Morphology and N2 Permeance of Sputtered Pd-Ag Ultra-Thin Film Membranes

The influence of the temperature during the growth of Pd-Ag films by PVD magnetron sputtering onto polished silicon wafers was studied in order to avoid the effect of the support roughness on the layer growth. The surfaces of the Pd-Ag membrane films were analyzed by atomic force microscopy (AFM), and the results indicate an increase of the grain size from 120 to 250–270 nm and film surface roughness from 4–5 to 10–12 nm when increasing the temperature from around 360–510 K. After selecting the conditions for obtaining the smallest grain size onto silicon wafer, thin Pd-Ag (0.5–2-µm thick) films were deposited onto different types of porous supports to study the influence of the porous support, layer thickness and target power on the selective layer microstructure and membrane properties. The Pd-Ag layers deposited onto ZrO2 3-nm top layer supports (smallest pore size among all tested) present high N2 permeance in the order of 10−6 mol•m−2•s−1•Pa−1 at room temperature.The presented work is funded within the FluidCELL project (Advanced m-CHP fuel CELL system based on a novel bio-ethanol Fluidized bed membrane reformer) as part of the European Union’s Seventh Framework Programme (FP7/2007-2013) for the Fuel Cells and Hydrogen Joint Technology (FCH JU) Initiative under Grant Agreement No. 621196. Note: “The present publication reflects only the authors’ views and the FCH JU and the Union are not liable for any use that may be made of the information contained therein”. This work is also partly funded by the MEMPORE project (Development of novel nanostructured membranes for micro-cogeneration (m-CHP)) (PI_2014_1_25) from the Basque Department of Education, Language policy and Culture. The authors would like to thank Rauschert Kloster Veilsdorf for providing the ceramic tubular supports

Pedro Alfonso y la iconografia religiosa europea

A biography of Pedro Alfonso is proposed from the information today known. There is reproduced our mathematical deduction of the icon Trinitario of a parchment of Chartres of the XIIIth century from a figure precabalística introduced in 1110 by Pedro Alfonso of Huesca and it is presented three other materializations of the «alternated link of three rings any two not linked».On propose une biographie de Petrus Alfonsi de Huesca. On reproduit notre déduction mathématique de l'icône Trinitaire d'un parchemin de Chartres, du XIII siècle, depuis Ia figure précabalistique de Petrus Alfonsi, qu'il a introduit dans son oeuvre Dialogue contre les juifs en l'année 1110. On présente aussi trois matérialisations de l' enlacement alterné de trois anneaux deux à deux non enlacés

Process Intensification via Membrane Reactors, the DEMCAMER Project

This paper reports the findings of a FP7 project (DEMCAMER) that developed materials (catalysts and membranes) and new processes for four industrially relevant reaction processes. In this project, active, stable, and selective catalysts were developed for the reaction systems of interest and their production scaled up to kg scale (TRL5 (TRL: Technology Readiness Level)). Simultaneously, new membranes for gas separation were developed; in particular, dense supported thin palladium-based membranes for hydrogen separation from reactive mixtures. These membranes were successfully scaled up to TRL4 and used in various lab-scale reactors for water gas shift (WGS), using both packed bed and fluidized bed reactors, and Fischer-Tropsch (FTS) using packed bed reactors and in prototype reactors for WGS and FTS. Mixed ionic-electronic conducting membranes in capillary form were also developed for high temperature oxygen separation from air. These membranes can be used for both Autothermal Reforming (ATR) and Oxidative Coupling of Methane (OCM) reaction systems to increase the efficiency and the yield of the processes. The production of these membranes was scaled up to TRL3–4. The project also developed adequate sealing techniques to be able to integrate the different membranes in lab-scale and prototype reactors

Preparation and characterization of metallic supported thin Pd-Ag membranes for hydrogen separation

This paper reports the preparation and characterization of thin-film (4-5 µm thick) Pd-Ag metallic supported membranes for high temperature applications. Various thin film membranes have been prepared by depositing a ceramic interdiffusion barrier layer prior to the simultaneous Pd-Ag electroless plating deposition. Two deposition techniques for ceramic layers (made of zirconia and alumina) have been evaluated: atmospheric plasma spraying and dip coating of a powder suspension. Initially, the prepared ceramic layers have been characterized for nitrogen permeation at room temperature and surface roughness for the selection of the appropriate type of ceramic layer. The most promising membranes have been tested at 400 – 600 ºC for single gas permeation (H2 and N2), and have shown extremely high H2/N2 permselectivities (>200,000)

Advanced m-CHP fuel cell system based on a novel bio-ethanol fluidized bed membrane reformer

Distributed power generation via Micro Combined Heat and Power (m-CHP) systems, has been proven to over-come disadvantages of centralized generation since it can give savings in terms of Primary Energy consumption and energy costs. The FluidCELL FCH JU/FP7 project aims at providing the Proof of Concept of an advanced high performance, cost effective bio-ethanol m-CHP cogeneration Fuel Cell system for decentralized off-grid applications by end of 2017. The main idea of FluidCELL is to develop a new bio-ethanol membrane reformer for pure hydrogen production (3.2 Nm3/h) based on Membrane Reactors in order to intensify the process of hydrogen production through the integration of reforming and purification in one single unit. The novel reactor could be more efficient than the state-of-the-art technology due to an optimal design aimed at circumventing mass and heat transfer resistances. Moreover, the design and optimization of the subcomponents for the BoP could also be improved. Particular attention has to be devoted to the optimized thermal integration that can improve the overall efficiency of the system at >90% and reducing the cost due to low temperature reforming. The main results obtained until now in terms of performance of the catalysts, membranes and the membrane reactors will be presented in this work

Advances in membranes and membrane reactors for the Fischer-Tropsch synthesis process for biofuel production

The biomass-to-liquid (BtL) process is a promising technology to obtain clean, liquid, second-generation biofuels and chemicals. The BtL process, which comprises several steps, is based upon the gasification of biomass and the catalytic transformation of the syngas that is obtained via the Fischer-Tropsch synthesis (FTS) reaction, producing a hydrocarbon pool known as syncrude. The FTS process is a well-established technology, and there are currently very large FTS plants operating worldwide that produce liquid fuels and hydrocarbons from natural gas (NG) (gas-to-liquids, GtL process) and coal (coal-to-liquids, CtL process). Due to the limited availability of local biomass, the size of the BtL plants should be downscaled compared to that of a GtL or CtL plant. Since the feasibility of the XtL (X refers to any energy source that can be converted to liquid, including coal, NG, biomass, municipal solid waste, etc.) processes is strongly influenced by the economies of scale, the viability of small-scale BtL plants can be compromised. An interesting approach to overcome this issue is to increase the productivity of the FTS process by developing reactors and catalysts with higher productivities to generate the desired product fraction. Recently, by integrating membrane reactors with the FTS process the gas feeding and separation unit have been demonstrated in a single reactor. In this review, the most significant achievements in the field of catalytic membrane reactors for the FTS process will be discussed. Different types of membranes and configurations of membrane reactors, including H2O separation and H2 -feed distribution, among others, will be analyzed.The authors acknowledge Project ENE2016-77055-C3-3-R from the Ministerio de Economia y Competitividad. In addition, the authors would like to thank the Membrane Technology and Process Intensification Department and the Sustainable Chemistry Department at Tecnalia and the Group of Energy and Sustainable Chemistry at CSIC

Advances in membranes and membrane reactors for the Fischer-Tropsch synthesis process for biofuel production

The biomass-to-liquid (BtL) process is a promising technology to obtain clean, liquid, second-generation biofuels and chemicals. The BtL process, which comprises several steps, is based upon the gasification of biomass and the catalytic transformation of the syngas that is obtained via the Fischer-Tropsch synthesis (FTS) reaction, producing a hydrocarbon pool known as syncrude. The FTS process is a well-established technology, and there are currently very large FTS plants operating worldwide that produce liquid fuels and hydrocarbons from natural gas (NG) (gas-to-liquids, GtL process) and coal (coal-to-liquids, CtL process). Due to the limited availability of local biomass, the size of the BtL plants should be downscaled compared to that of a GtL or CtL plant. Since the feasibility of the XtL (X refers to any energy source that can be converted to liquid, including coal, NG, biomass, municipal solid waste, etc.) processes is strongly influenced by the economies of scale, the viability of small-scale BtL plants can be compromised. An interesting approach to overcome this issue is to increase the productivity of the FTS process by developing reactors and catalysts with higher productivities to generate the desired product fraction. Recently, by integrating membrane reactors with the FTS process the gas feeding and separation unit have been demonstrated in a single reactor. In this review, the most significant achievements in the field of catalytic membrane reactors for the FTS process will be discussed. Different types of membranes and configurations of membrane reactors, including H2O separation and H2-feed distribution, among others, will be analyzed

Preparation and characterization of metallic supported Pd-Ag membranes for hydrogen separation

This paper reports the preparation and characterization of thin-film (4–5 μm thick) Pd–Ag metallic supported membranes for high temperature applications. Various thin film membranes have been prepared by depositing a ceramic interdiffusion barrier layer prior to the simultaneous Pd–Ag electroless plating deposition. Two deposition techniques for ceramic layers (made of zirconia and alumina) have been evaluated: Atmospheric Plasma Spraying and dip coating of a powder suspension. Initially, the prepared ceramic layers have been characterized for nitrogen permeation at room temperature and surface roughness for the selection of the appropriate type of ceramic layer. The most promising membranes have been tested at 400–600 °C for single gas permeation (H2 and N2), and have shown extremely high H2/N2 permselectivities (>200,000)

Catalytic membrane reactor for the production of biofuels

The H2-distributed feeding concept using Pd/Ag based membranes and Ru-based catalyst in Packed Bed Membrane Reactor (H2-PBMR) for the synthesis of biofuels via the so-called Fischer-Tropsch Synthesis has been demonstrated. The most successful approach resulted when H2-poor syngas (H2/CO=1) typically obtained from the gasification of biomass, was feed directly through the reaction chamber, i.e., to the catalyst bed, whereas the H2 needed to reach the proper stoichiometry for the FTS (H2/CO=2) was admitted, and properly distributed, into the catalyst bed through the Pd/Ag-based membrane by flowing H2/He mixtures at the outer side of the membrane. Under the optimum reaction conditions, the CO conversion recorded with the H2-distributed feeding concept is lower than that obtained in a conventional Packed Bed Reactor with H2/CO =2 (37.9 vs 50.7 %) but significantly higher than that obtained in a conventional reactor with H2/CO =1 (14.1 %). Remarkably, productivity towards high-molecular hydrocarbons increases by almost a 70 % and methane production decreases by one order of magnitude when H2-distributed feeding concept in Packed Bed Membrane Reactor is used