Browsing by Keyword "Membrane reactor"
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Item Advances in membranes and membrane reactors for the Fischer-Tropsch synthesis process for biofuel production(De Gruyter, 2020-03) Liuzzi, Dalia; Fernández-Gesalaga, E.; Perez Gil, Susana; Ipiñazar, Enrique; Arteche, Amaya; Garcia Fierro, Jose Luis; Viviente, José Luis; Pacheco-Tanaka, D.A.; Rojas, S.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.Item Direct route from ethanol to pure hydrogen through autothermal reforming in a membrane reactor: Experimental demonstration, reactor modelling and design: Experimental demonstration, reactor modelling and design(2018-01-15) Spallina, V.; Matturro, G.; Ruocco, C.; Meloni, E.; Palma, V.; Fernández-Gesalaga, E.; Melendez, J.; Pacheco Tanaka, David A.; Viviente Sole, J.L.; van Sint Annaland, M.; Gallucci, F.; Tecnalia Research & Innovation; TECNOLOGÍAS DE HIDRÓGENO; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThis work reports the integration of thin (∼3–4 μm thick) Pd-based membranes for H2 separation in a fluidized bed catalytic reactor for ethanol auto-thermal reforming. The performance of a fluidized bed membrane reactor has been investigated from an experimental and numerical point of view. The demonstration of the technology has been carried out over 50 h under reactive conditions using 5 thin Pd-based alumina-supported membranes and a 3 wt%Pt-10 wt%Ni catalyst deposited on a mixed CeO2/SiO2 support. The results have confirmed the feasibility of the concept, in particular the capacity to reach a hydrogen recovery factor up to 70%, while the operation at different fluidization regimes, oxygen-to-ethanol and steam-to-ethanol ratios, feed pressures and reactor temperatures have been studied. The most critical part of the system is the sealing of the membranes, where most of the gas leakage was detected. A fluidized bed membrane reactor model for ethanol reforming has been developed and validated with the obtained experimental results. The model has been subsequently used to design a small reactor unit for domestic use, showing that 0.45 m2 membrane area is needed to produce the amount of H2 required for a 5 kWe PEM fuel-cell based micro-CHP system.Item H2 production via ammonia decomposition in a catalytic membrane reactor(2021-06-01) Cechetto, Valentina; Di Felice, Luca; Medrano, Jose A.; Makhloufi, Camel; Zuniga, Jon; Gallucci, Fausto; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThe membrane reactor is proposed in this work as a system with high potential to efficiently recover the hydrogen (H2) stored in ammonia (NH3), which has been recently proposed as an alternative for H2 storage. With this technology, NH3 decomposition and high-purity H2 separation are simultaneously performed within the same unit, and high H2 separation efficiency is achieved at lower temperature compared to conventional systems, leading to energetic and economic benefits. NH3 decomposition was experimentally performed in a Pd-based membrane reactor over a Ru-based catalyst and the performance of the conventional packed bed reactor were used as benchmark for a comparison. The results demonstrate that the introduction of a membrane in a conventional reactor enhances its performance and allows to achieve conversion higher than the thermodynamic equilibrium conversion for sufficiently high temperatures. For temperatures from and above 425 °C, full NH3 conversion was achieved and more than 86% of H2 fed to the system as ammonia was recovered with a purity of 99.998%. The application of vacuum at the membrane permeate side leads to higher H2 recovery and NH3 conversions beyond thermodynamic restrictions. On the other hand, the reactor feed flow rate and operating pressure have not shown major impacts on NH3 conversion.Item The membrane-assisted chemical looping reforming concept for efficient H2 production with inherent CO2 capture: Experimental demonstration and model validation: Experimental demonstration and model validation(2018-04-01) Medrano, J.A.; Potdar, I.; Melendez, J.; Spallina, V.; Pacheco Tanaka, David A.; van Sint Annaland, M.; Gallucci, F.; Tecnalia Research & Innovation; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSIn this work a novel reactor concept referred to as Membrane-Assisted Chemical Looping Reforming (MA-CLR) has been demonstrated at lab scale under different operating conditions for a total working time of about 100 h. This reactor combines the advantages of Chemical Looping, such as CO2 capture and good thermal integration, with membrane technology for a better process integration and direct product separation in a single unit, which in its turn leads to increased efficiencies and important benefits compared to conventional technologies for H2 production. The effect of different operating conditions (i.e. temperature, steam-to-carbon ratio or oxygen feed in the reactor) has been evaluated in a continuous chemical looping reactor, and methane conversions above 90% have been measured with (ultra-pure) hydrogen recovery from the membranes. For all the cases a maximum recovery factor of around 30% has been measured, which could be increased by operating the concept at higher pressures and with more membranes. The optimum conditions have been found at temperatures around 600 °C for a steam-to-carbon ratio of 3 and diluted air in the air reactor (5% O2). The complete demonstration has been carried out feeding up to 1 L/min of CH4 (corresponding to 0.6 kW of thermal input) while up to 1.15 L/min of H2 was recovered. Simultaneously, a phenomenological model has been developed and validated with the experimental results. In general, good agreement is observed, with overall deviations below 10% in terms of methane conversion, H2 recovery and separation factor. The model allows better understanding of the behavior of the MA-CLR concept and the optimization and design of scaled-up versions of the concept.Item Mixed Ionic-Electronic Conducting Membranes (MIEC) for Their Application in Membrane Reactors: A Review: A review(2019-03-01) Arratibel Plazaola, Alba; Cruellas Labella, Aitor; Liu, Yuliang; Badiola Porras, Nerea; Pacheco Tanaka, David; Sint Annaland, Martin; Gallucci, Fausto; Tecnalia Research & Innovation; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSMixed ionic-electronic conducting membranes have seen significant progress over the last 25 years as efficient ways to obtain oxygen separation from air and for their integration in chemical production systems where pure oxygen in small amounts is needed. Perovskite materials are the most employed materials for membrane preparation. However, they have poor phase stability and are prone to poisoning when subjected to CO2 and SO2, which limits their industrial application. To solve this, the so-called dual-phase membranes are attracting greater attention. In this review, recent advances on self-supported and supported oxygen membranes and factors that affect the oxygen permeation and membrane stability are presented. Possible ways for further improvements that can be pursued to increase the oxygen permeation rate are also indicated. Lastly, an overview of the most relevant examples of membrane reactors in which oxygen membranes have been integrated are provided.Item On concentration polarisation in a fluidized bed membrane reactor for biogas steam reforming: modelling and experimental validation: Modelling and experimental validation(2018-09-15) de Nooijer, Niek; Gallucci, Fausto; Pellizzari, Emma; Melendez, Jon; Pacheco Tanaka, David A.; Manzolini, Giampaolo; van Sint Annaland, Martin; Tecnalia Research & Innovation; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThe production of pure hydrogen through the steam reforming of biogas in a fluidized bed membrane reactor has been studied. A phenomenological one-dimensional two-phase fluidized bed reactor model accounting for concentration polarisation with a stagnant film model has been developed and used to investigate the system performance. The validation of the model was performed with steam reforming experiments at temperatures ranging from 435 °C up to 535 °C, pressures between 2 to 5 bar and CO2/CH4 ratios up to 0.9. The permeation performance of the ceramic-supported PdAg thin-film membrane was first characterized separately for both pure gas and gas mixtures. Subsequently, the membrane was immersed into a fluidized bed containing Rh supported on alumina particles and the reactor performance, viz. the methane conversion, hydrogen recovery and hydrogen purity, was evaluated under biogas steam reforming conditions. The resulting hydrogen purity under biogas steam reforming conditions was up to 99.8%. The model results were in very good agreement with the experimental results, when assuming a thickness of the stagnant mass transfer boundary layer around the membrane equal to 0.54 cm. It is shown that the effects of concentration polarisation in a fluidized bed membrane reactor can be well described with the implementation of a film layer description in the two-phase model.Item Pd-based membranes performance under hydrocarbon exposure for propane dehydrogenation processes: Experimental and modeling: Experimental and modeling(2022-03-08) Brencio, C.; Fontein, F.W.A.; Medrano, J.A.; Di Felice, L.; Arratibel, A.; Gallucci, F.; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSIn this work, a novel Pd–Ag double-skinned (DS-) membrane is used for the first time in conditions typical of propane dehydrogenation (PDH). This membrane presents a protective layer on top of the H2-selective one, which acts as shield against chemical deactivation and mechanical erosion under reaction conditions. While the protective layer is already been proven as an efficient barrier against membrane erosion in fluidized beds, there is no validation yet under PDH reaction. The DS- membrane performance is compared with a conventional (C-) Pd–Ag membrane under alkane/alkene exposure, at 400–500 °C and 3 bar, to investigate whether the incorporation of the protective layer would be suited for H2 separation in PDH systems, and if coking rate would be affected. The novel membrane shows a H2 permeance of 2.28 × 10−6 mol∙m−2 s−1∙Pa−1 at 500 ᵒC and 4 bar of pressure difference, overcoming the performance of the conventional PdAg one (1.56x∙10−6 mol m−2 s−1∙Pa−1). Both membranes present a stable H2 flux under alkane exposure, while deactivation occurs under exposure to alkenes. A model able to describe the H2 flux through Pd-based membranes is presented to fit the experimental data and predict membrane performance. The model includes mass transfer limitations in the retentate and a corrective inhibition factor to account for the competitive adsorption of hydrocarbon species in the H2 selective layer. The experimental results obtained under alkene exposure deviates from model predictions; this can be attributed to carbon deposition on the surface of the selective layer, as further detected on the DS-membrane by Scanning Electron Microscopy (SEM)/Energy Dispersive X-Ray Analysis (EDX), which is the main factor for membrane deactivation.Item Recent Advances in Pd-Based Membranes for Membrane Reactors(2017-01-01) Arratibel Plazaola, Alba; Pacheco Tanaka, David A.; Van Sint Annaland, Martin; Gallucci, Fausto; Tecnalia Research & Innovation; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSPalladium-based membranes for hydrogen separation have been studied by several research groups during the last 40 years. Much effort has been dedicated to improving the hydrogen flux of these membranes employing different alloys, supports, deposition/production techniques, etc. High flux and cheap membranes, yet stable at different operating conditions are required for their exploitation at industrial scale. The integration of membranes in multifunctional reactors (membrane reactors) poses additional demands on the membranes as interactions at different levels between the catalyst and the membrane surface can occur. Particularly, when employing the membranes in fluidized bed reactors, the selective layer should be resistant to or protected against erosion. In this review we will also describe a novel kind of membranes, the pore-filled type membranes prepared by Pacheco Tanaka and coworkers that represent a possible solution to integrate thin selective membranes into membrane reactors while protecting the selective layer. This work is focused on recent advances on metallic supports, materials used as an intermetallic diffusion layer when metallic supports are used and the most recent advances on Pd-based composite membranes. Particular attention is paid to improvements on sulfur resistance of Pd based membranes, resistance to hydrogen embrittlement and stability at high temperature.Item Syngas upgrading in a membrane reactor with thin Pd-alloy supported membrane(2015-09-14) Brunetti, A.; Caravella, A.; Fernandez, E.; Pacheco Tanaka, D. A.; Gallucci, F.; Drioli, E.; Curcio, E.; Viviente, J. L.; Barbieri, G.; TECNOLOGÍAS DE HIDRÓGENO; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSIn hydrogen production, the syngas streams produced by reformers and/or coal gasification plants contain a large amount of H2 and CO in need of upgrading. To this purpose, reactors using Pd-based membranes have been widely studied as they allow separation and recovery of a pure hydrogen stream. However, the high cost of Pd-membranes is one of the main limitations for scaling up technology. Therefore, many researchers are now pursuing the possibility of using supported membranes with as thin as possible Pd-alloy layers. In this work, the upgrading of a syngas stream is experimentally investigated in a water gas shift membrane reactor operated in a high temperature range with an ultra-thin supported membrane (3.6 micron-thick). The membrane permeance was measured before and after catalyst packing and also after reaction for 2100 h of operation in total. Membrane reactor performance was evaluated as a function of operating conditions such as temperature, pressure, gas hourly space velocity, feed molar ratio, and sweep gas. A CO conversion significantly higher than the thermodynamics upper limit of a traditional reactor was achieved, even at high gas hourly space velocities and a 25% less reaction volume than that of a traditional reactor was enough to achieve a 90% equilibrium conversion.Item Ultra-pure hydrogen production via ammonia decomposition in a catalytic membrane reactor(2022-06-08) Cechetto, Valentina; Di Felice, Luca; Gutierrez Martinez, Rocio; Arratibel Plazaola, Alba; Gallucci, Fausto; Tecnalia Research & Innovation; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSIn this work two alternatives are presented for increasing the purity of hydrogen produced in a membrane reactor for ammonia decomposition. It is experimentally demonstrated that either increasing the thickness of the membrane selective layer or using a small purification unit in the permeate of the membranes, ultra-pure hydrogen can be produced. Specifically, the results show that increasing the membrane thickness above 6 μm ultra-pure hydrogen can be obtained at pressures below 5 bar. A cheaper solution, however, consists in the use of an adsorption bed downstream the membrane reactor. In this way, ultra-pure hydrogen can be achieved with higher reactor pressures, lower temperatures and thinner membranes, which result in lower reactor costs. A possible process diagram is also reported showing that the regeneration of the adsorption bed can be done by exploiting the heat available in the system and thus introducing no additional heat sources.