• Energy Research
• engineering and technology close
• EU close
• National Research Council close

Diesel engine exhausts from a common rail 3.0 L F1C diesel engine were analyzed at two different load conditions of the WLTC testing cycle downstream of both the diesel particulate filter (DPF) and selective catalytic reactor (SCR) to verify their effect on the characteristics of carbon particulate matter. An array of chemical, physical and spectroscopic techniques (gas chromatography coupled with mass spectrometry (GC-MS), mobility analyzer, UV-Visible absorption and fluorescence spectroscopy) was applied for characterizing polycyclic aromatic hydrocarbons (PAH), heavy aromatic compounds and soot, constituting the particulate matter (PM) sampled from the exhaust. The engine was operated in half load (HL) (188 Nm, representing the more common condition for engine in urban traffic) and full load (FL) (452 Nm, representing the best performance of the engine operation) conditions, at the same engine speed (2000 rpm). Soot formation was enhanced in HL condition, with respect to FL, but, just because of the much lower soot amount, the after-treatment systems in this last condition resulted to be less efficient in the soot abatement. Indeed, the abatement through DPF was about 40% lower in the FL condition with respect to HL condition, and any significant further concentration decrease was found after SCR, in both conditions. By contrast, PAH concentration after DPF abatement was found to be higher in the HL with respect to FL condition. A further PAH concentration decrease of about 30% was found after the SCR in the HL condition whereas in FL the reduction was only about 5-6%. Also the heavy aromatic compounds having molecular weight above the GC-MS detection limit (300 u), were mitigated by SCR. Therefore, SCR did not cause a further soot reduction, whereas it was effective in largely reducing PAH and heavy aromatics emissions, especially in the lower temperature condition featuring the half-load condition, when combustion efficiency is worse. Moreover, SCR system reduced the emission of small particles probably due to an enhanced agglomeration of particles, with beneficial effect on the harmfulness to human health.

The conversion of renewable biomasses into biofuels and chemicals represents a strategic way to reduce the use of fossil feedstock, by contributing in switching to a more sustainable society. The use of agro-industrial wastes does not subtract resources destined for food consumption. In addition, waste utilization would result in a reduction of its accumulation, with a consequent decrease of environmental impact and financial losses due to the relevant disposal. In this context, a wide variety of exploitable agricultural resources can be used to support this sustainable growth. However, the characterization represents the first step towards a targeted and proficient exploitation of the chemical and energetic potential of a residual biomass. In this work, some representative residual (Mexican) biomasses were investigated: pepper residues (Hungarian yellow and red variety), coconut shells (Cocos nucifera), flamboyant pods (Delonix regia), seeds of avocado (Persea Americana), palm (Palma de Coroco) and nance (Byrsonima crassifolia) were chemically characterized and the relevant potential applications for the synthesis of biofuels and fine chemicals were specifically evaluated. Lipids, structural carbohydrates, and lignin were specifically valorized in a proficient cascade of technologies, which aim to exploit the correspondent potential, according to the principles of biorefinery and circular economy.

This Round Robin Test program aims to establish the influence of the combined wave and current effect on the power capture and performance of a generic tidal turbine prototype. Three facilities offering similar range of experimental conditions have been selected on the basis that their dimensions along with the rotor diameter of the turbine translate into low blockage ratio conditions. The performance of the turbine shows differences between the facilities up to 25% in terms of average power coefficient, depending on the wave and current cases. To prevent the flow velocity increasing these differences, the turbine performance coefficients have been systematically normalized using a time-average disc-integrated velocity, accounting for vertical gradients over the turbine swept area. Differences linked to blockage effects and turbulence characteristics between facilities are both responsible for 5 to 10% of the power coefficient gaps. The intrinsic differences between the tanks play a significant role as well. A first attempt is given to show how the wave-current interaction effects can be responsible for differences in the turbine performance. In these tanks, the simultaneous generation of wave and current is a key part often producing disruptions in both of these flow characteristics.

Wood biomass is turned into industrial fuel through chipping. The efficiency of chipping depends on many factors, including chipper knife wear. Chipper knife wear was determined through a long-term follow-up study, conducted at a waste wood recycling yard. Knife wear determined a sharp drop of productivity (>20%) and a severe decay in product quality. Dry sharpening with a grinder mitigated this effect, but it could not replace proper wet sharpening. Increasing the frequency of wet sharpening sessions determined a moderate increase of knife depreciation cost, but it could drastically enhance machine performance and reduce biomass processing cost. Since benefits largely exceed costs, increasing the frequency of wet sharpening sessions may be an effective measure for reducing overall chipping cost. If the main goal of a chipper operator is to increase productivity and/or decrease fuel consumption, then managing knife wear should be a primary target. (C) 2014 Elsevier Ltd. All rights reserved.

Hybrid sorption-compression systems are gaining interest for heating/cooling/ refrigeration purposes in different applications, since they allow exploiting the benefits of both technologies and a better utilization of renewable sources. However, design of such components is still difficult, due to the intrinsic complexity of the systems and the lack of reliable models. In particular, the combination of adsorption-compression cascade unit has not been widely explored yet and there are no simulations or sizing tools reported in the literature. In this context, the present paper describes a model of a hybrid adsorption-compression system, realised in Modelica language using the commercial software Dymola. The models of the main components of the sorption and vapour compression unit are described in details and their validation presented. In addition, the integrated model is used for proving the feasibility of the system under dynamic realistic conditions and an example of the technical sizing that the model is able to accomplish is given.

In recent years, cultural sustainability has attracted increasing attention within the discourse of sustainable development and sustainable cities. Notwithstanding some effort put on conceptualizing the relationship between culture and sustainability, research on the issue is still in a pre-paradigmatic stage and related empirical studies are scant. In particular, further knowledge is required to understand not only how cultural sustainability has been addressed strategically but also implemented in practice. In this direction, research has pointed out the role of social structures (e.g., partnerships, collaborations, etc.) for achieving cultural sustainability goals. However, focusing on smart cities, attention is limited to how collaborative arrangements can be leveraged within the development of new city services (e.g., smart open innovation) to sustain goals of environmental, economic and social sustainability, with cultural sustainability still playing a marginal role. This paper develops a new framework linking together the strategic level and the practice level in addressing cultural sustainability and conceptualizing the role of collaborative structures in the development of smart innovation. The framework is then used as a frame of reference for analyzing the case of MuseoTorino, a new city museum realized within the smart city strategy of Turin (Italy). The analysis provides evidence of some practices adopted to leverage collaboration and stakeholders’ engagement to strategically address cultural sustainability and to realize it in practice throughout the new service development process.