 and 9,695mg/L, average biological oxygen demand of 2,375mg/L and average fats, oil and grease (FOG) of 554mg/L. The SGBR anaerobic reactor was operated for 9 weeks at different hydraulic retention times (HRTs), i.e. 55 and 40 h, with an average organic loading rate (OLR) of 1.01 and 3.14g COD/L.day. The SGBR results showed an average COD, total suspended solids (TSS) and FOG removal of 93%, 95% and 90% respectively, for both OLR. The UF post-treatment results showed an average of COD, TSS and FOG removal of 64%, 88% and 48%, respectively. The overall COD, TSS and FOG removal of the system (SGBR and UF membrane) was 98%, 99.8%, and 92.4%, respectively. The results of the combined SGBR reactor coupled with the UF membrane showed a potential to ensure environmentally friendly treatment of poultry slaughterhouse wastewater.

  13. Catalytic performance of strong acid catalyst: Methyl modified SBA-15 loaded perfluorinated sulfonic acid obtained by the waste perfluorinated sulfonic acid ion exchange membrane

    Science.gov (United States)

    Jiang, Tingshun; Huang, Qiuyan; Li, Yingying; Fang, Minglan; Zhao, Qian

    2018-02-01

    Mesoporous molecular sieve (SBA-15) was modified using the trimethylchlorosilane as functional agent and the silylation SBA-15 mesoporous material was prepared in this work. The alcohol solution of perfluorinated sulfonic acid dissolved from the waste perfluorinated sulfonic acid ion exchange membrane (PFSIEM) was loaded onto the resulting mesoporous material by the impregnation method and their physicochemical properties were characterized by FT-IR, N2-physisorption, XRD, TG-DSC and TEM. The catalytic activities of these synthesized solid acid catalysts were evaluated by alkylation of phenol with tert-butyl alcohol. The influence of reaction temperature, weight hour space velocity (WHSV) and reaction time on the phenol conversion and product selectivity were assessed by means of a series of experiments. The results showed that with the increase of the active component of the catalyst, these catalysts still remained good mesoporous structure, but the mesoporous ordering decreased to some extent. These catalysts exhibited good catalytic performance for the alkylation of phenol with tert-butanol. The maximum phenol conversion of 89.3% with 70.9% selectivity to 4-t-butyl phenol (4-TBP) was achieved at 120 °C and the WHSV is 4 h-1. The methyl group was loaded on the surface of the catalyst by trimethylchlorosilane. This is beneficial to retard the deactivation of the catalyst. In this work, the alkylation of phenol with tert-butyl alcohol were carried out using the methyl modified SBA-15 mesoporous materials loaded perfluorinated sulfonic acid as catalysts. The results show that the resulting catalyst exhibited high catalytic activity.

  14. Inverted sugar syrup attained from sucrose hydrolysis using a membrane reactor

    Directory of Open Access Journals (Sweden)

    Ester Junko Tomotani

    2010-09-01

    Full Text Available Invertase, whether adsorbed on styrene-divinylbenzene copolymers or otherwise, was used for continuous sucrose hydrolysis using a cell-type membrane reactor (CTMR, coupled with an ultra (UF-100kDa, or a microfiltration (MF- pore diameter of 5 µm membrane. In all tests, the pH (5.5, temperature (30 ºC, reaction volume (10 mL and agitation (100 rpm were set constant; whereas, variable parameters were: feeding rate (0.4, 0.8 and 1.6 h-1, inlet sucrose concentration (2.5, 6.5, 50 and 100 mM and enzyme/resin ratio (1.64 mg or 3.28 mg of protein per 25, 50 or 100 mg of resin. The best result (yield of 100%, steady-state duration over 20h and specific reaction rate over 243 x 10-3 mmol/h.mE was obtained when insoluble invertase (1.64 mg protein/100 mg resin was used to convert 50 mM or 100 mM of sucrose solution at 0.4 h-1 using a UF-CTMR.Invertase, na forma adsorvida ou não em copolímeros de estireno-divinilbenzeno, foi usada para a hidrólise contínua de sacarose utilizando um reator com membrana (RM, acoplado a uma membrana de ultrafiltração (UF-100kDa, ou de microfiltração (MF - um diâmetro de poro de 5µm. Em todos os testes, o pH (5,5, a temperatura (30ºC, o volume reacional (10mL e a agitação (100 rpm foram mantidas constantes; os parâmetros variados foram: a vazão de alimentação (0,4; 0,8 e 1,6 h-1, a concentração de sacarose alimentada (2,5; 6,5; 50 e 100 mM e a relação enzima/resina (1,64 mg ou 3,28 mg de proteína por 25, 50 ou 100 mg de resina. O melhor resultado (um rendimento de 100%, um período de estado estacionário acima de 20h e uma taxa de reação específica maior de 243 x 10-3 mmol/h.mE foi obtido quando a invertase insolúvel (1,64 mg de proteína/100 de mg resina foi usado para converter 50 mM ou 100 mM de solução de sacarose a 0,4 h-1 usando UF-RM.

  15. Advanced treatment of biologically pretreated coal gasification wastewater by a novel integration of three-dimensional catalytic electro-Fenton and membrane bioreactor.

    Science.gov (United States)

    Jia, Shengyong; Han, Hongjun; Hou, Baolin; Zhuang, Haifeng

    2015-12-01

    Laboratorial scale experiments were conducted to investigate a novel system three-dimensional catalytic electro-Fenton (3DCEF, catalyst of sewage sludge based activated carbon which loaded Fe3O4) integrating with membrane bioreactor (3DCEF-MBR) on advanced treatment of biologically pretreated coal gasification wastewater. The results indicated that 3DCEF-MBR represented high efficiencies in eliminating COD and total organic carbon, giving the maximum removal efficiencies of 80% and 75%, respectively. The integrated 3DCEF-MBR system significantly reduced the transmembrane pressure, giving 35% lower than conventional MBR after 30 days operation. The enhanced hydroxyl radical oxidation and bacteria self repair function were the mechanisms for 3DCEF-MBR performance. Therefore, the integrated 3DCEF-MBR was expected to be the promising technology for advanced treatment in engineering applications. Copyright © 2015. Published by Elsevier Ltd.

  16. Engineering development of ceramic membrane reactor system for converting natural gas to hydrogen and synthesis gas for liquid transportation fuels

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through April 1998.

  17. Commercial steam reforming catalysts to improve biomass gasification with steam-oxygen mixtures. 1: Hot gas upgrading by the catalytic reactor

    Energy Technology Data Exchange (ETDEWEB)

    Caballero, M.A.; Aznar, M.P.; Gil, J.; Martin, J.A.; Frances, E. [Univ. of Saragossa (Spain). Chemical and Environmental Engineering Dept.; Corella, J. [Univ. of Complutense of Madrid (Spain). Chemical Engineering Dept.

    1997-12-01

    Commercial steam reforming (nickel-based) catalysts are used for hot gas cleaning and upgrading in biomass gasification with steam-oxygen mixtures. The gasifier used was an atmospheric and bubbling fluidized bed with an internal diameter of 15 cm and a total height of 3.2 m and was continuously fed with 5--20 kg of biomass/h. Eight different catalysts from four different manufacturers (BASF AG, TOPSOE A/S, ICI, and UCI) have been tested. They were located in a downflow fixed-bed reactor of 4 cm i.d. placed in a slip flow after the gasifier. A guard bed with a calcined dolomite was also used before the catalytic bed to decrease the tar content in the raw gas below the limit of 2 g of tar/m{sup 3}{sub n}, thus avoiding the catalyst deactivation by coke formation. The main variables studied were the temperature of the catalytic bed and the gas composition in the bed. Effects concerning tar elimination will be reported in part 2 of this work. This paper is mainly devoted to characterization of catalysts and to upgrading of the flue gas. H{sub 2} and CO contents increased by 4--14 and 1--8 vol%, dry basis, respectively. CO{sub 2}, CH{sub 4}, and steam contents decreased by 0--14, 87--99, and 2--6 vol %, dry basis, respectively. Other parameters varied in the following ways: the lower heating value decreased by 0.3--1.7 MJ/m{sup 3}{sub n}, gas yield increased by 0.1--0.4 m{sup 3}{sub n}/kg of biomass daf, and apparent thermal efficiency increased by 1--20%. The results presented allow screening of the best catalysts to get an upgraded and useful gas in biomass gasification with steam-oxygen mixtures.

  18. Mixed ionic and electronic conducting ceramic membranes for hydrocarbon processing

    Science.gov (United States)

    Van Calcar, Pamela; Mackay, Richard; Sammells, Anthony F.

    2002-01-01

    The invention relates to mixed phase materials for the preparation of catalytic membranes which exhibit ionic and electronic conduction and which exhibit improved mechanical strength compared to single phase ionic and electronic conducting materials. The mixed phase materials are useful for forming gas impermeable membranes either as dense ceramic membranes or as dense thin films coated onto porous substrates. The membranes and materials of this invention are useful in catalytic membrane reactors in a variety of applications including synthesis gas production. One or more crystalline second phases are present in the mixed phase material at a level sufficient to enhance the mechanical strength of the mixture to provide membranes for practical application in CMRs.

  19. Metallic Membranes for High Temperature Hydrogen Separation

    DEFF Research Database (Denmark)

    Ma, Y.H.; Catalano, Jacopo; Guazzone, Federico

    2013-01-01

    Composite palladium membranes have extensively been studied in laboratories and, more recently, in small pilot industrial applications for the high temperature separation of hydrogen from reactant mixtures such as water-gas shift (WGS) reaction or methane steam reforming (MSR). Composite Pd...... than 1000, respectively. This chapter describes in detail composite Pd-based membrane preparation methods, which consist of the grading of the support and the deposition of the dense metal layer, their performances, and their applications in catalytic membrane reactors (CMRs) at high temperatures (400...

  20. Impact of heterotrophically stressed algae for biofuel production via hydrothermal liquefaction and catalytic hydrotreating in continuous-flow reactors

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, Karl O.; Zhu, Yunhua; Schmidt, Andrew J.; Billing, Justin M.; Hart, Todd R.; Jones, Susanne B.; Maupin, Gary; Hallen, Richard; Ahrens, Toby; Anderson, Daniel

    2016-03-01

    Two algal feedstocks were prepared for direct comparison of their properties when converted to liquid hydrocarbon fuel. The first feedstock was prepared by growing an algal strain phototrophically using a bio-film based approach. The second feedstock employed the same algal strain but was stressed heterotrophically to significantly increase the lipid concentration. The algal feedstocks were converted to liquid hydrocarbon fuels. First, the whole algae (i.e. not defatted or lipid extracted) were converted to an intermediate biocrude using continuous hydrothermal liquefaction (HTL) at 350°C and 3000 psig. The biocrudes were subsequently upgraded via catalytic hydrotreating (HT) at 400°C and 1500 psig to remove oxygen and nitrogen as well as increase the hydrogen-to-carbon ratio. The yield and composition of the products from HTL and HT processing of the feedstocks are compared. A techno-economic analysis of the process for converting each feedstock to liquid fuels was also conducted. The capital and operating costs associated with converting the feedstocks to finished transportation fuels are reported. A fuel minimum selling price is presented as a function of the cost of the algal feedstock delivered to the HTL conversion plant.

  1. Micro-scale H2-CO2 dynamics in a hydrogenotrophic methanogenic membrane reactor

    DEFF Research Database (Denmark)

    Garcia-Robledo, Emilio; Ottosen, Lars Ditlev Mørck; Voigt, Niels Vinther

    2016-01-01

    the activity and stratification of hydrogen consumption above such a membrane was investigated by use of microsensors for hydrogen and pH. A hydrogenotrophic methanogenic community that was able to consume the hydrogen flux within 0.5 mm of the membrane with specific rates of up to 30 m3 H2 m-3 day-1 developed...

  2. Study on treating of low-level radioactive reactor wastewater by combined membrane process (UF-RO)

    International Nuclear Information System (INIS)

    Lu Yunyun; Cao Qiru; Chen Yunming; Huang Lijuan; Bai Xiaofeng; Li Bing; Feng Liang

    2013-01-01

    According to the characteristics of radionuclide exists in the low-level radioactive reactor waste water from HFETR, we use a new combined membrane process separation technology to study the efficient treating of low-lever radioactive reactor wastewater. First, the prepared the simulated wastewater contained Cs + , Sr 2+ , CO 2+ , Ni 2+ , and Fe 3+ . Then, we sequentially investigated the pressure, ion concentration, pH value and EDTA, which have effects on the desalination rate of membrane processing metal ions in wastewater. The results show that: in the condition of pH = 7, and added 0.15 mol/L EDTA, the simulated wastewater separated by UF-RO, desalination rates of Cs + , Sr 2+ , CO 2+ , Ni 2+ and Fe 3+ are all above 95%; In the subsequent trials, adding 0.15 mol/L EDTA into the radioactive residuary solution, and then treating by UF-RO-RO, the decontamination efficiency can reach 95.7%. (authors)

  3. Orientation of the brush-border membranal proteinase which specifically splits the catalytic subunit of cAMP-dependent protein kinase.

    Science.gov (United States)

    De Jonge, H; Schmeeda, H; Shaltiel, S

    1987-12-15

    The active site of the rat intestinal brush-border membranal proteinase [Alhanaty E. and Shaltiel S. (1979) Biochem. Biophys. Res. Commun. 89, 323-332], which splits the catalytic subunit (C) of cAMP-dependent protein kinase with a remarkable specificity [Alhanaty E., Tauber-Finkelstein, M., Schmeeda, H. and Shaltiel, S. (1985) Curr. Topics Cell. Regul. 27, 267-277], is shown to face predominantly the cell exterior; vesicles prepared from these brush-borders (mostly sealed and right-side-out) fully express the proteinase activity as judged by the fact that there is no increase in activity upon rupture or solubilization of the vesicles. Although the brush-border vesicles contain a cAMP-dependent protein kinase, this membrane-bound kinase is not likely to be the physiological target of the proteinase, since it appears to have an intracellular orientation and, at least in the vesicles, to be inaccessible to the proteinase. It is, therefore, suggested that the physiological substrate of the proteinase might be either an extracellular cAMP-dependent protein kinase, which is lost (e.g. removed, inactivated or degraded) in the course of vesicle isolation, or a kinase domain in one of the family of proteins recently shown to have a considerable structural and conformational homology with C. Alternatively the physiological site of action of this kinase-splitting proteinase might be an intracellular organelle to which it is translocated by endocytosis.

  4. Insight into effects of antibiotics on reactor performance and evolutions of antibiotic resistance genes and microbial community in a membrane reactor.

    Science.gov (United States)

    Wen, Qinxue; Yang, Lian; Zhao, Yaqi; Huang, Long; Chen, Zhiqiang

    2018-04-01

    A lab-scale anoxic/oxic-membrane bioreactor was designed to treat antibiotics containing wastewater at different antibiotics concentrations (0.5 mg/L, 1 mg/L and 3 mg/L of each antibiotic). Overall COD and NH 4 + N removal (more than 90%) were not affected during the exposure to antibiotics and good TN removal was also achieved, while TP removal was significantly affected. The maximum removal efficiency of penicillin and chlorotetracycline reached 97.15% and 96.10% respectively due to strong hydrolysis, and sulfamethoxazole reached 90.07% by biodegradation. However, 63.87% of norfloxacin maximum removal efficiency was achieved mainly by sorption. The system had good ability to reduce ARGs, peaking to more than 4 orders of magnitude, which mainly depended on the biomass retaining of the membrane module. Antibiotics concentration influenced the evolution of ARGs and bacterial communities in the reactor. This research provides great implication to reduce ARGs and antibiotics in antibiotics containing wastewater using A/O-MBR. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Catalytic Intermediate Pyrolysis of Napier Grass in a Fixed Bed Reactor with ZSM-5, HZSM-5 and Zinc-Exchanged Zeolite-A as the Catalyst

    Directory of Open Access Journals (Sweden)

    Isah Yakub Mohammed

    2016-03-01

    Full Text Available The environmental impact from the use of fossil fuel cum depletion of the known fossil oil reserves has led to increasing interest in liquid biofuels made from renewable biomass. This study presents the first experimental report on the catalytic pyrolysis of Napier grass, an underutilized biomass source, using ZSM-5, 0.3HZSM-5 and zinc exchanged zeolite-A catalyst. Pyrolysis was conducted in fixed bed reactor at 600 °C, 30 °C/min and 7 L/min nitrogen flow rate. The effect of catalyst-biomass ratio was evaluated with respect to pyrolysis oil yield and composition. Increasing the catalyst loading from 0.5 to 1.0 wt % showed no significant decrease in the bio-oil yield, particularly, the organic phase and thereafter decreased at catalyst loadings of 2.0 and 3.0 wt %. Standard analytical methods were used to establish the composition of the pyrolysis oil, which was made up of various aliphatic hydrocarbons, aromatics and other valuable chemicals and varied greatly with the surface acidity and pore characteristics of the individual catalysts. This study has demonstrated that pyrolysis oil with high fuel quality and value added chemicals can be produced from pyrolysis of Napier grass over acidic zeolite based catalysts.

  6. Catalytic Synthesis of Substrate-Free, Aligned and Tailored High Aspect Ratio Multiwall Carbon Nanotubes in an Ultrasonic Atomization Head CVD Reactor

    Directory of Open Access Journals (Sweden)

    Fahad Ali Rabbani

    2016-01-01

    Full Text Available Chemical vapor deposition (CVD method has proven its benchmark, over other methods, for the production of different types of carbon nanotubes (CNT on commercial and lab scale. In this study, an injection vertical CVD reactor fitted with an ultrasonic atomization head was used in a pilot-plant scale (height 274 cm, radius 25 cm for semicontinuous production of multiwall carbon nanotubes (MWCNTs. p-Xylene was used as a hydrocarbon precursor in which ferrocene was dissolved and provided the cracking catalyst. Atomization of the feed solution resulted in full and even dispersion of the catalytic solution. This dispersion led to the production of high aspect ratio MWCNTs (ranging from 8,000 to 12,000 at 850°C. Different experimental parameters affecting the quality and quantity of the produced CNTs were investigated. These included temperature, reaction time, and flow rate of the reaction and carrier gases. Different properties of the produced CNTs were characterized using SEM and TEM, while TGA was used to evaluate their purity. Specific surface area of selected samples was calculated by BET.

  7. Integrated Removal of NOx with Carbon Monoxide as Reductant, and Capture of Mercury in a Low Temperature Selective Catalytic and Adsorptive Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Neville Pinto; Panagiotis Smirniotis; Stephen Thiel

    2010-08-31

    Coal will likely continue to be a dominant component of power generation in the foreseeable future. This project addresses the issue of environmental compliance for two important pollutants: NO{sub x} and mercury. Integration of emission control units is in principle possible through a Low Temperature Selective Catalytic and Adsorptive Reactor (LTSCAR) in which NO{sub x} removal is achieved in a traditional SCR mode but at low temperature, and, uniquely, using carbon monoxide as a reductant. The capture of mercury is integrated into the same process unit. Such an arrangement would reduce mercury removal costs significantly, and provide improved control for the ultimate disposal of mercury. The work completed in this project demonstrates that the use of CO as a reductant in LTSCR is technically feasible using supported manganese oxide catalysts, that the simultaneous warm-gas capture of elemental and oxidized mercury is technically feasible using both nanostructured chelating adsorbents and ceria-titania-based materials, and that integrated removal of mercury and NO{sub x} is technically feasible using ceria-titania-based materials.

  8. Catalytic pyrolysis of Alcea pallida stems in a fixed-bed reactor for production of liquid bio-fuels.

    Science.gov (United States)

    Aysu, Tevfik

    2015-09-01

    Pyrolysis of Alcea pallida stems was performed in a fixed-bed tubular reactor with and without catalyst at three different temperatures. The effects of pyrolysis parameters including temperature and catalyst on the product yields were investigated. It was found that higher temperature resulted in lower liquid (bio-oil) and solid (bio-char) yields and higher gas yields. Catalysts had different effects on product yields and composition of bio-oils. Liquid yields were increased in the presence of zinc chloride and alumina but decreased with calcium hydroxide, tincal and ulexite. The highest bio-oil yield (39.35%) by weight including aqueous phase was produced with alumina catalyst at 500 °C. The yields of bio-char, bio-oil and gas produced, as well as the compositions of the resulting bio-oils were determined by elemental analysis, TGA, FT-IR and GC-MS. 160 different compounds were identified by GC-MS in the bio-oils obtained at 500 °C. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Membrane technology as a promising alternative in biodiesel production: a review.

    Science.gov (United States)

    Shuit, Siew Hoong; Ong, Yit Thai; Lee, Keat Teong; Subhash, Bhatia; Tan, Soon Huat

    2012-01-01

    In recent years, environmental problems caused by the use of fossil fuels and the depletion of petroleum reserves have driven the world to adopt biodiesel as an alternative energy source to replace conventional petroleum-derived fuels because of biodiesel's clean and renewable nature. Biodiesel is conventionally produced in homogeneous, heterogeneous, and enzymatic catalysed processes, as well as by supercritical technology. All of these processes have their own limitations, such as wastewater generation and high energy consumption. In this context, the membrane reactor appears to be the perfect candidate to produce biodiesel because of its ability to overcome the limitations encountered by conventional production methods. Thus, the aim of this paper is to review the production of biodiesel with a membrane reactor by examining the fundamental concepts of the membrane reactor, its operating principles and the combination of membrane and catalyst in the catalytic membrane. In addition, the potential of functionalised carbon nanotubes to serve as catalysts while being incorporated into the membrane for transesterification is discussed. Furthermore, this paper will also discuss the effects of process parameters for transesterification in a membrane reactor and the advantages offered by membrane reactors for biodiesel production. This discussion is followed by some limitations faced in membrane technology. Nevertheless, based on the findings presented in this review, it is clear that the membrane reactor has the potential to be a breakthrough technology for the biodiesel industry. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. The application of membrane Bio-Reactor for East Java Domestic waste water treatment

    Directory of Open Access Journals (Sweden)

    Aisyah E. Palupi

    2008-01-01

    Full Text Available Membrane bioreactors for wastewater treatment research have been carried out. In this system, membrane replaces the function of the sedimentation tank. Until recent time, fouling was still the main problem for membrane processes. This research has investigated the effect of MLSS concentration and back flushing on external membrane bioreactor performances such as COD and BOD reduction, and the back flushing effect for domestic wastewater treatment. Polyacrylonitril hollow fiber membrane with pore diameter 0.1-0.01 m, surface area 0.075 m2 was used in this research. This process was at HRT 5 hour, no sludge disposal, intermittent operation, and permeate exiting from membrane shell side. Optimum condition was obtained at a transmembrane pressure (TMP of 1.45 bar. Back flushing was conducted for 10 minute at 3.0 bar pressure. Effective back flushing was shown after operation at MLSS of 7500 and 10000 mg/l. The result of this research shows that COD and BOD in the domestic wastewater decreased almost 98%. MLSS and MLVSS degradations were 98.6% and 98%, respectively.

  11. Multifunctional nanocomposite hollow fiber membranes by solvent transfer induced phase separation.

    Science.gov (United States)

    Haase, Martin F; Jeon, Harim; Hough, Noah; Kim, Jong Hak; Stebe, Kathleen J; Lee, Daeyeon

    2017-11-01

    The decoration of porous membranes with a dense layer of nanoparticles imparts useful functionality and can enhance membrane separation and anti-fouling properties. However, manufacturing of nanoparticle-coated membranes requires multiple steps and tedious processing. Here, we introduce a facile single-step method in which bicontinuous interfacially jammed emulsions are used to form nanoparticle-functionalized hollow fiber membranes. The resulting nanocomposite membranes prepared via solvent transfer-induced phase separation and photopolymerization have exceptionally high nanoparticle loadings (up to 50 wt% silica nanoparticles) and feature densely packed nanoparticles uniformly distributed over the entire membrane surfaces. These structurally well-defined, asymmetric membranes facilitate control over membrane flux and selectivity, enable the formation of stimuli responsive hydrogel nanocomposite membranes, and can be easily modified to introduce antifouling features. This approach forms a foundation for the formation of advanced nanocomposite membranes comprising diverse building blocks with potential applications in water treatment, industrial separations and as catalytic membrane reactors.

  12. Porous polyoxadiazole membranes for harsh environment

    KAUST Repository

    Maab, Husnul

    2013-10-01

    A series of polyoxadiazoles with exceptionally high stability at temperatures as high as 370°C and in oxidative medium has been synthesized by polycondensation and manufactured into porous membranes by phase inversion. The membranes were characterized by thermal analysis (TGA), chemical stability was measured by immersion test, oxidative stability by Fenton\\'s test, pore diameter by porosimetry and the morphology by FESEM. The polymers are soluble only in sulfuric acid and are stable in organic solvents like NMP, THF and isopropanol. The membranes selectivity was confirmed by separation of polystyrene standards with different molecular weights. Most membranes were characterized as having a cut-off of 60,000. g/mol. Being stable under harsh environments, the membranes have incomparable characteristics with perspectives of application in chemical and pharmaceutical industry, catalytic reactors, in combination with oxidative processes and other applications so far envisioned only for ceramic membranes. © 2013.

  13. Solar membrane natural gas steam-reforming process: evaluation of reactor performance

    NARCIS (Netherlands)

    de Falco, M.; Basile, A.; Gallucci, F.

    2010-01-01

    In this work, the performance of an innovative plant for efficient hydrogen production using solar energy for the process heat duty requirements has been evaluated via a detailed 2D model. The steam-reforming reactor consists of a bundle of coaxial double tubes assembled in a shell. The annular

  14. Enrichment of Thermophilic Syntrophic Anaerobic Glutamate-Degrading Consortia using a Dialysis Membrane Reactor

    NARCIS (Netherlands)

    Plugge, C.M.; Stams, A.J.M.

    2002-01-01

    A dialysis cultivation system was used to enrich slow-growing moderately thermophilic anaerobic bacteria at high cell densities. Bicarbonate buffered mineral salts medium with 5 mM glutamate as the sole carbon and energy source was used and the incubation temperature was 55 degrees C. The reactor

  15. Efficiency-optimized CO2 separation in IGCC power plants by water-gas shift membrane reactors

    International Nuclear Information System (INIS)

    Schiebahn, Sebastian Thomas

    2013-01-01

    The conversion of solid fuels such as coal and biomass into syngas in the integrated gasification combined cycle (IGCC) process is carried out at elevated pressure. Since, from a thermodynamic point of view, this is a crucial prerequisite for an efficient CO 2 separation step, IGCC has great potential for incorporating CO 2 separation with a low energy consumption. However, studies predict efficiency penalties in the range of 6-11 %-points depending on the respective gasification process utilized, thus revealing that the thermodynamic potential is not fully exploited. In this thesis, a specially adapted IGCC power plant concept for the optimized implementation of gas separation membranes was developed and investigated in order to evaluate the extent to which the auxiliary boundary conditions can be advantageously designed. To create a standard of comparison, a reference IGCC power plant as well as a Selexol-based CO 2 scrubbing process were designed and simulated, resulting in an overall efficiency reduction from 48.0 % to 38.4 %. This corresponds to an increase of 25 % in coal consumption. The analysis of the simulation results revealed that, besides the auxiliary demand of Selexol scrubbing and CO 2 compression subsequent to the low pressure regeneration of the solvent, the main contributor to the loss is the water-gas shift reaction. To reduce this high efficiency penalty, an integration concept was developed to optimize the use of the gas permeation membrane, with parameters better adapted to its special characteristics and mode of operation. The design process resulted in the use of an H 2 -selective membrane, which was combined with the water-gas shift reaction to create the water-gas shift membrane reactor (WGS-MR), and which was swept with recirculated flue gas at elevated pressure in countercurrent 4-End mode. In addition, the ''membrane steam recuperator'' was introduced as a new process unit and integrated to enhance the steam utilization within the

  16. Optimization of the biological process using flat membrane bioreactors. Maximum treatment performance with minimum reactor volume; Optimizacion del proceso biologico con BRM de membrana plana. Maximo rendimiento de depuracion con minimo volumen de reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lluch Vallmithana, S.; Lopez Gavin, A.

    2006-07-01

    In a conventional activated sludge process, the membranes are inside the biological reactor where they drain the water through suction or a water column. This system can be operated with heavy loads and sludge of 12-14 g/l or more, and is not affected by problems of bulking or foaming. This makes it suitable for treating difficult industrial waste waters, providing treated water that is free of bacteria and viruses. Micro filtration membranes are flat without any rubbing between them. The membranes require infrequent chemical cleaning and do not need back washing. As no final sedimented is needed, the waste water treatment plant occupies less space. (Author)

  17. An extractive membrane biofilm reactor as alternative technology for the treatment of methyl tert-butyl ether contaminated water.

    Science.gov (United States)

    Guisado, I M; Purswani, J; González-López, J; Pozo, C

    2016-09-01

    Among the strategies developed for contaminated groundwater bioremediation, those based on the use of bacteria adhering to inert supports and establishing biofilms have gained great importance in this field. Extractive membrane biofilm reactor (EMBFR) technology offers productive solutions for the removal of volatile and semi-volatile compounds. EMBFR technology is based on the use of extractive semipermeable membranes through which contaminants migrate to the biological compartment in which microorganisms with pollutant biotransformation and/or mineralization capacities can grow, forming an active biofilm on the membrane surface. The objective of this study was to assess the use of three bacterial strains (Paenibacillus sp. SH7 CECT 8558, Agrobacterium sp. MS2 CECT 8557, and Rhodococcus ruber EE6 CECT 8612), as inoculum in a lab-scale EMBFR running for 28 days under aerobic conditions to eliminate methyl tert-butyl ether (MTBE) from water samples. Three different hydraulic retention times (1, 6, and 12 h) were employed. MTBE degradation values were determined daily by a gas GC-MS technique, as well as suspended bacterial growth. The biofilm established by the bacterial strains on the semipermeable membrane was detected by Field-Emission Scanning Electron Microscopy (FESEM) at the end of each experiment. The acute toxicity of the treated effluents and biomedium was determined by Microtox © assay (EC 50 ).The results achieved from the MTBE degradation, biofilm formation, and toxicity analysis indicated that bacterial strains MS2 and EE6 were the best options as selective inoculum, although further research is needed, particularly with regard to their possible use as a mixed culture. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1238-1245, 2016. © 2016 American Institute of Chemical Engineers.

  18. Catalytic phosphonation of high performance polymers and POSS. Novel components for polymer blend and nanocomposite fuel cell membranes

    Energy Technology Data Exchange (ETDEWEB)

    Bock, T.R.

    2006-10-15

    Aim of this thesis was the preparation and evaluation of phosphonated high performance (HP) polyelectrolytes and polyhedral oligomeric silsesquioxanes (POSS) for polyelectrolyte membrane fuel cell (PEMFC) application. Brominated derivatives of the commercial high performance (HP) polymers poly(ethersulfone) (PES), poly(etheretherketone) (PEEK), poly(phenylsulfone) (PPSu), poly(sulfone) (PSU) and of octaphenyl-POSS of own production were phosphonated by Ni-catalysed Arbuzov reaction. Phosphonated PSU was cast into pure and blend films with sulfonated PEEK (s-PEEK) to investigate H+-conductivity, water uptake and film morphology. Blend films' properties were referenced to films containing unmodified blend partners. Solution-compounding of phosphonated octaphenyl-POSS and s-PEEK was used to produce novel nanocomposite films. An in-situ zirconisation method was assessed as convenient strategy for novel ionically crosslinked membranes of enhanced swelling resistance. Dibromo isocyanuric acid (DBI) and N-bromo succinimide (NBS) as brominating agents allowed polymer analogous preparation of the novel brominated PES and PEEK with precise reaction control. A random distribution of functional groups, i.e. polyelectrolytes' microstructural homogeneity was revealed as decisive factor concerning solubility of phosphonated PSU. Brominated phT8 was prepared with Br2 by a high temperature approach in tetrachloroethane (TCE). Brominated polymers were phosphonated by Ni-catalysis in non-coordinating high temperature solvents, such as diphenylether, benzophenone and diphenylsulfone without notable solvent influence. The lack of solvent - catalyst complexes and high reaction temperatures of 180-200 C led to halogen-free phosphonates with unprecedented high functionalities. Polymer analogous application of P(OSiMe3)3 offered a novel direct access to easily cleavable disilyl ester derivatives. These were obtained from PEEK and PSU in near quantitative yields at NiCl2-loads as

  19. Comparative study between chemostat and batch reactors to quantify membrane permeability changes on bacteria exposed to silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Anaya, Nelson M.; Faghihzadeh, Fatemeh [Department of Civil and Environmental Engineering, University of Rhode Island, 1 Lippitt Rd., Bliss Hall 203, Kingston, RI 02881 (United States); Ganji, Nasim; Bothun, Geoff [Department of Chemical Engineering, University of Rhode Island, 16 Greenhouse Rd., Crawford Hall, Kingston, RI 02881 (United States); Oyanedel-Craver, Vinka, E-mail: craver@uri.edu [Department of Civil and Environmental Engineering, University of Rhode Island, 1 Lippitt Rd., Bliss Hall 203, Kingston, RI 02881 (United States)

    2016-09-15

    Continuous and batch reactors were used to assess the effect of the exposure of casein-coated silver nanoparticles (AgNPs) on Escherichia coli (E. coli). Additionally, E. coli membrane extracts, membrane permeability and Langmuir film balance assays were used to determine integrity and changes in lipid composition in response to AgNPs exposure. Results showed that batch conditions were not appropriate for the tests due to the production of exopolymeric substances (EPS) during the growth phase. After 5 h of contact between AgNPs and the used growth media containing EPS, the nanoparticles increased in size from 86 nm to 282 nm reducing the stability and thus limiting cell-nanoparticle interactions. AgNPs reduced E. coli growth by 20% at 1 mg/L, in terms of Optical Density 670 (OD670), while no effect was detected at 15 mg/L. At 50 mg/L of AgNPs was not possible to perform the test due to aggregation and sedimentation of the nanoparticles. Membrane extract assays showed that at 1 mg/L AgNPs had a greater change in area (− 4.4cm{sup 2}) on bacteria compared to 15 mg/L (− 4.0cm{sup 2}). This area increment suggested that membrane disruption caused by AgNPs had a stabilizing/rigidifying effect where the cells responded by shifting their lipid composition to more unsaturated lipids to counteract membrane rigidification. In chemostats, the constant inflow of fresh media and aeration resulted in less AgNPs aggregation, thus increased the AgNPs-bacteria interactions, in comparison to batch conditions. AgNPs at 1 mg/L, 15 mg/L, and 50 mg/L inhibited the growth (OD670 reduction) by 0%, 11% and 16.3%, respectively. Membrane extracts exposed to 1 mg/L, 15 mg/L, and 50 mg/L of AgNPs required greater changes in area by − 0.5 cm{sup 2}, 2.7 cm{sup 2} and 3.6 cm{sup 2}, respectively, indicating that the bacterial membranes were disrupted and bacteria responded by synthesizing lipids that stabilize or strengthen membranes. This study showed that the chemostat is more

  20. Hollow fiber membrane based H-2 diffusion for efficient in situ biogas upgrading in an anaerobic reactor

    DEFF Research Database (Denmark)

    Luo, Gang; Angelidaki, Irini

    2013-01-01

    rate was increased to 1,760 ml/(l  day); however, the pH increased to around 8.3 due to bicarbonate consumption which hampered the anaerobic process. The biofilm formed on the HFM was found not to be beneficial for the process since it increased the resistance of H2 diffusion to the liquid. The study......Bubbleless gas transfer through a hollow fiber membrane (HFM) module was used to supply H2 to an anaerobic reactor for in situ biogas upgrading, and it creates a novel system that could achieve a CH4 content higher than 90 % in the biogas. The increase of CH4 content and pH, and the decrease...

  1. Effect of Mass-Transport Limitations on the Performance of a Packed Bed Membrane Reactor for Partial Oxidations. Intraparticle Mass Transport

    NARCIS (Netherlands)

    van Sint Annaland, M.; Kurten, U.; Kuipers, J.A.M.

    2007-01-01

    For partial oxidation systems, where the reaction order in oxygen of the formation rate of the target product is smaller than the reaction order in oxygen of the consecutive reaction rate toward the waste product, a packed bed membrane reactor can be applied to distributively dose oxygen along the

  2. Characterization of the gas releasing behaviors of catalytic pyrolysis of rice husk using potassium over a micro-fluidized bed reactor

    International Nuclear Information System (INIS)

    Liu, Yuan; Wang, Yan; Guo, Feiqiang; Li, Xiaolei; Li, Tiantao; Guo, Chenglong; Chang, Jiafu

    2017-01-01

    Highlights: • Releasing propensity of CO, CO 2 , CH 4 and H 2 was studied in a micro-fluidized bed. • Gas releasing pattern was influenced by temperature and potassium concentration. • Variations in gas forming E a are indicative of catalytic performance of potassium. - Abstract: Influence of potassium on the gas releasing behaviors during rice husk high-temperature pyrolysis was investigated under isothermal conditions in a two stage micro-fluidized bed reactor. Reaction kinetics for generating H 2 , CO, CO 2 and CH 4 was investigated based on the Friedman and model-fitting approaches. Results indicated that different gas species had different times to start and end the gas release process, particularly at 600 °C, representing different chemical routes and mechanics for generating these gas components. The resulting apparent activation energies for H 2 , CO, and CO 2 decreased from 23.10 to 12.00 kJ/mol, 15.48 to 14.03 kJ/mol and 10.14 to 7.61 kJ/mol respectively with an increase in potassium concentration from 0 to 0.5 mol/kg, while that for CH 4 increased from 16.85 to 19.40 kJ/mol. The results indicated that the addition of potassium could promote the generation reactions of H 2 , CO and CO 2 while hinder the generation reactions of CH 4 . The pyrolysis reaction was further found to be subject to the three-dimensional diffusion model for all the samples.

  3. Start-up strategies of membrane-aerated biofilm reactor (MABR) for completely autotrophic nitrogen removal

    DEFF Research Database (Denmark)

    Sun, Sheng-Peng; Pellicer i Nàcher, Carles; Terada, Akihiko

    2009-01-01

    Completely autotrophic nitrogen removal, coupling aerobic and anaerobic ammonium oxidation, can be achieved via redox stratified biofilms growing on gas-permeable membranes. These sequential reactions are mediated by aerobic and anaerobic ammonium oxidizing bacteria (AOB and AnAOB). The major...

  4. Reactor

    International Nuclear Information System (INIS)

    Fujibayashi, Toru.

    1976-01-01

    Object: To provide a boiling water reactor which can enhance a quake resisting strength and flatten power distribution. Structure: At least more than four fuel bundles, in which a plurality of fuel rods are arranged in lattice fashion which upper and lower portions are supported by tie-plates, are bundled and then covered by a square channel box. The control rod is movably arranged within a space formed by adjoining channel boxes. A spacer of trapezoidal section is disposed in the central portion on the side of the channel box over substantially full length in height direction, and a neutron instrumented tube is disposed in the central portion inside the channel box. Thus, where a horizontal load is exerted due to earthquake or the like, the spacers come into contact with each other to support the channel box and prevent it from abnormal vibrations. (Furukawa, Y.)

  5. Reactor

    International Nuclear Information System (INIS)

    Evans, R.M.

    1976-01-01

    Disclosed is a neutronic reactor having a moderator, coolant tubes traversing the moderator from an inlet end to an outlet end, bodies of material fissionable by neutrons of thermal energy disposed within the coolant tubes, and means for circulating water through said coolant tubes characterized by the improved construction wherein the coolant tubes are constructed of aluminum having an outer diameter of 1.729 inches and a wall thickness of 0.059 inch, and the means for circulating a liquid coolant through the tubes includes a source of water at a pressure of approximately 350 pounds per square inch connected to the inlet end of the tubes, and said construction including a pressure reducing orifice disposed at the inlet ends of the tubes reducing the pressure of the water by approximately 150 pounds per square inch. 1 claim, 16 figures

  6. Reactor building 3D-model for evaluating the pressures on concrete regularization and foundation waterproofing membrane

    International Nuclear Information System (INIS)

    Mello Junior, Glauco J.T.; Cardoso, Tarcisio de F.; Prates, Carlos L.M.

    2009-01-01

    Angra dos Reis site in Brazil has already 2 operating PWR NPPs. Unit 3, with identical design to Unit 2, also a 1350 MW PWR, is expected to have its construction started in 2009. This new plant shall be founded directly on sound rock. The first step is to prepare this rock surface with a concrete regularization and a foundation waterproofing membrane. This study presents a 3D model approach of the corresponding reactor building to verify the maximum pressure acting on this surface. The 3D model permits to show a more realistic pressure distribution at every foundation specific detail. A static analysis is performed using ANSYS Mechanical Release 11.1. Dead weight, permanent and live loads, Safe Shutdown Earthquake (SSE) combined with Burst Pressure Wave (BPW) from the Feedwater Tank (SSB=SSE+BPW) and differences of temperature are taken into account. Considering all foundation nodes , the pressure distribution on the waterproofing membrane for each load case is obtained for vertical and horizontal directions, which corresponds to compression and tangential reaction loads. The maximum values occur in distinct positions for each load case. The maximum results are obtained according to DIN 25449 (2008) load combination criteria. The results are compared to a simplified analysis performed before, showing a good agreement in global values. (author)

  7. Effects of COD/N ratio on soluble microbial products in effluent from sequencing batch reactors and subsequent membrane fouling.

    Science.gov (United States)

    Ly, Quang Viet; Nghiem, Long D; Sibag, Mark; Maqbool, Tahir; Hur, Jin

    2018-05-01

    The relative ratios of chemical oxygen demand (COD) to nitrogen (N) in wastewater are known to have profound effects on the characteristics of soluble microbial products (SMP) from activated sludge. In this study, the changes in the SMP characteristics upon different COD/N ratios and the subsequent effects on ultrafiltration (UF) membrane fouling potentials were examined in sequencing batch reactors (SBR) using excitation emission matrix-parallel factor analysis (EEM-PARAFAC) and size exclusion chromatography (SEC). Three unique fluorescent components were identified from the SMP samples in the bioreactors operated at the COD/N ratios of 100/10 (N rich), 100/5 (N medium), and 100/2 (N deficient). The tryptophan-like component (C1) was the most depleted at the N medium condition. Fulvic-like (C2) and humic-like (C3) components were more abundant with N rich wastewater. Greater abundances of large size biopolymer (BP) and low molecular weight neutrals (LMWN) were found under the N deficient and N rich conditions, respectively. SMPs from various COD/N exhibited a greater degree on membrane fouling following the order of 100/2 > 100/10 > 100/5. C1 and C2 had close associations with reversible and irreversible fouling, respectively, while the reversible fouling potential of C3 depended on the COD/N ratios. No significant impact of COD/N ratio was observed on the relative contributions of SMP size fractions to either reversible or irreversible fouling potential. However, the COD/N ratios likely altered the BP foulants' composition with greater contribution of proteinaceous substances to reversible fouling under the N deficient condition than at other N richer conditions. The opposite trend was observed for irreversible fouling. Our results provided further insight into changes in different SMP constitutes and their membrane fouling in response to microbial activities under different COD/N ratios. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Membrane biofouling in a wastewater nitrification reactor: Microbial succession from autotrophic colonization to heterotrophic domination.

    Science.gov (United States)

    Lu, Huijie; Xue, Zheng; Saikaly, Pascal; Nunes, Suzana P; Bluver, Ted R; Liu, Wen-Tso

    2016-01-01

    Membrane biofouling is a complex process that involves bacterial adhesion, extracellular polymeric substances (EPS) excretion and utilization, and species interactions. To obtain a better understanding of the microbial ecology of biofouling process, this study conducted rigorous, time-course analyses on the structure, EPS and microbial composition of the fouling layer developed on ultrafiltration membranes in a nitrification bioreactor. During a 14-day fouling event, three phases were determined according to the flux decline and microbial succession patterns. In Phase I (0-2 days), small sludge flocs in the bulk liquid were selectively attached on membrane surfaces, leading to the formation of similar EPS and microbial community composition as the early biofilms. Dominant populations in small flocs, e.g., Nitrosomonas, Nitrobacter, and Acinetobacter spp., were also the major initial colonizers on membranes. In Phase II (2-4 d), fouling layer structure, EPS composition, and bacterial community went through significant changes. Initial colonizers were replaced by fast-growing and metabolically versatile heterotrophs (e.g., unclassified Sphingobacteria). The declining EPS polysaccharide to protein (PS:PN) ratios could be correlated well with the increase in microbial community diversity. In Phase III (5-14 d), heterotrophs comprised over 90% of the community, whereas biofilm structure and EPS composition remained relatively stable. In all phases, AOB and NOB were constantly found within the top 40% of the fouling layer, with the maximum concentrations around 15% from the top. The overall microbial succession pattern from autotrophic colonization to heterotrophic domination implied that MBR biofouling could be alleviated by forming larger bacterial flocs in bioreactor suspension (reducing autotrophic colonization), and by designing more specific cleaning procedures targeting dominant heterotrophs during typical filtration cycles. Copyright © 2015 Elsevier Ltd. All

  9. Membrane biofouling in a wastewater nitrification reactor: microbial succession from autotrophic colonization to heterotrophic domination

    KAUST Repository

    Lu, Huijie

    2015-10-22

    Membrane biofouling is a complex process that involves bacterial adhesion, extracellular polymeric substances (EPS) excretion and utilization, and species interactions. To obtain a better understanding of the microbial ecology of biofouling process, this study conducted rigorous, time-course analyses on the structure, EPS and microbial composition of the fouling layer developed on ultrafiltration membranes in a nitrification bioreactor. During a 14-day fouling event, three phases were determined according to the flux decline and microbial succession patterns. In Phase I (0-2 days), small sludge flocs in the bulk liquid were selectively attached on membrane surfaces, leading to the formation of similar EPS and microbial community composition as the early biofilms. Dominant populations in small flocs, e.g., Nitrosomonas, Nitrobacter, and Acinetobacter spp., were also the major initial colonizers on membranes. In Phase II (2-4 d), fouling layer structure, EPS composition, and bacterial community went through significant changes. Initial colonizers were replaced by fast-growing and metabolically versatile heterotrophs (e.g., unclassified Sphingobacteria). The declining EPS polysaccharide to protein (PS:PN) ratios could be correlated well with the increase in microbial community diversity. In Phase III (5-14 d), heterotrophs comprised over 90% of the community, whereas biofilm structure and EPS composition remained relatively stable. In all phases, AOB and NOB were constantly found within the top 40% of the fouling layer, with the maximum concentrations around 15% from the top. The overall microbial succession pattern from autotrophic colonization to heterotrophic domination implied that MBR biofouling could be alleviated by forming larger bacterial flocs in bioreactor suspension (reducing autotrophic colonization), and by designing more specific cleaning procedures targeting dominant heterotrophs during typical filtration cycles.

  10. An isoelectrically trapped enzyme reactor operating in an electric field.

    Science.gov (United States)

    Righetti, P G; Bossi, A

    1998-06-01

    Membrane enzyme reactors constitute an attempt at integrating catalytic conversion, product separation and/or concentration and catalyst recovery into a single operation. Whereas conventional membrane reactors confine an enzyme, in a free form, to one side of a membrane by size exclusion, electrostatic repulsion, or physical or chemical immobilization onto an intermediate support (gel, liposome), the membrane reactor here described is shown to operate under an entirely new principle: enzyme confinement into an isoelectric trap located in a multicompartment electrolyzer operating in an electric field. Two isoelectric membranes, having pI values encompassing both the enzyme pI and the pH of its optimum of activity, act by continuously titrating the enzyme trapped inside, thus preventing it from escaping the reaction chamber. Charged products generated by the enzyme catalysis are continuously electrophoretically transported away from the reaction chamber and collected into other chambers stacked either towards the cathodic or anodic sides. In a urease reactor, ammonia is continuously harvested towards the cathode, thus allowing >95% substrate consumption with maintenance of enzyme integrity over much longer time periods than in a batch reactor. In a trypsin reactor, casein is digested and biologically active peptides are continuously harvested in a pure form into appropriate isoelectric traps. In a third example, pure D-phenylglycine is produced from a racemate mixture, via an acylation reaction onto a cosubstrate (the ester methyl-4-hydroxyphenyl acetate), brought about by the enzyme penicillin G acylase.

  11. Autotrophic Nitrogen Removal in a Membrane-Aerated Biofilm Reactor Under Continuous Aeration: A Demonstration

    DEFF Research Database (Denmark)

    Gilmore, Kevin R.; Terada, Akihiko; Smets, Barth F.

    2013-01-01

    and allowed anaerobic ammonium-oxidizing bacteria (AnaerAOB) to develop and be retained for > 250 days. Daily autotrophic nitrogen removal of 1.7 g N/m(2) (75% of influent N load) was achieved at an oxygen/nitrogen surface loading ratio of 2.2, with up to 85% of the influent N proceeding through Anaer...... nearest to and AnaerAOB furthest from the membrane. Despite the presence of nitrite-oxidizing bacteria, this work demonstrated that these autotrophic processes can be successfully coupled in an MABR with continuous aeration, achieving the benefits of competitive specific N removal rates...

  12. Innovation in sodium erythorbate production. The use of membrane-reactors

    Energy Technology Data Exchange (ETDEWEB)

    Spigno, G. [Piacenza Univ. Cattolica del S. Cuore, Piacenza (Italy). Ist. di Enologia e Ingegneria Alimentare

    2001-04-01

    Isoascorbic or erythorbic acid is a stereoisomer of ascorbic acid acting as a preservative against oxidation and decoloration, recently approved for food use also in the European Market. Actually erythorbate is produced by means of a complex and long process after bio-fermentation of dextrose. In order to simplify and improve this process a membrane system was conceived able to induce acid 2-ketogluconic diffusion from fermentation broth directly into methanol where it esterficates. Acid 2-ketogluconic methyl ester is the intermediate for erythorbic acid. The principal problem was to perfectly separate water methanol to avoid saponification instead of esterification. [Italian] L'acido eritorbico o isoascorbico, recentemente approvato per uso alimentare anche in Europa, e' uno stereoisomero dell'acido ascorbico e agisce come antiossidante e preservante del colore. Attualmente viene prodotto con un complicato processo dopo fermentazione del destrosio. Per semplificare e migliorare questo processo, e' stato studiato un sistema a membrane in grado di trasferire direttamente l'acido 2-chetogluconico dal brodo di fermentazione al metanolo, dove esterifica. L'estere metilico dell'acido 2-chetogluconico e' l'intermedio dell'acido eritorbico. Il problema maggiore era quello di mantenere separati l'acqua ed il metanolo, per evitare la saponificazione al posto della esterificazione.

  13. Catalytic combustion of hydrogen as a countermeasure to the risk of deflagration in a nuclear reactor containment in a severe accident situation: study of the poisoning of catalysts in a representative atmosphere

    International Nuclear Information System (INIS)

    Morfin, F.

    2000-06-01

    In case of a severe nuclear reactor accident (beyond design basis accident), with extensive fuel rod damage, a significant quantity of hydrogen would be produced in the reactor primary circuit. Build-up of this combustible gas in the air-filled reactor building could eventually lead to an explosion and, in extreme conditions, to the failure of the containment. In situ catalytic combustion of this hydrogen is one of the mitigation techniques proposed to reduce the so-called hydrogen risk in post-accident PWR containments. In a nuclear safety perspective, we have studied the performances of Passive Auto-catalytic (hydrogen) Recombiners (or PARs) in a representative atmosphere including, beside air, steam and hydrogen, a complex mixture of aerosol particles and vapours incorporating chemical elements (e.g., I or Te) known to be potential poisons of the catalytic materials making-up the recombiners. This study is based on 1) phenomenological (or 'global') experiments, in a containment mock-up (H2-PAR) at the 1/22 scale, making it possible to investigate into the efficiency of recombiners immersed in the representative atmosphere, and on 2) analytical experiments (catalyst testing) in a small laboratory reactor exposing catalysts to iodine and iodine compounds. The analytical experiments shed light on properties of the catalysts that could not be investigated in the containment mock-up, such as the relative catalytic activity of Pt, Pd and a Pt-Pd alloy, and their resistance to poisoning by I 2 and by AgI, CsI, InI or CdI 2 . The remarkable resistance to poisoning of the industrial catalysts under scrutiny is interpreted as a consequence of the low poison to catalyst ratio and of the diffusion regime of recombiner operation. At last, experiments with iodides showed that a possible modification of the post-accident containment atmosphere induced by the catalysts is worth examining, since it could alter the iodine source-term in a containment fitted out with recombiners

  14. Prospects and problems of dense oxygen permeable membranes

    DEFF Research Database (Denmark)

    Hendriksen, P.V.; Larsen, P.H.; Mogensen, Mogens Bjerg

    2000-01-01

    The prospects of using mixed ionic/electronic conducting ceramics for syngas production in a catalytic membrane reactor are analysed. Problems relating to limited thermodynamic stability and poor dimensional stability of candidate materials are addressed, The consequences for these problems......, of flux improving measures like minimization of membrane thickness and minimization of the losses due to oxygen exchange over the membrane surfaces, are discussed. The analysis is conducted on two candidate materials: La0.6Sr0.4Co0.2Fe0.8O3-delta and SrFeCo0.5Ox. Finally. experimental investigations...

  15. Monitoring and modeling of nitrogen conversions in membrane-aerated biofilm reactors: Effects of intermittent aeration

    DEFF Research Database (Denmark)

    Ma, Yunjie

    relevant biological N2O production pathways. Sensitive kinetic parameters were estimated with long-term bulk performance data. With the calibrated model, roles of HB and AnAOB were discussed and evaluated in mitigating N2O emissions in auto-trophic nitrogen removal MABRs. Moreover, I developed a 1-D...... process. On the other hand, the presence of multiple simultaneous chemical gradients complicates the performance opti-mization. Mathematical modeling offers a way to describe and analyze multi-ple processes that occur simultaneously in time and space in biofilm systems. This PhD project investigated NH4...... the membrane, whilst NH4+ is provid-ed from the bulk liquid phase. The counter substrate supply not only offers flexible aeration control, but also supports the development of a unique mi-crobial community and spatial structure inside the biofilm. In this study, lab-scale MABRs were operated under two types...

  16. Photocatalytic Membrane Reactor for the Removal of C.I. Disperse Red 73

    Directory of Open Access Journals (Sweden)

    Valentina Buscio

    2015-06-01

    Full Text Available After the dyeing process, part of the dyes used to color textile materials are not fixed into the substrate and are discharged into wastewater as residual dyes. In this study, a heterogeneous photocatalytic process combined with microfiltration has been investigated for the removal of C.I. Disperse Red 73 from synthetic textile effluents. The titanium dioxide (TiO2 Aeroxide P25 was selected as photocatalyst. The photocatalytic treatment achieved between 60% and 90% of dye degradation and up to 98% chemical oxygen demand (COD removal. The influence of different parameters on photocatalytic degradation was studied: pH, initial photocatalyst loading, and dye concentration. The best conditions for dye degradation were pH 4, an initial dye concentration of 50 mg·L−1, and a TiO2 loading of 2 g·L−1. The photocatalytic membrane treatment provided a high quality permeate, which can be reused.

  17. Application of acidogenic fixed-bed reactor prior to anaerobic membrane bioreactor for sustainable slaughterhouse wastewater treatment

    International Nuclear Information System (INIS)

    Saddoud, Ahlem; Sayadi, Sami

    2007-01-01

    High rate anaerobic treatment systems such as anaerobic membrane bioreactors (AMBR) are less popular for slaughterhouse wastewater due to the presence of high fat oil and suspended matters in the effluent. This affects the performance and efficiency of the treatment system. In this work, AMBR has been tried for slaughterhouse wastewater treatment. After the start up period, the reactor was operated with an average organic loading rate (OLR) of 4.37 kg TCOD m -3 d -1 with gradual increase to an average of 13.27 kg TCOD m -3 d -1 . At stable conditions, the treatment efficiency was high with an average COD and BOD 5 reduction of 93.7 and 93.96%, respectively. However, a reduction in the AMBR performance was shown with the increase of the OLR to 16.32 kg TCOD m -3 d -1 . The removal efficiencies of SCOD and BOD 5 were drastically decreased to below 53.6 and 73.3%, respectively. The decrease of the AMBR performance was due to the accumulation of VFAs. Thus, a new integrated system composed of a FBR for the acidogenesis step followed by the AMBR for methanogenesis step was developed. At high ORL, the integrated system improved the performance of the anaerobic digestion and it successfully overcame the VFA accumulation problem in the AMBR. The anaerobic treatment led to a total removal of all tested pathogens. Thus, the microbiological quality of treated wastewater fits largely with WHO guidelines

  18. Use of new membrane-reactor saccharification assay to evaluate the performance of cellulases under simulated SSF conditions

    Energy Technology Data Exchange (ETDEWEB)

    Baker, J.O.; Vinzant, T.B.; Ehrman, C.I. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1997-12-31

    A new saccharification assay has been devised, in which a continuously buffer-swept membrane reactor is used to remove the solubilized saccharification products, thus allowing high extents of substrate conversion without significant inhibitory effects from the buildup of either cellobiose or glucose. This diafiltration saccharification assay (DSA) can, therefore, be used to obtain direct measurements of the performance of combinations of cellulose and substrate under simulated SSF conditions, without the saccharification results being complicated by factors that may influence the subsequent fermentation step. This assay has been used to compare the effectiveness of commercial and special in-house-produced Trichoderma reesei cellulose preparations in the saccharification of a standardized microcrystalline (Sigmacell) substrate and a dilute-acid pretreated lignocellulosic substrate. Initial results strongly suggest that enzyme preparations produced in the presence of the targeted lignocellulosic substrate will saccharify that substrate more effectively. These results call into question the widespread use of the {open_quotes}filter paper assay{close_quotes} as a reliable predictor of enzyme performance in the extensive hydrolysis of substrates that are quite different from filter paper in both physical properties and chemical composition. 14 refs., 6 figs.

  19. Advanced Treatment of Wastewater from UASB Reactor by Microfiltration Membrane Associated With Disinfection by Ultraviolet Radiation

    Directory of Open Access Journals (Sweden)

    André Aguiar Battistelli

    2016-03-01

    Full Text Available The low efficiency of UASB bioreactors, regarding the removal of nutrient, organic matter and pathogens, makes it necessary to carry out a post treatment, in order to improve the quality of the effluent. Accordingly, this research has examined the use of microfiltration associated to the disinfection by the ultraviolet radiation, as an option to this post treatment. For so, were collected samples of UASB reactors’ effluent, in order to carry out some tests on a pilot microfiltration system, using in one of the samples pre-coagulation with vegetable tannin. After, all the microfiltrated samples were inserted in a UV reactor, applying different radiation doses, ranging from 43.8 to 194.9 mWs.cm-2, to simulate the disinfection. The system used showed good results in terms of turbidity removal, apparent color, true color, phosphorus, nitrogen, total solids, total suspended solids and COD, reaching in the best operating condition, the following values: 1.90 uT, 15 uC, 10 uC, 0.94 mg/L, 17.64 mg/L, 123 mg/L, 0 mg/L and 10 mg/L, respectively, which represent the following removal percentages: 91.3%, 93.6%, 82.0%, 55.1%, 26.3%, 35% and 86.1%. The inactivation obtained for E. coli, total coliforms, colifagos and Clostridium perfrigens was satisfactory, achieving a higher inactivation than the detection limit of the method used, when submitted to the highests tested radiation doses. The average permeate flux ranged from 55.2 to 133.6 L.m-2.h-1.

  20. Nitrogen Removal Characteristics of Two Kinds of Water Quality by Bamboo Biological Membrane Reactor

    Science.gov (United States)

    Sun, Ling; Cao, Wenping; Zhang, Huifang

    2017-12-01

    The effect of nitrogen removal was investigated using a Bamboo filament bioreactor to treat wastewater with high organic load and low C/N ratio. Results showed that total nitrogen removal efficiency was 26.6∼96.95%, effluent BOD/COD ratio was 0.07∼0.74 when influent COD was 790∼5000 mg/L, BOD 60.0∼1100mg/L and the BOD/COD ratio was respectively 0.02∼0.44. When COD was 130.0∼278.0 mg/L, BOD was 42.5∼96.7mg/L, NH4 +-N was 16.2∼98.1mg/L, TN was 28.7∼103.8 mg/L, COD/TN was 1.6∼4.7, TN removal rate was 29.4%∼58.8%. This indicated that good TN removal efficiency can be achieved when using a Bamboo filament bioreactor to treat wastewater with high organic load and low C/N ratio; Nitrogen removal fluctuated was due to secretion of bamboo juice secreted from the cavity of filamentous bamboo. The distribution characteristics of the main bacteria was investigated to show that total number of bacteria at inlet and outlet were same roughly during the wastewater treatment, while bacteria, nitrifying bacteria were distributed in outlet, and Nitrifying bacteria accounted for 1.57% of total bacteria, while denitrifying bacteria evenly distributed in the reactor.

  1. Effect of Preparation Condition of TiO Film and Experimental Condition on CO Reduction Performance of TiO Photocatalyst Membrane Reactor

    Directory of Open Access Journals (Sweden)

    Akira Nishimura

    2011-01-01

    Full Text Available It was previously reported that CO2 could be reduced into CO, CH4, and so forth, which can be used as fuels, by TiO2 as the photocatalyst under UV radiation. To increase the concentration of fuel and improve CO2 reduction performance on TiO2 photocatalyst, a membrane reactor composed of TiO2 and gas separation membrane prepared by sol-gel and dip-coating method has been built. Factors such as rising speed (RS in the dip-coating process and the timing and amount of water injected in the membrane reactor in CO2 reduction experiment have been investigated. As a result, the largest amount of TiO2 film is obtained for RS=0.66 mm/s among various RS conditions investigated in this study. According to CO2 reduction experiment by gas circulation type reactor, too much water which cannot be consumed in CO2 reduction process would not help improving the CO2 reduction performance.

  2. Development of a membrane-assisted fluidized bed reactor - 1 - Gas phase back-mixing and bubble-to-emulsion phase mass transfer using tracer injection and ultrasound experiments

    NARCIS (Netherlands)

    Deshmukh, S.A.R.K.; Laverman, J.A.; Cents, A.H.G.; van Sint Annaland, M.; Kuipers, J.A.M.

    2005-01-01

    A small laboratory-scale membrane-assisted fluidized bed reactor (MAFBR) was constructed in order to experimentally demonstrate the benefits of this reactor concept, especially the enhanced bubble-to-emulsion phase mass transfer and the reduced overall axial gas phase back-mixing, due to the

  3. A new degassing membrane coupled upflow anaerobic sludge blanket (UASB) reactor to achieve in-situ biogas upgrading and recovery of dissolved CH4 from the anaerobic effluent

    International Nuclear Information System (INIS)

    Luo, Gang; Wang, Wen; Angelidaki, Irini

    2014-01-01

    Highlights: • A new UASB configuration was developed by coupling with degassing membrane. • In-situ biogas upgrading was achieved with high methane content (>90%). • Decrease of dissolved methane in the anaerobic effluent was achieved. - Abstract: A new technology for in-situ biogas upgrading and recovery of CH 4 from the effluent of biogas reactors was proposed and demonstrated in this study. A vacuum degassing membrane module was used to desorb CO 2 from the liquid phase of a biogas reactor. The degassing membrane was submerged into a degassing unit (DU). The results from batch experiments showed that mixing intensity, transmembrane pressure, pH and inorganic carbon concentration affected the CO 2 desorption rate in the DU. Then, the DU was directly connected to an upflow anaerobic sludge blanket (UASB) reactor. The results showed the CH 4 content was only 51.7% without desorption of CO 2 , while it increased when the liquid of UASB was recycled through the DU. The CH 4 content increased to 71.6%, 90%, and 94% with liquid recirculation rate through the DU of 0.21, 0.42 and 0.63 L/h, respectively. The loss of methane due to dissolution in the effluent was reduced by directly pumping the reactor effluent through the DU. In this way, the dissolved CH 4 concentration in the effluent decreased from higher than 0.94 mM to around 0.13 mM, and thus efficient recovery of CH 4 from the anaerobic effluent was achieved. In the whole operational period, the COD removal efficiency and CH 4 yield were not obviously affected by the gas desorption

  4. Application of acidogenic fixed-bed reactor prior to anaerobic membrane bioreactor for sustainable slaughterhouse wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Saddoud, Ahlem [Laboratoire des Bio-procedes, Centre de Biotechnologie de Sfax, BP: K, Sfax 3038 (Tunisia); Sayadi, Sami [Laboratoire des Bio-procedes, Centre de Biotechnologie de Sfax, BP: K, Sfax 3038 (Tunisia)], E-mail: sami.sayadi@cbs.rnrt.tn

    2007-11-19

    High rate anaerobic treatment systems such as anaerobic membrane bioreactors (AMBR) are less popular for slaughterhouse wastewater due to the presence of high fat oil and suspended matters in the effluent. This affects the performance and efficiency of the treatment system. In this work, AMBR has been tried for slaughterhouse wastewater treatment. After the start up period, the reactor was operated with an average organic loading rate (OLR) of 4.37 kg TCOD m{sup -3} d{sup -1} with gradual increase to an average of 13.27 kg TCOD m{sup -3} d{sup -1}. At stable conditions, the treatment efficiency was high with an average COD and BOD{sub 5} reduction of 93.7 and 93.96%, respectively. However, a reduction in the AMBR performance was shown with the increase of the OLR to 16.32 kg TCOD m{sup -3} d{sup -1}. The removal efficiencies of SCOD and BOD{sub 5} were drastically decreased to below 53.6 and 73.3%, respectively. The decrease of the AMBR performance was due to the accumulation of VFAs. Thus, a new integrated system composed of a FBR for the acidogenesis step followed by the AMBR for methanogenesis step was developed. At high ORL, the integrated system improved the performance of the anaerobic digestion and it successfully overcame the VFA accumulation problem in the AMBR. The anaerobic treatment led to a total removal of all tested pathogens. Thus, the microbiological quality of treated wastewater fits largely with WHO guidelines.

  5. Catalytic gasification of automotive shredder residues with hydrogen generation

    Science.gov (United States)

    Lin, Kuen-Song; Chowdhury, Sujan; Wang, Ze-Ping

    Hydrogen is a clean and new energy carrier to generate power through the Proton exchange membrane fuel cell (PEMFC) system. Hydrogen can be effectively turned out through the catalytic gasification of organic material such as automotive shredder residues (ASR). The main objective of this manuscript is to present an analysis of the catalytic gasification of ASR for the generation of high-purity hydrogen in a lab-scale fixed-bed downdraft gasifier using 15 wt.% NiO/Al 2O 3 catalysts at 760-900 K. In the catalytic gasification process, reduction of Ni(II) catalyst into Ni(0) has been confirmed through XANES spectra and consequently EXAFS data shows that the central Ni atoms have Ni-O and Ni-Ni bonds with bond distances of 2.03 ± 0.05 and 2.46 ± 0.05 Å, respectively. ASR is partially oxidized and ultimately converts into hydrogen rich syngas (CO and H 2) and increases of the reaction temperature are favored the generation of hydrogen with decomposition of the CO. As well, approximately 220 kg h -1 of ASR would be catalytically gasified at 760-900 K and 46.2 atm with the reactor volume 0.27 m 3 to obtain approximately 3.42 × 10 5 kcal h -1 of thermal energy during over 87% syngas generation with the generation of 100 kW electric powers.

  6. In-Situ Catalytic Surface Modification of Micro-Structured La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF Oxygen Permeable Membrane Using Vacuum-Assisted technique

    Directory of Open Access Journals (Sweden)

    Othman Nur Hidayati

    2016-01-01

    Full Text Available This paper aims at investigating the means to carry out in-situ surface modification of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF oxygen permeable membrane by using vacuum assisted technique. The unique structure of the LSCF hollow fibre membrane used in this study, which consists of an outer dense oxygen separation layer and conical-shaped microchannels open at the inner surface has allowed the membrane to be used as oxygen separation membrane and as a structured substrate for where catalyst can be deposited. A catalyst solution of similar material, LSCF was prepared using sol-gel technique. Effects of calcination temperature and heating rate were investigated using XRD and TGA to ensure pure perovskites structure of LSCF was obtained. It was found that a lower calcination temperature can be used to obtain pure perovskite phase if slower heating rate is used. The SEM photograph shows that the distribution of catalyst onto the membrane microchannels using in-situ deposition technique was strongly related to the viscosity of LSCF catalytic sol. Interestingly, it was found that the amount of catalyst deposited using viscous solution was slightly higher than the less viscous sol. This might be due to the difficulty of catalyst sol to infiltrate the membrane and as a result, thicker catalyst layer was observed at the lumen rather than onto the conical-shaped microchannels. Therefore, the viscosity of catalyst solution and calcination process should be precisely controlled to ensure homogeneous catalyst layer deposition. Analysis of the elemental composition will be studied in the future using energy dispersive X-ray Spectroscopy (EDX to determine the elements deposited onto the membranes. Once the elemental analysis is confirmed, oxygen permeation analysis will be carried out.

  7. CO-free hydrogen production by steam reforming of acetic acid carried out in a Pd-Ag membrane reactor: The effect of co-current and counter-current mode

    Energy Technology Data Exchange (ETDEWEB)

    Iulianelli, A.; Longo, T.; Basile, A. [CNR-ITM, Institute on Membrane Technology, c/o University of Calabria, Via Pietro Bucci, Cubo 17/C, 87030 Rende, Cosenza (Italy)

    2008-08-15

    In this experimental work, a dense tubular Pd-Ag membrane reactor is used for carrying out the acetic acid steam reforming reaction for producing a CO-free hydrogen stream. The influence of the different flow configurations, as well as the sweep factor and the reaction pressure is analysed. A Ni-based commercial catalyst was packed in the lumen side of the membrane reactor and the experimental tests were performed at a reaction temperature of 400 C and at a H{sub 2}O/acetic acid feed molar ratio of 10/1. Results in terms of CO-free hydrogen recovery, hydrogen yield and products selectivities are proposed. Moreover, a comparison between the performances of the membrane reactor and a traditional reactor working at the same operative conditions is illustrated and discussed. (author)

  8. Influence of air scouring on the performance of a Self Forming Dynamic Membrane BioReactor (SFD MBR) for municipal wastewater treatment.

    Science.gov (United States)

    Salerno, Carlo; Vergine, Pompilio; Berardi, Giovanni; Pollice, Alfieri

    2017-01-01

    The Membrane BioReactor (MBR) is a well-established filtration-based technology for wastewater treatment. Despite the high quality of the effluent produced, one of the main drawbacks of the MBR is membrane fouling. In this context, a possible evolution towards systems having potentially lower installation and operating costs is the Self Forming Dynamic Membrane BioReactor (SFD MBR). Key of this technology is the self-formation of a biological filtering layer on a support of inert material. In this work, a lab-scale aerobic SFD MBR equipped with a nylon mesh was operated at approximately 95Lm -2 h -1 . Two mesh pore sizes (20 and 50μm) and three air scouring flow rates (150, 250, and 500mL air min -1 ) were tested at steady state. Under all the tested conditions, the SFD MBR effectively treated real municipal wastewater. The quality of the produced effluent increased for lower mesh size and lower air scouring intensity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Janus Reactors with Highly Efficient Enzymatic CO2Nanocascade at Air-Liquid Interface.

    Science.gov (United States)

    Gao, Song; Mohammad, Munirah; Yang, Hao-Cheng; Xu, Jia; Liang, Kang; Hou, Jingwei; Chen, Vicki

    2017-12-13

    Though enzymatic cascade reactors have been the subject of intense research over the past few years, their application is still limited by the complicated fabrication protocols, unsatisfactory stability and lack of effective reactor designs. In addition, the spatial positioning of the cascade reactor has so far not been investigated, which is of significant importance for biphase catalytic reaction systems. Inspired by the Janus properties of the lipid cellular membrane, here we show a highly efficient Janus gas-liquid reactor for CO 2 hydration and conversion. Within the Janus reactor, nanocascades containing the nanoscale compartmentalized carbonic anhydrase and formic dehydrogenase were positioned at a well-defined gas-liquid interface, with a high substrate concentration gradient. The Janus reactor exhibited 2.5 times higher CO 2 hydration efficiency compared with the conventional gas-liquid contactor with pristine membranes, and the formic acid conversion rate can reach approximately 90%. Through this work, we provide evidence that the spatial arrangement of the nanocascade is also crucial to efficient reactions, and the Janus reactor can be a promising candidate for the biphase catalytic reactions in environmental, biological and energy aspects.

  10. Application of hollow fiber supported liquid membrane as a chemical reactor for esterification of lactic acid and ethanol to ethyl lactate

    International Nuclear Information System (INIS)

    Teerachaiyapat, Thanyarutt; Ramakul, Prakorn

    2016-01-01

    Hollow fiber supported liquid membrane was applied as a reactor to synthesize ethyl lactate from lactic acid. Lactic acid in the feed solution was extracted by tri-n-octylamine (TOA) and stripped by ethanol with p-toluene sulfonic acid acting as the catalyst to form ethyl lactate. Central composite design (CCD) was used to determine the significant factors and their interactions. The response surface was applied for optimization. An optimized yield of 30% was predicted and its validity was evaluated by comparison with experimental results at different concentrations of lactic acid in the feed solution, with good agreement achieved.

  11. Operando UV-Vis spectroscopy of a catalytic solid in a pilos-scale reactor: deactivation of a CrOx/Al2O3 propane dehydrogenation catalyst

    NARCIS (Netherlands)

    Sattler, J.J.H.B.; Gonzalez-Jimenez, I.D.; Mens, A.J.M.; Arias, M.J.; Visser, T.; Weckhuysen, B.M.

    2013-01-01

    A novel operando UV-Vis spectroscopic set-up has been constructed and tested for the investigation of catalyst bodies loaded in a pilot-scale reactor under relevant reaction conditions. Spatiotemporal insight into the formation and burning of coke deposits on an industrial CrOx/Al2O3 catalyst during

  12. Enhanced electricity generation by triclosan and iron anodes in the three-chambered membrane bio-chemical reactor (TC-MBCR).

    Science.gov (United States)

    Song, Jing; Liu, Lifen; Yang, Fenglin; Ren, Nanqi; Crittenden, John

    2013-11-01

    A three-chambered membrane bio-chemical reactor (TC-MBCR) was developed. The stainless steel membrane modules were used as cathodes and iron plates in the middle chamber served as the anode. The TC-MBCR was able to reduce fouling, remove triclosan (TCS) from a synthetic wastewater treatment and enhance electricity generation by ~60% compared with the cell voltage before TCS addition. The TC-MBCR system generated a relatively stable power output (cell voltage ~0.2V) and the corrosion of iron plates contributed to electricity generation together with microbes on iron anode. The permeation flow from anode to cathode chamber was considered important in electricity generation. In addition, the negatively charged cathode membrane and Fe(2+)/Fe(3+) released by iron plates mitigated membrane fouling by approximately 30%, as compared with the control. The removal of COD and total phosphorus was approximately 99% and 90%. The highest triclosan removal rate reached 97.9%. Copyright © 2013. Published by Elsevier Ltd.

  13. Potential of Pervaporation and Vapor Separation with Water Selective Membranes for an Optimized Production of Biofuels—A Review

    Directory of Open Access Journals (Sweden)

    Catia Cannilla

    2017-06-01

    Full Text Available The development of processes based on the integration of new technologies is of growing interest to industrial catalysis. Recently, significant efforts have been focused on the design of catalytic membrane reactors to improve process performance. In particular, the use of membranes, that allow a selective permeation of water from the reaction mixture, positively affects the reaction evolution by improving conversion for all reactions thermodynamically or kinetically limited by the presence of water. In this paper, how pervaporation (PV and vapor permeation (VP technologies can improve the catalytic performance of reactions of industrial interest is considered. Specifically, technological approaches proposed in the literature are discussed with the aim of highlighting advantages and problems encountered in order to address research towards the optimization of membrane reactor configurations for liquid biofuel production in large scale.

  14. Design, construction and implementation of a packed reactor system to study the production of hydrogen by the catalytic reaction of reforming of oxygenated hydrocarbons

    International Nuclear Information System (INIS)

    Salas Aguilar, Cesar Augusto

    2014-01-01

    The Laboratorio de Quimica Inorganica of the Universidad de Costa Rica has evaluated the performance of several types of catalysts and supports in steam reforming reactions, using different conditions for synthesis of the same. The construction of a reaction system at laboratory scale is described to improve the conditions of the reforming process compared to previous projects. Catalysts synthesized and characterized are used but providing better disposal through a packed bed reactor. The system has had the necessary instrumentation for proper measurement of the temperature at the entrance and inside the reactor, proper feeding of reactants, flow measurement and sampling and measurement system. The conceptual design of the reactions system presented has taken into account the income of reactants through a peristaltic pump, preheating or vaporization of reagents, income and measurement of carrier gas sampling, take of sampling, flow measurement product, reactor packed and cooler product. The order of each stage is defined and positioning in the entire system. The design of a preheater and a tubular reactor is detailed, taking into account the dimensions and construction materials of each of the pieces. The design is presented in a series of diagrams and then the result of the construction is illustrated by photographs, all work done also has been described. The implementation of the system has described by the coupling of all parties and the respective tests. A basic experimental plan is presented to evaluate the performance of the reaction system, using glycerin as a reactant, demonstrating ability to react and take effective data. Four experiments are performed: vacuum reactor, packed reactor with two types of filling and reactor with an exposed surface cobalt oxide (II) reduced, the gases produced in the reaction are analyzed by gas chromatography. The results are discussed and analyzed, focusing on the overall selectivity of hydrogen relative to methane, and the

  15. Water-Gas-Shift Membrane Reactor for High-Pressure Hydrogen Production. A comprehensive project report (FY2010 - FY2012)

    Energy Technology Data Exchange (ETDEWEB)

    Klaehn, John [Idaho National Lab. (INL), Idaho Falls, ID (United States); Peterson, Eric [Idaho National Lab. (INL), Idaho Falls, ID (United States); Orme, Christopher [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bhandari, Dhaval [General Electric Global Research, Niskayuna, New York (United States); Miller, Scott [General Electric Global Research, Niskayuna, New York (United States); Ku, Anthony [General Electric Global Research, Niskayuna, New York (United States); Polishchuk, Kimberly [General Electric Global Research, Niskayuna, New York (United States); Narang, Kristi [General Electric Global Research, Niskayuna, New York (United States); Singh, Surinder [General Electric Global Research, Niskayuna, New York (United States); Wei, Wei [General Electric Global Research, Niskayuna, New York (United States); Shisler, Roger [General Electric Global Research, Niskayuna, New York (United States); Wickersham, Paul [General Electric Global Research, Niskayuna, New York (United States); McEvoy, Kevin [General Electric Global Research, Niskayuna, New York (United States); Alberts, William [General Electric Global Research, Niskayuna, New York (United States); Howson, Paul [General Electric Global Research, Niskayuna, New York (United States); Barton, Thomas [Western Research inst., Laramie, WY (United States); Sethi, Vijay [Western Research inst., Laramie, WY (United States)

    2013-01-01

    Idaho National Laboratory (INL), GE Global Research (GEGR), and Western Research Institute (WRI) have successfully produced hydrogen-selective membranes for water-gas-shift (WGS) modules that enable high-pressure hydrogen product streams. Several high performance (HP) polymer membranes were investigated for their gas separation performance under simulated (mixed gas) and actual syngas conditions. To enable optimal module performance, membranes with high hydrogen (H2) selectivity, permeance, and stability under WGS conditions are required. The team determined that the VTEC PI 80-051 and VTEC PI 1388 (polyimide from Richard Blaine International, Inc.) are prime candidates for the H2 gas separations at operating temperatures (~200°C). VTEC PI 80-051 was thoroughly analyzed for its H2 separations under syngas processing conditions using more-complex membrane configurations, such as tube modules and hollow fibers. These membrane formats have demonstrated that the selected VTEC membrane is capable of providing highly selective H2/CO2 separation (α = 7-9) and H2/CO separation (α = 40-80) in humidified syngas streams. In addition, the VTEC polymer membranes are resilient within the syngas environment (WRI coal gasification) at 200°C for over 1000 hours. The information within this report conveys current developments of VTEC PI 80-051 as an effective H2 gas separations membrane for high-temperature syngas streams.

  16. The energy-saving anaerobic baffled reactor membrane bioreactor (EABR-MBR) system for recycling wastewater from a high-rise building.

    Science.gov (United States)

    Ratanatamskul, Chavalit; Charoenphol, Chakraphan

    2015-01-01

    A novel energy-saving anaerobic baffled reactor-membrane bioreactor (EABR-MBR) system has been developed as a compact biological treatment system for reuse of water from a high-rise building. The anaerobic baffled reactor (ABR) compartment had five baffles and served as the anaerobic degradation zone, followed by the aerobic MBR compartment. The total operating hydraulic retention time (HRT) of the EABR-MBR system was 3 hours (2 hours for ABR compartment and very short HRT of 1 hour for aerobic MBR compartment). The wastewater came from the Charoen Wisawakam building. The results showed that treated effluent quality was quite good and highly promising for water reuse purposes. The average flux of the membrane was kept at 30 l/(m2h). The EABR-MBR system could remove chemical oxygen demand, total nitrogen and total phosphorus from building wastewater by more than 90%. Moreover, it was found that phosphorus concentration was rising in the ABR compartment due to the phosphorus release phenomenon, and then the concentration decreased rapidly in the aerobic MBR compartment due to the phosphorus uptake phenomenon. This implies that phosphorus-accumulating organisms inside the EABR-MBR system are responsible for biological phosphorus removal. The research suggests that the EABR-MBR system can be a promising system for water reuse and reclamation for high-rise building application in the near future.

  17. Influence of Irradiance, Flow Rate, Reactor Geometry, and Photopromoter Concentration in Mineralization Kinetics of Methane in Air and in Aqueous Solutions by Photocatalytic Membranes Immobilizing Titanium Dioxide

    Directory of Open Access Journals (Sweden)

    Ignazio Renato Bellobono

    2008-01-01

    Full Text Available Photomineralization of methane in air (10.0–1000 ppm (mass/volume of C at 100% relative humidity (dioxygen as oxygen donor was systematically studied at 318±3 K in an annular laboratory-scale reactor by photocatalytic membranes immobilizing titanium dioxide as a function of substrate concentration, absorbed power per unit length of membrane, reactor geometry, and concentration of a proprietary vanadium alkoxide as photopromoter. Kinetics of both substrate disappearance, to yield intermediates, and total organic carbon (TOC disappearance, to yield carbon dioxide, were followed. At a fixed value of irradiance (0.30 W⋅cm-1, the mineralization experiments in gaseous phase were repeated as a function of flow rate (4–400 m3⋅h−1. Moreover, at a standard flow rate of 300 m3⋅h−1, the ratio between the overall reaction volume and the length of the membrane was varied, substantially by varying the volume of reservoir, from and to which circulation of gaseous stream took place. Photomineralization of methane in aqueous solutions was also studied, in the same annular reactor and in the same conditions, but in a concentration range of 0.8–2.0 ppm of C, and by using stoichiometric hydrogen peroxide as an oxygen donor. A kinetic model was employed, from which, by a set of differential equations, four final optimised parameters, k1 and K1, k2 and K2, were calculated, which is able to fit the whole kinetic profile adequately. The influence of irradiance on k1 and k2, as well as of flow rate on K1 and K2, is rationalized. The influence of reactor geometry on k values is discussed in view of standardization procedures of photocatalytic experiments. Modeling of quantum yields, as a function of substrate concentration and irradiance, as well as of concentration of photopromoter, was carried out very satisfactorily. Kinetics of hydroxyl radicals reacting between themselves, leading to hydrogen peroxide, other than with substrate or

  18. Enhancement of acetate productivity in a thermophilic (55 °C) hollow-fiber membrane biofilm reactor with mixed culture syngas (H2/CO2) fermentation.

    Science.gov (United States)

    Wang, Yun-Qi; Yu, Shi-Jin; Zhang, Fang; Xia, Xiu-Yang; Zeng, Raymond J

    2017-03-01

    Conversion of organic wastes to syngas is an attractive way to utilize wastes. The produced syngas can be further used to produce a variety of chemicals. In this study, a hollow-fiber membrane biofilm reactor with mix cultures was operated at 55 °C to convert syngas (H 2 /CO 2 ) into acetate. A high concentration of acetate (42.4 g/L) was reached in batch experiment while a maximum acetate production rate of 10.5 g/L/day was achieved in the continuous-flow mode at hydraulic retention time (HRT) of 1 day. Acetate was the main product in both batch and continuous-flow experiments. n-Butyrate was the other byproduct in the reactor. Acetate accounted for more than 98.5 and 99.1% of total volatile fatty acids in batch and continuous modes, respectively. Illumina Miseq high-throughput sequencing results showed that microorganisms were highly purified and enriched in the reactor. The main genus was Thermoanaerobacterium (66% of relative abundance), which was usually considered as H 2 producer in the literature, however, likely played a role as a H 2 consumer in this study. This study provides a new method to generate the high producing rate and purity of acetate from syngas.

  19. Process for producing curved surface of membrane rings for large containers, particulary for prestressed concrete pressure vessels of nuclear reactors

    International Nuclear Information System (INIS)

    Kumpf, H.

    1977-01-01

    Membrane rings for large pressure vessels, particularly for prestressed-concrete pressure vessels, often have curved surfaces. The invention describes a process of producing these at site, which is particularly advantageous as the forming and installation of the vessel component coincide. According to the invention, the originally flat membrane ring is set in a predetermined position, is then pressed in sections by a forming tool (with a preformed support ring as opposite tool), and shaped. After this, the shaped parts are welded to the ring-shaped wall parts of the large vessel. The manufacture of single and double membrane rings arrangements is described. (HP) [de

  20. Photocatalytic reactor

    Science.gov (United States)

    Bischoff, Brian L.; Fain, Douglas E.; Stockdale, John A. D.

    1999-01-01

    A photocatalytic reactor for processing selected reactants from a fluid medium comprising at least one permeable photocatalytic membrane having a photocatalytic material. The material forms an area of chemically active sites when illuminated by light at selected wavelengths. When the fluid medium is passed through the illuminated membrane, the reactants are processed at these sites separating the processed fluid from the unprocessed fluid. A light source is provided and a light transmitting means, including an optical fiber, for transmitting light from the light source to the membrane.

  1. Multifaceted effects of HZSM-5 (Proton-exchanged Zeolite Socony Mobil-5) on catalytic cracking of pinewood pyrolysis vapor in a two-stage fixed bed reactor.

    Science.gov (United States)

    Wang, Yimeng; Wang, Jie

    2016-08-01

    The pinewood was pyrolyzed in the first reactor at a heating rate of 10°Cmin(-1) from room temperature to 700°C, and the vapor was allowed to be cracked through the second reactor in a temperature range of 450-750°C without and with HZSM-5. Attempts were made to determine a wide spectrum of gaseous and liquid products, as well as the mass and element partitions to gas, water, bio-oil, coke and char. HZSM-5 showed a preferential deoxygenation effect via the facilitated decarbonylation and decarboxylation with the inhibited dehydration at 550-600°C. This catalyst also displayed a high selectivity for the formations of aromatic hydrocarbons and olefins by the promoted hydrogen transfer to these products at 550-600°C. The bio-oil produced with HZSM-5 at 500-600°C had the yields of 14.5-16.8%, the high heat values of 39.1-42.4MJkg(-1), and the energy recoveries of 33-35% (all dry biomass basis). Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Study for increasing the stabilization time of a catalytic dye to facilitate the fabrication of membrane electrode assemblies; Estudio para incrementar el tiempo de estabilizacion de una tinta catalitica para facilitar la fabricacion de ensambles membrana-electrodo

    Energy Technology Data Exchange (ETDEWEB)

    Flores Hernandez, J. Roberto [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)] e-mail: jrflores@iie.org.mx; Martinez Vado, F. Isaias [Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Mexico D.F. (Mexico); Cano Castillo, Ulises, Albarran Sanchez, Lorena [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2009-09-15

    An infrastructure project has been underway for hydrogen technology and fuel cells at the Electrical Research Institute (IIE, Spanish acronym). Part of this project is an activity for the fabrication of membrane electrode assemblies (MEA). Currently, a fabrication process is well-established for the MEA using the spray technique. In addition, a catalytic dye base composition has been developed for use in the fabrication of high-quality MEA with a good degree of reproducibility. Nevertheless, the instability of the dye over time prevents continuous fabrication of MEA. This document presents the results obtained, to-date, of research conducted at the IIE aimed at increasing the stability of the catalytic dye by adding a surfactant with different concentrations and increasing the concentration of the Nafion® solution. It was found that the effect of adding the surfactant to the catalytic dye results in a qualitative decrease in the agglomerate sizes, while also decreasing the porosity of the dye once it has dried. In addition, it was found that increasing the amount of Nafion® in the catalytic die increases the porosity. [Spanish] En el Instituto de Investigaciones Electricas (IIE) se ha venido trabajando en un proyecto de infraestructura sobre la tecnologia de hidrogeno y celdas de combustible. Dentro de este proyecto se tiene una actividad orientada a la fabricacion de Ensambles Membrana-Electrodo (MEA's). Actualmente se tiene un proceso de fabricacion bien establecido para la elaboracion de MEA's utilizando la tecnica de rociado, asimismo, se tiene una composicion base de tinta catalitica con la cual se fabrican MEA's de buena calidad y con buen grado de reproducibilidad. Sin embargo, la inestabilidad de la tinta con respecto al tiempo impide tener una fabricacion continua de los MEA's. En este documento se presentan los resultados obtenidos hasta ahora de una investigacion que se realiza en el IIE orientada a incrementar la estabilidad de la

  3. Catalytic devices

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ming; Zhang, Xiang

    2018-01-23

    This disclosure provides systems, methods, and apparatus related to catalytic devices. In one aspect, a device includes a substrate, an electrically insulating layer disposed on the substrate, a layer of material disposed on the electrically insulating layer, and a catalyst disposed on the layer of material. The substrate comprises an electrically conductive material. The substrate and the layer of material are electrically coupled to one another and configured to have a voltage applied across them.

  4. Fluidised bed membrane reactor for ultrapure hydrogen production via methane steam reforming: Experimental demonstration and model validation

    NARCIS (Netherlands)

    Patil, C.S.; van Sint Annaland, M.; Kuipers, J.A.M.

    2007-01-01

    Hydrogen is emerging as a future alternative for mobile and stationary energy carriers in addition to its use in chemical and petrochemical applications. A novel multifunctional reactor concept has been developed for the production of ultrapure hydrogen View the MathML source from light hydrocarbons

  5. Engineering Development of Ceramic Membrane Reactor System for Converting Natural Gas to Hydrogen and Synthesis Gas for Liquid Transportation Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Air Products and Chemicals

    2008-09-30

    An Air Products-led team successfully developed ITM Syngas technology from the concept stage to a stage where a small-scale engineering prototype was about to be built. This technology produces syngas, a gas containing carbon monoxide and hydrogen, by reacting feed gas, primarily methane and steam, with oxygen that is supplied through an ion transport membrane. An ion transport membrane operates at high temperature and oxygen ions are transported through the dense membrane's crystal lattice when an oxygen partial pressure driving force is applied. This development effort solved many significant technical challenges and successfully scaled-up key aspects of the technology to prototype scale. Throughout the project life, the technology showed significant economic benefits over conventional technologies. While there are still on-going technical challenges to overcome, the progress made under the DOE-funded development project proved that the technology was viable and continued development post the DOE agreement would be warranted.

  6. Development of a high-temperature durable catalyst for use in catalytic combustors for advanced automotive gas turbine engines

    Science.gov (United States)

    Tong, H.; Snow, G. C.; Chu, E. K.; Chang, R. L. S.; Angwin, M. J.; Pessagno, S. L.

    1981-01-01

    Durable catalytic reactors for advanced gas turbine engines were developed. Objectives were: to evaluate furnace aging as a cost effective catalytic reactor screening test, measure reactor degradation as a function of furnace aging, demonstrate 1,000 hours of combustion durability, and define a catalytic reactor system with a high probability of successful integration into an automotive gas turbine engine. Fourteen different catalytic reactor concepts were evaluated, leading to the selection of one for a durability combustion test with diesel fuel for combustion conditions. Eight additional catalytic reactors were evaluated and one of these was successfully combustion tested on propane fuel. This durability reactor used graded cell honeycombs and a combination of noble metal and metal oxide catalysts. The reactor was catalytically active and structurally sound at the end of the durability test.

  7. Association with the Plasma Membrane Is Sufficient for Potentiating Catalytic Activity of Regulators of G Protein Signaling (RGS) Proteins of the R7 Subfamily.

    Science.gov (United States)

    Muntean, Brian S; Martemyanov, Kirill A

    2016-03-25

    Regulators of G protein Signaling (RGS) promote deactivation of heterotrimeric G proteins thus controlling the magnitude and kinetics of responses mediated by G protein-coupled receptors (GPCR). In the nervous system, RGS7 and RGS9-2 play essential role in vision, reward processing, and movement control. Both RGS7 and RGS9-2 belong to the R7 subfamily of RGS proteins that form macromolecular complexes with R7-binding protein (R7BP). R7BP targets RGS proteins to the plasma membrane and augments their GTPase-accelerating protein (GAP) activity, ultimately accelerating deactivation of G protein signaling. However, it remains unclear if R7BP serves exclusively as a membrane anchoring subunit or further modulates RGS proteins to increase their GAP activity. To directly answer this question, we utilized a rapidly reversible chemically induced protein dimerization system that enabled us to control RGS localization independent from R7BP in living cells. To monitor kinetics of Gα deactivation, we coupled this strategy with measuring changes in the GAP activity by bioluminescence resonance energy transfer-based assay in a cellular system containing μ-opioid receptor. This approach was used to correlate changes in RGS localization and activity in the presence or absence of R7BP. Strikingly, we observed that RGS activity is augmented by membrane recruitment, in an orientation independent manner with no additional contributions provided by R7BP. These findings argue that the association of R7 RGS proteins with the membrane environment provides a major direct contribution to modulation of their GAP activity. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. Carbogenic molecular sieves for reaction and separation by design: A novel approach to shape selective super base, super acid and catalytic membranes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Foley, Henry C.

    2002-03-18

    This report details the findings of three years of research plus one year of a no-cost extension. Primary results are the work with supported nanoporous carbon membranes for separation and reaction as well as with cesium-nanoporous carbon catalysts. The work resulted in 17 plus 2 papers (2 are in progress) and partial or full support for five Ph.D. students. Two patents were filed based on this research.

  9. Quantifying contribution of synthrophic acetate oxidation to methane production in thermophilic anaerobic reactors by membrane inlet mass spectrometry

    DEFF Research Database (Denmark)

    Mulat, Daniel Girma; Ward, Alastair James; Adamsen, Anders Peter S

    2014-01-01

    A unique method was developed and applied for monitoring methanogenesis pathways based on isotope labeled substrates combined with online membrane inlet quadrupole mass spectrometry (MIMS). In our study, a fermentation sample from a full-scale biogas plant fed with pig and cattle manure, maize...

  10. Wastewater treatment by means of thermophilic aerobic membrane reactors: respirometric tests and numerical models for the determination of stoichiometric/kinetic parameters.

    Science.gov (United States)

    Collivignarelli, Maria Cristina; Bertanza, Giorgio; Abbà, Alessandro; Torretta, Vincenzo; Katsoyiannis, Ioannis Anastasios

    2017-10-09

    Existing wastewater/aqueous waste treatment plants often need to be upgraded in order to improve their performance. The satisfactory operation of biological treatment plants requires appropriate monitoring, and respirometric techniques are needed to determine the kinetic parameters that regulate biological processes. Innovative technologies are treating industrial wastewater/aqueous waste, such as thermophilic aerobic treatments. Thermophilic aerobic biological systems operate at temperatures higher than 45°C. Such temperature levels can be reached, at a reasonable cost, using wastewater with a high organic loading and reactors, which are appropriately thermally insulated. This kind of treatment shows high removal kinetics of biodegradable substrates and a very low sludge production. This paper describes the application of respirometric tests in thermophilic conditions on the biomass derived from a thermophilic aerobic membrane reactor in order to model the process, with a particular focus on the rapidly biodegradable chemical oxygen demand (rbCOD). The utility of rbCOD determination is related to the optimal treatment that the aqueous waste should undergo. Calculating the kinetic parameters is critical to the biological modelling used in the management and control of wastewater treatment plants.

  11. An Integrated Membrane Process for Butenes Production

    Directory of Open Access Journals (Sweden)

    Leonardo Melone

    2016-11-01

    Full Text Available Iso-butene is an important material for the production of chemicals and polymers. It can take part in various chemical reactions, such as hydrogenation, oxidation and other additions owing to the presence of a reactive double bond. It is usually obtained as a by-product of a petroleum refinery, by Fluidized Catalytic Cracking (FCC of naphtha or gas-oil. However, an interesting alternative to iso-butene production is n-butane dehydroisomerization, which allows the direct conversion of n-butane via dehydrogenation and successive isomerization. In this work, a simulation analysis of an integrated membrane system is proposed for the production and recovery of butenes. The dehydroisomerization of n-butane to iso-butene takes place in a membrane reactor where the hydrogen is removed from the reaction side with a Pd/Ag alloys membrane. Afterwards, the retentate and permeate post-processing is performed in membrane separation units for butenes concentration and recovery. Four different process schemes are developed. The performance of each membrane unit is analyzed by appropriately developed performance maps, to identify the operating conditions windows and the membrane permeation properties required to maximize the recovery of the iso-butene produced. An analysis of integrated systems showed a yield of butenes higher than the other reaction products with high butenes recovery in the gas separation section, with values of molar concentration between 75% and 80%.

  12. Model-Based Feasibility Assessment of Membrane Biofilm Reactor to Achieve Simultaneous Ammonium, Dissolved Methane, and Sulfide Removal from Anaerobic Digestion Liquor

    Science.gov (United States)

    Chen, Xueming; Liu, Yiwen; Peng, Lai; Yuan, Zhiguo; Ni, Bing-Jie

    2016-01-01

    In this study, the membrane biofilm reactor (MBfR) is proposed to achieve simultaneous removal of ammonium, dissolved methane, and sulfide from main-stream and side-stream anaerobic digestion liquors. To avoid dissolved methane stripping, oxygen is introduced through gas-permeable membranes, which also from the substratum for the growth of a biofilm likely comprising ammonium oxidizing bacteria (AOB), anaerobic ammonium oxidation (Anammox) bacteria, denitrifying anaerobic methane oxidation (DAMO) microorganisms, aerobic methane oxidizing bacteria (MOB), and sulfur oxidizing bacteria (SOB). A mathematical model is developed and applied to assess the feasibility of such a system and the associated microbial community structure under different operational conditions. The simulation studies demonstrate the feasibility of achieving high-level (>97.0%), simultaneous removal of ammonium, dissolved methane, and sulfide in the MBfRs from both main-stream and side-stream anaerobic digestion liquors through adjusting the influent surface loading (or hydraulic retention time (HRT)) and the oxygen surface loading. The optimal HRT was found to be inversely proportional to the corresponding oxygen surface loading. Under the optimal operational conditions, AOB, DAMO bacteria, MOB, and SOB dominate the biofilm of the main-stream MBfR, while AOB, Anammox bacteria, DAMO bacteria, and SOB coexist in the side-stream MBfR to remove ammonium, dissolved methane, and sulfide simultaneously. PMID:27112502

  13. Numerical Simulation of Fixed-Bed Catalytic Reforming Reactors: Hydrodynamics / Chemical Kinetics Coupling Simulation numérique des réacteurs de reformage catalytique en lit fixe : couplage hydrodynamique-cinétique chimique

    Directory of Open Access Journals (Sweden)

    Ferschneider G.

    2006-11-01

    Full Text Available Fixed bed reactors with a single fluid phase are widely used in the refining or petrochemical industries for reaction processes catalysed by a solid phase. The design criteria for industrial reactors are relatively well known. However, they rely on a one-dimensional writing and on the separate resolution of the equation of conservation of mass and energy, and of momentum. Thus, with complex geometries, the influence of hydrodynamics on the effectiveness of the catalyst bed cannot be taken into account. The calculation method proposed is based on the multi-dimensional writing and the simultaneous resolution of the local conservation equations. The example discussed concerns fixed-bed catalytic reactors. These reactors are distinguished by their annular geometry and the radial circulation of the feedstock. The flow is assumed to be axisymmetric. The reaction process is reflected by a simplified kinetic mechanism involving ten chemical species. Calculation of the hydrodynamic (mean velocities, pressure, thermal and mass fields (concentration of each species serves to identify the influence of internal components in two industrial reactor geometries. The map of the quantity of coke formed and deposited on the catalyst, calculated by the model, reveals potential areas of poor operation. Les réacteurs à lit fixe avec une seule phase fluide sont largement utilisés dans l'industrie du raffinage et de la pétrochimie, pour mettre en oeuvre un processus réactionnel catalysé par une phase solide. Les règles de conception des réacteurs industriels sont relativement bien connues. Cependant, elles reposent sur l'écriture monodimensionnelle et la résolution séparée, d'une part, des équations de conservation de la masse et de l'énergie et d'autre part, de la quantité de mouvement. Ainsi dans le cas de géométries complexes, l'influence de l'hydrodynamique sur l'efficacité du lit catalytique ne peut être prise en compte. La méthode de calcul

  14. [Effect of extra-cellular polymeric substances on filtration of modified non-woven fabric in membrane bio-reactor].

    Science.gov (United States)

    Zhang, Chun-hua; Yang, Feng-lin; Wang, Wen-jun; An, Xiao-wen; Zhang, Feng-jie

    2008-06-01

    The effect of extra-cellular polymeric substances (EPS) on filtration of polyvinyl alcohol modified polypropylene non-woven in submerged membrane bioreactor (SMBR) was investigated by statistical method. The results show that soluble extra-cellular polymeric substances (EPSs) of activated sludge on the non-woven modules surface, components (protein/carbohydrate, P/C) of EPSs and relative hydrophobicity (RH) have a significant influence on filtration performance of module B, the Pearson's correlation coefficient (r(p)) related to membrane fouling resistance are 0.868, 0.840, 0.890, respectively. Modified module can effectively restrict the adsorption of EPSs, can reduce the ratio of P/C in EPSs and can decrease the accumulation of activated sludge. After hydrophilic modification of non-woven, the filtration performance is improved obviously and the un-fouling performance is increased.

  15. Catalytic autothermal reforming of diesel fuel for hydrogen generation in fuel cells. I. Activity tests and sulfur poisoning

    Science.gov (United States)

    Cheekatamarla, Praveen K.; Lane, Alan M.

    Polymer electrolyte membrane (PEM) fuel cells require hydrogen as the fuel source for generating power. Hydrogen can be produced in a fuel processor by the catalytic reforming of hydrocarbons. The objective of this paper is to present an analysis of the autothermal reforming (ATR) of synthetic diesel fuel in an adiabatic reactor using a Pt/ceria catalyst. ATR combines endothermic steam reforming and exothermic partial oxidation reactions in a single unit. This simple system provides higher efficiency and higher energy density than other conventional processes. The product composition as a function of the operating variables and the temperature and concentration profile inside the reactor were studied. Hydrogen was generated under adiabatic conditions by heating the feed mixture and ATR reactor to only 400 °C in contrast to higher temperatures reported in the literature. The stability of the catalyst and its response to the presence of S poison was also investigated.

  16. Potential Applications of Zeolite Membranes in Reaction Coupling Separation Processes

    Science.gov (United States)

    Daramola, Michael O.; Aransiola, Elizabeth F.; Ojumu, Tunde V.

    2012-01-01

    Future production of chemicals (e.g., fine and specialty chemicals) in industry is faced with the challenge of limited material and energy resources. However, process intensification might play a significant role in alleviating this problem. A vision of process intensification through multifunctional reactors has stimulated research on membrane-based reactive separation processes, in which membrane separation and catalytic reaction occur simultaneously in one unit. These processes are rather attractive applications because they are potentially compact, less capital intensive, and have lower processing costs than traditional processes. Therefore this review discusses the progress and potential applications that have occurred in the field of zeolite membrane reactors during the last few years. The aim of this article is to update researchers in the field of process intensification and also provoke their thoughts on further research efforts to explore and exploit the potential applications of zeolite membrane reactors in industry. Further evaluation of this technology for industrial acceptability is essential in this regard. Therefore, studies such as techno-economical feasibility, optimization and scale-up are of the utmost importance.

  17. Potential Applications of Zeolite Membranes in Reaction Coupling Separation Processes

    Directory of Open Access Journals (Sweden)

    Tunde V. Ojumu

    2012-10-01

    Full Text Available Future production of chemicals (e.g., fine and specialty chemicals in industry is faced with the challenge of limited material and energy resources. However, process intensification might play a significant role in alleviating this problem. A vision of process intensification through multifunctional reactors has stimulated research on membrane-based reactive separation processes, in which membrane separation and catalytic reaction occur simultaneously in one unit. These processes are rather attractive applications because they are potentially compact, less capital intensive, and have lower processing costs than traditional processes. Therefore this review discusses the progress and potential applications that have occurred in the field of zeolite membrane reactors during the last few years. The aim of this article is to update researchers in the field of process intensification and also provoke their thoughts on further research efforts to explore and exploit the potential applications of zeolite membrane reactors in industry. Further evaluation of this technology for industrial acceptability is essential in this regard. Therefore, studies such as techno-economical feasibility, optimization and scale-up are of the utmost importance.

  18. [Studies on photo-electron-chemical catalytic degradation of the malachite green].

    Science.gov (United States)

    Li, Ming-yu; Diao, Zeng-hui; Song, Lin; Wang, Xin-le; Zhang, Yuan-ming

    2010-07-01

    A novel two-compartment photo-electro-chemical catalytic reactor was designed. The TiO2/Ti thin film electrode thermally formed was used as photo-anode, and graphite as cathode and a saturated calomel electrode (SCE) as the reference electrode in the reactor. The anode compartment and cathode compartment were connected with the ionic exchange membrane in this reactor. Effects of initial pH, initial concentration of malachite green and connective modes between the anode compartment and cathode compartment on the decolorization efficiency of malachite green were investigated. The degradation dynamics of malachite green was studied. Based on the change of UV-visible light spectrum, the degradation process of malachite green was discussed. The experimental results showed that, during the time of 120 min, the decolouring ratio of the malachite green was 97.7% when initial concentration of malachite green is 30 mg x L(-1) and initial pH is 3.0. The catalytic degradation of malachite green was a pseudo-first order reaction. In the degradation process of malachite green the azo bond cleavage and the conjugated system of malachite green were attacked by hydroxyl radical. Simultaneity, the aromatic ring was oxidized. Finally, malachite green was degraded into other small molecular compounds.

  19. Membranes for corrosive oxidations. Final CRADA report.

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, S. W.; Energy Systems

    2010-02-01

    The objective of this project is to develop porous hydrophilic membranes that are highly resistant to oxidative and corrosive conditions and to deploy them for recovery and purification of high tonnage chemicals such as hydrogen peroxide and other oxychemicals. The research team patented a process for membrane-based separation of hydrogen peroxide (US Patent No. 5,662,878). The process is based on using a hydrophilic membrane to separate hydrogen peroxide from the organic working solution. To enable this process, a new method for producing hydrophilic membrane materials (Patent No.6,464,880) was reported. We investigated methods of producing these hydrophilic materials and evaluated separations performance in comparison to membrane stability. It was determined that at the required membrane flux, membrane stability was not sufficient to design a commercial process. This work was published (Hestekin et al., J. Membrane Science 2006). To meet the performance needs of the process, we developed a membrane contactor method to extract the hydrogen peroxide, then we surveyed several commercial and pre-commercial membrane materials. We identified pre-commercial hydrophilic membranes with the required selectivity, flux, and stability to meet the needs of the process. In addition, we invented a novel reaction/separations format that greatly increases the performance of the process. To test the performance of the membranes and the new formats we procured and integrated reactor/membrane separations unit that enables controlled mixing, flow, temperature control, pressure control, and sampling. The results were used to file a US non-provisional patent application (ANL-INV 03-12). Hydrogen peroxide is widely used in pulp and paper applications, environmental treatment, and other industries. Virtually all hydrogen peroxide production is now based on a process featuring catalytic hydrogenation followed by auto-oxidation of suitable organic carrier molecules. This process has several

  20. Biotransformation of a highly chlorinated PCB mixture in an activated sludge collected from a Membrane Biological Reactor (MBR) subjected to anaerobic digestion

    International Nuclear Information System (INIS)

    Bertin, Lorenzo; Capodicasa, Serena; Fedi, Stefano; Zannoni, Davide; Marchetti, Leonardo; Fava, Fabio

    2011-01-01

    The role of anaerobic digestion (AD) on the decontamination and biomethanization of a PCB-spiked sludge obtained from a Membrane Biological Reactor (MBR) pilot plant was investigated throughout a 10-month batch experiment. The study was carried out under mesophilic (35 deg. C) and thermophilic (55 deg. C) conditions and was monitored by means of an integrated chemical, microbiological and molecular biology strategy. Remarkable PCB depletions (higher than 50% of the overall spiked PCBs) and dechlorinations were achieved under methanogenic conditions. The process was not affected by yeast extract addition. Both acetoclastic and hydrogenotrophic methanogens, together with some fermentative eubacteria, were found to persist in all PCB biodegrading microcosms. This finding, together with those obtained from parallel microcosms where specific populations were selectively inhibited, suggested that native methanogens played a key role in the biodegradation and dechlorination of the spiked PCBs. Taken together, the results of this study indicate that AD is a feasible option for the decontamination and the efficient disposal (with the production of a CH 4 -rich biogas) of contaminated MBR sludge, which can be then employed as a fertilizer for agricultural purposes.

  1. Vapor Phase Catalytic Ammonia Reduction

    Science.gov (United States)

    Flynn, Michael T.; Harper, Lynn D. (Technical Monitor)

    1994-01-01

    This paper discusses the development of a Vapor Phase Catalytic Ammonia Reduction (VPCAR) teststand and the results of an experimental program designed to evaluate the potential of the technology as a water purification process. In the experimental program the technology is evaluated based upon product water purity, water recovery rate, and power consumption. The experimental work demonstrates that the technology produces high purity product water and attains high water recovery rates at a relatively high specific power consumption. The experimental program was conducted in 3 phases. In phase I an Igepon(TM) soap and water mixture was used to evaluate the performance of an innovative Wiped-Film Rotating-Disk evaporator and associated demister. In phase II a phenol-water solution was used to evaluate the performance of the high temperature catalytic oxidation reactor. In phase III a urine analog was used to evaluate the performance of the combined distillation/oxidation functions of the processor.

  2. Studies of Catalytic Model Systems

    DEFF Research Database (Denmark)

    Holse, Christian

    of the Cu/ZnO nanoparticles is highly relevant to industrial methanol synthesis for which the direct interaction of Cu and ZnO nanocrystals synergistically boost the catalytic activity. The dynamical behavior of the nanoparticles under reducing and oxidizing environments were studied by means of ex situ X...... as the nanoparticles are reduced. The Cu/ZnO nanoparticles are tested on a  µ-reactor platform and prove to be active towards methanol synthesis, making it an excellent model system for further investigations into activity depended morphology changes....

  3. Catalytic Combustion of Ethyl Acetate

    OpenAIRE

    ÖZÇELİK, Tuğba GÜRMEN; ATALAY, Süheyda; ALPAY, Erden

    2014-01-01

    The catalytic combustion of ethyl acetate over prepared metal oxide catalysts was investigated. CeO, Co2O3, Mn2O3, Cr2O3, and CeO-Co2O3 catalysts were prepared on monolith supports and they were tested. Before conducting the catalyst experiments, we searched for the homogeneous gas phase combustion reaction of ethyl acetate. According to the homogeneous phase experimental results, 45% of ethyl acetate was converted at the maximum reactor temperature tested (350 °C). All the prepare...

  4. Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hogerton, John

    1964-01-01

    This pamphlet describes how reactors work; discusses reactor design; describes research, teaching, and materials testing reactors; production reactors; reactors for electric power generation; reactors for supply heat; reactors for propulsion; reactors for space; reactor safety; and reactors of tomorrow. The appendix discusses characteristics of U.S. civilian power reactor concepts and lists some of the U.S. reactor power projects, with location, type, capacity, owner, and startup date.

  5. Catalytic tar removal from biomass producer gas with secondary air

    Energy Technology Data Exchange (ETDEWEB)

    Lammers, G.; Beenackers, A.A.C.M. [University of Groningen (Netherlands). Dept. of Chemical Engineering; Corella, J. [Universidad Complutense, Madrid (Spain)

    1997-12-31

    The effect of air addition on biomass tar conversion in catalytic packed bed crackers was studied using both an isothermal micro reactor and a fluidised bed bench scale biomass gasification set up with down stream tar crackers. The micro reactor was applied for experiments with artificial biomass producer gas containing naphthalene as a model tar compound. Experiments were carried out with inert silica and catalytically active calcined dolomite bed material both with and without air addition. Experimental results with real tar from the fluidised bed bench scale gasification set up were in qualitative agreement with results from the micro reactor experiments. (author)

  6. A review of investigations on wastewater treatment with MSOBR (membrane supported and oxygenated biofilm reactors); Una revision de las investigaciones sobre el tratamiento de aguas residuales con RBSOM (reactores de biopelicula que emplean membranas con material soporte y medio de oxigenacion)

    Energy Technology Data Exchange (ETDEWEB)

    Esteban Garcia, A. L.; Tejero Monzon, I.

    2007-07-01

    MSOBR (membrane supported and oxygenated biofilm reactors) are biological reactors for wastewater treatment in which biofilm support and oxygenation functions are carried out by gas permeable membranes. In these conditions, with oxygen and substratum (carbonaceous, nitroge neous) diffusing into the biofilm from opposite sides, different environments are developed inside the biofilm, allowing simultaneous nitrification, denitrification and carbon removal. Other added advantages, such us the possibility of a high oxygen transfer efficiency or those derived from the absence of bubbles in aeration (minimizing foaming and VOC emissions), have lead numerous research groups to work in the development of different MSOBR systems, with promising results that make possible to consider their practical applicability in the near future. (Author) 69 refs.

  7. Inertial thermonuclear reactors

    International Nuclear Information System (INIS)

    Madarame, Haruki; Oomura, Hiroshi; Nakamura, Norio.

    1984-01-01

    Purpose: To improve the durability of the first wall. Constitution: A reactor cavity for performing inertial thermofusion is defined within a vessel of a thermonuclear reactor, and the first wall of a tubular structure flowing coolants for taking out thermonuclear energy generated in the reactor cavity as the heat energy to the outside of the reactor is disposed, in which jet nozzles are disposed to the inside of the first wall that pulse-width jet coolants to form coolant membranes on the inner circumferential surface of the first wall to thereby surround the fire ball by the membrane of the coolants. Thus, the energy of the fire ball can be reduced by the membrane of the coolants, whereby the thermal loads and impact loads to the first wall can be moderated to substantially increase the working life and improve the safety of the first wall for which the greatest stress load is expected. (Yoshihara, H.)

  8. Catalytic cracking of lignites

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, M.; Nowak, S.; Naegler, T.; Zimmermann, J. [Hochschule Merseburg (Germany); Welscher, J.; Schwieger, W. [Erlangen-Nuernberg Univ. (Germany); Hahn, T. [Halle-Wittenberg Univ., Halle (Germany)

    2013-11-01

    A most important factor for the chemical industry is the availability of cheap raw materials. As the oil price of crude oil is rising alternative feedstocks like coal are coming into focus. This work, the catalytic cracking of lignite is part of the alliance ibi (innovative Braunkohlenintegration) to use lignite as a raw material to produce chemicals. With this new one step process without an input of external hydrogen, mostly propylene, butenes and aromatics and char are formed. The product yield depends on manifold process parameters. The use of acid catalysts (zeolites like MFI) shows the highest amount of the desired products. Hydrogen rich lignites with a molar H/C ratio of > 1 are to be favoured. Due to primary cracking and secondary reactions the ratio between catalyst and lignite, temperature and residence time are the most important parameter to control the product distribution. Experiments at 500 C in a discontinuous rotary kiln reactor show yields up to 32 wt-% of hydrocarbons per lignite (maf - moisture and ash free) and 43 wt-% char, which can be gasified. Particularly, the yields of propylene and butenes as main products can be enhanced four times to about 8 wt-% by the use of catalysts while the tar yield decreases. In order to develop this innovative process catalyst systems fixed on beads were developed for an easy separation and regeneration of the used catalyst from the formed char. (orig.)

  9. Catalytic production of biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Theilgaard Madsen, A.

    2011-07-01

    The focus of this thesis is the catalytic production of diesel from biomass, especially emphasising catalytic conversion of waste vegetable oils and fats. In chapter 1 an introduction to biofuels and a review on different catalytic methods for diesel production from biomass is given. Two of these methods have been used industrially for a number of years already, namely the transesterification (and esterification) of oils and fats with methanol to form fatty acid methyl esters (FAME), and the hydrodeoxygenation (HDO) of fats and oils to form straight-chain alkanes. Other possible routes to diesel include upgrading and deoxygenation of pyrolysis oils or aqueous sludge wastes, condensations and reductions of sugars in aqueous phase (aqueous-phase reforming, APR) for monofunctional hydrocarbons, and gasification of any type of biomass followed by Fischer-Tropsch-synthesis for alkane biofuels. These methods have not yet been industrialised, but may be more promising due to the larger abundance of their potential feedstocks, especially waste feedstocks. Chapter 2 deals with formation of FAME from waste fats and oils. A range of acidic catalysts were tested in a model fat mixture of methanol, lauric acid and trioctanoin. Sulphonic acid-functionalised ionic liquids showed extremely fast convertion of lauric acid to methyl laurate, and trioctanoate was converted to methyl octanoate within 24 h. A catalyst based on a sulphonated carbon-matrix made by pyrolysing (or carbonising) carbohydrates, so-called sulphonated pyrolysed sucrose (SPS), was optimised further. No systematic dependency on pyrolysis and sulphonation conditions could be obtained, however, with respect to esterification activity, but high activity was obtained in the model fat mixture. SPS impregnated on opel-cell Al{sub 2}O{sub 3} and microporous SiO{sub 2} (ISPS) was much less active in the esterification than the original SPS powder due to low loading and thereby low number of strongly acidic sites on the

  10. The coupling effect of gas-phase chemistry and surface reactions on oxygen permeation and fuel conversion in ITM reactors

    KAUST Repository

    Hong, Jongsup

    2015-08-01

    © 2015 Elsevier B.V. The effect of the coupling between heterogeneous catalytic reactions supported by an ion transport membrane (ITM) and gas-phase chemistry on fuel conversion and oxygen permeation in ITM reactors is examined. In ITM reactors, thermochemical reactions take place in the gas-phase and on the membrane surface, both of which interact with oxygen permeation. However, this coupling between gas-phase and surface chemistry has not been examined in detail. In this study, a parametric analysis using numerical simulations is conducted to investigate this coupling and its impact on fuel conversion and oxygen permeation rates. A thermochemical model that incorporates heterogeneous chemistry on the membrane surface and detailed chemical kinetics in the gas-phase is used. Results show that fuel conversion and oxygen permeation are strongly influenced by the simultaneous action of both chemistries. It is shown that the coupling somewhat suppresses the gas-phase kinetics and reduces fuel conversion, both attributed to extensive thermal energy transfer towards the membrane which conducts it to the air side and radiates to the reactor walls. The reaction pathway and products, in the form of syngas and C2 hydrocarbons, are also affected. In addition, the operating regimes of ITM reactors in which heterogeneous- or/and homogeneous-phase reactions predominantly contribute to fuel conversion and oxygen permeation are elucidated.

  11. Industrial applications of membrane processes in chemistry and energy generation; Applications industrielles des procedes membranaires en chimie et production d'energie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    process for the processing of industrial effluents; 6 - membrane reactors: membrane catalytic reactors: extraction, isobutane dehydrogenation and xylenes isomerization; selective oxidation of n-butane, water treatment by gas-liquid processes; selectiveness improvement of the butadiene selective hydrogenation with the use of a membrane reactor; comparison of the efficiency of three catalytic reactors for the destruction of VOCs; 7 - gases and vapors separation: a new generation of particulate filters with catalyst impregnation for DeNox function; use of membranes for uranium enrichment: example of the EURODIF plant; inorganic membranes for integration in power generation cycles and hydrogen production; treatment of natural gas with Air Liquide-MEDAL hollow fiber membranes; 8 - liquids separation: nano-filtration in organic environment: state-of-the-art; recycling of organic compounds by inverse osmosis and seawater sulfate removing by nano-filtration; use of organic and mineral membranes in chemistry; membrane separation in chemicals manufacture; advantages and drawbacks of different membrane systems for the treatment of industrial water; concentration and recovery of organic pigments using ceramic membranes; 9 - membranes, processes and simulation: industrial experience with hybrid distillation - pervaporation or vapor permeation applications; electro-dialysis integration in amines and glycol solutions purification processes; integration of MFI membranes in the light gasoline isomerization process. (J.S.)

  12. Continuous production of glycerol by catalytic high pressure hydrogenolysis of sucrose

    NARCIS (Netherlands)

    van Ling, Gerrit; Driessen, Alfons J.; Piet, Arie C.; Vlugter, Jozef C.

    1970-01-01

    Several continuous reactor systems have been discussed for the catalytic high pressure hydrogenolysis of sucrose to glycerol. Theoretically and actually, continuous reactors lead to lower glycerol yields than in a batch process. Two continuous stirred tank reactors in cascade constitute a reasonable

  13. Functional nanofibers and membranes by electrospinning

    Science.gov (United States)

    Formo, Eric Victor

    This research focuses on advances in the fabrication of functional membranes through the process of electrospinning to either alter the arrangement or composition of nanofiber arrays. To control nanofiber arrangement, easily reconfigurable collectors were constructed that could direct the deposition over large areas (>50 cm2) and pattern the membranes into various designs, including parallel, fan-out, and spiral arrays. Subsequently, the composition of electrospun membranes was modified using the sol-gel method to yield fibers composed of TiO2 (anatase and rutile) and ZrO 2 (tetragonal) phases. Implementing the polyol reduction method, these nanofiber surfaces were coated with Pt, Pd, and Rh nanoparticles of 2-5 nm or Pt nanowires with lengths up to 125 nm. Interestingly, by calcining the ZrO2 at a lower temperature, the nanofibers could mediate the growth of Pt nanostars or Pt nanowires by adjusting the Pt precursor concentration in the polyol reduction bath. The anatase membranes could also be modified through the self-assembly of various silanes to give either thiol or amine surface groups. The functionalized membranes were then tested for a number of applications associated with the catalysis field. Specifically, anatase fiber membranes coated with Pt and Pd nanoparticles were used as catalysts in a continuous flow reactor for either hydrogenation or cross-coupling reactions, respectively, which was proven to operate with a high yield, a rapid flow rate, and were readily recyclable. The effects of both the coverage and morphology of the Pt-decorated anatase fibers on the methanol oxidation reaction were then studied. Nanofibers with a submonolayer of Pt nanoparticles or Pt nanowires were found to display improved catalytic durability over commercial Pt/C as determined by chronoamperometry. Further, by utilizing the oxygen reduction reaction, results showed that the Pt nanostars had superior electrochemical properties in comparison to Pt black. Finally, the

  14. Dispersible Exfoliated Zeolite Nanosheets and Their Application as a Selective Membrane

    Science.gov (United States)

    Varoon, Kumar; Zhang, Xueyi; Elyassi, Bahman; Brewer, Damien D.; Gettel, Melissa; Kumar, Sandeep; Lee, J. Alex; Maheshwari, Sudeep; Mittal, Anudha; Sung, Chun-Yi; Cococcioni, Matteo; Francis, Lorraine F.; McCormick, Alon V.; Mkhoyan, K. Andre; Tsapatsis, Michael

    2011-10-01

    Thin zeolite films are attractive for a wide range of applications, including molecular sieve membranes, catalytic membrane reactors, permeation barriers, and low-dielectric-constant materials. Synthesis of thin zeolite films using high-aspect-ratio zeolite nanosheets is desirable because of the packing and processing advantages of the nanosheets over isotropic zeolite nanoparticles. Attempts to obtain a dispersed suspension of zeolite nanosheets via exfoliation of their lamellar precursors have been hampered because of their structure deterioration and morphological damage (fragmentation, curling, and aggregation). We demonstrated the synthesis and structure determination of highly crystalline nanosheets of zeolite frameworks MWW and MFI. The purity and morphological integrity of these nanosheets allow them to pack well on porous supports, facilitating the fabrication of molecular sieve membranes.

  15. Evaluation of catalytic combustion of actual coal-derived gas

    Science.gov (United States)

    Blanton, J. C.; Shisler, R. A.

    1982-01-01

    The combustion characteristics of a Pt-Pl catalytic reactor burning coal-derived, low-Btu gas were investigated. A large matrix of test conditions was explored involving variations in fuel/air inlet temperature and velocity, reactor pressure, and combustor exit temperature. Other data recorded included fuel gas composition, reactor temperatures, and exhaust emissions. Operating experience with the reactor was satisfactory. Combustion efficiencies were quite high (over 95 percent) over most of the operating range. Emissions of NOx were quite high (up to 500 ppm V and greater), owing to the high ammonia content of the fuel gas.

  16. Titanium(III, IV-Containing Catalytic Systems for Production of Ultrahigh Molecular Weight Polyethylene Nascent Reactor Powders, Suitable for Solventless Processing—Impact of Oxidation States of Transition Metal

    Directory of Open Access Journals (Sweden)

    Vladislav A. Tuskaev

    2017-12-01

    Full Text Available Catalytic systems containing TiCl4 or TiCl3, THF, organomagnesium (n-Bu2Mg and organoaluminum compounds capable of producing ultrahigh molecular weight polyethylene (UHMWPE were developed. The resulting polymers were characterized by a molecular weight in the range of (1.8–7.8 × 106 Da and desirable morphology, suitable for modern methods of polymer processing—the solvent-free solid-state processing of superhigh-strength (tensile strength up to 2.1 GPa and high-modulus (elastic modulus up to 125 GPa oriented films and film tapes. The impacts of a THF additive, the oxidation state of the titanium atom, and the composition and nature of the nontransition organometallic compounds on the formation of catalytic systems for UHMWPE production were evaluated. The results indicate the suitability of individual titanium chloride tetrahydrofuran complex application for the formation of THF-containing catalytic systems. This approach also results in a significant increase in the system catalytic activity and mechanical properties of UHMWPE. The catalysts based on Ti(III were inferior to systems containing Ti(IV in productivity but were markedly superior in the mechanical properties of UHMWPE.

  17. Etching nano-holes in silicon carbide using catalytic platinum nano-particles

    Science.gov (United States)

    Moyen, E.; Wulfhekel, W.; Lee, W.; Leycuras, A.; Nielsch, K.; Gösele, U.; Hanbücken, M.

    2006-09-01

    The catalytic reaction of platinum during a hydrogen etching process has been used to perform controlled vertical nanopatterning of silicon carbide substrates. A first set of experiments was performed with platinum powder randomly distributed on the SiC surface. Subsequent hydrogen etching in a hot wall reactor caused local atomic hydrogen production at the catalyst resulting in local SiC etching and hole formation. Secondly, a highly regular and monosized distribution of Pt was obtained by sputter deposition of Pt through an Au membrane serving as a contact mask. After the lift-off of the mask, the hydrogen etching revealed the onset of well-controlled vertical patterned holes on the SiC surface.

  18. Oscillatory Behavior during the Catalytic Partial Oxidation of Methane: Following Dynamic Structural Changes of Palladium Using the QEXAFS Technique

    DEFF Research Database (Denmark)

    Stoetzel, Jan; Frahm, Ronald; Kimmerle, Bertram

    2012-01-01

    as a combination of total oxidation and reforming in the catalytic capillary reactor was observed. This change in catalytic performance was directly linked to changes in the oxidation state of the Pd/Al2O3 catalysts at different positions along the catalytic reactor. During the ignition of the catalytic partial......Pd/Al2O3 catalysts oscillate between ignition and extinction of the catalytic partial oxidation of methane when they are exposed to a 2:1 reaction mixture of methane and oxygen. The oscillations of the catalytic performance and the structure of Pd/Al2O3 catalysts in a fixed-bed reactor were...... by the oven temperature than the ignition behavior of the catalytic partial oxidation of methane. This indicates that deactivation is caused by an autoreduction of the palladium at the beginning of the catalyst bed due to the high temperature achieved by total oxidation of methane....

  19. Catalytic Oligopeptide Synthesis.

    Science.gov (United States)

    Liu, Zijian; Noda, Hidetoshi; Shibasaki, Masakatsu; Kumagai, Naoya

    2018-02-02

    Waste-free catalytic assembly of α-amino acids is fueled by a multiboron catalyst that features a characteristic B 3 NO 2 heterocycle, providing a versatile catalytic protocol wherein functionalized natural α-amino acid units are accommodated and commonly used protecting groups are tolerated. The facile dehydrative conditions eliminate the use of engineered peptide coupling reagents, exemplifying a greener catalytic alternative for peptide coupling. The catalysis is sufficiently robust to enable pentapeptide synthesis, constructing all four amide bond linkages in a catalytic fashion.

  20. Heterogeneous catalytic materials solid state chemistry, surface chemistry and catalytic behaviour

    CERN Document Server

    Busca, Guido

    2014-01-01

    Heterogeneous Catalytic Materials discusses experimental methods and the latest developments in three areas of research: heterogeneous catalysis; surface chemistry; and the chemistry of catalysts. Catalytic materials are those solids that allow the chemical reaction to occur efficiently and cost-effectively. This book provides you with all necessary information to synthesize, characterize, and relate the properties of a catalyst to its behavior, enabling you to select the appropriate catalyst for the process and reactor system. Oxides (used both as catalysts and as supports for cata