Steam reforming of model compounds from biomass fermentation over nanometric ruthenium modified nickel-lanthanum perovskites catalysts

Nanometric ruthenium-modified LaNiO3 perovskites prepared by coprecipitation method in aqueous and non-aqueous solvents were tested as catalysts in the steam reforming of butanol, acetone and ethanol and their mixture, named ABE, usually produced by fermentation. ABE is potentially of great interest for hydrogen production, notwithstanding the strong tendency of this mixture of oxygenated compounds to produce coke in the steam reforming conditions. The tested catalyst showed high feed conversions with improved stability

Biomass Gasification and Tar Reforming in a Two-stage Reactor

Abstract Gasification is recognized as one of the most promising technologies to convert low quality fuels into more valuable ones. The principal problem related with the use of biomass in gasification processes is the high amount of tar released during the pyrolysis step. It is thus necessary to recover the tar and to transform it in lighter combustible gas species such as CH4, CO and H2 by means of catalytic processes. In this work the gasification of olive husk is performed in order to produce a high quality syngas, composed principally by carbon monoxide and hydrogen, using an innovative laboratory scale two-stage reactor. The first stage is used for gasification and the second for catalytic reforming. It is thus possible to recover the tar energy converting it into CO and H2. Ce-promoted bimetallic Ni-Co catalyst was tested and compared with Ni catalyst, both supported on γ-Al2O3

On the enhancement of vehicle handling and energy efficiency of electric vehicles with multiple motors: the iCOMPOSE project

Electric vehicles with multiple motors allow torque-vectoring, i.e., the individual control of each powertrain torque. Torque-vectoring (TV) can provide: i) enhancement of vehicle safety and handling, via the generation of a direct yaw moment to shape the understeer characteristics and increase yaw and sideslip damping; and ii) energy consumption reductions, via appropriate torque allocation to each motor. The FP7 European project iCOMPOSE thoroughly addressed i) and ii). Theoretical analyses were carried out to design state-of-the art TV controllers, which were validated through: a) vehicle simulations; and b) extensive experimental tests, which were performed at rolling road facilities and proving grounds, using a Range Rover Evoque prototype equipped with four identical on-board electric powertrains. This paper provides an overview of the TV-related contributions of iCOMPOSE

Detection of Zak phases and topological invariants in a chiral quantum walk of twisted photons

Topological insulators are fascinating states of matter exhibiting protected edge states and robust quantized features in their bulk. Here, we propose and validate experimentally a method to detect topological properties in the bulk of one-dimensional chiral systems. We first introduce the mean chiral displacement, and we show that it rapidly approaches a multiple of the Zak phase in the long time limit. Then we measure the Zak phase in a photonic quantum walk, by direct observation of the mean chiral displacement in its bulk. Next, we measure the Zak phase in an alternative, inequivalent timeframe, and combine the two windings to characterize the full phase diagram of this Floquet system. Finally, we prove the robustness of the measure by introducing dynamical disorder in the system. This detection method is extremely general, as it can be applied to all one-dimensional platforms simulating static or Floquet chiral systems.Comment: 10 pages, 7 color figures (incl. appendices) Close to the published versio

Pure hydrogen production by steam-iron process. The synergic effect of MnO2 and Fe2O3

In the energy transition from fossil to clean fuels, hydrogen plays a key role. Proton-exchange membrane fuel cells (PEMFCs) represent the most promising hydrogen application, but they require a pure hydrogen stream (CO < 10 ppm). The steam iron process represents a technology for the production of pure H2, exploiting iron redox cycles. If renewable reducing agents are used, the process can be considered completely green. In this context, bio-ethanol can be an interesting solution that is still not thoroughly explored. In this work, the use of ethanol as a reducing agent in the steam iron process will be investigated. Ethanol, at high temperature, decomposes mainly in syngas but can also form coke, which can compromise the process effectiveness, reacting with water and producing CO together with H2. In this work, the deposition of coke is avoided by controlling the duration of the reduction step; in fact, the data demonstrated that coke deposition is significantly dependent on reduction time. Tests were carried out in a fixed bed reactor using hematite (Fe2O3) as raw iron oxide adopting several reduction times (7 minutes-25 minutes), which correspond to different amount of ethanol fed (5 mmolC2H5OH/gFe2O3-17,95 mmolC2H5OH/gFe2O3). The effect of the addition of MnO2 to increase the reduction degree of iron oxides was explored using different amount of MnO2 (10 wt% and 40 wt% with respect to Fe2O3). The tests were performed at fixed temperatures of 675°C and atmospheric pressure. The optimization of the reduction time, in the chosen operating condition, performed only with Fe2O3, shows that, feeding an amount of 5 mmolC2H5OH/gFe2O3, coke deposition is avoided and, therefore, a pure H2 stream in oxidation is obtained. The addition of MnO2 leads to increased H2 yield and process efficiency, confirming its positive effect on the reduction degree of the solid bed. A reaction pathway to demonstrate the synergic effect of Fe2O3 and MnO2 in the reduction step was proposed in this article

Viable Recycling of Polystyrene via Hydrothermal Liquefaction and Pyrolysis

Chemical recycling is considered one of the most sustainable solutions to limit the environmental issues related to plastic waste pollution, whereby plastic is converted into more valuable compounds when mechanical recycling is not feasible. Among the most critical fast-growing components of municipal solid waste, polystyrene represents 1/3 of the filling materials in landfills. In this work, the chemical recycling of polystyrene via two main thermochemical processes is investigated: pyrolysis and hydrothermal liquefaction (HTL). The influence of temperature (HTL: 300-360 & DEG;C and pyrolysis: 400-600 & DEG;C) and reaction time (HTL: 1-4 h; pyrolysis: 30 min) on the products obtained was studied. The obtained liquid and solid products were analyzed by using gas chromatography-mass spectrometry (GC-MS), an elemental analysis (EA), Fourier-transform infrared spectroscopy (FT-IR) and a thermogravimetric analysis (TGA). During HTL, a temperature of 360 & DEG;C and reaction time of 4 h were needed to completely decompose the polystyrene into mainly oil (83%) and water-soluble compounds (10%). The former was mainly composed of aromatics while the water phase was mainly composed of aromatics and oxygenated compounds (benzaldehyde and acetophenone). The pyrolysis led to the formation of 45% gas and 55% oil at 500 & DEG;C, and the oil was 40% styrene. Pyrolysis was thus more selective towards the recovery of the styrene monomer while the HTL can be an effective process to produce renewable aromatics

Design, synthesis and biological activity of selective hCAs inhibitors based on 2-(benzylsulfinyl)benzoic acid scaffold

A large library of derivatives based on the scaffold of 2-(benzylsulfinyl)benzoic acid were synthesised and tested as atypical inhibitors against four different isoforms of human carbonic anhydrase (hCA I, II, IX and XII, EC 4.2.1.1). The exploration of the chemical space around the main functional groups led to the discovery of selective hCA IX inhibitors in the micromolar/nanomolar range, thus establishing robust structure-activity relationships within this versatile scaffold. HPLC separation of some selected chiral compounds and biological evaluation of the corresponding enantiomers was performed along with molecular modelling studies on the most active derivatives

Fibrinogen-elongated Chain Inhibits Thrombin-induced Platelet Response, Hindering the Interaction with Different Receptors

The expression of the elongated fibrinogen γ chain, termed γ′, derives from alternative splicing of mRNA and causes an insertion sequence of 20 amino acids. This insertion domain interacts with the anion-binding exosite (ABE)-II of thrombin. This study investigated whether and how γ′ chain binding to ABE-II affects thrombin interaction with its platelet receptors, i.e. glycoprotein Ibα (GpIbα), protease-activated receptor (PAR) 1, and PAR4. Both synthetic γ′ peptide and fibrinogen fragment D*, containing the elongated γ′ chain, inhibited thrombin-induced platelet aggregation up to 70%, with IC50 values of 42 ± 3.5 and 0.47 ± 0.03 μm, respectively. Solid-phase binding and spectrofluorimetric assays showed that both fragment D* and the synthetic γ′ peptide specifically bind to thrombin ABE-II and competitively inhibit the thrombin binding to GpIbα with a mean Ki ≈ 0.5 and ≈35 μm, respectively. Both these γ′ chain-containing ligands allosterically inhibited thrombin cleavage of a synthetic PAR1 peptide, of native PAR1 molecules on intact platelets, and of the synthetic chromogenic peptide d-Phe-pipecolyl-Arg-p-nitroanilide. PAR4 cleavage was unaffected. In summary, fibrinogen γ′ chain binds with high affinity to thrombin and inhibits with combined mechanisms the platelet response to thrombin. Thus, its variations in vivo may affect the hemostatic balance in arterial circulation

On the Energy Efficiency of Electric Vehicles with Multiple Motors

Electric Vehicles (EVs) with multiple motors permit to design the steady-state cornering response by imposing reference understeer characteristics according to expected vehicle handling quality targets. To this aim a direct yaw moment is generated by assigning different torque demands to the left and right vehicle sides. The reference understeer characteristic has an impact on the drivetrain input power as well. In parallel, a Control Allocation (CA) strategy can be employed to achieve an energy-efficient wheel torque distribution generating the reference yaw moment and wheel torque. To the knowledge of the authors, for the first time this paper experimentally compares and critically analyses the potential energy efficiency benefits achievable through the appropriate set-up of the reference understeer characteristics and wheel torque CA. Interestingly, the experiments on a four wheel-drive EV demonstrator show that higher energy savings can be obtained through the appropriate tuning of the reference cornering response rather than with an energy efficient CA

Polaron features for long-range electron-phonon interaction

The polaron features for long-range electron-phonon interaction are investigated by extending a variational approach previously proposed for the study of systems with local coupling. The ground-state spectral weight, the average kinetic energy, the mean number of phonons, and the electron-lattice correlation function are discussed for a wide range of model parameters focusing on the adiabatic regime and comparing the results with the short-range case (Holstein model). A strong mixing of electronic and phononic degrees of freedom for small values of the electron-phonon coupling constant is found in the adiabatic case due to the long-range interaction. Finally a polaron "phase diagram" is proposed.Comment: 4 figs., to appear in J. Phys.:Condens. Matte