Menú secundario

Artículos SCI



2021


Materiales y Procesos Catalíticos de Interés Ambiental y Energético

Elucidating the nature of Mo species on ZSM-5 and its role in the methane aromatization reaction

Lopez-Martin, A.; Platero, F; Colon, G.; Caballero, A.
Reaction Chemistry & Engineering

Show abstract ▽

The valorization of methane is one of the most important goals during the transition period to the general use of renewable energies. Its transformation into a valuable chemical like benzene by direct aromatization of methane (DAM) reaction has been extensively studied in the past years, mainly using Mo/ZSM-5 catalytic systems. Although viable, this DAM reaction poses a number of issues mainly derived from poor conversion and deactivation processes. Therefore, a deeper knowledge of these systems is needed. Herein, by combining chemical (TPR), spectroscopic (XPS), HAADF and other techniques, we have identified the different Mo precursors stabilized in the calcined ZSM-5 support, their nature (monomers, dimers and bulk Mo oxides), location in the zeolite framework (external surface or micropores), and the partial segregation of aluminum during the preparation of catalysts. The role of each Mo phase promoting or hindering the transformation of methane in aromatics has been also clarified.


Abril, 2021 | DOI: 10.1039/d1re00044f

Materiales para Bioingeniería y Regeneración Tisular

Nanofibrous Gelatin-Based Biomaterial with Improved Biomimicry Using D-Periodic Self-Assembled Atelocollagen

Borrego-Gonzalez, S; Dalby, MJ; Diaz-Cuenca, A
Biomimetics, 6 (2001) 20

Show abstract ▽

Design of bioinspired materials that mimic the extracellular matrix (ECM) at the nanoscale is a challenge in tissue engineering. While nanofibrillar gelatin materials mimic chemical composition and nano-architecture of natural ECM collagen components, it lacks the characteristic D-staggered array (D-periodicity) of 67 nm, which is an important cue in terms of cell recognition and adhesion properties. In this study, a nanofibrous gelatin matrix with improved biomimicry is achieved using a formulation including a minimal content of D-periodic self-assembled atelocollagen. We suggest a processing route approach consisting of the thermally induced phase separation of the gelatin based biopolymeric mixture precursor followed by chemical-free material cross-linking. The matrix nanostructure is characterized using field emission gun scanning electron microscopy (FEG-SEM), transmission electron microscopy (TEM), wide angle X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). The cell culture assays indicate that incorporation of 2.6 wt.% content of D-periodic atelocollagen to the gelatin material, produces a significant increase of MC3T3-E1 mouse preosteoblast cells attachment and human mesenchymal stem cells (hMSCs) proliferation, in comparison with related bare gelatin matrices. The presented results demonstrate the achievement of an efficient route to produce a cost-effective, compositionally defined and low immunogenic “collagen-like” instructive biomaterial, based on gelatin.


Marzo, 2021 | DOI: 10.3390/biomimetics6010020

Nanotecnología en Superficies y Plasma

Electrical and reaction performances of packed-bed plasma reactors moderated with ferroelectric or dielectric materials

Gomez-Ramirez, A; Alvarez, R; Navascues, P; Garcia-Garcia, FJ; Palmero, A; Cotrino, J; Gonzalez-Elipe, AR
Plasma Processes and Polymers, (2021) e2000193

Show abstract ▽

The operational behavior of packed-bed plasma reactors depends on the dimension, shape, and chemical properties of the pellets used as moderators, but little information exists about the influence of their specific dielectric properties. Herein, we comparatively study the electrical behavior of a packed-bed reactor filled with pellets of either dielectric (Al2O3 and glass) or ferroelectric (BaTiO3 and lead zirconate titanate) materials. We found that plasma current was higher for ferroelectrics and presented a nonlineal dependence on voltage. Moreover, for BaTiO3, we found a drastic decrease at around its relatively low Curie temperature. Differences in electrical behavior have a direct effect on the reactor performance, as illustrated for the ammonia synthesis, demonstrating the importance of moderator material dielectric properties and their dependence on temperature.


Marzo, 2021 | DOI: 10.1002/ppap.202000193

Química de Superficies y Catálisis

Synergizing carbon capture and utilization in a biogas upgrading plant based on calcium chloride: Scaling-up and profitability analysis

Baena-Moreno, FM; Reina, TR; Rodriguez-Galan, M; Navarrete, B; Vilches, LF
Science of The Total Environment, 758 (2021) 143645

Show abstract ▽

Herein we analyze the profitability of a novel regenerative process to synergize biogas upgrading and carbon dioxide utilization. Our proposal is a promising alternative which allows to obtain calcium carbonate as added value product while going beyond traditional biogas upgrading methods with high thermal energy consumption. Recently we have demonstrated the experimental viability of this route. In this work, both the scale-up and the profitability of the process are presented. Furthermore, we analyze three representative scenarios to undertake a techno-economic study of the proposed circular economy process. The scale-up results demonstrate the technical viability of our proposal. The precipitation efficiency and the product quality are still remarkable with the increase of the reactor size. The techno-economic analysis reveals that the implementation of this circular economy strategy is unprofitable without subsidies. Nonetheless, the results are somehow encouraging as the subsides needed to reach profitability are lower than in other biogas upgrading and carbon dioxide utilization proposals. Indeed, for the best-case scenario, a feed-in tariff incentive of 4.3 (sic)/MWh makes the approach profitable. A sensitivity study through tornado analysis is also presented, revealing the importance of reducing bipolar membrane electrodialysis energy consumption. Overall our study envisages the big challenge that the EU faces during the forthcoming years. The evolution towards bio-based and circular economies requires the availability of economic resources and progress on engineering technologies.


Marzo, 2021 | DOI: 10.1016/j.scitotenv.2020.143645

Materiales Avanzados

Mining Wastes of an Albite Deposit as Raw Materials for Vitrified Mullite Ceramics

Sanchez-Soto, PJ; Garzon, E; Perez-Villarejo, L; Angelopoulos, GN; Eliche-Quesada, D
Minerals, 11 (2021) 232

Show abstract ▽

In this work, an examination of mining wastes of an albite deposit in south Spain was carried out using X-ray Fluorescence (XRF), X-ray diffraction (XRD), particle size analysis, thermodilatometry and Differential Thermal Analysis (DTA) and Thermogravimetric (TG) analysis, followed by the determination of the main ceramic properties. The albite content in two selected samples was high (65-40 wt. %), accompanied by quartz (25-40 wt. %) and other minor minerals identified by XRD, mainly kaolinite, in agreement with the high content of silica and alumina determined by XRF. The content of Na2O was in the range 5.44-3.09 wt. %, being associated with albite. The iron content was very low (<0.75 wt. %). The kaolinite content in the waste was estimated from similar to 8 to 32 wt. %. The particle size analysis indicated values of 11-31 wt. % of particles <63 mu m. The ceramic properties of fired samples (1000-1350 degrees C) showed progressive shrinkage by the thermal effect, with water absorption and open porosity almost at zero at 1200-1250 degrees C. At 1200 ffiC, the bulk density reached a maximum value of 2.38 g/cm(3). An abrupt change in the phase evolution by XRD was found from 1150 to 1200 degrees C, with the disappearance of albite by melting in accordance with the predictions of the phase diagram SiO2-Al2O3-Na2O and the system albite-quartz. These fired materials contained as main crystalline phases quartz and mullite. Quartz was present in the raw samples and mullite was formed by decomposition of kaolinite. The observation of mullite forming needle-shape crystals was revealed by Scanning Electron Microscopy (SEM). The formation of fully densified and vitrified mullite materials by firing treatments was demonstrated.


Marzo, 2021 | DOI: 10.3390/min11030232

 

 

 

 

 

icms