In this paper, the second generation pathway for bioethanol from hornbeam residues was investigated, in order to define the optimum operative conditions of steam explosion pretreatment and ...subsequently enzymatic hydrolysis maximizing the glucose amount for fermentation process.
The whole experimental procedure was designed and analyzed by Response Surface Methodology, a statistic multivariate model that allows to investigate the effect of different parameters on a process and define the optimum values of these variables to optimize the response.
The glucose yield from enzymatic hydrolysis was maximize as function of three variables: the severity factor of pretreatment (log R0), the total solids (TS%) of the enzymatic hydrolysis and enzyme loading (EL%) in the enzymatic hydrolysis stage.
The Design of Experiment (DoE), based on central composite model, was characterized by 17 tests, varying the variables at five levels, log R0 (3.92, 4.08, 4.31, 4.54, 4.7), TS% (5, 7, 10, 13, 15), EL% (5, 7, 10, 13, 15).
The optimization allows to define the best operative condition that is log R0 = 3.97, TS% = 6, EL% = 15 which leads to an overall fermentable sugars yield of 67.8% respect to the initial sugars content in the raw material that corresponds to a theoretical amount of producible ethanol of 251 L/ton dry raw material.
•Hornbeam residues were investigated as feedstock for cellulosic ethanol production.•Steam explosion pretreatment is a efficient way for hornbeam wastes conversion.•RSM was adopted as methodology for sugars production optimization.•Three variables of pretreatment and saccharification were used in the DoE.
The integrated low-level trigger and data acquisition (TDAQ) system of the NA62 experiment at CERN is described. The requirements of a large and fast data reduction in a high-rate environment for a ...medium-scale, distributed ensemble of many different sub-detectors led to the concept of a fully digital integrated system with good scaling capabilities. The NA62 TDAQ system is rather unique in allowing full flexibility on this scale, allowing in principle any information available from the detector to be used for triggering. The design concept, implementation and performances from the first years of running are illustrated.
•Ultrasound (US)-assisted liquefaction of solid digestate from industrial waste is optimized.•US-assisted liquefaction increases high calorific value of residues from biogas plant.•US-assisted direct ...liquefaction is an energy saving process to provide bio-oil.•Bio-oil production as precursor of fuel and polymers through biorefinery is proposed.
Among the possibilities for industrial waste valorization, liquefaction is gaining interest as it may provide alternative energy and high value-added products. In this context, this work focuses on the production of bio-oil through ultrasound (US)-assisted direct liquefaction. For the reaction, polyethylene glycol (PEG) and crude glycerol were selected. As this process is conducted by raising reaction temperature, US provided it, while shortening reaction time, through the cavitation phenomenon. For liquefaction reaction optimization, a response surface methodology (Box-Behnken design) was performed. As independent variables, US-amplitude, reaction time and solvent-to-biomass ratio were selected. On the other side, bio-oil yield, high calorific value (HCV) and energy consumption were chosen as dependent responses. Optimal results showed a bio-oil yield of 34.17% (reached in<20 min), HCV of 28.44 MJ/kg and energy consumption (US) of 11.477 kJ. Moreover, differences between predicted and experimental values were found to be negligible. Bio-oil was also characterized using Fourier transform infrared (FT-IR) and chromatography-mass spectrometry gas (GC–MS). Both techniques showed a profile rich in phenols and poly-oils, which can be used as precursors for industrial products, i.e. polymers. Finally, to check the impact of liquefaction on solid digestate, scanning electron microscopy (SEM) analysis was carried out. Results showed an increase in porosity, fragment and conglomerate. It may be concluded that the use of US as auxiliary energy in solid digestate liquefaction, to produce bio-oil, provides energy saving. Thus, the proposed valorization path aids consolidating the concept of circular economy through an efficient biorefinery model.
•Three different oak woods were investigated for ethanol production.•EH yield and overall sugar yield were optimized by RSM.•Severity factor, total solid and enzyme loading were used as variables in ...the DoE.•Steam explosion pretreatment is a good process for oak wood conversion.
Fermentable sugars production from three kind of steam-exploded oak wood was optimized by Response Surface Methodology (RSM), using the severity factor (R0), the pretreated total solids (TS%) and the enzyme loading (EL%) as variables of a central composite design. A total of 17 experiments for each biomass were carried out. The optimal conditions established with RSM were: severity, 4.46 for holm, 4.03 for turkey oak and 3.92 for downey oak; total solids, 5.4% for holm, 5.0% for turkey oak and 12.7% for downey oak; and enzyme concentration, 9.6% for holm, 15.0% for turkey oak and 15.0% for downey oak. Under these conditions, the model predicted an overall sugar yield of 67.1% for holm, 79.9% for turkey oak and 68.4% for downey oak. The results of the confirmation experiments under optimal conditions agreed well with model predictions. Oak wood species may be a good feedstock for the production of reducing sugars.
The evaluation of the thermal performance building components requires a high level of accuracy. Windows, doors and thermal bridges are not homogeneous, and their thermal transmittance can be ...evaluated by means of Hot-Box, used for full-scale elements. For homogeneous materials and one-dimensional heat flux, the thermal conductivity can be easily measured through other experimental apparatuses, such as the guarded hot plate and the heat flow meters. This study presents a new experimental apparatus named Small Hot-Box, built at the University of Perugia. No European standards are available for this innovative facility, but it takes into account some prescriptions of EN ISO 8990 and EN ISO 12567; it was built for the evaluation of the thermal properties of small specimens. The apparatus was designed, built, and calibrated by means of preliminary measurements. It is composed of a hot and a cold side, and the external walls are made of thick insulation. The thermal conductivity can be calculated by two different methodologies: the Hot-Box and the thermal flux meter method. Preliminary calibrations were carried out and different materials with known thermal transmittance were tested. The aim is the development of a new experimental apparatus; guidance documents could be defined for the measurements methodology requirements.
Due to be launched in late 2021, the imaging X-ray polarimetry explorer (IXPE) is a NASA Small Explorer mission designed to perform polarization measurements in the 2-8-keV band, complemented with ...imaging, spectroscopy, and timing capabilities. At the heart of the focal plane, there are a set of three polarization-sensitive gas pixel detectors, each based on a custom-integrated circuit acting as a charge-collecting anode, with their readout electronics. We designed an integrated test equipment based on the VMEbus protocol to characterize the performance of such detectors, debug the IXPE readout electronics, and perform stable data acquisitions to study the whole system. The test campaign was conducted to validate the readout processor against the mission requirements in more demanding conditions than the worst case foreseen for in-orbit operations. The test showed that the device under test could sustain an event rate with a 5.9-keV source, nearly twice the worst case of 300 Hz at 3 keV, with a dead time down to 1.1 ms. Additionally, we performed various scans in the readout electronics parameter space to optimize its performance in observing celestial sources. The success of the test campaign proved the robustness and reliability of the system in these conditions, legitimating its adoption for the IXPE mission.
Glycerol is a co-product compound of biodiesel production with an interesting heating value. In this work pyrolysis kinetic parameters for a pellet made with a mass fraction of 90% sawdust and a mass ...fraction of 10% glycerol are derived through thermogravimetric analysis. A new parallel reaction scheme with four components (cellulose, hemicellulose, lignin and glycerol) is adopted and the kinetic triplet for each component is derived using a model fitting approach applied to this particular kind of pellet. The isoconversional method Kissinger-Akahira-Sunose is employed both to provide initial values for model fitting simulations and to check final results. Results show that activation energies and pre-exponential factors are respectively: 149.7 kJ mol−1 and 1.98*1011 s−1 for hemicellulose, 230.1 kJ mol−1 and 1.84*1017 s−1 for cellulose, 154.3 kJ mol−1 and 5.14*109 s−1 for lignin, 74.5 kJ mol−1 and 2.17*105 s−1 for glycerol with a first reaction order for all components, except for lignin (n = 2.6). Through evolved gas analysis it was demonstrated that the thermal degradation of glycerol contained in the pellet can increase hydrogen content in pyrolysis gases.
•Glycerol can be used as an additive in biomass pelletisation.•Model fitting and isoconversional methods are used to derive kinetic triplets.•A model with parallel reactions of 4 pseudo components was used to simulate the co-pyrolysis of glycerol and sawdust.•Evolved Gas Analysis has demonstrated glycerol can increase hydrogen release during pellet pyrolysis.•The addition of glycerol to biomass can improve pyrolysis performances.
•Co-combustion behaviour of PR with 2PH and 3PH was studied.•Effects of blending ratio and heating rate on the combustion process were analysed.•A synergistic effect was observed in PR-2PH and PR-3PH ...blends.•Reactivity of the blends increase with increasing PR.•The minimum apparent activation energy was obtained for 25PR752PH mixture.
The kinetic behaviour of olive tree pruning (PR), two- (2PH) and three-phase (3PH) olive pomace and their blends was investigated under combustion condition using thermogravimetric analysis. PR was blended with 2PH and 3PH at different ratios (25:75, 50:50 and 75:25) and tested in the temperature range from ambient to 1000°C in order to evaluate the co-combustion behaviour. Results showed that the thermal degradation of all samples can be divided into three regions (drying, devolatilisation, char oxidation) with different combustion properties, depending on the percentage of PR. Significant interaction was detected between the fuels, and reactivity of 2PH and 3PH was improved upon blending with PR. The iso-conversional methods, Ozawa–Flynn–Wall and Vyazovkin, were employed for the kinetic analysis of the oxidation process. The results revealed that the activation energy of PR was higher than the one of 2PH and 3PH, and the minimum value was obtained for 25PR752PH sample.
The FOOT (FragmentatiOn Of Target) experiment aims to measure the fragmentation cross-section of protons into H, C, O targets at beam energies of interest for hadrontherapy (50-250 MeV for H and ...50-400 MeV/u for C ions).
Given the short range of the fragments, an inverse kinematic approach requiring precise tracking capabilities in a magnetic volume has been chosen.
A key subsystem of this experiment will be the Microstrip Silicon Detector, based on 3 X-Y measuring station, each composed of two 150
μm
thick single side microstrip sensors. In this work, we present the results of characterization of the new version of a 64 channel low-noise/low power high dynamic range readout ASIC and subsequent tests of the first 150 um thick sensor prototype.
A series of tests were also performed to validate a novel “grazing angle” approach, where it is possible to change the track length below a given strip varying the incoming particle’s incident angle onto the sensor to test the electronics dynamic range without using high Z ions.
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