Browsing by Keyword "Environmental Chemistry"
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Item Application of ecological risk assessment based on a novel TRIAD-tiered approach to contaminated soil surrounding a closed non-sealed landfill(2015-05-01) Gutiérrez, Laura; Garbisu, Carlos; Ciprián, Estela; Becerril, José M.; Soto, Manu; Etxebarria, Javier; Madariaga, Juan M.; Antigüedad, Iñaki; Epelde, Lur; Tecnalia Research & Innovation; MercadoThe Ecological Risk Assessment (ERA) is a reliable tool for communicating risk to decision makers in a comprehensive and scientific evidence-based way. In this work, a site-specific ERA methodology based on the TRIAD approach was applied to contaminated soil surrounding a closed non-sealed landfill, as a case study to implement and validate such ERA methodology in the Basque Country (northern Spain). Initially, the procedure consisted of the application of a Parameter Selection Module aimed at selecting the most suitable parameters for the specific characteristics of the landfill contaminated soil, taking into consideration the envisioned land use, intended ecosystem services and nature of contaminants. Afterwards, the selected parameters were determined in soil samples collected from two sampling points located downstream of the abovementioned landfill. The results from these tests were normalized to make them comparable and integrable in a risk index. Then, risk assessment criteria were developed and applied to the two landfill contaminated soil samples. Although the lack of a proper control soil was evidenced, a natural land use was approved by the ERA (at Tier 2) for the two landfill contaminated soils. However, the existence of a potential future risk resulting from a hypothetical soil acidification must be considered.Item Assessment of nanoparticles release into the environment during drilling of carbon nanotubes/epoxy and carbon nanofibres/epoxy nanocomposites(2017-10-15) Starost, Kristof; Frijns, Evelien; Van Laer, Jo; Faisal, Nadimul; Egizabal, Ainhoa; Elizetxea, Cristina; Blazquez, Maria; Nelissen, Inge; Njuguna, James; Elizextea, Cristina; Biomateriales; POLIMEROSThe risk assessment, exposure and understanding of the release of embedded carbon nanotubes (CNTs) and carbon nanofibers (CNFs) from commercial high performance composites during machining processes are yet to be fully evaluated and quantified. In this study, CNTs and CNFs were dispersed in epoxy matrix through calendaring process to form nanocomposites. The automated drilling was carried out in a specially designed drilling chamber that allowed elimination of background noise from the measurements. Emission measurements were taken using condensed particle counter (CPC), scanning mobility particle sizer (SMPS) and DMS50 Fast Particulate Size Spectrometer. In comparison to the neat epoxy, the study results revealed that the nano-filled samples produced an increase of 102% and 227% for the EP/CNF and EP/CNT sample respectively in average particle number concentration emission. The particle mass concentration indicated that the EP/CNT and EP/CNF samples released demands a vital new perspective on CNTs and CNFs embedded within nanocomposite materials to be considered and evaluated for occupational exposure assessment. Importantly, the increased concentration observed at 10 nm aerosol particle sizes measurements strongly suggest that there are independent CNTs being released at this range.Item Development of highly permeable ultra-thin Pd-based supported membranes(2016-12-01) Fernandez, Ekain; Sanchez-Garcia, Jose Angel; Melendez, Jon; Spallina, Vincenzo; van Sint Annaland, Martin; Gallucci, Fausto; Pacheco Tanaka, D. A.; Prema, Radha; TECNOLOGÍAS DE HIDRÓGENO; Tecnalia Research & Innovation; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThis paper reports the preparation and characterization of ultra-thin (∼1 μm thick) Pd-based supported membranes for hydrogen purification. Ultra-thin membranes have been prepared by a combination of PVD magnetron sputtering and electroless plating techniques. The membranes have been characterized for single gas and mix gas permeation at temperatures between 350 and 500 °C and they have shown to exhibit very high hydrogen fluxes combined with a good perm-selectivity (H2/N2 ≈ 500). These results have been compared with the performance of highly permeable membranes reported in the literature. The influence of the morphology of the deposited Pd-based layers on the membrane performance has been investigated and discussed.Item The effect of nanosilica (SiO2) and nanoalumina (Al2O3) reinforced polyester nanocomposites on aerosol nanoparticle emissions into the environment during automated drilling(2017-05) Starost, Kristof; Frijns, Evelien; Van Laer, Jo; Faisal, Nadimul; Egizabal, Ainhoa; Elizetxea, Cristina; Nelissen, Inge; Blázquez, María; Njuguna, James; Biomateriales; POLIMEROSThe aim of this study is to investigate the effect nanosilica and nanoalumina has on nanoparticle release from industrial nanocomposites due to drilling for hazard reduction whilst simultaneously obtaining the necessary mechanical performance. This study is therefore specifically designed such that all background noise is eliminated in the measurements range of 0.01 particles/cm3 and ±10% at 106 particles/cm3. The impact nano-sized SiO2 and Al2O3 reinforced polyester has on nanoparticle aerosols generated due to drilling is investigated. Real-time measurement was conducted within a specially designed controlled test chamber using a condensation particle counter (CPC) and a scanning mobility particle sizer spectrometer (SMPS). The results show that the polyester nanocomposite samples displayed statistically significant differences and an increase in nanoparticle number concentration by up to 228% compared to virgin polyester. It is shown that the nanofillers adhered to the polyester matrix showing a higher concentration of larger particles released (between 20 – 100 nm). The increase in nanoparticle reinforcement weight concentration and resulting nanoparticle release vary considerably between the nanosilica and nanoalumina samples due to the nanofillers presence. This study indicates a future opportunity to safer by design strategy that reduces number of particles released concentration and sizes without compromising desired mechanical properties for engineered polymers and composites.Item Electrosynthesis of 2,3-butanediol and methyl ethyl ketone from acetoin in flow cells(2019) Ochoa-Gómez, José R.; Fernández-Carretero, Francisco; Río-Pérez, Francisca; García-Luis, Alberto; Roncal, Tomás; García-Suárez, Eduardo J.; Tecnalia Research & Innovation; TECNOLOGÍAS DE HIDRÓGENO; BIOECONOMÍA Y CO2Acetoin could shortly become a platform molecule due to current progress in fermentation technology, the megatrend for shifting from an oil-based economy to one based on biomass, the quest for green manufacturing processes and its two highly reactive carbonyl and hydroxyl moieties. In this paper, the successful electro-conversion of acetoin into two valuable chemicals, 2,3-butandiol (2,3-BD) and methyl ethyl ketone (MEK), at constant electrical current in aqueous phase at room temperature using both divided and undivided 20 cm2 filter-press flow cells under experimental conditions suitable for industrial production is reported. Cathode material is the key parameter to drive the electroreduction towards one or another chemical. 2,3-BD is the major chemical produced by electrohydrogenation when low hydrogen overvoltage cathodes, such as Pt and Ni, of high surface area obtained by PVD coating on a carbon gas diffusion layer are used, while MEK is the principal product produced by electrohydrogenolysis when high hydrogen overvoltage cathodes, such as graphite, Pb and Cd foils, are employed. 2,3-BD and MEK can be obtained, respectively, in 92.8% and 85.7% selectivities, 71.7% and 80.4% current efficiencies, with 1.21 and 1.08 kg.h-1.m-2 productivities and power consumptions of 2.94 and 4.1 kWh.kg-1 using undivided cells and aqueous K2HPO4 electrolysis media at pHs of 3.6 and 5.5. The reported electroconversion of acetoin is highly flexible because 2,3-BD and MEK can be produced by changing just the cathode but using the same cell, with the same electrolyte at the same current density.Item End-of-life management of single-use baby diapers: Analysis of technical, health and environment aspects: Analysis of technical, health and environment aspects(2022-08-25) Płotka-Wasylka, Justyna; Makoś-Chełstowska, Patrycja; Kurowska-Susdorf, Aleksandra; Treviño, María José Santoyo; Guzmán, Sergio Zarazúa; Mostafa, Heba; Cordella, Mauro; Tecnalia Research & InnovationSingle-use baby diapers belongs to an important group of products used in the parenting journey because of their high performance and convenience. Single-use baby diapers are normally thrown away after one-time use, resulting in a waste management problem. The goal of this paper was to better understand main environmental concerns of different types of diapers and address how to reduce them, with a special consideration of waste management strategies and user behaviour practices. Furthermore, health and environmental hazards potentially associated with materials included in diapers, or substances formed from diapers during the waste treatment stage, are also analysed (e.g., phthalates, pesticides, dioxins, pesticides). Three main types of baby diapers have been analysed: single-use baby diapers, reusable baby diapers, and biodegradable single-use diapers. Each type of diaper comes with technical characteristics and environmental concerns and challenges, which are discussed in this paper to support the development of measures for the safe(r) and sustainable design, use and end of life management of baby diapers.Item Energy-socio-economic-environmental modelling for the EU energy and post-COVID-19 transitions(2022-01-20) Cazcarro, Ignacio; García-Gusano, Diego; Iribarren, Diego; Linares, Pedro; Romero, José Carlos; Arocena, Pablo; Arto, Iñaki; Banacloche, Santacruz; Lechón, Yolanda; Miguel, Luis Javier; Zafrilla, Jorge; López, Luis-Antonio; Langarita, Raquel; Cadarso, María-Ángeles; Tecnalia Research & Innovation; PLANIFICACIÓN ENERGÉTICARelevant energy questions have arisen because of the COVID-19 pandemic. The pandemic shock leads to emissions’ reductions consistent with the rates of decrease required to achieve the Paris Agreement goals. Those unforeseen drastic reductions in emissions are temporary as long as they do not involve structural changes. However, the COVID-19 consequences and the subsequent policy response will affect the economy for decades. Focusing on the EU, this discussion article argues how recovery plans are an opportunity to deepen the way towards a low-carbon economy, improving at the same time employment, health, and equity and the role of modelling tools. Long-term alignment with the low-carbon path and the development of a resilient transition towards renewable sources should guide instruments and policies, conditioning aid to energy-intensive sectors such as transport, tourism, and the automotive industry. However, the potential dangers of short-termism and carbon leakage persist. The current energy-socio-economic-environmental modelling tools are precious to widen the scope and deal with these complex problems. The scientific community has to assess disparate, non-equilibrium, and non-ordinary scenarios, such as sectors and countries lockdowns, drastic changes in consumption patterns, significant investments in renewable energies, and disruptive technologies and incorporate uncertainty analysis. All these instruments will evaluate the cost-effectiveness of decarbonization options and potential consequences on employment, income distribution, and vulnerability.Item Field-scale demonstration of in situ immobilization of heavy metals by injecting iron oxide nanoparticle adsorption barriers in groundwater(2021-02) Mohammadian, Sadjad; Krok, Beate; Fritzsche, Andreas; Bianco, Carlo; Tosco, Tiziana; Cagigal, Ekain; Mata, Bruno; Gonzalez, Veronica; Diez-Ortiz, Maria; Ramos, Vanesa; Montalvo, Daniela; Smolders, Erik; Sethi, Rajandrea; Meckenstock, Rainer U.; TRAZABILIDAD CIRCULARRemediation of heavy metal-contaminated aquifers is a challenging process because they cannot be degraded by microorganisms. Together with the usually limited effectiveness of technologies applied today for treatment of heavy metal contaminated groundwater, this creates a need for new remediation technologies. We therefore developed a new treatment, in which permeable adsorption barriers are established in situ in aquifers by the injection of colloidal iron oxides. These adsorption barriers aim at the immobilization of heavy metals in aquifers groundwater, which was assessed in a large-scale field study in a brownfield site. Colloidal iron oxide (goethite) nanoparticles were used to install an in situ adsorption barrier in a very heterogeneous, contaminated aquifer of a brownfield in Asturias, Spain. The groundwater contained high concentrations of heavy metals with up to 25 mg/L zinc, 1.3 mg/L lead, 40 mg/L copper, 0.1 mg/L nickel and other minor heavy metal pollutants below 1 mg/L. High amounts of zinc (>900 mg/kg), lead (>2000 mg/kg), nickel (>190 mg/kg) were also present in the sediment. Ca. 1500 kg of goethite nanoparticles of 461 ± 266 nm diameter were injected at low pressure (< 0.6 bar) into the aquifer through nine screened injection wells. For each injection well, a radius of influence of at least 2.5 m was achieved within 8 h, creating an in situ barrier of 22 × 3 × 9 m. Despite the extremely high heavy metal contamination and the strong heterogeneity of the aquifer, successful immobilization of contaminants was observed in the tested area. The contaminant concentrations were strongly reduced immediately after the injection and the abatement of the heavy metals continued for a total post-injection monitoring period of 189 days. The iron oxide particles were found to adsorb heavy metals even at pH-values between 4 and 6, where low adsorption would have been expected. The study demonstrated the applicability of iron oxide nanoparticles for installing adsorption barriers for containment of heavy metals in contaminated groundwater under real conditions.Item The future of isosorbide as a fundamental constituent for polycarbonates and polyurethanes(2021) Gómez-de-Miranda-Jiménez-de-Aberasturi, Olga; Centeno-Pedrazo, Ander; Prieto Fernández, Soraya; Rodriguez Alonso, Raquel; Medel, Sandra; María Cuevas, Jose; Monsegue, Luciano G.; De Wildeman, Stefaan; Benedetti, Elena; Klein, Daniela; Henneken, Hartmut; Ochoa-Gómez, José R.; Tecnalia Research & Innovation; BIOECONOMÍA Y CO2; GENERAL; POLIMEROSIsosorbide is a biobased compound which could become in the near future an advantageous competitor of petroleum-derived components in the synthesis of polymers of different nature. When the reactivity of isosorbide is not enough, it can be successfully transformed into secondary building blocks, such as isosorbide bis(methyl carbonate), which provides extra functionalities for polymerization reactions with diols or diamines. The present review summarizes the possibilities for isosorbide as a green raw material to be used in the synthesis of polycarbonates and polyurethanes to obtain products of similar or enhanced properties to the commercial equivalents.Item Improving the understanding of Circular Economy potential at territorial level using Systems Thinking(2021-07) Bassi, Dr. Andrea Marcello; Bianchi, Dr. Marco; Guzzetti, Mr. Marco; Pallaske, Mr. Georg; Tapia, Dr. Carlos; ECONOMÍA CIRCULAR; Tecnalia Research & InnovationThe definition of Circular Economy (CE) has evolved over time. It includes intervention options for reducing consumption, improving the efficiency of production, introducing recycling and reuse for materials management, including new business models geared at waste prevention. With the use of Systems Thinking and the creation of Causal Loop Diagrams (CLDs) we explore how CE strategies are related to territorial dynamics and how the outcomes of such strategies can support sustainable development. We first reviewed the literature, to identify the main drivers of change (i.e. feedback loops) triggered by CE interventions. We then applied the same systemic approach to six case studies across Europe in synergy with ESPON CIRCTER project. This allowed us to review, validate and improve the general systemic approach and further explore the role that specific territorial characteristics can play in the identification, selection and effective implementation of CE interventions. We find that some of the feedback loops emerged from the case studies are not found in the literature. On the one hand, new balancing loops have emerged, representing localized challenges to the implementation of CE strategies. On the other hand, new dynamics related to behavioural change have also emerged, which lead to self-reinforcing mechanisms in the case studies analysed, creating a stronger will for the implementation of CE interventions. The main result of our research is comprehensive CLD that can be used to assess and compare different CE strategies, fully considering the complexity of the CE and its various outcomes across social, economic and environmental indicators.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 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 Preparation and characterization of metallic supported thin Pd–Ag membranes for hydrogen separation(2016-12-01) Fernandez, Ekain; Medrano, Jose Antonio; Melendez, Jon; Parco, Maria; Viviente, Jose Luis; van Sint Annaland, Martin; Gallucci, Fausto; Pacheco Tanaka, D. A.; TECNOLOGÍAS DE HIDRÓGENO; Tecnalia Research & Innovation; EXTREMAT; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThis 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).Item Removal of TiO 2 nanoparticles from water by low pressure pilot plant filtration(2018-03-15) Olabarrieta, Josune; Monzón, Oihane; Belaustegui, Yolanda; Alvarez, Jon-Iñaki; Zorita, Saioa; VALORIZACIÓN DE RESIDUOS; ADAPTACIÓN AL CAMBIO CLIMÁTICORising use of nanoparticles in manufacturing as well as in commercial products bring issues related to environmental release and human exposure. A large amount of TiO2 nanoparticles will eventually reach wastewater treatment plants. Low pressure membrane filtration has been suggested as a feasible treatment of water streams. This study investigated first at laboratory scale the influence of: i) membrane material, ii) pore size and iii) water chemistry on nTiO2 removal. TiO2 retention was governed by the cake layer formation mechanism and significant retention of nanoparticles was observed even for filters having considerably larger pores than nTiO2. PVDF showed a great potential for nTiO2 rejection. Additionally, filtration pilot plant experiments were carried out using PVDF membranes (0.03 and 0.4 μm pore size). The release of nTiO2 in the pilot scale filtration system was always above the instrumental detection limit (> 1.5 μg/L) and in most cases below 100 μg/L regardless of the pore size and applied conditions. The nTiO2 membrane breakthrough predominantly occurred in the first few minutes after backwashes and ceased when the cake layer was formed. Ultrafiltration and microfiltration were comparable with rejection of nTiO2 above 95% at similar permeate flow rates. Nevertheless, ultrafiltration is more promising than microfiltration because it allowed longer operation times between backwash cycles.Item Revisiting the role of steam methane reforming with CO2 capture and storage for long-term hydrogen production(2021-06-01) Navas-Anguita, Zaira; García-Gusano, Diego; Dufour, Javier; Iribarren, Diego; Tecnalia Research & Innovation; PLANIFICACIÓN ENERGÉTICARoad transport is associated with high greenhouse gas emissions due to its current dependence on fossil fuels. In this regard, the implementation of alternative fuels such as hydrogen is expected to play a key role in decarbonising the transport system. Nevertheless, attention should be paid to the suitability of hydrogen production pathways as low-carbon solutions. In this work, an energy systems optimisation model for the prospective assessment of a national hydrogen production mix was upgraded in order to unveil the potential role of grey hydrogen from steam methane reforming (SMR) and blue hydrogen from SMR with CO2 capture and storage (CCS) in satisfying the hydrogen demanded by fuel cell electric vehicles in Spain from 2020 to 2050. This was done by including CCS retrofit of SMR plants in the energy systems model, as a potential strategy within the scope of the European Hydrogen Strategy. Considering three hypothetical years for banning hydrogen from fossil-based plants without CCS (2030, 2035, and 2040), it was found that SMR could satisfy the whole demand for hydrogen for road transport in the short term (2020–2030), while being substituted by water electrolysis in the medium-to-long term (2030–2050). Furthermore, this trend was found to be associated with an appropriate prospective behaviour in terms of carbon footprint.Item Selective leaching of copper and zinc from primary ores and secondary mineral residues using biogenic ammonia(2021-02-05) Williamson, Adam J.; Verbruggen, Florian; Chavez Rico, Vania S.; Bergmans, Jef; Spooren, Jeroen; Yurramendi, Lourdes; Laing, Gijs Du; Boon, Nico; Hennebel, Tom; VALORIZACIÓN DE RESIDUOSWith the number of easily accessible ores depleting, alternate primary and secondary sources are required to meet the increasing demand of economically important metals. Whilst highly abundant, these materials are of lower grade with respect to traditional ores, thus highly selective and sustainable metal extraction technologies are needed to reduce processing costs. Here, we investigated the metal leaching potential of biogenic ammonia produced by a ureolytic strain of Lysinibacillus sphaericus on eight primary and secondary materials, comprised of mining and metallurgical residues, sludges and automotive shredder residues (ASR). For the majority of materials, moderate to high yields (30–70%) and very high selectivity (>97% against iron) of copper and zinc were obtained with 1 mol L−1 total ammonia. Optimal leaching was achieved and further refined for the ASR in a two-step indirect leaching system with biogenic ammonia. Copper leaching was the result of local corrosion and differences in leaching against the synthetic (NH4)2CO3 control could be accounted for by pH shifts from microbial metabolism, subsequently altering free NH3 required for coordination. These results provide important findings for future sustainable metal recovery technologies from secondary materials.Item Tailoring pore structure and surface chemistry of microporous Alumina-Carbon Molecular Sieve Membranes (Al-CMSMs) by altering carbonization temperature for optimal gas separation performance: An investigation using low-field NMR relaxation measurements: An investigation using low-field NMR relaxation measurements(2021-11-15) Forster, Luke; D'Agostino, Carmine; Anabell Llosa-Tanco, Margot; Spallina, Vincenzo; Brencio, Camilla; Gallucci, Fausto; Lindley, Matthew; Haigh, Sarah J.; Alfredo Pacheco-Tanaka, David; Tecnalia Research & Innovation; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSIn this work we applied low-field, NMR spin-lattice measurements to evaluate for the first time the effect of carbonization temperature (range 600 - 1000 ℃) on the preparation of Alumina-Carbon Molecular Sieve Membranes (Al-CMSMs), providing new insights into intra-pore fluid interactions. The results show that the average Al-CMSM pore size generally increases with carbonization temperature whilst the hydrophilicity of the pore surface, and the amount of strongly adsorbed H2O, decreases with an increasing carbonization temperature. As such, lower carbonization temperatures produce more hydrophilic membranes, with further evidence provided by FTIR measurements demonstrating the presence of polar functional groups on the surface, with water interacting more strongly with the membrane surface, as evidenced by NMR. It was found that the Al-CMSM carbonization temperature significantly affected permeance and H2O/CH4 permselectivity by altering the membrane pore size distribution and pore hydrophilicity. H2O permeance values are seen to be up to 100 times larger than respective CH4 permeance values. The greater permeance of H2O is attributed to the larger kinetic diameter of CH4 relative to H2O and the adsorption of water in the hydrophilic pores enhancing the adsorption-diffusion transport mechanism. Optimal water permeation temperatures are thus higher for the more hydrophilic membranes, obtained at lower carbonization temperatures, as more energy is required to remove strongly adsorbed water blocking the pores. At higher carbonization temperatures, the Knudsen diffusion mechanism of permeance dominates over the adsorption-diffusion mechanism thereby reducing permeance as diffusion slows due to collisions between gas molecules and the pore walls. CH4 permeation always occurs via Knudsen diffusion with CH4 permeance increasing with permeation temperature due to the increased rate of CH4 diffusion.Item Taking advantage of an existing indoor climate monitorization for measuring occupancy(2017) Saralegui, Unai; Anton, Miguel Angel; Ordieres-Mere, Joaquin; Tecnalia Research & Innovation; DIGITALIZACIÓN Y AUTOMATIZACIÓN DE LA CONSTRUCCIÓNThis paper describes a procedure to gain additional information from an already existing infrastructure primarily designed for other purposes. The deployed sensor network consists of wirelessly communicated indoor climate monitoring sensors, for which it is tried to extend its usage by determining occupancy in the room they are located, in that way the system provides a higher level aspect of the house usage. An elderly caring institution’s building has been monitored for one year obtaining data about temperature, relative humidity and CO2 levels from five different rooms. Such data shows some interesting patterns as the air flow between the rooms which should be considered in any real case scenario. The data has been used to train some machine learning models, which show acceptable quality overall suggesting to use this kind of sensing equipment to perform an occupancy monitoring non-intrusively. The acquired knowledge could bring additional opportunities in the care of the elderly, especially for specific diseases that are usually accompanied by changes in patterns of behaviour. By using the occupancy status it could be possible to determine changes in the daily patterns in that segment of the population which could be an indicative of the initial states of a disease or a worsening in it.Item Three-dimensional reduced graphene oxide decorated with iron oxide nanoparticles as efficient active material for high performance capacitive deionization electrodes(2021-05-15) Belaustegui, Yolanda; Rincón, Inés; Fernández-Carretero, Francisco; Azpiroz, Patxi; García-Luís, Alberto; Tanaka, David Alfredo Pacheco; Tecnalia Research & Innovation; VALORIZACIÓN DE RESIDUOS; TECNOLOGÍAS DE HIDRÓGENO; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSA three-dimensional reduced graphene oxide decorated with iron oxide nanoparticles (3D rGO-Fe2O3) material with a suitable porous structure was synthesised using a one-step hydrothermal process in order to fabricate novel electrodes for capacitive deionization (CDI) water desalination. The morphological and structural properties of the as-synthesised compounds were characterised by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), Raman spectroscopy (RS), X-ray diffraction (XRD) and thermal gravimetric analysis (TGA). The CDI electrodes were electrochemically analysed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). A maximum value of specific capacitance of 345 F g−1 was achieved at 5 mV s−1 scan rate using a NaCl 0.1 mol L−1 solution. The ion removal performance of the CDI electrodes was evaluated with NaCl solutions of different concentrations, showing electrosorption capacities as high as 945 mg g−1 for 11,700 mg L−1 (200 mmol L−1) NaCl solutions, which substantially surpasses results of other carbon-based CDI electrodes.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.