Browsing by Author "Gallucci, F."
Now showing 1 - 9 of 9
Results Per Page
Sort Options
Item Carbon molecular sieve membranes for selective CO2 separation at elevated temperatures and pressures(2023-02) Rahimalimamaghani, A.; Godini, H.R.; Mboussi, M.; Pacheco Tanaka, A.; Llosa Tanco, M.; Gallucci, F.; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThe use of Carbon Molecular Sieve Membranes (CMSM) for selective CO2 separation from post-combustion CO2-rich streams from steel plant was experimentally evaluated and reported in this paper. Efficient CMSMs were developed for such application and their promising potentials in operating at elevated temperatures and pressures were experimentally demonstrated. The best performance in terms of flux as well as perm-selectivity, above the Robeson upper bound, was obtained using a CMSM developed with ethylenediamine in the dip-coating stage of the fabrication. In fact, adding ethylenediamine was proven to be particularly important in narrowing down the pore size distribution to ultra-micropore and establishing effective CO2 adsorption site over the membrane surface and the pores wall. It was shown that using a tailored CMSM with a precursor synthesized by co-polymerization of ethylenediamine with Novolac can improve the CO2/N2 ideal perm-selectivity from 33 to 97 at operational conditions of 200 °C and 20 bar.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 Effect of aluminium acetyl acetonate on the hydrogen and nitrogen permeation of carbon molecular sieves membranes(2022-04-15) Rahimalimamaghani, A.; Pacheco Tanaka, D.A.; Llosa Tanco, M.A.; Neira D'Angelo, F.; Gallucci, F.; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSWith a growing interest in hydrogen as energy carrier, the efficient purification of hydrogen from gaseous mixtures is very important. This paper addresses the separation of hydrogen using Carbon Molecular Sieves Membranes (CMSM), which show an attractive combination of high permeability, selectivity and stability. Supported CMSM containing various amounts of aluminium have been prepared from novolac and aluminium acetyl acetonate (Al(acac)3) as carbon and alumina precursors. The thickness of the CMSM layers depend on the content of Al(acac)3 in the dipping solution, which also has influence in the pore size and pore size distribution of the membranes. The permeation properties of the membranes against the Al content in the membrane follows a volcano shape, where the membrane containing 4 wt (%) of Al(acac)3 has the best properties and was stable during 720 h for hydrogen at 150 °C and 6 bar pressure difference. All the CMSM have permeation properties well above the Robeson Upper limit.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 New hydrophilic carbon molecular sieve membranes for bioethanol dehydration via pervaporation(2022-05-01) Rahimalimamaghani, A.; Pacheco Tanaka, D.A.; Llosa Tanco, M.A.; Neira D'Angelo, F.; Gallucci, F.; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSTubular supported carbon molecular sieve membranes (CMSMs) with high hydrophilicity and perm-selectivities for water suitable for ethanol dehydration were developed from a Novolac oligomer phenolic resin as precursor. Alpha alumina supported CMSMs resulted in 1.69 times higher surface roughness than zirconia supports. The higher surface roughness resulted in 48% higher selective layer thickness. According to pervaporation results, water permeance decreased by the increase in selective layer thickness and mole based selectivity of water- ethanol was enhanced. The oligomer with 3982 g/mol molecular weight enabled membrane to reach high selectivity with one-layer coating. Performance of the membranes are compared with literature data in terms of mole-based selectivity vs. water permeance. CMSMs could be a potential substitution for traditional ethanol dehydration methods with offering higher performance and as a result reducing the final price of bioethanol to be used as a sustainable energy source.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 Preparation and characterization of thin-film Pd-Ag supported membranes for high-temperature applications(2015-10-19) Fernandez, E.; Coenen, K.; Helmi, A.; Melendez, J.; Zuñiga, J.; Pacheco Tanaka, D. A.; Van Sint Annaland, M.; Gallucci, F.; TECNOLOGÍAS DE HIDRÓGENO; Tecnalia Research & Innovation; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThis paper reports the preparation, characterization and stability tests of thin-film Pd-Ag supported membranes for high-temperature fluidized bed membrane reactor applications. Various thin-film supported membranes have been prepared by simultaneous Pd-Ag electroless plating and have been initially sealed with a sealing procedure previously validated for Water gas shift (WGS) application (400 °C). The membranes have been characterized for single gas and mixed gas permeation, and for methane steam and autothermal reforming in a fluidized bed membrane reactor at 550-600 °C using a Ru-based catalyst. In addition, the performance of these membranes was compared to commercial membranes from REB Research & Consulting under the same reaction conditions. The applied sealing showed nitrogen leaks at 600 °C and different sealing approaches were tested solving this problem. Finally, also the long-term stability of the thin-film Pd-Ag supported membrane at 600 °C has been investigated.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 Upgrading biogas with novel composite carbon molecular sieve (CCMS) membranes: Experimental and techno-economic assessment: Experimental and techno-economic assessment(2020-08-15) Medrano, J.A.; Llosa-Tanco, M.A.; Cechetto, V.; Pacheco-Tanaka, D.A.; Gallucci, F.; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThe use of biogas as feedstock for hydrogen production was widely proposed in the literature in the last years as a strategy to reduce anthropogenic carbon emissions. However, its lower heating value compared to natural gas hampers the revamping of existing reforming plants. The use of composite carbon molecular sieve membranes for biogas upgrading (CO2 removal from biogas) was investigated experimentally in this work. In particular, ideal perm-selectivities and permeabilities above the Robeson plot for CO2/CH4 mixtures have been obtained. These membranes show better performances compared to polymeric membranes, which are nowadays commercialized for CO2 separation in natural gas streams. Compared to polymeric membranes, carbon membranes do not show deactivation by plasticization when exposed to CO2, and thus can find industrial application. This work was extended with a techno-economic analysis where carbon membranes are installed in a steam methane reforming plant. Results have been first validated with data from literature and show that the use of biogas increases the costs of hydrogen production to a value of 0.25 €/Nm3 compared to the benchmark technology (0.21 €/Nm3). On the other hand, the use of biogas leads to a decrease in carbon emissions up to 95%, thus the use of biogas for hydrogen production is foreseen as a very interesting alternative to conventional technologies in view of the reduction in the carbon footprint in the novel technologies that are to be installed in the near future.